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Fresh fish, and especially fatty species, are highly perishable due to oxidative deterioration of fish flesh and the elevated microbial load on fish surface. The implementation of a variety of “mild hurdles” may significantly decrease the rates of fish chemical degradation and microbiological spoilage, by better retaining the initial quality, compared to more intense preservation techniques. The aim of this work is the comparative study of different, single or combined, treatments at 15 °C on the quality and shelf life of chilled eel fillets. Fish fillets were treated using osmotic solutions consisting of glycerol (30%–40%–45%) and 5% NaCl with and without former antioxidant impregnation by using Rosemary Serum. In all cases, water activity decreased to approximately 0.90 after 420 min of osmotic treatment. Untreated and osmotically treated fish fillets were subsequently stored at 4 °C and their stability under chill conditions was assessed based on microbial growth and oxidative deterioration. Microbial growth of treated samples was significantly delayed, especially due to the osmotic step (OS) and the derived water activity decrease. Lipid oxidation, a major cause of rejection for fatty fish such as eel, was greatly inhibited in treated fillets, owing to both ‘hurdles’, aw lowering (OS) and antioxidant impregnation with rosemary serum (RS/OS), showing the synergistic effect of these successive procedures. Shelf life of treated eel fillets exhibited a more than 10-fold increase, as compared to the untreated samples, based on chemical composition and a 2 to 3-fold shelf life improvement, in terms of microbial growth.

In this study, different sizes of microcapsules with alginate and bentonite as natural macromolecular materials were prepared to investigate the release property of Pseudomonas putida Rs-198. The characteristics of three microcapsules were evaluated by SEM, FTIR, TG-DSC, XRD and wall thickness. The sizes of three microcapsules (MA, MB, and MC) were 1,270.50, 831.79 and 42.52 μm, respectively. First, the encapsulation efficiency of three MA, MB, and MC microcapsules were 82.20%, 90.41%, and 85.84%, respectively. Second, the contact angles of MA and MB samples were similar, while smaller microcapsules MC have higher contact angle (85.05°), indicating poor hydrophilia and decreasing the swelling degrees. Third, the release cumulant of Rs-198 and macromolecule BSA linear stage was fitted to self-established mathematic model. Results show that the microcapsule size had a considerably positive effect on release detail. The large microcapsule possessed strong leak-tightness for Rs-198 as a slow-release microbial agent. Furthermore, the porosity of microcapsules determined their swelling and release and may affect bacterial growth and survival. In conclusion, the Rs-198 microcapsule with different sizes will be pertinently selected based on the characteristics of agricultural production requirements.

Reference methods developed for detection of Listeria monocytogenes are commonly used for detection of Listeria at the genus level. Improved method performance data are needed because this genus has expanded from 6 to 26 species and now includes several Listeria sensu lato species, which can have phenotypes distinct from those of Listeria sensu stricto. We evaluated growth of 19 Listeria species, including 12 recently described Listeria sensu lato species, using the media specified by (i) the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual, (ii) the U.S. Department of Agriculture (USDA) Microbiology Laboratory Guidebook, and (iii) the International Organization for Standardization (ISO). The FDA broth enrichment procedure allowed all species to grow to detectable levels (≥4 log CFU/mL), yielded the highest mean growth (7.58 log CFU/mL), and was the only procedure with which no Listeria sensu lato species yielded significantly higher growth than did a comparison Listeria sensu stricto species. With the USDA and ISO broth enrichment procedures, several Listeria sensu lato species yielded significantly higher growth than did either Listeria seeligeri or Listeria ivanovii, suggesting that these two Listeria sensu stricto species could be outgrown by Listeria sensu lato species. On selective and differential agar media, L. seeligeri, L. ivanovii, and Listeria grayi produced colonies with atypical morphology and/or growth of these species was inhibited (which may lead to incorrect classification of a sample as negative), whereas several newly described Listeria sensu lato species grew to high levels and produced colonies with typical morphology. Overall, our study results indicate that the ability to detect various Listeria species can be impacted by the specific broth and selective and differential agar used. Our data can help guide selection of appropriate media and detection methods for environmental Listeria monitoring programs and methods that are most likely to detect the targeted Listeria groups (e.g., Listeria sensu stricto, which appear to be the most appropriate index organisms for the pathogen L. monocytogenes).

Green synthesis of nanoparticles is gaining importance and has been suggested as possible alternatives to chemical and physical methods. The present work reports low- cost, green synthesis of zinc oxide (ZnO) & Ag doped ZnO nanoparticles using Vitis vinifera leaf extract. The biosynthesized nanoparticles were characterized by SEM, EDX, UV–vis, and FTIR. In the present work, the biosynthesized ZnO nanoparticle & Ag doped ZnO nanoparticles have been used for antibacterial and photocatalytic applications. The antibacterial activity of characterized samples was determined against Gram-positive and Gram-negative bacteria. The obtained results revealed that the bacterial growth decreases with increase in the concentration of biosynthesized ZnO nanoparticles. Also, Gram-positive bacteria seemed to be more sensitive to ZnO & Ag doped ZnO nanoparticles than Gram-negative bacteria. The biosynthesized ZnO nanoparticles showed photocatalytic activity under the UV light enhancing the degradation rate of methylene blue (MB), which is one of the main water- pollutants released by textile industries.

Microalgae biomass is considered an important feedstock for biofuels and other bioactive compounds due to its faster growth rate, high biomass production and high biomolecules accumulation over first and second-generation feedstock. This research aimed to maximize the specific growth rate of fresh water green microalgae Closteriopsis acicularis, a member of family Chlorellaceae under the effect of pH and phosphate concentration to attain enhanced biomass productivity. This study investigates the individual and cumulative effect of phosphate concentration and pH on specific growth characteristics of Closteriopsis acicularis in autotrophic mode of cultivation for bioethanol production. Central-Composite Design (CCD) strategy and Response Surface Methodology (RSM) was used for the optimization of microalga growth and ethanol production under laboratory conditions. The results showed that high specific growth rate and biomass productivity of 0.342 day−1 and 0.497 g L−1 day−1 respectively, were achieved at high concentration of phosphate (0.115 g L−1) and pH (9) at 21st day of cultivation. The elemental composition of optimized biomass has shown enhanced elemental accumulation of certain macro (C, O, P) and micronutrients (Na, Mg, Al, K, Ca and Fe) except for nitrogen and sulfur. The Fourier transform infrared spectroscopic analysis has revealed spectral peaks and high absorbance in spectral range of carbohydrates, lipids and proteins, in optimized biomass. The carbohydrates content of optimized biomass was observed as 58%, with 29.3 g L−1 of fermentable sugars after acid catalyzed saccharification. The bioethanol yield was estimated as 51 % g ethanol/g glucose with maximum of 14.9 g/L of bioethanol production. In conclusion, it can be inferred that high specific growth rate and biomass productivity can be achieved by varying levels of phosphate concentration and pH during cultivation of Closteriopsis acicularis for improved yield of microbial growth, biomass and bioethanol production.

Background Sodium chloride (NaCl) is an essential food additive used for preservation/flavor enhancement. Food processing with NaCl has higher sodium contents, raising the concern between the excess of dietary sodium as a risk factor for several health problems. Thus, there is a growing demand for alternatives to reduce sodium in processed foods. Scope and approach This systematic review comprehensively discusses how NaCl replacement can affect microbiological, sensory, and physicochemical attributes of processed fish products, besides identifying the current trend of a potential substitute. Key findings and conclusions KCl, K-lactate, CaCl2, MgCl2, SODA-LO salt microspheres were the main NaCl replacers found in smoked, restructured, fermented, read-to-eat, sushi, and fried cake fish products evaluating microbiological, physicochemical, and sensory parameters. The effectiveness of NaCl substitution is closely related to the particular characteristics of each fish product. Nevertheless, no study analyzed all quality parameters in each product, making it challenging to identify sodium substitution efficiency. KCl has higher research attention: the substitution of 25–50% of NaCl by KCl in combination with packaging conditions was enough to control microbial growth and reduce the prooxidant effect. However, the sensory quality was compromised, and adverse effects of high potassium intakes on health should be considered. Few studies analyzed the proximate composition, although seafood products have high protein and essential lipid content. Novel salt technologies as SODA-LO were identified as the current trend to lower sodium in fish products without taste impairment. Nevertheless, more studies are needed to elucidate the effects of its use on the overall quality of products.

Graphical abstract, Highlights • Nano-silver synthesized via solution evaporation method with octahedral crystal structure and crystallite size of 28 to 39 nm. • Irregular and non-uniform surface morphology. • Different functional on the surface of nano-silver included CH, CH2, OH, alkyne, and an alkyl halide. • Nano-silver synthesized at 70 °C and a dose of 3.0 g/L caused effective inhibition of E. coli., The modulation of antimicrobial properties of nanomaterials can be achieved through various physical and chemical processes, which ultimately affect subsequent properties. In this study, the antibacterial potential of nano-silver was investigated at 0.5, 1.0, 2.0, and 3.0 g/L, and its differential temperature synthesis was achieved at 20, 50, and 70 °C using the solvent evaporation method. Nano-silver particles exhibited FCC (octahedral) crystalline structure with crystallite sizes ranging between 28 and 39 nm calculated using XRD analysis. Moreover, irregular and non-uniform surface morphology was evident from SEM micrographs. The UV–Vis absorbance spectrum of nano-silver exhibited wave maxima at 433 nm, while the FTIR analysis depicted different modes of vibration indicating the CH, OH, C≡C, C-Cl, and CH2 functional groups attached to the surface. Lastly, nano-silver caused prominent inhibition (12.5 mm) in the Escherichia coli growth, particularly at 70 °C synthesis temperature and 3.0 g/L dose. It is concluded that both the nano-silver crystal growth temperature and dose contributed substantially to bacterial growth inhibition linked with subsequent size, shape-dependent properties.

Lettuce is a perishable vegetable that its shelf life is limited by detrimental texture changes and enzymatic activities during postharvest storage. One of solutions that can be used in storage and distribution of this product is modified atmosphere packaging (MAP). But its effects on the mechanical properties of the product have not been studied. This information would be beneficial in inspection of eating quality and later processing such as cutting and shredding. This research aimed to study effect of active MAP technology on the postharvest mechanical properties of lettuce at different storage periods. It was found that MAP had a significant effect on the tension property of the lettuce leaf. MAP treatment preserved the brittleness of the specimens during storage, but the control ones lost their brittleness and tolerated greater tension. Stiffness and rupture energy were significantly affected by MAP with P values of 0.01 and 0.05, respectively. Also, stiffness of the MAP-treated samples was higher than the control at the same storage time. The findings are due to reducing respiration, transpiration and bacterial growth by MAP which delays nutrient decomposition and maintains the original color and texture.

Microbial infections are a general public health problem worldwide, and their resistance to antibiotics has increased rapidly. The prevention of microbial growth on the surface of cotton fabric is essential to control skin-related infections. In this work, we evaluated A.calamus- zinc oxide nanoparticle (AC-ZnONPs) coated cotton fabrics for antibacterial and cytotoxic activities. The formulated AC-ZnONPs were characterized by UV-spectrophotometer, SEM, EDX, FT-IR, and TEM studies. The AC-ZnONPs amalgamation into the cotton fabrics was done by the dipping technique. The antimicrobial activity and cytotoxic activity were executed by standard approaches. The results of UV-spectrophotometer, TEM, and SEM, and EDX proved the formation and existence of AC-ZnONPs on the fabrics' surface. FT-IR results demonstrated the existence of numerous functional groups. AC-ZnONPs efficiently suppressed the growth of the pathogenic microbes with a maximum inhibition at 60 μg of AC-ZnONPs against E.coli and S.aureus. The AC-ZnONPs coated fabrics also prevented microbial growth with maximum inhibition against P.aeruginosa, K.oxytoca, and A.baumanii. In addition, AC-ZnONPs efficiently suppressed the viability of SK-MEL-3 cells. Altogether, our findings disclosed that the AC-ZnONPs coated fabrics displayed excellent antimicrobial activity against the pathogenic microbes and could be utilized in the medical fields in the future.

Microbes are decomposers of crop residues, and climatic factors and residue composition are known to influence microbial growth and community composition, which in turn regulate residue decomposition. However, the succession of the bacterial community during residue decomposition in Northeast China is not well understood. To clarify the property of bacterial community succession and the corresponding factors regulating this succession, bags containing maize residue were buried in soil in Northeast China in October, and then at different intervals over the next 2 years, samples were analyzed for residue mass and bacterial community composition. After residue burial in the soil, the cumulative residue mass loss rates were 18, 69, and 77% after 5, 12, and 24 months, respectively. The release of residue nitrogen, phosphorus, and carbon followed a similar pattern as mass loss, but 79% of residue potassium was released after only 1 month. The abundance, richness, and community diversity of bacteria in the residue increased rapidly and peaked after 9 or 20 months. Residue decomposition was mainly influenced by temperature and chemical composition in the early stage, and was influenced by chemical composition in the later stage. Phyla Actinobacteria, Bacteroidetes, and Firmicutes dominated the bacterial community composition in residue in the early stage, and the abundances of phyla Chloroflexi, Acidobacteria, and Saccharibacteria gradually increased in the later stage of decomposition. In conclusion, maize residue decomposition in soil was greatly influenced by temperature and residue composition in Northeast China, and the bacterial community shifted from dominance of copiotrophic populations in the early stage to an increase in oligotrophic populations in the later stage.

The application of plant extracts (PEs) could be a promising option to satisfy consumers' demand for natural additives to inhibit growth of variable pathogenic bacteria. Thus, the aim of this study was to develop a standardized microdilution method to examine the antimicrobial effects of 10 hydrophilic PEs against two strains of Clostridium perfringens facing various food-relevant influencing factors. Because of the high opacity of PEs, resazurin was used as an indicator for bacterial growth instead of pellet formation. The highest value of the MIC of the replications of each PE was defined as effective plant extract concentration (EPC), whereas the next concentration beneath the lowest MIC was defined as the ineffective plant extract concentration (IEPC). The EPCs of seven PEs, allspice, cardamom, cinnamon, clove, coriander, ginger, and mace, were between 0.625 and 10 g/kg, whereas extracts of caraway, nutmeg, and thyme showed no antimicrobial activity up to the maximum concentration tested (10 g/kg) against C. perfringens in vitro. Two intrinsic factors, sodium chloride (NaCl) and sodium nitrite (NaNO2), displayed either synergistic or additive effects or no interaction with most PEs. By combination with PEs at their IEPC (0.08 to 1.25 g/kg), MIC of NaCl and NaNO2 decreased from between 25 and 50 g/kg to between 6 and 25 g/kg and from more than 200 mg/kg to between 0.2 and 100 mg/kg, respectively. In contrast, lipid (sunflower oil) at a low concentration inhibited the antimicrobial effects of all tested PEs. For extrinsic factors, only allspice, ginger, and coriander could maintain their antimicrobial effects after being heated to 78°C for 30 min. The synergistic effect between PEs and pH values (5.0 and 5.5) was also found for all PEs. The established screening method with resazurin and defining EPC and IEPC values allows the verification of antimicrobial effects of PEs under various food-relevant influencing factors in a fast and reproducible way. HIGHLIGHTS

The exopolysaccharide (EPS) from the mycelial fermentation of a medicinal fungus Cordyceps sinensis Cs-HK1 had shown significant anti-inflammatory activity previously, and EPS-LM was a highly active fraction with a relatively low molecular weight (MW) isolated from the Cs-HK1 EPS. This study was to assess the effects of Bifidobacterial fermentation in anaerobic conditions on the molecular properties and anti-inflammatory activity of EPS-LM. In both Bifidobacterial cultures (B. breve and B. longum), EPS-LM was fractionally consumed as a carbon source, increasing the bacterial growth and acetic acid production. Analytical results from the fermentation digesta (supernatant) suggested that EPS-LM was partially degraded to lower molecular weight (MW) products with modified structures during the Bifidobacterial fermentation. More interestingly, the higher MW digesta fraction containing the partially degraded EPS-LM showed even stronger inhibiting activity than the original EPS-LM on the LPS-induced pro-inflammatory responses in THP-1 cell culture, including NF-κB activation, release of NO, TNF-α and IL-8. The study has shown that the fermentation by selected Bifidobacterial strains is effective to modify natural polysaccharides with enhanced bioactivities.

Background The global consumption of soy products has increased due to their excellent nutritional value and associated health benefits. Scope and approach Various factors affect the composition, texture properties, nutritional value and shelf life of tofu. Coagulant type, coagulant concentration, oil-protein interactions, protein-protein interactions, freezing, pH, lipid oxidation, biogenic amines (BAs) rate, and other factors impact the final product. Thermal processing has been employed in the food industry for many decades to ensure food safety, enhance shelf life, and preserve quality. However, due to the length of the process and application of high temperatures, the quality of a product does not always meet consumer expectations. Key findings and conclusion Recently, researchers have investigated emerging thermal processing technologies and non-thermal technologies as alternatives to traditional thermal processing. This review discusses the advantages and disadvantages of these methods in terms of the characteristics, shelf life and nutritional value of tofu. Cold atmospheric pressure plasma (CAPP) negatively affected tofu texture and slightly affected microbial population inactivation. In turn, pressure activated water (PAW) controlled microbial growth and improved functional value compared to thermally treated tofu. Researchers demonstrated that reactive species penetration generated from CAPP into the cell wall of microbes was significantly impressive at low pH. High intensity ultrasound (HIU) has been recommended as a novel method for increasing phenolic phytonutrient levels in tofu whey, and thus, improving the quality and nutritional content. High hydrostatic pressure (HHP) reduced immunoreactivity significantly, but its impact on the protein denaturation of solid soy products is not well understood. Although all previous literature has praised non-thermal methods for antimicrobial effectiveness, the mechanisms of reactive species emitted from non-thermal techniques and cellular component interactions remain unknown.

In recent years, bacterial drug resistance has become a major health concern worldwide owing to the limited efficacy of some traditional antibiotics after long-term usage. Here, to search for potent bacteriostatic agents, six cationic antimicrobial peptides (AMPs) were investigated. L-GL13K, D-GL13K, MSI-594, indolicidin, Ib-M6 and nisinA-S29A were selected to study their bactericidal efficiency and the antibacterial mechanisms against Escherichia coli (E. coli). In addition to half-maximal inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) determinations using the standard method, the initial bacterial growth profiles at 4 h of AMP exposure were used to study the possible antibacterial mechanisms. The AMP-treated E. coli exhibited collapsed cell walls and various nanosized and microsized pores on the bacterial surface, which led to transmembrane channels and pore formation. Among the studied peptides, MSI-594, D-GL13K, and L-GL13K (in decreasing order) were identified as superior bactericidal agents, which may be attributed to the suitable conformational structure and surface charge during the interaction between these AMPs and bacteria.

In the search for a healthy indoor climate, chemical cleaning agents are replaced by bacillus strains to create an indoor ecosystem in which these harmless bacteria clean the surfaces by consuming the organic molecules in dust and dirt. To optimise these ecosystems, it is important to monitor the bacterial growth and activity, but the reference methods are time consuming and involve a serious time delay. Therefore, the potential of fluorescence spectroscopy for monitoring the activity of bacillus strains was investigated in this study. We confirmed that fluorescence signals could be detected for Bacillus vegetative cells at a load above 108 cells mL−1. As the fluorescence emission was mostly in the 330–400 nm range after excitation in the 280–290 nm range, we could attribute this signal to the tryptophan residues. The Bacillus fluorescence signals could be distinguished from those released by pure l -tryptophan, plate count agar medium, and Bacillus spores, which were classified with 100% accuracy by PLSDA. In comparison to other microbes, bacillus strains, Escherichia coli (MG1655) and Saccharomyces cerevisiae were found to produce an indistinguishable peak at 340 nm in response to excitation at 280 nm. However, using a hybrid multivariate classifier involving PCA combined with a One-Class SVM on the area-normalised fluorescence emission spectra in response to excitation at 280 nm allowed footprints of Bacillus cells to be identified with a classification accuracy of 78%.

In this research, carbon nanotube decorated with Cu nanoparticles (CNT/Cu) was synthesized by a new solvothermal process. Solvothermal treatment of CuSO4 and NaOH was completed in ethanol containing ultrasonically dispersed CNTs at 160 degrees C for 3 h. In the solvothermal process, Cu nanoparticles were heterogeneously deposited on the surface of COOH-functionalized CNTs through the reduction of the Cu+2 ions. Cu nanoparticles with the size of approximate to 8 nm on CNTs (and some in the solution) and strong bonding between Cu and CNT were obtained by the used process. Microstructural characterization revealed that the solvothermal method is an appropriate method for producing homogenous CNT/Cu nanostructure. Also, the antibacterial activity of the synthesized powder was investigated by disc diffusion, direct contact and colony counting methods. CNT/Cu nanopowder inhibited bacteria growth within the tested concentration range, while CNTs did not show any considerable antibacterial response. Minimum inhibitory concentration and minimum bactericidal concentration of CNT/Cu nanopowder were 500 mu g/ml and 250 mu g/ml against E. coli, and 250 mu g/ml and 125 mu g/ml against S. aureus, respectively. S. aureus was more sensitive than E. Coli to CNT/Cu nanopowder which can be attributed to the absence of a cell wall in gram positive bacteria.

Actinomycetes have been identified as an origin of many secondary metabolites, antibiotics and active components that impact microbial growth. Mediated mutations using UV in practice for the breeding of organisms. The objective of this study is to analyses the impact of UV radiation on the (O-7) Actinomycete isolate. This was a prospective analytical study of a several of actinomycetes. The isolates were screened for antimicrobial efficacy against multiple Gram-positive, Gram-negative bacteria, yeast, and fungi. Various factors such as UV, temperature, pH, light, agitation, fermentation durations and aeration have also been boosted for optimal antimicrobial production. The isolate (O-7) Actinomycete has been recognized as a highly bioactive producing organism. The isolate was exposed to various wavelengths, times under numerous growth conditions. It was found that 4% concentration of glucose as a carbon source is significantly optimal for the production of antibiotic for (O-7) UV exposed strain, however, concentration of 1% of lactose is significantly optimal for the production of antibiotic for (O-7) UV exposed strain. Yeast extract at a concentration of 1% was found to be the best source of nitrogen for (O-7) UV exposed, while pH 7.0 was found to be the most suitable for the same isolate. From the temperature optimization study, it was observed that (O-7) exposed strain showed good growth and maximum antibiotic production at 28 °C. The soil-isolated biological compounds (O-7) were effective against certain types of bacteria and fungi, and the research also demonstrated that exposure to UV radiation enhanced the production of these compounds.

Orthopedic infections pose severe societal and economic burden and interfere with the capability of the implanted devices to integrate in the host bone, thus significantly increasing implants failure rate. To address infection and promote integration, here nanostructured antibacterial and bioactive thin films are proposed, obtained, for the first time, by Ionized Jet Deposition (IJD) of silver-substituted tricalcium phosphate (Ag-TCP) targets on titanium. Coatings morphology, composition and mechanical properties are characterized and proof-of-concept of biocompatibility is shown. Antimicrobial efficacy is investigated against four Gram positive and Gram negative bacterial strains and against C. albicans fungus, by investigating the modifications in planktonic bacterial growth in the absence and presence of silver. Then, for all bacterial strains, the capability of the film to inhibit bacterial adhesion is also tested. Results indicate that IJD permits a fine control over films composition and morphology and deposition of films with suitable mechanical properties. Biological studies show a good efficacy against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis and against fungus Candida albicans, with evidences of efficacy against planktonic growth and significant reduction of bacterial cell adhesion. No cytotoxic effects are evidenced for equine adipose tissue derived mesenchymal stem cells (ADMSCs), as no reductions are caused to cells viability and no interference is assessed in cells differentiation towards osteogenic lineage, in the presence of silver. Instead, thanks to nanostructuration and biomimetic composition, tricalcium phosphate (TCP) coatings favor cells viability, also when silver-substituted. These findings show that silver-substituted nanostructured coatings are promising for orthopedic implant applications., Graphical abstract Image 1, Highlights • Silver-substituted TCP films on titanium are prepared by Ionized Jet Deposition • Films are nanostructured, hard, with submicron thickness • Adipose mesenchymal stem cells differentiate into osteogenic lineage on the surface of films • Films show antimicrobial and anti-adhesive activity against several microorganisms • Films are promising for application in orthopedic titanium implants

Background The fungi present in the decaying remains enable a better understanding of the processes of decomposition after death. There are not many studies about fungi on decaying bodies and it is not known which fungal sampling methods are effective. Aims The main objective of this study was to find the best method for sampling fungi in carcasses, prove the effectiveness of this method and identify the fungal colonies in animal carcasses from experimental burials. Methods Samples from 13 carcasses of Sus scrofa domestica, from the experimental project Taphos-m, were taken with different materials: spatula, sterile swabs and RODAC contact plates. Results RODAC contact plates with the RBA culture medium showed higher proliferation of fungal colonies. Thirty genera of fungi were isolated from different substrates (bone, tissue, lime). Most of the fungi genera or groups identified have been described before in the literature, but the substrates they came from were different in some cases. Conclusions Sampling with RODAC contact plates was found to be the most effective method, as it provides a nutritional culture medium that may allow growth since the moment of sampling. Fungi colonies grew better in RBA culture medium because bacterial growth is inhibited. Most of the observed fungi are related to the environment but some others have been found related to decomposing bodies for the first time.

Made available in DSpace on 2021-06-25T10:56:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Porosity and pore size distribution are influencing factors of several physical properties of porous media. For solid-state cultivation (SSC), this structural information is also important to determine the free space available for the microbial growth. The aim of this work was to determine the porosity and the pore size distribution of packed beds of pure sugarcane bagasse (SCB) and mixtures of SCB with wheat bran (WB) with and without cultivation with the fungus Myceliophthora thermophila I-1D3b. Computer-aided 2D photographic technique was used to evaluate the changes of the bed porosity due to the fungal growth in a mixture of SCB:WB with weight proportion 7:3 at 75% moisture content after 48 h of cultivation. The results showed a steep reduction of more than 50% of the porosity due to the fungal mycelium. A longitudinal porosity profile was found, and the midsection of the bed was poorly colonized due to the steric hindrance. In the uncultivated beds, no change of the porosity was found when changing moisture content of the samples of SCB and SCB:WB 7:3. A wide pore size distribution was observed for the uncultivated media, with the majority of the voids being too narrow for an adequate fungal growth and quite few, though very large, voids ensuring enough space for the mycelial expanse. X-ray tomography (μ-CT) imaging was used to assess the 3D structure of the bed and the complex network of voids. The 3D images reveal an average porosity quite close to the one obtained using the 2D image analysis. The results here obtained will be of help for more realistic models of heat, mass and momentum transfer to be proposed considering porosity variation and pore size distribution in this SSC system. The 2D technique is quite simple to apply and it is able to provide bulk bed structure, while the 3D technique is sophisticated and will allow detailed microstructure information in future experiments. Food Engineering and Technology Department Institute of Biosciences Humanities and Exact Sciences (IBILCE) São Paulo State University (UNESP), Cristóvão Colombo 2265, Jardim Nazareth Institute of Process Engineering Otto-von-Guericke-University Magdeburg Food Engineering and Technology Department Institute of Biosciences Humanities and Exact Sciences (IBILCE) São Paulo State University (UNESP), Cristóvão Colombo 2265, Jardim Nazareth

The influence of Ni2+ concentration on biohydrogen production was investigated using waste activated sludge as substrate. The degradation of substrate, accumulation of volatile fatty acids (VFAs) and distribution of microbial community were analyzed to provide information for influencing mechanisms of Ni2+ addition. The experimental results demonstrated that the efficiency of hydrogen fermentation from waste activated sludge could be significantly improved. The optimal Ni2+ concentration was 5 mg/L, and under this concentration, the cumulative hydrogen production was 1.29 times of the control group. The degradation of soluble chemical oxygen demand (SCOD) increased from 25.21% to 27.69% when the added Ni2+ concentration was 5 mg/L. The analysis of microbial community distribution revealed that Ni2+ decreased the microbial diversity, and provided more suitable condition for the microbial growth and activity of hydrogen-producers. Citrobacter was the dominant hydrogen-producers in the control group, they changed into Enterococcus when 5 mg/L Ni2+ was added. Besides, the proportion of Clostridium_sensu_stricto_1, which is regarded as the primary hydrogen-producing bacteria under numerous operating conditions, was also significantly increased in the presence of Ni2+.

In this study, bacterial urease activity was optimized by response surface methodology (RSM), based on carbon source, nitrogen source, inorganic salt, pH, and other conditions required for bacterial growth. This resulted in improvement of coal dust suppression ability of bacterial mineralization. RSM showed that when the concentration of sucrose, sodium chloride, and yeast extract was optimized to 8.99, 11.27, and 8.83 g·L−1, respectively, bacterial urease activity increased by 2.60 times compared to its original activity. Microscopic scanning indicated that the optimized dust suppressant showed larger mineral size (~40 μm diameter). X-ray diffraction results showed that contained calcite and vaterite crystals exhibited larger size (639 and 454 A) and higher crystallinity (90.30 and 94.96%). The dust suppression effect test results indicated that the sample's wind resistance was 8.88% higher than that before optimization. This study indicates that material optimization of microbial dust suppressants contributes significantly to the field of dust suppression.

Stochastic approaches for describing microbial growth and/or death responses in foods have gained increased attention in the field of predictive microbiology and quantitative microbial risk assessment. Particularly, recent studies have focused on describing variability and uncertainty of microbial responses. Although variability due to individual cell heterogeneity is inherent in a small number of bacteria during the inactivation process, an appropriate theoretical stochastic description for the variability in individual cell heterogeneity has not been achieved. This article reviews recent advances in the development of models for describing the variability in individual cell heterogeneity from the perspective of bacterial inactivation as a stochastic process of bacterial cell numbers. Large numbers of replicated experiments, computer simulations, and mathematical formulations have led to novel techniques for describing variability in individual cell heterogeneity during the microbial survival process. The proposed stochastic theory will enable reinterpretation of conventional bacterial behavior based on the average bacterial numbers.

It is necessary to enhance the barrier performance of cutoff walls in order to improve the contamination control level, especially for reconstruction or expansion of existing landfill sites. This paper presents a comprehensive laboratory investigation on the synergistic effects of microorganisms and fibers on the hydraulic conductivity of silty sand to evaluate the applicability to the field condition as an alterative barrier material. Inside the soil, the added carbon fibers not only provided good biocompatibility, but also formed spatial three-dimensional network between soil particles to improve the bacterial adhesion that eventually caused 2–3 orders of magnitude decrease in soil permeability. The resistance of the biofilm to extreme conditions was tested by permeation with solutions of different salinity and pH values, and by subjecting specimens to various hydraulic gradients and soil conditions. Despite the microbial growth inhibition occurred at these conditions, however, biofilm can largely remain intact and continue to reduce k, which due to the gradual adaptation of microorganisms to the extreme environment and the gradual recovery of their activity. Results of these tests demonstrate that biofilm treatment may be a feasible technology for creating waste containment barriers in soil.

Biotrickling filters (BTFs) for hydrophobic chlorobenzene (CB) purification are limited by mass transfer and biodegradation. The CB mass transfer rate could be improved by 150 mg/L rhamnolipids. This study evaluated the combined use of Fe3+ and Zn2+ to enhance biodegradation in a BTF over 35 day. The effects of these trace elements were analysed under different inlet concentrations (250, 600, 900, and 1200 mg/L) and empty bed residence times (EBRTs; 60, 45, and 32 sec). Batch experiments showed that the promoting effects of Fe3+/Zn2+ on microbial growth and metabolism were highest for 3 mg/L Fe3+ and 2 mg/L Zn2+, followed by 2 mg/L Zn2+, and lowest at 3 mg/L Fe3+. Compared to BTF in the absence of Fe3+ and Zn2+, the average CB elimination capacity and removal efficiency in the presence of Fe3+ and Zn2+ increased from 61.54 to 65.79 g/(m3⋅hr) and from 80.93% to 89.37%, respectively, at an EBRT of 60 sec. The average removal efficiency at EBRTs of 60, 45, and 32 sec increased by 2.89%, 5.63%, and 11.61%, respectively. The chemical composition (proteins (PN), polysaccharides (PS)) and functional groups of the biofilm were analysed at 60, 81, and 95 day. Fe3+ and Zn2+ significantly enhanced PN and PS secretion, which may have promoted CB adsorption and biodegradation. High-throughput sequencing revealed the promoting effect of Fe3+ and Zn2+ on bacterial populations. The combination of Fe3+ and Zn2+ with rhamnolipids was an efficient method for improving CB biodegradation in BTFs.

Background The perishable nature of fruits and vegetables makes their shelf-life limited. Environmental factors, transportation and preservation conditions through postharvest could decrease the storage time and quality. Therefore, prolonging supply time of fruits and vegetables by safer postharvest treatments direct the preservation methods to edible coatings. Active edible coatings incorporating different types of functional substances can be used as a preservation method to boost strategies in improving quality, safety and shelf-life of fruits and vegetables upon storage. Scope and approach This review attempts to present a complete overview of carboxymethyl cellulose (CMC) and pectin as a basis for edible coatings and recent developments related to their application as active coatings for preservation of fruits and vegetables quality. Key findings and conclusion CMC and pectin are two main polysaccharides with great potential in making edible coatings. The CMC- and pectin-based edible coatings are commonly odorless, tasteless, non-toxic, non-allergic, water-soluble, transparent and resistant to oil and fats. CMC and pectin, additionally, could be good carriers for active additives. In this sense, CMC and pectin-based active coatings could provide a great potential both for their protective effect and carrying functional compounds such as antimicrobials, antioxidants, anti-browning agents, texture enhancers and nutraceuticals into their coating matrix to prevent unwanted reactions (e.g., microbial growth, oxidation, enzymatic browning and softening) in horticultural products. Such strategy could inhibit microbial decays and enzymatic or biochemical damages and prevent physical or textural deteriorations in fruits and vegetables during storage.

American foulbrood (AFB) and European foulbrood (EFB) are the two major bacterial diseases affecting honeybees, leading to a decrease in viability of the hive, decreasing honey production, and resulting in significant economic losses to beekeepers. Due to the inefficiency and/or low efficacy of some antibiotics, researches with nanotechnology represent, possibly, new therapeutic strategies. Nanostructure drugs have presented some advantagesover the conventional medicines, such as slow, gradual and controlled release, increased bioavailability, and reduced side-effects. In this study, different infected larvae were collected from two apiaries; the combs that had symptoms of American and European foulbrood were isolated. In vitro antimicrobial activity of camphor tree silver nano-particles against foulbrood diseases were characterized using UV-Vis spectrophotometry and scanning electron microscope (SEM) that proves the formation of silver nanoparticles with size range 160-660 nm. The antimicrobial activity of the silver nanoparticles was tested using agar diffusion assay and proved their ability to effectively cease the pathogenic bacterial growth in both AFB and EFB. DGGE-PCR technique has been applied for the identification of un-common bacterial infections honeybees depending on 16S rRNA amplification from their total extracted DNA and has been identified as Serratia marcescens (TES), deposited in GenBank with a new accession number (MT240613). The results were confirmed strain has been detected by DGGE-PCR analysis causing uniquely infected brood that was attacked by the American Foulbrood It could be concluded that greenly synthesized silver nanoparticles is projected to be used as effective treatment for honeybee bacterial diseases. These material need more investigations under field conditions and study the possibility of its residues in honeybee products such as honey, and beeswax.

Chemical tools capable of detecting ferrous iron with oxidation-state specificity have only recently become available. Coincident with this development in chemical biology has been increased study and appreciation for the importance of ferrous iron during infection and more generally in host-pathogen interaction. Some of the recent findings are surprising and challenge long- standing assumptions about bacterial iron homeostasis and the innate immune response to infection. Here we review these recent developments and their implications for antibacterial therapy.

In this study, the phytochemical, phenolic, flavonoid and bioactive compounds were successfully screened from crude extract of Sargassum wightii by LC-MS analysis after NIST interpretation. Bacterial growth inhibition study result was shown with 24 mm zone inhibition at 200 µg/mL concentration against P. aeruginosa. The increased phenolic content was much closed to gallic acid and the range was observed at 250 μg/mL concentration. In addition, flavonoid contents of the algae extract was indicated more significant with rutin at 200 μg/mL. In result, both the phenolic and flavonoid contents of the extract were more correlated with gallic acid and rutin. Further, the total anti-oxidant and DPPH radical scavenging activities were shown increased activity at 200 μg/mL concentrations. Furthermore, the excellent anti-bacterial alteration result was observed at 200 μg/mL concentration by minimum inhibition concentration. Therefore, the result was revealed that the marine algae Sargassum wightii has excellent phytochemical and anti-oxidant activities, and it has improved anti-bacterial activity against P. aeruginosa.

To combat the emergence of drug-resistant bacteria, a locally isolated bacteriophage (HZJ) targeting H5α Escherichia coli was used as an antibacterial agent to make wound dressing samples in this study. The phages were physically embedded within an alginate hydrogel sample so that they could later be released with their tails being free during the infection process, which preserves their lytic activity. The HZJ phage isolated in the study have a 20 min latent period and are stable between pH 6 and pH 9 and at temperatures below 45 °C. The addition of phage to an E. coli culture suppressed over 99% of bacterial growth in 2-h (p 0.001). Phage-embedded hydrogel fibers were used to create porous wound dressing material using three-dimensional (3D) printing. The majority of phage lytic activity (85%-90%) was preserved after encapsulation. After they were embedded in samples, HZJ lysed 57% to 67% of bacteria (p 0.001) within 2 h and the antibacterial effects lasted at least 24 h. The small amount of phage released in 2 h was able to quickly replicate and effectively lysed the majority of the bacterial hosts. Phage-embedded alginate samples released 10% of its incorporated phage particles in 24 h. The SEM micrographs show that, compared to phage-free samples, fewer E.coli cells were observed on phage-embedded samples 2 h after bacteria were exposed to the samples. The phage-embedded sample was not cytotoxic to L929 cells. The presence of HZJ in alginate hydrogel promoted cell growth (p 0.01) and adhesion to the samples. Further, the existence of phage did not alter the tensile strength and modulus of samples (p 0.05). An antibacterial dressing capable of slowly releasing lytic phages and effectively suppressing bacterial growth for up to 24 h was produced in this study. This model represents an attractive means to reduce use of antibiotics and other additives in conventional dressings.

Quorum sensing (QS) exists in bacteria to communicate with each other and regulate group behaviors in a cell density-dependent manner, which uses signal molecule autoinducer-2 (AI-2) to intra- and inter-species communication. Effects of exogenous AI-2 on biofilm formation and environmental tolerance in Lactobacillus plantarum are the focus of this review. The responses to the exogenous AI-2 cross multiple physiological metabolic behaviors involving the bacteria growth, morphological characterization, biofilm development, extracellular polysaccharides (EPS) amount and related genes expression as well as the environmental stresses tolerance. The cell surface was smoother in the AI-2 supplemented treatments than without AI-2. Meanwhile, AI-2 had ability to promote the growth and formation of biofilm by increasing the yield of EPS, the main components of biofilm. The changes in lamC and ftsH gene expression point to altered regulation for hydrolysis process of polysaccharides as well as the potential for enhanced biofilm formation. The presence of AI-2 also significantly improved (p < 0.01) the tolerance of bile salts in L. plantarum, but the same results did not appear in acid tolerance. In conclusion, AI-2 supplementation could improve the biofilm formation and bile salts tolerance in L. plantarum, and this effect was likely modulated by facilitating EPS production and suppression polysaccharides hydrolysis.

Microbial residents of floral nectar must survive in a carbohydrate-rich yet seemingly nitrogen-poor environment. A new study shows that Acinetobacter spp., common nectar-inhabiting bacteria, differentially induce the pollen commonly found in nectar to germinate and burst, releasing nutrients for microbial growth.

The present work reports the synthesis of bimetallic Ag and Cu nanoparticles using aqueous extract of the leaf of Majorana hortensis plant. The resulting single pot green synthesized nanoparticles were characterized by analytical and spectral techniques. The analysis of elemental composition by EDAX revealed the presence of silver and copper elements in the sample. Transmission electron microscopy images visibly envisaged the formation of spherical nanoparticles with an average size of 10 nm. The formation of the nanoparticles was further manifested through FTIR, UV–visible, and XRD spectral data. The antibacterial activities of the nanoparticles were divulged against some human pathogenic bacteria. It was found that these nanoparticles can inhibit the bacterial growth and hence can be used as antibacterial agents.

An anti-bacterial material coating can help to break the spread of bacteria and viruses via metallic surfaces of biomedical devices, communication devices, food packages, research laboratories and public infrastructures like shopping malls, transports, toilets, etc. In addition, anti-bacterial material coatings owing to adequate tribomechanical and anti-corrosion properties can also help to resolve a major engineering problem of biofouling on marine installations and watercrafts’ surfaces. In recent times, the use of anti-bacterial nanocomposites coatings is emerging rapidly for various engineering applications. Here, metal matrix nanocomposites (MMNCs) are acquiring a significant role in the upcoming field of anti-bacterial material applications owing to high tribo-mechanical and anti-corrosion properties. The bio-responsive mechanism of MMNC coatings to perform anti-bacterial activities can protect the surfaces in biological environments. The nanofillers in the metal matrix plays a key role during anti-bacterial activities to kill the microbials. The composition of nanofillers can be inorganic, organic and hybrid, including advance nano tropes (i.e., allotropes of carbon and BNNT), which can be reinforced in metal matrix. This review study is addressing a problem of bacterial colonization on the surfaces that causing microbial growth based novel engineering problems and suggesting a facile and low-cost solution through an anti-bacterial MMNC coating.

The fungistatic activity of a lactic acid bacterium, which had been isolated from yellow pitahaya cultures, against fungi associated with basal rot (Fusarium oxysporum and Fusarium fujikuroi) was measured in the present study. Its activity was assessed in three fractions: fermented (S1), metabolic products (S2), and biomass (S3), using two fermentation substrates: Man Rogosa Sharpe agar (MRS) and potato dextrose agar (PDA). The bacterium was molecularly identified as Lactobacillus plantarum. S3 reduced F. fujikuroi growth by 100% over 48 h of fermentation, which occurred during the stationary phase of bacterial growth. The three fractions’ fungistatic activity against F. fujikuroi depended on the substrate employed. The fermentation kinetic parameters for L. plantarum indicated that its specific growth rate was 0.46 h–1, with 93.63% substrate consumption, 0.045 kg kg–1 cell yield, and 0.54 kg kg–1 product yield. The kinetic parameters calculated will allow for bacteria production scaling. These in-vitro trials reveal L. plantarum’s possible application as a biocontrol agent for diseases associated with Fusarium. However, further ex-vivo and in-vivo researches are required to demonstrate its behavior in crops.

This work aims to synthesis silver nanoparticles using the extract of resurrection plant as a reducing agent. The resulting product of silver nanoparticles was characterized using XRD and TEM and the results show that there is a pure silver nanoparticles was produced with sphere-like nano silver of 30–50 nm. Furthermore, the as-prepared nanosilver was used as potential anti-bacterial against two Gram positive bacteria; s. aureus and s. epidermidis. The results prove that the as-prepared silver nanosphere is able to inhibit the bacteria growth with maximum inhibition zone diameter of 15 mm (s. aureus) and 20 mm (s. epidermidis) using 160 µg/ml concentration from Ag nanospheres.

P. aeruginosa causes mostly both community-acquired and nosocomial infections, which leads to serious therapeutic challenges for treatment and requirement of appropriate therapeutic agent is needed which can combat antibiotic resistance. The research work was performed to investigate the effect of Zinc Oxide nanoparticles (ZnO NPs) in combination with Meropenem, Ciprofloxacin, and Colistin against clinical isolated strains of P. aeruginosa and ATCC 27853 strain. The minimum inhibitory concentration (MIC) of ZnO NPs and the antibiotics (Meropenem, Ciprofloxacin, and Colistin), was determined by the microdilution method and the results of MIC values were ranging between 1 and 16 µg/mL was found to be shown for antibiotics and ZnO NPs found to showed highest MIC values ranging from 2000 to 4000 µg/mL. The fractional inhibitory concentration index (FICI) was calculated using checkerboard method to test the combinations of ZnO NPs and the antibiotics (Meropenem, Ciprofloxacin, and Colistin), and among all the six P. aeruginosa clinical isolated strains P. aeruginosa (MRO-16-3 and MRO-16-4), showed FICI as 0.24 and 0.39 9, whereas P. aeruginosa ATCC 27853 strain showed FICI as 0.41 which indicates synergistic effect with Colistin. The time kill growth curve showed synergistic effect for the combination of Colistin and ZnO NPs against P. aeruginosa (MRO-16-3 and MRO-16-) strains. P. aeruginosa (MRO-16-3) was found to be highly sensitive to Colistin with an MIC of 2 µg/mL, which has shown to reduced bacterial growth to zero colonies after 24 h of incubation. In conclusion, combination of Colistin and ZnO NPs at appropriate dosage intervals might be beneficial as using therapeutic agent in treatment of P. aeruginosa ailments.

The advantages of microbial induced carbonate mineralization for soil-stabilization and building-material industries are under extensive investigation. The pH is one of the influential parameters on the desired calcium carbonate mineralization due to the resulting textures of this mineral. Moreover, the decrease in microbial growth under the extreme alkaline environment compatible with the sustainability of concrete has been the bottleneck for an effective application of Microbial Induced Carbonate Precipitation (MICP) in the concrete industry. Microbial consortia have shown more robustness in their resistance to environmental fluctuations than pure cultures. In addition, microorganisms obtained from alkaline environments could facilitate their adaptation to extreme alkalinity. The aim of this study was to obtain urease producing bacteria (UPB) able to maintain a high MICP performance under extremely alkaline conditions compatible with concrete by adapting native microorganisms obtained from extreme environments. The growth performance, urease activity, strength of the generated biocement, and CaCO3 mineralogy were compared with the best-performer urease-producing bacteria (UPB), S. pasteurii DSMZ 33. The native bacteria presented a similar performance in growth and urease activity than S. pasteurii under extreme alkaline conditions (pH 12.5). However, the generated biocement of native Sporosarcina sp. achieved 461 % more unconfined compressive strength (UCS) and 120 % more CaCO3 content than the biocement generated by S. pasteurii DSMZ 33. The careful adaptation process performed in this study for native UPB and S. pasteurii DSMZ 33 is an interesting approach with promising and projectable results for future engineering and biotechnological applications. These results have important implications for the design of engineering solutions involving MICP. Statement of Significance A consolidated and strong biocement was generated by a native species obtained from extreme ecosystems in an effort of bioprospecting to enhance the performance of biotechnological solutions for geotechnical applications in the concrete and soil-improvement industries. Biocement generated by the native species was stronger than the generated by one of the best-described biocementation performers. This native species was able to actively growing and do perform microbial-induced-carbonate-mineralization under extreme alkalinity conditions after a careful laboratory adaptation process. The native species presented unique and differentiating traits that gave it a better adaptability and biocementation performance. The same occurs with a priceless microbial diversity inhabiting little explored and unprotected extreme ecosystems. Extreme environments house a fascinating biodiversity with potential value for ecosystem services.

Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p

In the present study, we fabricated a glycol chitosan/oxidized hyaluronic acid hydrogel film with promising potential for the dual ophthalmic delivery of dexamethasone (Dex) and levofloxacin (Lev). Utilizing different oxidation degrees of oxidized hyaluronic acid (OHA), several blank hydrogel films and Lev-loaded hydrogel films were successfully fabricated. With an increase in the oxidation degree of OHA, the swelling ratio of the hydrogel films decreased accordingly. The hydrogel films displayed a stepwise release of Lev and Dex, with Lev rapidly released from the hydrogel film, followed by a sustained release of Dex. Lev-loaded hydrogel films revealed a potent capacity to inhibit bacterial growth in different bacterial strains. In lipopolysaccharide-activated RAW264.7 macrophages, the formulated hydrogel films displayed potent in vitro anti-inflammatory activity by significantly downregulating various inflammatory cytokines. Overall, the fabricated hydrogel film acting as a dual drug delivery system might be a promising vehicle for the treatment of postoperative endophthalmitis.

Chronic wounds are developed as a consequence of prolonged wound healing and due to bacterial infection and its resistance. An antimicrobial dressing could be fabricated by integration of activated carbon (AC), keratin and homogenized aqueous garlic extract. The constituents were inspected independently for the evaluation of their efficiency as wound dressing component. The activated carbon was observed to adsorb keratin protein efficiently which could act as a carrier. Anti-bacterial tests were performed for the garlic extracts and found that 5% to 10% of extracts could inhibit the bacterial growth effectively. These components were shown to be potential candidates for fabrication of wound dressing material which could be developed into an ideal dressing material after further process optimization.

Consumption of seeds has increased in recent years due to their high nutrient content. However, Salmonella outbreaks associated with the consumption of low-water-activity food items have also increased, although these food items do not support microbial growth. The main goal of this study was to quantify microbial indicators and to determine the prevalence and content of Salmonella in chia, amaranth, and sesame seeds obtained from Mexican retail outlets. In addition, the behavior of this pathogen on seeds was evaluated. One hundred samples of each product (chia, amaranth, and sesame seeds) were collected from Queretaro City markets. Aerobic plate count, coliforms, and Escherichia coli bacteria were quantified, and the presence and number of Salmonella pathogens were also determined. Chia, amaranth, and sesame seeds (1 kg each) were inoculated with a cocktail of five Salmonella strains (∼6 log CFU mL-1) and stored at ambient temperature, and then populations of Salmonella were quantified. The median aerobic plate count contents in chia, amaranth, and sesame seeds were 2.1, 2.4, and 3.8 log CFU g-1, respectively, and the content of coliforms on the seeds ranged from 0.48 to 0.56 log most probable number (MPN) per g. E. coli was present at low concentrations in the three types of seeds. Salmonella was detected in chia (31%), amaranth (15%), and sesame (12%) seeds, and the population ranged from 0.48 to 0.56 log MPN g-1. Salmonella levels decreased through 240 days of storage, showing inactivation rates of 0.017, 0.011, and 0.016 log CFU h-1 in chia, amaranth, and sesame seeds, respectively. The high prevalence of Salmonella in the seeds highlights potential risks for consumers, particularly given that seeds are generally consumed without treatments guaranteeing pathogen inactivation. HIGHLIGHTS

In this study, hierarchical Ag/La2O2CO3 micro/nanostructures (MNSs) were synthesized by in situ loading Ag nanoparticles (NPs) on the surface of the La2O2CO3 MNSs. The prepared La2O2CO3 MNSs present flower-like shape and can be tuned by the molar ratio of La (NO3)3 and CO(NH2)2. In the molar ratio of 1:2 to 1:55, the La2O2CO3 MNSs mainly consist of polyhedral rods, irregular rods and irregular spindles and their size is about 10, 8 and 7 μm, respectively. After loading Ag NPs, the spindle-like Ag/La2O2CO3 MNSs were used for phosphate removal and antibacterial activity. At the initial phosphate concentration of 20 mg/L, the removal rate is 59.6%. The Ag/La2O2CO3 MNSs have significant antibacterial activity and their MIC values for S. aureus and E. coli are 31.3 and 15.6 μg/mL, respectively. The results indicate that Ag/La2O2CO3 MNSs may have good application prospects in open water to inhibit bacterial growth.

The purpose of this study was to prepare and characterize an optimized system of tannic acid-loaded niosomes as a potential carrier for antibacterial and anti-biofilm delivery. The niosomal formulation was optimized using response surface methodology (RSM). The effects of the molar ratio of surfactant to cholesterol, drug concentration, and molar ratio of Span 60 to Tween 60 on particle size and drug entrapment efficiency of the niosomal nanocarrier were studied. The optimized nanoparticles were characterized in terms of the morphology, in vitro release profile, and antibacterial properties. Moreover, Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) techniques were utilized to investigate drug-excipient interactions. Antibacterial and anti-biofilm activities of free tannic acid and tannic acid-loaded niosome were investigated against selected pathogenic bacteria including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Furthermore, the expression level of biofilm-associated genes was evaluated in selected pathogenic bacteria using Real-Time PCR. According to the results, the dependent variables (particle size and entrapment efficiency) were best fitted to the quadratic model. The particle size and entrapment efficiency of the best niosomal formulation were 89 nm and 82%, respectively. The in vitro release of the optimized formulation showed a controlled release profile. Release kinetics indicated a diffusion-based release of the drug. FTIR and DSC studies also confirmed the absence of drug-excipient interactions. The optimized formulation exhibited higher antibacterial effects as compared with the free drug solution. Moreover, the time-kill assay of the encapsulated drug revealed a slow and controlled inhibition of bacterial growth for 72 h while the free drug was used up in the first hours. Moreover, tannic acid-loaded niosome reduced biofilm formation capacity in selected strains and down-regulated the biofilm gene expression as compared to free tannic acid. The optimized formulation containing tannic acid can be a promising candidate for designing a new delivery system for this antibacterial and anti-biofilm agent.

This study evaluated the effect of some natural additives and the structure imparted by them on microbial growth and rheological characteristics in acidic model foods with reduced glycidic content. Systems were formulated using gellan gum, as gelling agent; xylitol, as aw depressor; and natamycin, as antimicrobial. Additive-free control systems were prepared. The pH was adjusted to 3.50 or 5.50 as required. Systems were inoculated with Zygosaccharomyces bailii. The effect of additives alone and combined on Z. bailii growth was studied. In some cases, the possible use of additives as yeast nutrients was evaluated. Furthermore, systems rheological characterization was performed. Additives and the structure given by gellan gum significantly affected yeast growth. Gellan gum initially slowed Z. bailii development, but as storage progressed, it acted as yeast carbon source, promoting its growth. A similar trend was observed when xylitol effect was studied. Natamycin inhibited yeast growth in all systems assayed. Additives modified the rheological characteristics of the gels and this effect depended on gellan gum concentration and pH. Obtained results emphasize the importance of considering the different effects that additives and their combinations can exert on the growth of deteriorating microorganisms and on the physical characteristics of gels.

Thermophilic spore-forming bacteria are found ubiquitously in natural environments and, therefore, are present in a number of agricultural food products. Spores produced by these bacteria can survive harsh environmental conditions encountered during food processing and have been implicated in food spoilage. During research efforts to develop a standardized method for enumerating spores in dairy powders, the dairy powder-associated thermophilic sporeformer Anoxybacillus flavithermus was discovered growing in uninoculated control plates of tryptic soy agar (TSA) supplemented with 1% (w/v) starch, after incubation at thermophilic (55°C) growth temperatures. This article reports the investigation into the source of this thermophilic sporeformer in TSA medium components and characterization of the bacterial isolates collected. Aqueous solutions of tryptic soy broth powder from four suppliers and four agar-agar powders (two manufacturing lots from one supplier [agar A_1 and agar A_2] and two from separate suppliers [agar B and agar C]) were subjected to two different autoclave cycle times (121°C for 15 min or 121°C for 30 min) and then prepared as TSA. After incubation at 55°C for 48 h, bacterial growth was observed only in media prepared from both lots of agar A agar-agar powder, and only when they were subjected to a 15-min autoclave cycle, implicating these powders as a source of the sporeformer contamination. Genetic characterization of 49 isolates obtained indicated the presence of five unique rpoB allelic types of the thermophilic sporeformer Geobacillus spp. in agar-agar powder from agar A. These results not only highlight the importance of microbiological controls but also alert researchers to the potential for survival of thermophilic sporeformers such as Anoxybacillus and Geobacillus in microbiological media used for detection and enumeration of these same thermophilic sporeformers in products such as dairy powders. HIGHLIGHTS

To remediate petroleum-contaminated soil, a DC powered electrokinetic reactor was used with amended biosurfactant concentrations of 28 g/L, 56 g/L, and 84 g/L to enhance the extraction of oil from the soil and aid in the biodegradation of the remaining oil by hydrocarbon-degrading microbes. The highest oil extraction of 83.15 ± 1.97 % was obtained with the biosurfactant concentration of 56 g/L while the highest degradation was observed when 84 g/L of biosurfactants were used. The bacteria survived the electro-halo-thermal environment and degraded the remaining hydrocarbons to as low as 0.0405 ± 0.057 mg of carbon/mg of soil when 84 g/L of biosurfactants were used. Microbial growth was however affected by the relentlessly changing pH in the reactor. The presence of biosurfactants significantly aided in oil recovery and biodegradation in the first 96 h of the experiments.

Contaminated poultry meat is a major source of human foodborne illnesses. Many interventions have been developed to reduce and/or eliminate human foodborne pathogens in poultry products; however, treatments with cold plasma or carnosine or their combination have not been extensively investigated. In this study, the bacterial microflora of poultry meat samples after treatments with cold plasma and carnosine were characterized with EcoPlates in the OmniLog system. The plates were incubated at 25°C for 7 days in the OmniLog chamber, and bacterial growth was monitored by recording formazan production every 30 min at an optical density of 590 nm. The kinetics of lag, log, and stationary phases of bacterial growth followed the Gompertz sigmoidal model but with different inflection times and asymptotes at the log phase and the stationary phase, respectively. Results indicated that treatment of poultry meat samples with cold plasma technology and carnosine could inhibit growth of the bacteria in the treated meat samples. Of 31 chemicals tested, phenylethylamine, α-d-lactose, d,l-α-glycerol phosphate, 2-hydroxybenzoic acid, γ-hydroxybutyric acid, α-ketobutyric acid, and d-malic acid could not be metabolized by bacteria in the meat samples. Future research is required to determine whether these seven chemicals that inhibited growth of bacteria in these meat samples can be used as food preservatives for extending the shelf life of these products. Whether the bacterial flora can be an indicator of effectiveness for meat samples treated with cold plasma, carnosine, or both needs further study. HIGHLIGHTS

Managing the vast amounts of eggshell and sea-shell waste that is produced globally each year is becoming very problematic as this material is simply disposed of in landfills. This waste results in odor production and microbial growth directly leading to environmental stresses. Transforming this waste into valuable biomaterials pose significant environmental and economic advantages as discarded waste have materials that can be utilized. The objective of this work was to develop inexpensive, bioactive hydroxyapatite-based scaffolds for tissue engineering applications by using an eco-friendly and sustainable approach. Engineering nano hydroxyapatite (EnHA) was derived from chicken eggshell and clam sea-shell waste by using an energy efficient microwave assisted wet chemical precipitation method. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), and Energy dispersive spectroscopy (EDS) were used to analyze the biomaterials. Results show that the particles are highly crystalline hydroxyapatite (HA) with acicular shapes and within nanometer size ranges. The chemical compositions match exactly that of naturally occurring HA. The EnHA infused polymer scaffolds were fabricated using slurry-based solution 3D printing techniques. The slurry solutions composed of 70 wt% EnHA and 30 wt% Polycarpolactone (PCL). The XRD, SEM, EDS, and in vitro cell studies were conducted to determine the ability of the scaffolds to support cell adhesion and maintain viability. The scaffolds supported cellular attachment and maintenance when observed over a period of several days, suggesting their potential for future tissue regeneration research and applications.