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Background: Built environments (BEs) are typically considered to be oligotrophic and harsh environments for microbial communities under normal, non-damp conditions. However, the metabolic functions of microbial inhabitants in BEs remain poorly understood. This study aimed to shed light on the functional capabilities of microbes in BEs by analyzing 860 representative metagenome-assembled genomes (rMAGs) reconstructed from 738 samples collected from BEs across the city of Hong Kong and from the skin surfaces of human occupants. The study specifically focused on the metabolic functions of rMAGs that are either phylogenetically novel or prevalent in BEs. Results: The diversity and composition of BE microbiomes were primarily shaped by the sample type, with Micrococcus luteus and Cutibacterium acnes being prevalent. The metabolic functions of rMAGs varied significantly based on taxonomy, even at the strain level. A novel strain affiliated with the Candidatus class Xenobia in the Candidatus phylum Eremiobacterota and two novel strains affiliated with the superphylum Patescibacteria exhibited unique functions compared with their close relatives, potentially aiding their survival in BEs and on human skins. The novel strains in the class Xenobia possessed genes for transporting nitrate and nitrite as nitrogen sources and nitrosative stress mitigation induced by nitric oxide during denitrification. The two novel Patescibacteria strains both possessed a broad array of genes for amino acid and trace element transport, while one of them carried genes for carotenoid and ubiquinone biosynthesis. The globally prevalent M. luteus in BEs displayed a large and open pangenome, with high infraspecific genomic diversity contributed by 11 conspecific strains recovered from BEs in a single geographic region. The versatile metabolic functions encoded in the large accessory genomes of M. luteus may contribute to its global ubiquity and specialization in BEs. Conclusions: This study illustrates that the microbial inhabitants of BEs possess metabolic potentials that enable them to tolerate and counter different biotic and abiotic conditions. Additionally, these microbes can efficiently utilize various limited residual resources from occupant activities, potentially enhancing their survival and persistence within BEs. A better understanding of the metabolic functions of BE microbes will ultimately facilitate the development of strategies to create a healthy indoor microbiome. Bh9ATT9ssZEtNaJHv1wg7G Video Abstract [ABSTRACT FROM AUTHOR]

Ribavirin and its analogues exhibit an in vitro antiproliferative effect in cancer cells. In this work, we studied the biological activities of a number of alkyl/aryloxymethyl derivatives of ribavirin's aglycon—1,2,4-triazole-3-carboxamide. Alkyl/arylxymethyl derivatives of 1,2,4-triazole-3-carboxamide with substitutions at the fifth or first position of the triazole ring, were synthesized and their antiproliferative and antimicrobial effects were assessed. For both series, the presence of an antiproliferative effect was investigated, and 1-alkyl/aryloxymethyl derivatives were shown an antimicrobial potential against a Gram-positive bacteria Micrococcus luteus and Gram-negative bacterium Pseudomonas aeruginosa. The obtained results showed that the n-decyloxymethyl derivatives induced leukemia cell death at low micromolar concentrations. We confirmed that n-decyloxymethyl derivatives of ribavirin inhibited the cell cycle progression and induced an accumulation of leukemia cells in the subG1-phase. The molecular docking results suggest that alkyl/aryloxymethyl derivatives may act by inhibiting translation initiation, due to interference with eIF4E assembly. The outcome results revealed that active derivatives (1- or 5-n-decyloxymethyl-1,2,4-triazole-3-carboxamides) can be considered as a lead compound for anticancer treatments. [ABSTRACT FROM AUTHOR]

Atopic dermatitis is the most common inflammatory skin condition with a severe negative impact on patients' quality of life. The etiology of AD is complex and depends on age, genetics, the immune system, environmental factors, and the skin microbiome, with a key role for pathogenic Staphylococcus aureus in the development of severe AD. However, the composition of the skin microbiome in mild AD is understudied. Here, using metagenomic shallow shotgun sequencing, we showed that mild AD lesions did not show a significant difference in the diversity of the skin microbiome compared to samples from non-AD patients and that the relative abundance of S. aureus did not differ in these mild AD lesions. However, when we assessed other taxa, Mycobacterium ostraviense, Pedobacter panaciterrae_A and four Streptomyces species were identified with higher abundances in mild AD lesions and species of 15 genera were decreased in abundance. The highest fold decreases were observed for Paracoccus marcusii, Microbacterium lacticum, Micrococcus luteus, and Moraxella sp002478835. These microbiome compositional insights are a first step towards novel microbiome-based diagnostics and therapeutics for early intervention at the stage of mild AD and provide a path forward for the functional study of species involved in this often-overlooked patient population. [ABSTRACT FROM AUTHOR]

This study aimed to optimize the production of carotenoid pigments from Micrococcus luteus (ATCC 9341) through the statistical screening of media components and the characterization of antimicrobial, antioxidant, cytogenetic and cytotoxic activities. A BOX-Behnken design was used to assess the effects of whey concentration, inoculum size, pH, temperature, and agitation speed on carotenoid yield. The optimum combination increased production to 2.19 g/L, with a productivity of 0.045 g L-1 h−1 and a productivity yield of 0.644 g/g, as confirmed by an observed carotene production of 2.19 g/L. The final response surface model fitting the data had an R2 of 0.9461. High-performance liquid chromatography (HPLC) analysis identified 12 carotenoid pigment compounds produced by M. luteus. The extracts displayed moderate antimicrobial efficacy against Gram-positive bacteria such as Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 6538), and E. faecalis (ATCC 19433), with inhibition zone diameters (IZD) of 29.0, 14.0, and 37.0 mm, respectively, at 1000 μg/mL. However, its effectiveness against Gram-negative bacteria is limited. In comparison, tetracycline exhibited greater antimicrobial potency. The IC50 value of carotenoids was used to indicate the antioxidant activity. IC50 value from the DPPH assay was 152.80 mg/100mL. An IC50 cytotoxicity value greater than 300 μg/mL was found against normal mouse liver cells, with over 68% cell viability even at 300 μg/mL, indicating low toxicity. Histological structure studies revealed normal myocardial muscle tissue, lung tissue, and kidney tissue sections, whereas liver tissue sections revealed ballooning degeneration of hepatocytes and disorganization of hepatic cords. Cytogenetic parameters revealed that the carotene treatment group had a mitotic index (70%) lower than that of the control but higher than that of the positive control, mitomycin, and did not substantially increase numerical (1.2%) or structural aberrations compared with those of the control, suggesting a lack of genotoxic effects under the experimental conditions. In conclusion, optimized culture conditions enhanced carotenoid yields from M. luteus, and the extracts displayed promising bioactivity as moderate antibiotics against certain gram-positive bacteria and as antioxidants. The high IC50 values demonstrate biosafety. Overall, this bioprocess for enhanced carotenoid production coupled with bioactivity profiling and low cytotoxicity support the application of M. luteus carotenoids. [ABSTRACT FROM AUTHOR]

The contamination of surfaces by antibiotic-resistant pathogens presents an escalating challenge, especially on touchscreens in public settings such as hospitals, airports, and means of transport. Traditional chemical cleaning agents are often ineffective and leave behind harmful residues. Thus, the application of optical radiation is gaining relevance as a rapid, effective, and environmentally friendly disinfection method. This study examines the contamination of publicly accessible touchscreens and the efficacy of an irradiation approach for the radiation disinfection of microorganisms on quartz surfaces with UVC LEDs. In this setup, the LED radiation is laterally coupled into a quartz plate that serves as cover glass of a simplified touchscreen model. The process allows for the irradiation of microorganisms on the surface, without the user being exposed to hazardous radiation. To assess the efficacy of the disinfection process, a range of bacteria, mostly ESKAPE surrogates, such as Staphylococcus carnosus, Acinetobacter kookii, Escherichia coli, Enterococcus mundtii, and additionally Micrococcus luteus, were spread over a quartz plate with a homebuilt nebulization system. After operating the side-mounted LEDs for 30 s, a reduction in all bacteria except M. luteus by more than three orders of magnitude was observed. In the case of M. luteus, a significant reduction was achieved after 60 s (p < 0.05). This result demonstrates the potential of side-mounted UVC LEDs for rapid disinfection of touchscreens between two users and thus for reducing the spread of pathogens without irradiating humans. [ABSTRACT FROM AUTHOR]

Dynamic thermodynamic resolution of amino acids (AAs) using Ni(II) chiral Schiff bases is one of the simplest and most efficient methods to obtain optically active AAs. A comparison of the reactivity of 36 rac‐AAs with the Ni(II) complex revealed that this method can be easily applied to dynamic thermodynamic resolution and S/R interconversion of AAs with unprotected active functional groups. It can also be really applied for the side‐chain modification of AA derivatives with active functional groups on the Ni(II) complex. Furthermore, the antimicrobial activities of the synthesized Ni(II) complexes were evaluated, and the Ni(II) complexes [(S,S)−3 g, (S,S)−3 h, and (S,S)−3 i] showed remarkable antibacterial activity against Micrococcus luteus, a Gram positive bacterium. [ABSTRACT FROM AUTHOR]

The present study uses Adenanthera pavonina L. plant extract to synthesize Y/Fe2O3 nanoparticles in a sustainable and efficient manner. Several physicochemical investigations were performed on the synthesized Y/Fe2O3 to evaluate its structure and morphological characteristics. The high crystallinity of Fe2O3 and decreased crystal size of Y/Fe2O3 were revealed by the XRD study. The formulated Y/Fe2O3 was spherical in shape. Y/Fe2O3 has shown potential photocatalytic activity in the degradation of congo red and brilliant green dyes in the presence of visible light. Degradation efficiency is higher than 90% for both dyes. In addition, the antibacterial activity of Y/Fe2O3 was measured against pathogenic strains of Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Proteus mirabilis, Pseudomonas putida, Shigella dysenteriae, and Staphylococcus aureus. Y/Fe2O3 showed promising antibacterial activity against all microorganisms. Micrococcus luteus showed a higher zone of inhibition (equal to 35 mm in diameter) than other microorganisms using Y/Fe2O3. Thus, it is established that the green synthesized Y/Fe2O3 nanoparticles are active catalysts for the photocatalytic degradation of hazardous dyes and have antibacterial properties against different bacterial stains. [ABSTRACT FROM AUTHOR]

In various Southeast Asian countries, people have long incorporated the young green seeds of Parkia speciosa, commonly known as stink beans, into their culinary traditions. These seeds can be prepared using various cooking methods, including boiling, microwaving, stir-frying, or even consuming them raw. While several studies have explored the pharmaceutical properties of raw stink beans, this study seeks to expand our knowledge of how different extraction methods can influence the release of bioactive compounds from these young stink bean seeds. Three distinct extraction methods, namely (1) microwave-assisted water extraction, (2) boiling water extraction and (3) 50 % ethanol extraction were employed in this research. The study focused on total phenolic content and antioxidant activities, with the 50 % ethanol extraction method yielding the most promising results. Moreover, only the extract obtained from the 50 % ethanol method exhibited antimicrobial activity against 4 gram-positive bacteria, including Methicillin-Resistant Staphylococcus aureus, Staphylococcus aureus, Bacillus cereus, Micrococcus luteus and 1 gram-negative bacterium, Salmonella typhi. Notably, extracts obtained from the 3 extraction methods of young stink bean seeds exhibit varying degrees of inhibition of cancer cell growth with low cell toxicity. Taken together, our findings suggest that distinct extraction methods play a key role in obtaining different sets of bioactive compounds from the young seeds of stink beans. Therefore, various cooking methods, including stir-frying, microwaving and pickling in alcohol, may offer diverse sources of bioactive compounds for promoting consumer health. [ABSTRACT FROM AUTHOR]

In light of the growing need to mitigate viral infections, such as SARS-CoV-2, which has caused over 770 million infections and 7 million deaths worldwide, the role of architectural design in reducing pathogen spread has become paramount. This study explores how different buffer room configurations impact microbial isolation using the bacterium Micrococcus luteus and bacteriophage phi6 as test organisms. Through a comprehensive approach integrating architecture, technology, and scientific methodologies, we developed strategies to optimise safe buffer environments. Comparative analyses of various isolation systems highlighted significant variations in their effectiveness at reducing bioaerosol concentrations, directly influenced by the design and layout of buffer rooms. These findings are crucial for the effective design of medical and public spaces, particularly during pandemics, where preventing virus transmission is critical for public health. [ABSTRACT FROM AUTHOR]

Context: Chia (Salvia hispanica L.), a nutrient-rich crop with potential application in different industries, is sensitive to salinity. Halotolerant plant-growth promoting bacteria could be a biotechnological strategy to increase chia's salinity tolerance. Aims: The aim of this study was to determine the morphological and physiological response of chia plants inoculated with free-living halotolerant plant-growth promoting bacteria and grown in saline soils under greenhouse conditions. Methods: A total of 15 bacterial treatments were inoculated to plants potted in soils with three electrical conductivity levels: 0.5, 4, and 6 dS m−1. Mortality and morphological and physiological parameters were evaluated. The measured variables were used to calculate a relative growth index. Key results: Bacterial inoculation had a positive effect on plants at 4 dS m−1. Plants inoculated with Pseudomonas sp. AN23, Kushneria sp. T3.7, and C6 (Halomonas sp. 3R12 + Micrococcus luteus SA211) exhibited the best morphological and physiological performance (51% longer shoots, up to 90% heavier roots and up to 400% higher photosynthetic rate than control plants). Moreover, plants inoculated with Kushneria sp. T3.7 and C5 (Halomonas sp. 3R12 + Pseudomonas sp. AN23) showed significant increase in stomatal conductance and transpiration rate (up to 12 times) and in proline production (up to 345 μg g−1 leaf fresh weight) with respect to control plants (8 μg g−1 leaf fresh weight) under saline conditions. Conclusions: The analysed extremophilic plant-growth promoting bacteria enhanced growth and stress tolerance in chia, a salt-sensitive crop. Implications: Free-living plant-growth promoting bacteria isolated from hypersaline environments have potential for bioinoculant formulation for salinity-sensitive crops. Salinity is a major threat to global agriculture due to the loss of productive land and the sensitivity of most crops, limiting the variety of production. Halotolerant plant growth-promoting bacteria show promise for increasing stress tolerance of sensitive crops like chia (Salvia hispanica). This research is the first to evaluate inoculation of soil for chia plants with free-living bacteria of this kind. The bacteria tested improved plant growth and stress tolerance, showing their potential as bioinoculants for crops under salt stress. [ABSTRACT FROM AUTHOR]

The emergence of antibiotic-resistant bacteria presents significant public health threat, triggering a growing demand for natural compounds possessing antibacterial properties within the realm of Complementary and Alternative Medicine (CAM). Our previous research identified allylpyrocatechol from Piper betle as having strong antibacterial and QS inhibition properties. However, isolating phenolic compounds is time-consuming and relies on significant organic solvent use through methods like chromatography. The aqueous two-phase system (ATPS) emerges as an innovative, efficient, and eco-friendly approach for biomolecule recovery. This study assesses ATPS efficiency in allylpyrocatechol recovery from P. betle , optimizing parameters such as phase component, composition, crude load, and pH. Optimal conditions include 22% 1-propanol, 24% ammonium sulfate at pH 7, and a 10% sample load, resulting in a higher yield (5.82±0.04 g/kg plant material) and purity (14.09±0.10%) compared to hydrodistillation (yield: 0.29±0.01 g/kg plant material, purity: 7.17±0.17%). The ATPS extract demonstrates greater antibacterial potency against Staphylococcus aureus (MIC: 500 µg/mL) and Micrococcus luteus (MIC: 500 µg/mL) than hydrodistillation (1000 µg/mL respectively). Additionally, it possesses stronger inhibition effect on violacein (48.00±0.83%) and biofilm production (43.70±1.22%) while hydrodistillation only inhibits by 35.44±0.60% and 33.15±0.66%, respectively. This study underscores ATPS as rapid and effective method for phenolic compound recovery, exemplified by allylpyrocatechol from P. betle. [Display omitted] • ATPS, based on the formation of two immiscible phases, outperforms hydrodistillation. • Optimal ATPS conditions: 22% 1-propanol, 24% ammonium sulphate, pH 7, 10% sample load. • ATPS achieves higher purity (14.09%) and yield (60.41%) than hydrodistillation. • ATPS extract shows stronger antibacterial action than hydrodistillation extract. • Extract inhibits C. violaceum quorum sensing (48%) and P. aeruginosa biofilm (43.70%). [ABSTRACT FROM AUTHOR]

The principal objective of the present study is to evaluate both the chemical composition and antibacterial effectiveness of essential oil of Clinopodium nepeta subs ascendens (CNEO) against three Gram-positive bacteria (Staphylococcus aureus, Micrococcus luteus, and Bacillus subtilis) and three Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae). Additionally, this research aims to explore potential synergies between CNEO and established antibiotics. The phytochemical composition of CNEO was thoroughly examined via gas chromatography mass spectrometry (GC-MS), revealing neoisomenthol (37.89%), pulegone (20.11%), and dihydrocarvone (19.01%) as the primary bioactive molecules. CNEO exhibited substantial antibacterial activity, with minimum inhibitory concentration (MIC) values ranging from 0.10 against E. coli to 1 mg/mL against K. pneumoniae. This promising antimicrobial activity, especially noteworthy against antibiotic-resistant bacteria, prompted an evaluation of CNEO's synergistic potential with antibiotics using the Fractional Inhibitory Concentration Index (FICI). The FICI analysis, especially with ampicillin against P. aeruginosa, uncovered an optimal synergistic interaction at a FICI of 0.31. Notably, observed reductions in MIC values for CNEO and antibiotics, ranging from 2-7 folds, highlight the heightened efficacy of these combinations. These findings hold significance for developing new approaches to address the increasing challenges of bacterial infections resistant to conventional treatments. [ABSTRACT FROM AUTHOR]

Ticks are obligate hematophagous arthropods that transmit a wide range of pathogens to humans as well as wild and domestic animals. They also harbor a non-pathogenic microbiota, although our previous study has shown that the diverse bacterial microbiome in the midgut of Ixodes ricinus is quantitatively poor and lacks a core. In artificial infections by capillary feeding of ticks with two model bacteria (Gram-positive Micrococcus luteus and Gram-negative Pantoea sp.), rapid clearance of these microbes from the midgut was observed, indicating the presence of active immune mechanisms in this organ. In the current study, RNAseq analysis was performed on the midgut of I. ricinus females inoculated with either M. luteus or Pantoea sp. or with sterile water as a control. While no immune-related transcripts were upregulated by microbial inoculation compared to that of the sterile control, capillary feeding itself triggered dramatic transcriptional changes in the tick midgut. Manual curation of the transcriptome from the midgut of unfed I. ricinus females, complemented by the proteomic analysis, revealed the presence of several constitutively expressed putative antimicrobial peptides (AMPs) that are independent of microbial stimulation and are referred to here as 'guard' AMPs. These included two types of midgut-specific defensins, two different domesticated amidase effector 2 (Dae2), microplusin/ricinusin-related molecules, two lysozymes, and two gamma interferon-inducible lysosomal thiol reductases (GILTs). The in vitro antimicrobial activity assays of two synthetic mature defensins, defensin 1 and defensin 8, confirmed their specificity against Gram-positive bacteria showing exceptional potency to inhibit the growth of M. luteus at nanomolar concentrations. The antimicrobial activity of midgut defensins is likely part of a multicomponent system responsible for the rapid clearance of bacteria in the tick midgut. Further studies are needed to evaluate the role of other identified 'guard' AMPs in controlling microorganisms entering the tick midgut. [ABSTRACT FROM AUTHOR]

N-Furfuryl allylamines react with a broad range of isocyanates, isothiocyanates, isoselenocyanates with the formation of a 3a,6-epoxyisoindole core in one synthetic stage. The interaction sequence involves two consecutive steps: the nucleophilic addition reaction and the intramolecular Diels–Alder furane (IMDAF) reaction. The scope and limitations of the proposed method were thoroughly investigated, and it was revealed that the key [4+2] cycloaddition step proceeds through an exo-transition state, giving rise to the exclusive formation of a single diastereomer of the target heterocycle. Dynamic temperature NMR analysis allowed to fully investigating a case of coalescence of NMR signals and determined the coalescence temperature during the transition O → Se. The antimicrobial properties of the obtained compounds against sensitive strains of yeast Candida albicans, fungus Aspergillus niger and bacteria including Staphylococcus aureus, Micrococcus luteus, Pseudomonas fluorescens were identified. [ABSTRACT FROM AUTHOR]

Mentha longifolia (Lamiaceae) is regarded as highly valuable aromatic medicinal species with wide range of pharmaceutical application. In the present work, leaf essential oil of M. longifolia was applied for the assessment of in vitro pharmacological potentials and compositional analysis. A sum of 15 compounds were detected by GC-FID and GC-MS analysis of M. longifolia essential oil with total area of 99.98% where major compounds were carvone (59.56%), D-limonene (20.81%), eucalyptol (10.08%). The anti-oxidant potency of M. longifolia was estimated using two methods viz., ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assay where M. longifolia essential oil showed moderate anti-oxidant potency. M. longifolia essential oil revealed high anti-inflammatory and tyrosinase inhibitory activity with an IC50 value 3.68 μL/mL and 1.22 μL/mL respectively compared to standard sodium diclofenac (5.33 μL/mL) and kojic acid (2.28 μL/mL). The acetylcholinesterase (AchE) inhibitory and genotoxic assay was performed, where M. longifolia essential oil revealed strong anti-acetylcholinesterase and anti-genotoxic activity. Anti-microbial potential of M. longifolia essential oil was also where strong anti-bacterial activity was shown against Salmonella typhimurium, Bacillus cereus, Staphylococcus aureus, Micrococcus luteus. For anti-fungal activity, M. longifolia essential oil showed no zone of inhibition against any used strains except Aspergillus flavus. From the present research it was established that M. longifolia essential oil possesses pharmaceutical potential with strong AchE inhibitory, anti-inflammatory, anti-microbial, anti-tyrosinase, anti-genotoxic and anti-oxidant activity which can be used for plant-based drug development in future endeavor. [ABSTRACT FROM AUTHOR]

In this study, we investigated the antibacterial activity of the coumarin component isolated from lime peel and coumarin derivatives synthesized using various techniques against eight types of food-poisoning bacteria. The minimum inhibitory concentration (MIC) for the 3b [5,7-dihydroxy-4-trifluoromethylcoumarin] derivative was measured as 1.5 mM in Bacillus cereus, Micrococcus luteus, Listeria monocytogenes, and Staphylococcus aureus subsp. aureus; that for the 3c [7-hydroxy-4-trifluoromethylcoumarin] derivative was 1.7 mM in Enterococcus facium; and that for the 3n [dicoumarol] derivative was 1.2 mM in L. monocytogenes. These results confirmed that coumarin derivatives with CF3 and OH substituents had enhanced antibacterial activity. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent years, the use of alternative animal models to vertebrates for the study of infectious processes and antimicrobial drug development has become a major challenge in experimentation. Insects, in particular Galleria mellonella, may represent a good model for preclinical studies, as their response to infections allows for the preliminary selection of molecules with biological activity in a potential sepsis event. However, discordant data are often reported in the literature, and this is often due to the different methods implemented in many laboratories. The aim of this work was therefore to develop a standard protocol for infection with a Gram-positive bacterium, as we consider it important to apply these unified methodologies in order to obtain reproducible data. Our results made it possible to define a correct growth curve of Micrococcus luteus and, in parallel, an infection methodology that would provide consistent and repeatable data. We are therefore confident that this work can be a support for preclinical studies on model insects, as a link between the development of new drugs and its availability for patients. The aim of this work was to develop an experimental protocol for the infection of Galleria mellonella with Gram-positive bacteria. Some physiological characteristics of these insects are comparable to those of vertebrates, therefore allowing the replacement of mammals in the preclinical phases of drug development. G. mellonella Linnaeus 1758 (Lepidoptera: Pyralidae) is accepted as an alternative model for the study of infectious diseases. Since data on infection procedures with different bacterial strains are scarce and sometimes conflicting, also due to different and non-uniform protocols, we developed an experimental protocol that would allow for controlled and repeatable infections, using the Gram-positive bacterium GRAS (Generally Regarded As Safe) Micrococcus luteus. After analyzing the morphology and defining the growth rate of M. luteus, doses of between 101 and 106 CFU/larvae were administered to late-stage larvae. The survival rate of the larvae was monitored up to 7 days and the LD50 determined. The bacterial clearance capacity of the larvae after injection with 103 and 105 CFU/larvae was assessed by hemolymph bacterial load analysis. The results made it possible to define the growth curve of M. luteus correlated with the CFU count; based on the LD50 (103.8 CFU/larvae) calculated on the survival of G. mellonella, infections were carried out to evaluate the immune efficiency of the larvae in bacterial clearance. This protocol, standardized on G. mellonella larvae, could provide a functional tool to study the course of bacterial infections. [ABSTRACT FROM AUTHOR]

The spread of multidrug-resistant mycobacterium strains requires the development of new approaches to combat diseases caused by these pathogens. For that, photodynamic inactivation (PDI) is a promising approach. In this study, a tricarbocyanine (TCC) is used for the first time as a near-infrared (740 nm) activatable PDI photosensitizer to kill mycobacteria with deep light penetration. For better targeting, a novel tricarbocyanine dye functionalized with two trehalose units (TCC2Tre) is developed. The photodynamic effect of the conjugates against mycobacteria, including Mycobacterium tuberculosis, is evaluated. Under irradiation, TCC2Tre causes more effective killing of mycobacteria compared to the photosensitizer without trehalose conjugation, with 99.99% dead vegetative cells of M. tuberculosis and M. smegmatis. In addition, effective photoinactivation of dormant forms of M. smegmatis is observed after incubation with TCC2Tre. Mycobacteria treated with TCC2Tre are more sensitive to 740 nm light than the Gram-positive Micrococcus luteus and the Gram-negative Escherichia coli. For the first time, this study demonstrates the proof of principle of in vitro PDI of mycobacteria including the fast-growing M. smegmatis and the slow-growing M. tuberculosis using near-infrared activatable photosensitizers conjugated with trehalose. These findings are useful for the development of new efficient alternatives to antibiotic therapy. [ABSTRACT FROM AUTHOR]

Probiotics in cosmetics represent a new and burgeoning area of research, attracting attention from cosmetic manufacturers and customers looking for natural or additional alternatives in their skincare regimens. Probiotics not only promote beneficial microbiomes to improve skin health but can also modulate the visual, topographical, and mechanical attributes to improve skin quality. This study was conducted in healthy adults to determine the effect of direct skin application of a topical serum formulation containing the live probiotic Micrococcus luteus Q24 on several key cosmetic skin quality parameters and its beneficial impact on the modulation of the skin microbiome. Quantitative changes in various skin parameters were measured using a skin analyser device and skin swabs were analysed using whole-genome sequencing to monitor microbial diversity and levels of probiotic colonization. Compared to the baseline, significant reductions in the pores, spots, wrinkles, and impurities scores, and an increase of 101% in the hydration score were observed. Additionally, 45–80% of participants showed a decrease in pores, spots, wrinkles, and impurities and 90% of participants showed an increase in hydration after 25 days of probiotic serum application. The WGS analysis of the skin swab samples showed a significant increase in the relative abundance of M. luteus Q24. The results from this study indicate that topical application of a serum containing the probiotic M. luteus Q24 offers the benefit of improving skin health quality. [ABSTRACT FROM AUTHOR]

Quinoa, scientifically known as Chenopodium quinoa Willd. is well recognized for its exceptional nutritional composition and potential benefits for human health. This research aims to conduct a phytochemical analysis of nutraceutical properties and biologcal activities of seven different quinoa cultivars, namely, red, white, Amarilla marangani , kancolla, Giza 02, Amarilla sacaca , and black. The analysis of ground seeds revealed that Giza 02, white, and A. marangani had the most significant protein, fat, ash, and carbohydrates, respectively. Furthermore, the MeOH extracts of the various quinoa genotypes exhibited high levels of total phenolic, flavonoid, condensed tannin and reducing sugar contents in the seed extracts obtained using consecutive solvents. In addition, HPLC-DAD analysis revealed the presence of seven phenolic compounds, which may be classified into four families: phenolic acid, flavonoids, coumarins, and stilbenes. The IC50 values for the antioxidant activity ranged from 6.4 to 7.7 µg/mL. Furthermore, the variability in the antibacterial activity across different genotypes and gram-positive and gram-negative bacterial species was observed, and the efficacy of the CYHA-red extract against Micrococcus luteus was the highest. The findings of this study indicate that the incorporation of quinoa into the arid and Saharan cultivation system has the potential to enhance the nutritional and nutraceutical characteristics of the seeds. [ABSTRACT FROM AUTHOR]

Cryptomeria japonica wood industry generates large amounts of foliage biomass residues. Due to the increasing applications and markets for essential oils (EOs), fresh Azorean C. japonica foliage (Az–CJF) residues are used for local EO production. Hydrodistillation (HD), a common process for obtaining EOs, also provides the possibility to fractionate them. Thus, this study evaluated the in vitro antimicrobial and antioxidant activities of six Az–CJF EO fractions (Frs. 1–6), collected at sequential HD timeframes (HDTs: 0–2, 2–10, 10–30, 30–60, 60–120, and 120–240 min), in comparison to the crude EO, obtained from a non-fractionated HD (0–240 min HDT). Antimicrobial activities were assessed via disc diffusion method against seven bacteria (foodborne and/or human pathogens) and two Penicillium spp. (phytopathogenic fungi), and antioxidant activity was estimated using DPPH and ABTS assays. Concerning the antibacterial activity, all the EO samples were effective only toward Gram-positive bacteria. Fractions 1–3 (<30 min HDT) were the most active, with growth inhibition zones (GIZ) of 7.0–23.3 mm (1.4–2.2 times higher than those of the crude EO), being Bacillus spp. (B. licheniformis and B. subtilis) the most sensitive, followed by Staphylococcus aureus and Micrococcus luteus. Regarding the antifungal activity, Frs. 1–3 also displayed the best activities, but only against P. italicum (GIZ around 9.0 mm), while the crude EO showed no antifungal activity. Overall, the best antimicrobial properties of Frs. 1–3 could be attributed, at least in part, to their highest content in α-pinene and bornyl acetate. On the other hand, Frs. 4–6 (>30 min HDT) exhibited the strongest antioxidant activities (EC50 values: 1.5–2.3 and 1.0–1.7 mg mL−1 for DPPH and ABTS, respectively), being at least 1.3-fold higher than those of the crude EO. The presence of nezukol, elemol, and eudesmol isomers could strongly contribute to the best free radical scavenging properties of Frs. 4–6. In conclusion, HD was found to be an efficient process for obtaining new Az–CJF EO fractions with variable and enhanced bioactivities due to their differential composition, as assessed using GC–MS. Hence, these findings could contribute to increasing the commercial potential of the C. japonica EO industry, namely, the Fr2 and Fr6, which presented the most significant activities and can have potential applications in the food, medical, and agriculture sectors. [ABSTRACT FROM AUTHOR]

Background: Bacterial antimicrobial resistance poses a severe threat to humanity, necessitating the urgent development of new antibiotics. Recent advances in genome sequencing offer new avenues for antibiotic discovery. Paenibacillus genomes encompass a considerable array of antibiotic biosynthetic gene clusters (BGCs), rendering these species as good candidates for genome-driven novel antibiotic exploration. Nevertheless, BGCs within Paenibacillus genomes have not been extensively studied. Results: We conducted an analysis of 554 Paenibacillus genome sequences, sourced from the National Center for Biotechnology Information database, with a focused investigation involving 89 of these genomes via antiSMASH. Our analysis unearthed a total of 848 BGCs, of which 716 (84.4%) were classified as unknown. From the initial pool of 554 Paenibacillus strains, we selected 26 available in culture collections for an in-depth evaluation. Genomic scrutiny of these selected strains unveiled 255 BGCs, encoding non-ribosomal peptide synthetases, polyketide synthases, and bacteriocins, with 221 (86.7%) classified as unknown. Among these strains, 20 exhibited antimicrobial activity against the gram-positive bacterium Micrococcus luteus, yet only six strains displayed activity against the gram-negative bacterium Escherichia coli. We proceeded to focus on Paenibacillus brasilensis, which featured five new BGCs for further investigation. To facilitate detailed characterization, we constructed a mutant in which a single BGC encoding a novel antibiotic was activated while simultaneously inactivating multiple BGCs using a cytosine base editor (CBE). The novel antibiotic was found to be localized to the cell wall and demonstrated activity against both gram-positive bacteria and fungi. The chemical structure of the new antibiotic was elucidated on the basis of ESIMS, 1D and 2D NMR spectroscopic data. The novel compound, with a molecular weight of 926, was named bracidin. Conclusions: This study outcome highlights the potential of Paenibacillus species as valuable sources for novel antibiotics. In addition, CBE-mediated dereplication of antibiotics proved to be a rapid and efficient method for characterizing novel antibiotics from Paenibacillus species, suggesting that it will greatly accelerate the genome-based development of new antibiotics. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate antibacterial activity of pigment extracted from bacteria, isolated from soil samples. During the study, 20 soil samples were collected from different areas (forest, agriculture fields, river sides and dumping sites) of Kathmandu and Lalitpur districts which were processed for isolation of pigment producing bacteria by spread plate technique. The pigmented bacterial isolates were identified and enriched in nutrient broth. Then, pigment was extracted in 95% methanol as solvent, which was further characterized using UV-Vis Spectrophotometric and TLC analysis. The obtained crude pigment extract was processed to carry out the antimicrobial susceptibility assay using agar well diffusion method. Out of 13 total pigmented bacteria isolates, four different colored pigmented bacterial isolates (S4O, S11Y, S14P and S17G) which produced efficient pigment on nutrient agar were chosen and they were further processed. Among these isolates, S4O was identified as Staphylococcus aureus, S11Y was identified as Micrococcus luteus, S14P was identified as Micrococcus roseus and S17G was identified as Pseudomonas aeruginosa respectively. On characterization using UV-Vis Spectrophotometric and TLC analysis, the pigment extracted from isolates S4O, S11Y and S14P were found to be Carotenoids and from isolate S17G was found to be Pyocyanin in nature. The maximum antibacterial activity was shown against Staphylococcus aureus from all the four pigments extracts. The green color pigment extract from isolate S17G was found to be most effective against all the Gram-positive and Gram-negative test bacteria. This study suggests that these pigment extracts from pigmented bacteria may have beneficial antibacterial roles that can be exploited in controlling unwanted bacterial growth. [ABSTRACT FROM AUTHOR]

Boza, a cereal‐based beverage popular in southeast Europe, is fortified with probiotics and is believed to positively impact the composition of the gut microflora. This investigation focused on fermented cereal‐based beverage boza to identify strains of probiotic Lactobacillus spp. capable of inhibiting carbohydrate‐hydrolysing enzymes α‐glucosidase (AG) and α‐amylase (AA). The isolated bacterial strains underwent a comprehensive assessment, including biochemical, molecular, and probiotic trait analyses such as tolerance survivability, adhesion, safety, and health‐promoting attributes. We evaluated the inhibitory potential of the supernatant, cell lysate, and intact cells of Lactobacillus spp. Molecular analysis has revealed that isolates RAMULAB30 and RAMULAB29 exhibit a significant genetic similarity (>97%) to Lacticaseibacillus paracasei and Limosilactobacillus fermentum, respectively. These findings are documented in the NCBI database. They exhibited significant resistance to gastrointestinal and intestinal fluids, also indicating their potential for adhesion. Additionally, the isolates showed a significant antibacterial activity, particularly against Micrococcus luteus. They showed resistance to vancomycin and methicillin antibiotics but were more susceptible to streptomycin and ampicillin. Furthermore, the strains demonstrated antioxidant properties. To ensure their safety, a haemolytic assay was conducted despite their general recognition as safe (GRAS) status. The study primarily aimed to evaluate the inhibitory effects of the extract on enzymes AG and AA. Bacterial isolates demonstrated a significant inhibitory activity against both enzyme AG (32%–67% inhibition) and enzyme AA (18%–46% inhibition) in different forms, including supernatant (CS), lysed extract (CE), and intact cell (IC). These findings underscore the potential of bacterial isolates to inhibit the enzyme activity effectively. Furthermore, the L. fermentum RAMULAB29 and L. paracasei RAMULAB30 strains exhibit remarkable antidiabetic potential. Food products incorporating these strains have promising prospects as nutraceuticals, providing improved health benefits. [ABSTRACT FROM AUTHOR]

Contamination of arsenic in drinking water and foods is a threat for human beings. To achieve the goal for the reduction of arsenic availability, besides conventional technologies, arsenic bioremediation by using some potent bacteria is one of the hot topics for researchers. In this context, bacterium, AKS4c was isolated from arsenic contaminated water of Purbasthali, West Bengal, India, and through draft genome sequence; it was identified as a strain of Micrococcus luteus that comprised of 2.4 Mb genome with 73.1% GC content and 2256 protein coding genes. As the accessory genome, about 22 genomic islands (GIs) associated with many metal-resistant genes were identified. This strain was capable to tolerate more than 46,800 mg/L arsenate and 390 mg/L arsenite salts as well as found to be tolerable to multi-metals such as Fe, Pb, Mo, Mn, and Zn up to a certain limit of concentrations. Strain AKS4c was able to oxidize arsenite to less toxic arsenate, and its arsenic adsorption property was qualitatively confirmed through X-ray fluorescence (XRF) and Fourier transform infrared spectroscopy (FTIR) analysis. Quantitative estimation of plant growth-promoting attributes like Indole acetic acid (IAA), Gibberellic acid (GA), and proline production and enhancement of rice seedling growth in laboratory condition leads to its future applicability in arsenic bioremediation as a plant growth-promoting rhizobacteria (PGPR). [ABSTRACT FROM AUTHOR]

In the present study, copper oxide (CuO) nanoparticles were biosynthesized from an Aspergillus niger cell-free extract (CFE), and several optimal operating parameters that affected the formation and dimensions of the CuO nanoparticles were determined, as follows: 15 mmol/L metal salt and 90 mL of CFE at room temperature for 24 h, to achieve an average size of 77 nm. Spectroscopic studies revealed an association between alcohol, alkene, and amine functional groups and the grain-shaped CuO nanoparticles. The elemental composition of the nanoparticles was confirmed by energy dispersive X-ray spectroscopy (EDX) data. Mycogenic CuO nanoparticles exhibited excellent antibacterial activity against Gram-positive bacterial species compared with Gram-negative bacterial species, i.e., Streptococcus pneumoniae MTCC 2672, Staphylococcus aureus MTCC 737, Micrococcus luteus MTCC 11948, Pseudomonas aeruginosa MTCC 424, and Escherichia coli MTCC 443, at 200 mg/mL, with inhibition zones of 9.2, 8.3 7.7, 7.2, and 6.1 mm, respectively. Finally, myogenic CuO nanoparticles exhibited good antifungal activity against Aspergillus fumigatus and Aspergillus versicolor. [ABSTRACT FROM AUTHOR]

Murraya koenigii (L.) Spreng., is a renowned medicinal and aromatic plant having antimicrobial and broad biological activities. In the present study, the essential oil chemical profile of the leaf and floral part were analysed using GC-FID and GC-MS, and the antimicrobial activities were determined by disk diffusion assay. The scientific analysis revealed α-pinene (40.41%) was the major compound of leaf essential oil (MKL) followed by sabinene (29.66%), β-pinene (7.92%), caryophyllene (4.24%), limonene (3.39%), terpinen-4-ol (3.25%), γ-terpinene (2.63%), terpinolene (1.58%), linalool (1.32%), along with other trace components. The floral part (MKF) contains the compounds α-pinene (74.02%) as the major compound followed by β-pinene (7.17%), sabinene (5.72%), limonene (4.19%), β-myrcene (1.98%), γ-terpinene (1.47%) and terpinen-4-ol (1.41%) along with other trace compounds. The MIC result revealed essential oil showed effectiveness against Escherichia coli (40 μg/mL), Micrococcus luteus (80 μg/mL), Aspergillus fumigatus (60 μg/mL) and Aspergillus brasiliensis (80 μg/mL) for MKL while MKF did not exhibit potent antimicrobial activities. The essential oils revealed potent antioxidant potential as determined by DPPH method with IC50 values of 14.02 μL/mL (MKL) and 5.45 μL/mL (MKF) and the ABTS method with IC50 values of 5.07 μL/mL and 8.38 μL/mL in MKL and MKF respectively as compared to that of the standards. The essential oils revealed potent antidiabetic activity with 6.02 μL/mL (MKL) and 8.18 μL/mL (MKF) as that of the standard. However, both MKL and MKF were not much effective in protease inhibitory activity and anti-tyrosinase activity. The study results exhibited a potent bioactivity profile and revealed many new utilization aspects of this essential oil. [ABSTRACT FROM AUTHOR]

The present study focused on the antioxidant, cytotoxic, antimicrobial, and DNA-protective effects of Usnea lapponica, Usnea intermedia, and Usnea florida, which are distributed in Turkey. The methanol extracts of these three lichen species were subjected to high-performance liquid chromatography (HPLC) analysis to quantify the amount of usnic acid and the highest amount was found in U. lapponica (3345.9±92.18 mg/gextract). Furthermore, the total phenolic and flavonoid contents were analyzed. Antioxidant capacity was evaluated by different chemical assays, together with antimicrobial, cytotoxic, and DNA-protective properties. The results of the antioxidant assays showed that U. lapponica exhibited the highest DPPH radical scavenging activity, whereas the extract that scavenged ABTS radicals more potently was identified as U. intermedia. The disc diffusion method was used to investigate the antimicrobial activity, and the strongest effect was observed in U. intermedia methanol extract with a zone value of 13 mm on Micrococcus luteus. In cytotoxicity experiments, U. florida extract (250 µg/mL; 36.03% viability) exhibited a high antiproliferative effect on A549 cells and U. intermedia (62.5 µg/mL; 23.65% viability) on MDA-MB-231 cells. DNA-protective effects were investigated using pBR322 plasmid DNA, and all the studied species were found to have DNA-protective effects. These results suggest that Usnea species may be potential candidates for the development of new phytopharmaceuticals and functional ingredients. [ABSTRACT FROM AUTHOR]

Prediction of the antibacterial activity of new chemical compounds is an important task, due to the growing problem of bacterial drug resistance. Generalized linear models (GLMs) were created using 85 amidrazone derivatives based on the results of antimicrobial activity tests, determined as the minimum inhibitory concentration (MIC) against Gram-positive bacteria: Staphylococcus aureus, Enterococcus faecalis, Micrococcus luteus, Nocardia corallina, and Mycobacterium smegmatis. For the analysis of compounds characterized by experimentally measured MIC values, we included physicochemical properties (e.g., molecular weight, number of hydrogen donors and acceptors, topological polar surface area, compound percentages of carbon, nitrogen, and oxygen, melting points, and lipophilicity) as potential predictors. The presence of R1 and R2 substituents, as well as interactions between melting temperature and R1 or R2 substituents, were also considered. The set of potential predictors also included possible biological effects (e.g., antibacterial, antituberculotic) of tested compounds calculated with the PASS (Prediction of Activity Spectra for Substances) program. Using GLMs with least absolute shrinkage and selection (LASSO), least-angle regression, and stepwise selection, statistically significant models with the optimal value of the adjusted determination coefficient and of seven fit criteria were chosen, e.g., Akaike's information criterion. The most often selected variables were as follows: molecular weight, PASS_antieczematic, PASS_anti-inflam, squared melting temperature, PASS_antitumor, and experimental lipophilicity. Additionally, relevant to the bacterial strain, the interactions between melting temperature and R1 or R2 substituents were selected, indicating that the relationship between MIC and melting temperature depends on the type of R1 or R2 substituent. [ABSTRACT FROM AUTHOR]

Human lysozyme (hLYZ) has attracted considerable research attention due to its natural and efficient antibacterial abilities and widespread uses. In this study, hLYZ was modified to enhance its enzyme activity and expressed in a Pichia pastoris expression system. A combination mutant HZM(2R-K)-N88D/V110S demonstrated the highest enzyme activity (6213 ± 164 U/mL) in shake flasks, which was 4.07-fold higher when compared with the original strain. Moreover, the recombinant P. pastoris was inducted in a 3 L bioreactor plus methanol/sorbitol co-feeding. After 120 h induction, the antibacterial activity of hLYZ reached 2.23 ± 0.12 × 105 U/mL, with the specific activity increasing to 1.89 × 105 U/mg, which is currently the highest specific activity obtained through recombinant expression of hLYZ. Also, hLYZ supernatants showed 2-fold inhibitory effects toward Staphylococcus aureus and Micrococcus lysodeikticus when compared with HZM(2R-K). Our research generated a hLYZ mutant with high antibacterial capabilities and provided a method for screening of high-quality enzymes. [ABSTRACT FROM AUTHOR]

Rosa damascena Mill. is widely known for its essential oil. The root part of this plant is not explored. Fresh, shade-dried roots of R. damascena were used for hydrodistillation and a 0.02 % (v/w) yield of volatile organic compounds (VOCs) was obtained. The chemical profile of VOCs was determined by gas chromatography-mass spectrometry (GC–MS) and further quantified by a gas chromatography-flame ionization detector (GC-FID). Screening for antidiabetic potential has been conducted by determining inhibitory effect of α-amylase and α-glucosidase with IC 50 values of 0.95±0.20 mg/mL and 0.92±0.11 mg/mL, respectively. In-vitro studies for the determination of antimicrobial potential against, three Gram-positive, three Gram-negative pathogenic bacterial strains, and two fungal pathogenic strains were also conducted, which showed promising results. Among all the tested pathogenic bacterial strains, Micrococcus luteus MTCC 2470 was found highly sensitive against VOCs with the inhibition zone diameter of 41 ± 1 mm and the minimum inhibitory concentration (MIC) of 0.39 mg/mL. Further, out of two tested pathogenic fungal strains, VOCs showed the highest inhibition potential against Fusarium graminearum MTCC 1893 with the inhibition zone diameter of 39.33±1.53 mm. This study revealed that hexadecane (12.06 %), octadecane (10.73 %), n-hexadecanoic acid, (8.32 %) tetradecane (7.93 %), tetradec‑1-ene (7.53 %), icosane (7.49 %), and hexadec‑1-ene (7.47 %), were the most abundant volatile components. In silico study has been conducted for antidiabetic and antimicrobial. However, after 10–12 years of planting, uprooting is done. After uprooting, the root part is usually burned or disposed. In this study, we demonstrated a possible utilization of root part by extracting VOCs and evaluated their biological significance. [Display omitted] • Rosa damascena Mill. is well known species and it is globally cultivated. • After uprooting of plant, root becomes the waste, usually burned, or discarded. • Around 2,49,750 tonnes of uprooting is done in every decade. • Qualitative and quantitative chemical profiling of VOCs present in root part. • Antidiabetic and antimicrobial potential studied through In-vitro and In-silico. [ABSTRACT FROM AUTHOR]

OBJECTIVE To evaluate the prevalence of oral bacteria in the conjunctiva of brachycephalic and nonbrachycephalic dogs. ANIMALS 12 brachycephalic (9.58 ± 3.55 years) and 12 nonbrachycephalic (8.33 ± 4.92 years) dogs without systemic disease, regardless of breed and sex, were included in the study, and half of the dogs in each group had periodontitis. METHODS This prospective study investigated clinical data including craniofacial ratio, ophthalmic examination results, and periodontal status of the included dogs. Bacterial samples were collected by swabbing the oral mucosa and conjunctival surfaces. The presence and quantity of bacteria were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 16S rRNA sequencing analysis, and the 10-fold dilution method. Statistical analyses were performed to assess correlations and factors influencing the presence of oral bacteria in the conjunctiva. RESULTS The most common bacteria in the conjunctival flora in both groups were Micrococcus luteus, Corynebacterium spp, and Staphylococcus spp. The prevalence of oral bacteria on the conjunctival surface was 33%, with a significantly higher incidence in brachycephalic dogs (P = .027). Oral bacteria detected in the conjunctiva were predominantly Frederiksenia canicola, Neisseria spp, and Moraxella spp. Multiple regression analysis identified age, craniofacial ratio, and gingival index as factors influencing the presence of oral bacteria in the conjunctival flora. CLINICAL RELEVANCE Oral resident bacteria have often been isolated from severe infectious corneal ulcers. This study provided evidence that brachycephalic dogs may require dental prophylaxis to reduce their oral bacterial load and that the association of oral bacteria in ocular diseases should be considered. [ABSTRACT FROM AUTHOR]

Speleotherapy is one of the non-pharmacological methods for the treatment and rehabilitation of patients with chronic respiratory diseases, especially those with chronic obstructive pulmonary disease (COPD) and asthma. On the one hand, one of the alleged main advantages of speleotherapeutic caves is the low microbial load in the air and the absence of other aeroallergens, but on the other hand, due to the lack of comprehensive air monitoring, there is little information on the pristine and human-influenced aerobiota in such environments. The aim of this study was to assess the anthropogenic effects of speleotherapy on the air microbiota and to investigate its potential impact on human health in Sežana Hospital Cave (Slovenia). From May 2020 to January 2023, air samples were collected in the cave before and after speleotherapeutic activities using two different volumetric air sampling methods—impaction and impingement—to isolate airborne microbiota. Along with sampling, environmental data were measured (CO2, humidity, wind, and temperature) to explore the anthropogenic effects on the aerobiota. While the presence of patients increased microbial concentrations by at least 83.3%, other parameters exhibited a lower impact or were attributed to seasonal changes. The structure and dynamics of the airborne microbiota are similar to those in show caves, indicating anthropization of the cave. Locally, concentrations of culturable microorganisms above 1000 CFU/m3 were detected, which could have negative or unpredictable effects on the autochthonous microbiota and possibly on human health. A mixture of bacteria and fungi typically associated with human microbiota was found in the air and identified by MALDI-TOF MS with a 90.9% identification success rate. Micrococcus luteus, Kocuria rosea, Staphylococcus hominis, and Staphylococcus capitis were identified as reliable indicators of cave anthropization. [ABSTRACT FROM AUTHOR]

Spontaneous Bacterial Peritonitis (SBP) is a serious complication and a common cause of death in patients with liver cirrhosis. Between January 2017 and March 2024, a retrospective study was conducted involving 302 patients (>18 years old) with ascites treated at a tertiary referral center in south-eastern Poland. Microbiological analysis of the ascitic fluids was performed in all patients. The presence of microorganisms was found in samples from 17 patients, and 21 pathogens were isolated, including 15 Gram-positive bacteria and 6 Gram-negative bacteria. Staphylococcus epidermidis, MRCNS (methicillin-resistant coagulase-negative staphylococci, resistant to all beta-lactam antibiotics: penicillins, penicillins with beta-lactamase inhibitor, cephalosporins and carbapenems) was the main pathogen detected (19.05%, 4/21), followed by Enterococcus faecalis (9.52%, 2/21), Enterococcus faecium (9.52%, 2/21), Staphylococcus haemolyticus, MRCNS (4.76%, 1/21), Streptococcus mitis (9.52%, 2/21), Streptococcus parasanguinis (9.52%, 2/21), Micrococcus luteus (4.76%, 1/21) and Bacillus spp. (4.76%, 1/21). The following Gram-negative bacteria were also found in the specimens examined: Escherichia coli, ESBL (extended-spectrum β-lactamase producing E. coli) (4.76%, 1/21), Escherichia coli (4.76%, 1/21), Pseudomonas aeruginosa (4.76%, 1/21), Klebsiella oxytoca (9.52%, 2/21) and Sphingomonas paucimobilis (4.76%, 1/21). Gram-positive bacteria caused nosocomial infections in nine patients with SBP, Gram-negative bacteria caused nosocomial infections in two patients. In six patients with SBP, community-acquired infections caused by Gram-negative bacteria were found in three cases, Gram-positive bacteria in two cases, and in one case, community-acquired infection was caused by mixed Gram-positive and Gram-negative. Bacteria isolated from patients with hospital-acquired SBP showed higher drug resistance than those found in patients with non-hospital SBP. Bacterial infections in cirrhotic patients with complications may be responsible for their deteriorating health. Prompt intervention is critical to reducing mortality. [ABSTRACT FROM AUTHOR]

Bioremediation aspects of crude oil-polluted fields can be achieved by isolating and identifying bacterial species from oil-contaminated soil. This allows for the selection of the most active isolates and the enhancement of the effectiveness of other bacteria. This project will be a base to use green technology for clean the oil contaminated soil in Jordan. This study involved the isolation and identification of oil-degrading microbes from soil samples contaminated with oil in the northeastern region of Jordan. The morphological and biochemical tests were used to characterize twenty-five bacterial isolates. Molecular identification of a universal primer 16S rDNA gene was used to identify bacterial isolates. Total petroleum hydrocarbons were analyzed using gas chromatography for soil samples. All soil samples were analyzed for heavy metal contamination (Cu, Cd, Mn, Zn, and Pb). The bacterial growth count (CFU/g) was between 1.06×105 and 2.80×1017. The identified bacterial genera included: Staphylococcus, Citrobacter, Lactobacillus, Alcaligin's, Pseudomonas, Micrococcus, Serratia, Enterobacter, Bacillus, Salmonella, Mycobacterium, Corynebacterium, and, Microbacterium. The most species showed high growth rates on different types of hydrocarbons such as toluene, naphthalene, and hexane were Lactobacillus casei, Staphylococcus intermedius, Micrococcus luteus, Pseudomonas putida, Mycobacterium phlei, Corynebacterium xerosis. Soil sample M1A contains the highest levels of Fe, Cd, and Pb and Cu,. While M1C contains the highest levels of Fe and Mn. On the other hand, M2A, and M2C have the least levels of Mn and Fe. While M3C has the least level of Zn and Pb. our study conclude the bacterial isolates could be used for in situ and ex situ cleanup of oil-contaminated desert soil in northeastern part of Jordan. [ABSTRACT FROM AUTHOR]

Nanotechnology and nanoparticles have gained massive attention in the scientific community in recent years due to their valuable properties. Among various AgNPs synthesis methods, microbial approaches offer distinct advantages in terms of cost-effectiveness, biocompatibility, and eco-friendliness. In the present research work, investigators have synthesized three different types of silver nanoparticles (AgNPs), namely AgNPs-K, AgNPs-M, and AgNPs-E, by using Klebsiella pneumoniae (MBC34), Micrococcus luteus (MBC23), and Enterobacter aerogenes (MBX6), respectively. The morphological, chemical, and elemental features of the synthesized AgNPs were analyzed by using UV-Vis spectroscopy (UV-Vis), Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy-dispersive spectroscopy (EDX). UV-Vis absorbance peaks were obtained at 475, 428, and 503 nm for AgNPs-K, AgNPs-M, and AgNPs-E, respectively. The XRD analysis confirmed the crystalline nature of the synthesized AgNPs, having peaks at 26.2°, 32.1°, and 47.2°. At the same time, the FTIR showed bands at 599, 963, 1,693, 2,299, 2,891, and 3,780 cm−1 for all the types of AgNPs indicating the presence of bacterial biomolecules with the developed AgNPs. The size and morphology of the AgNPs varied from 10 nm to several microns and exhibited spherical to porous sheets-like structures. The percentage of Ag varied from 37.8% (wt.%) to 61.6%, i.e., highest in AgNPs-K and lowest in AgNPs-M. Furthermore, the synthesized AgNPs exhibited potential for environmental remediation, with AgNPs-M exhibiting the highest removal efficiency (19.24% at 120 min) for methyl orange dye in simulated wastewater. Further, all three types of AgNPs were evaluated for the removal of methyl orange dye from the simulated wastewater, where the highest dye removal percentage was 19.24% at 120 min by AgNPs-M. Antibacterial potential of the synthesized AgNPs assessment against both Gram-positive (GPB) Bacillus subtilis (MBC23), B. cereus (MBC24), and Gram-negative bacteria Enterococcus faecalis (MBP13) revealed promising results, with AgNPs-M, exhibiting the largest zone of inhibition (12 mm) against GPB B. megaterium. Such investigation exhibits the potential of the bacteria for the synthesis of AgNPs with diverse morphology and potential applications in environmental remediation and antibacterial therapy-based synthesis of AgNPs. [ABSTRACT FROM AUTHOR]

Introduction: This study investigates the biological activities of Lavandula pinnata essential oil (LPEO), an endemic lavender species from the Canary Islands, traditionally used in treating various ailments. Methods: LPEO was extracted by hydrodistillation and analyzed using GC-MS. Antioxidant activity was assessed by DPPH radical scavenging and total antioxidant capacity assays. Antimicrobial activity was evaluated by disc diffusion, MIC, MBC, and MFC determination against bacterial (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa) and fungal (Candida glabrata, Rhodotorula glutinis, Aspergillus niger, Penicillium digitatum) strains. Antidiabetic and anti-gout potential were investigated through α-amylase, α-glucosidase, and xanthine oxidase inhibition assays. Antityrosinase activity was determined using a modified dopachrome method. Cytotoxicity was assessed by MTT assay against breast (MCF-7, MDA-MB-468), liver (HepG2), colon (HCT-15) cancer cells, and normal cells (PBMCs). Results and discussion: LPEO exhibits potent antiradical activity (IC50 = 148.33 ± 2.48 μg/mL) and significant antioxidant capacity (TAC = 171.56 ± 2.34 μg AA/mg of EO). It demonstrates notable antibacterial activity against four strains (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, and Pseudomonas aeruginosa) with inhibition zones ranging from 18.70 ± 0.30mm to 29.20 ± 0.30 mm, along with relatively low MIC and MBC values. LPEO displays significant antifungal activity against four strains (Candida glabrata, Rhodotorula glutinis, Aspergillus niger, and Penicillium digitatum) with a fungicidal effect at 1 mg/mL, surpassing the positive control (cycloheximide), and MIC and MFC values indicating a fungicidal effect. It exhibits substantial inhibition of xanthine oxidase enzyme (IC50 = 26.48 ± 0.90 μg/mL), comparable to allopurinol, and marked inhibitory effects on α-amylase (IC50 = 31.56 ± 0.46 μg/mL) and α-glucosidase (IC50 = 58.47 ± 2.35 μg/mL) enzymes.The enzyme tyrosinase is inhibited by LPEO (IC50 = 29.11 ± 0.08 mg/mL). LPEO displays moderate cytotoxic activity against breast, liver, and colon cancer cells, with low toxicity towards normal cells (PBMC). LPEO exhibits greater selectivity than cisplatin for breast (MCF-7) and colon (HCT-15) cancer cells but lower selectivity for liver (HepG2) and metastatic breast (MDA-MB-468) cancer cells. These findings suggest the potential of LPEO as an antioxidant, antimicrobial, antigout, antidiabetic, and anticancer agent. [ABSTRACT FROM AUTHOR]

Human skin acts as a protective barrier between the body and the external environment. Skin microbiome and intercellular lipids in the stratum corneum (SC) are essential for maintaining skin barrier function. However, the interplay between skin bacteria and the lipids is not fully understood. In this study, we characterized the skin microbiome and SC lipid profiles from the forearm and face in a cohort of 57 healthy participants. 16S rRNA gene sequencing showed the skin microbial composition is significantly different between body locations and genders. Female forearm samples have the highest microbial diversity. The relative abundance of Staphylococcus hominis, Micrococcus luteus, Corynebacterium tuberculostearicum, Finegoldia magna, and Moraxellaceae sp. are significantly higher in the forearm than the face. The predictive functional analysis of 16S rRNA gene sequencing by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) and ANCOM-BC showed different bacterial metabolic pathway profiles between body locations or genders, and identified 271 differential pathways, including arginine and polyamine biosynthesis, chorismate biosynthesis pathways, which are more abundant in the female forearm, and sulfur oxidation pathway, which is more abundant in the male face. The SC lipid profiles differ between the body locations as well. Total free fatty acids (FFA), cholesterol sulfate and sphingosine are more abundant in the face. Dihydro-/6-hydroxy/phyto-ceramides are more abundant in the forearm. The correlation analysis of 16S rRNA gene sequencing and lipids revealed novel interplay between the bacteria and skin lipids. Shannon entropy and S. hominis negatively correlated with FFA, cholesterol sulfate and sphingosine; while positively correlated with dihydro-/6-hydroxy/phytoceramides. The correlation of predictive pathway profiles and lipids identified pathways involved in amino acids metabolism, carbohydrates degradation, aromatic compounds metabolism and fatty acid degradation metabolism are positively correlated with dihydro-/6-hydroxy/phyto-ceramides and negatively correlated with FFA, cholesterol sulfate and sphingosine. This study provides insights on the potential correlation between skin microbiome and lipids. [ABSTRACT FROM AUTHOR]

Insects have innate immunity comprising cellular and humoral defense reactions. Nodulation is a predominant cellular immune response to bacterial infections and the prophenoloxidase (PPO)-activating system acts in nodulation with a melanization reaction that darkens the nodules and produces reactive oxygen species that probably kill the bacteria. Although several eicosanoid actions have been reported in insect immune functions, these actions are relatively understudied among dipterans. We addressed this gap by exploring nodulation reactions to bacterial infections in the 3rd instar of the flesh fly Thomsonea argyrostoma. The Gram-positive bacterium, Micrococcus luteus, was injected either alone or coupled with eicosanoids biosynthesis inhibitors (EBIs). Nodulation exhibits a maximum at 24 h post injection. At zero time of control larvae, a constitutive level of phenoloxidase (PO) was found in plasma. Intrahemocoelic injection of M. luteus induces biosynthesis of PPO in hemocytes, and also its release into and activation in plasma via M. luteus challenge. EBIs suppress nodulation and PPO content of both hemocytes and plasma, but not PO content of plasma. The results imply the mediation of eicosanoids in PPO biosynthesis in hemocytes and its release, but not its activation in plasma. The injection of biogenic monoamines Octopamine (OA) and 5-hydroxytryptamine (5-HT) elevates nodulation and PPO biosynthesis and its activation in plasma. [ABSTRACT FROM AUTHOR]

This work was the first investigation of the essential oil composition of Goniothalamus tortilipetalus M.R.Hend. The aim of this study is to investigate the essential oil composition extracted from different parts of Goniothalamus tortilipetalus M.R.Hend., including flowers, leaves, and twigs, and to evaluate their antioxidant and antibacterial activities. The Clevenger apparatus was used for hydrodistillation to prepare the essential oils. The essential oils were investigated using gas chromatography–mass spectrometry (GC-MS). The three major compounds of the flowers were bicyclogermacrene (15.81%), selin-11-en-4-α-ol (14.68%), and E-caryophyllene (7.02%), whereas the leaves were p-cymene (39.57%), ascaridole (9.39%), and α-copaene (9.12%). In the case of the twigs, α-copaene (10.34%), selin-11-en-4-α-ol (8.85%), and p-cymene (7.76%) were the major compounds. The flower essential oil showed antioxidant activities with IC50 values of 725.21 µg/mL and 123.06 µg/mL for DPPH and ABTS assays, respectively. The flower essential oil also displayed antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus, Salmonella typhimurium, and Shigella flexneri, with the same MIC value of 640 µg/mL. [ABSTRACT FROM AUTHOR]

We have synthesized and characterized N-substituted-1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carbohydrazide derivatives and were evaluated for their antibacterial activity against Staphylococcus Aureus, Micrococcus Luteus, Bacillus subtilis and Gram-negative Escherichia Coli, Pseudomonas aeruginosa and Flavobacterium Devorans pathogens and found that any modification is done at C-3 position then the activity of quinolone scaffold is decreased. This shows that presence of carboxylic acid group at C-3 position is very important for antibacterial activities. To gain more molecular insight into the binding interaction of the synthesized compounds, docking studies with to S. aureus DNA gyrase (PDB: 2XCT) were conducted. Based on its potential anti-bacterial properties, the most active molecule, 5a, was submitted to molecular docking simulations using Schrödinger Glide software. The fluoroquinolones mechanism of action is entirely compatible with the binding interaction of the compound 5a. Further, all the synthesized compounds tested for In Silico ADME prediction and observed that all the compounds followed the criteria for orally active drug and therefore, these compounds can be further developed an oral drug candidate. [ABSTRACT FROM AUTHOR]

The non-aromatic, heterocyclic hexamine is one of the most refractory pollutants in some industrial effluents and food-grade plastics. This compound and its derivatives harm human health with limited options for eco-friendly biological treatment. This study reports the characterization of two rapid hexamine-removing bacterial isolates, Micromonospora citrea SRCHD01 and Micrococcus luteus SRCHD02, from wastewater of Hexamine producing plant at Vishakapatnam, India. The former is a structured biofilm former while the latter is a weak biofilm former with both isolates dividing faster under immobilized conditions. Isolate SRCHD01 could reduce 200 mg/L hexamine to 84.91 mg/L in 24 h with associated Chemical Oxygen Demand (COD) reduction of 99% from an initial concentration of 8028.93 mg/L within 120 h, making it the fastest hexamine-removing bacteria reported till date. The investigation opens a new avenue for studying the bioremediation of hexamine in biofilm reactors ensuring environmental protection. [ABSTRACT FROM AUTHOR]

This article reports on the first documented case of Micrococcus luteus causing bacterial blight in pomegranate trees in India. Pomegranate is an economically important fruit crop in India, and the disease was observed in orchards in Maharashtra. The infected leaves showed symptoms of bacterial leaf blight, including chlorosis, brown spots, and leaf loss. The pathogenicity of the bacteria was confirmed through laboratory tests and molecular identification. This finding is significant for growers as it provides valuable information for disease control measures. [Extracted from the article]

Transcriptomic and proteomic analysis were performed on 72 h biofilms of the acneic strain Cutibacterium acnes and planktonic cultures in the presence of epinephrine. Epinephrine predominantly downregulated genes associated with various transporter proteins. No correlation was found between proteomic and transcriptomic profiles. In control samples, the expression of 51 proteins differed between planktonic cultures and biofilms. Addition of 5 nM epinephrine reduced this number, and in the presence of 5 µM epinephrine, the difference in proteomic profiles between planktonic cultures and biofilms disappeared. According to the proteomic profiling, epinephrine itself was more effective in the case of C. acnes biofilms and potentially affected the tricarboxylic acid cycle (as well as alpha-ketoglutarate decarboxylase Kgd), biotin synthesis, cell division, and transport of different compounds in C. acnes cells. These findings are consistent with recent research on Micrococcus luteus , suggesting that the effects of epinephrine on actinobacteria may be universal. [ABSTRACT FROM AUTHOR]

The present work, explores the antimicrobial and antioxidant activity of medicinal plant Ipomoea quamoclit L. Priliminary screening of the plant leaves for phytochemicals shows the presence of flavanoids, phenols, terpenoids etc. The dried leaf extract is characterized using UV-Vis spectrum and FTIR shows the maximum absorbance at 260nm with N-H, C-H and C=O stretching. The antimicrobial activity of the leaf extract is tested against the bacterial species Enterobacter cloacae, Micrococcus luteus, Klebsiella pneumoniae, Staphylococcus aureus and two fungal species Aspergillus niger and Candida albicans. The maximum zone of inhibition (mm) 23 mm/ml and 25 mm/ml were observed for gram positive and gram negative bacteria, respectively. In fungi, the maximum zone of inhibition 23 mm/ml was obtained. The antioxidant behavior of the leaf extract is analyzed using DPPH scavenging assay and Hydrogen peroxide scavenging assay. IC50 values obtained are 115.6 μg/ml and 35.60 μg/ml, respectively. The present result demonstrates the potential of Ipomoea quamoclit L. as folk medicine with improved antimicrobial and antioxidant activity and thus justifies the medicinal use for various ailments. [ABSTRACT FROM AUTHOR]

A new series of 1-aryl-2-benzoyl-3-(trifluoromethyl)-1H-benzo[f]chromenes were synthesized via multicomponent reaction of substituted benzaldehydes, naphthalen-2-ol, and 4,4,4-trifluoro-1-phenylbutane-1,3-dione using aminoglucose-functionalized NiFe2O4@Silicapropyl magnetic nanoparticles (MNPs) as green, efficient, and magnetically recoverable catalyst under solvent-free condition. This approach is advantageous due to high yield, short reaction time, mild solvent-free condition, and recyclability of the catalyst. The structures of the synthesized trifluoromethyl-1H-benzo[f]chromenes were confirmed by 1H and 13C NMR and IR spectral data and elemental analyses. Their antibacterial activity was assessed against both gram-negative (Pseudomonas aeruginosa, Escherichia coli) and gram-positive bacteria (Micrococcus luteus, Bacillus subtilis), and most of them showed high antibacterial activity. [ABSTRACT FROM AUTHOR]

Odd-numbered fatty acids (FAs) have been widely used in nutrition, agriculture, and chemical industries. Recently, some studies showed that they could be produced from bacteria or yeast, but the products are almost exclusively odd-numbered long-chain FAs. Here we report the design and construction of two biosynthetic pathways in Saccharomyces cerevisiae for de novo production of odd-numbered medium-chain fatty acids (OMFAs) via ricinoleic acid and 10-hydroxystearic acid, respectively. The production of OMFAs was enabled by introducing a hydroxy fatty acid cleavage pathway, including an alcohol dehydrogenase from Micrococcus luteus , a Baeyer-Villiger monooxygenase from Pseudomonas putida , and a lipase from Pseudomonas fluorescens. These OMFA biosynthetic pathways were optimized by eliminating the rate-limiting step, generating heptanoic acid, 11-hydroxyundec-9-enoic acid, nonanoic acid, and 9-hydroxynonanoic acid at 7.83 mg/L, 9.68 mg/L, 9.43 mg/L and 13.48 mg/L, respectively. This work demonstrates the biological production of OMFAs in a sustainable manner in S. cerevisiae. • Developing an engineered yeast for the first microbial de novo production of OMFAs. • Providing oleate 12-hydroxylase and hydratase for the de novo production of two HFAs. • Identifying a de novo way for the production of OMFAs through a FA cleavage process. • Highlighting the importance of BVMO in the biological FA cleavage pathway. [ABSTRACT FROM AUTHOR]

Nitrilase (EC 3.5.5.1) is an important biological catalyst with industrial application, which can directly convert nitrile compounds into corresponding carboxylic acids and ammonia under mild conditions. Nitrilase is used to convert molecules containing nitrile groups into carboxylic acid derivatives, and it is also used in many industries such as the textile industry. Studies should be conducted on the production of nitrilase, which is widely used in industry and has the potential to be used in other industrial areas, from different sources. Since reducing the cost in the industry will reflect positively on the consumer, high-activity nitrilases should be obtained. For this purpose, optimization of the production mediums gains importance in the production of nitrilase from microbial sources. The present study deals with the production and optimization of the microbial nitrilase (EC 3.5.5.1). Microbial strains stored in the laboratory were used in this study. All selected strains (Pseudomonas aeruginosa (ATCC 27853), Enterococcus faecalis (ATCC 29212), Pseudomonas putida (ATCC 17514), Pseudomonas fluorescens (DSM 6521), Pseudomonas oleovorans (DSM 50188), and Micrococcus luteus (DSM 20030)) from stock were screened on 3 different mediums. The acetonitrile showed to be an inducer for nitrilase production. The most active bacterium produced about 41.11 U/ml of nitrilase activity and was identified as Pseudomonas putida (ATCC 17514). Maximum nitrilase production was obtained using the medium (3) with 0.50 g/L (v/v) acetonitrile as an inducer. The effects of different parameters (chemical and physical) on the nitrilase (EC 3.5.5.1) production were studied. When bacterial growth at pH 8.0 and 28 ºC was cultured for 20 h, and medium containing starch as a carbon source and peptone-yeast extract as a nitrogen source, the nitrilase activity peaked at 172.76 U/ml. Enzyme activity could be increased 4.2 times with optimization studies. By optimization of enzyme production, a significant increase in activity may be achieved. In this study, when compared with similar studies about nitrilase production from bacteria in the literature, high-activity nitrilase production from Pseudomonas putida (ATCC 17514) was achieved. [ABSTRACT FROM AUTHOR]