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An antagonistic yeast strain was isolated from the strawberry fruit cv. Paros, and its antifungal properties against Botrytis cinerea causal agent of strawberry grey mold disease were evaluated under in vitro and in vivo experiments. The isolate was tentatively identified as Tetrapisispora sp. strain 111A-NL1 based on phenotypic characteristics and sequence analysis of D1/D2 domains of the 26S rRNA gene. Volatile organic compounds (VOCs) produced by the 111A-NL1 strain inhibited the mycelial growth of fungal pathogen (75.19%) and conidial germination (63.34%); however, inhibition percentage of mycelial growth of pathogen by dual culture test was less (19.49%). Also, the strain produced pectinase, siderophore, chitinase, IAA, as well as gibberellin, and could solubilize phosphate. Additionally, the disease severity of strawberry grey mold was decreased by employing living cells and volatile metabolites methods by 47.61% and 74.05%, respectively, in comparison with untreated control seven days after inoculation. Therefore, its mode of action might consist of antibiosis and VOCs production by yeast strain 111A-NL1 against B. cinerea. The VOCs released by strain 111A-NL1 were analyzed, and thirty-three chemical compounds were determined by gas chromatography-mass spectroscopy (GC-MS). Out of them, Decane (12.79%), Squalene (9.60%), Undecane (7.98%), Benzene, 1,2,3-trimethyl- (7.67%), Nonane, 2,6-dimethyl- (5.69%), Benzene, 1-ethyl-3-methyl- (5.55%), Mesitylene (4.17%), and Phenylethyl Alcohol (3.33%) were the major components. In addition, the selected strain reduced natural decay incidence and weight loss of fruit, and preserved quality parameters of strawberry fruit including firmness, soluble solids content, and titratable acidity. This research averred, for the first time, that the creation of VOCs by Tetrapisispora sp. strain 111A-NL1 could play an essential role as a biofumigant in the antifungal activity against strawberry grey mold.

About 80% higher risk of amputation resulted from microbial infection was indicated for patients with diabetic foot ulcers (DFUs). Micro and nano-scaffolds made of natural polymers specifically cellulose, chitosan, and collagen can donate the biocompatibility, biodegradability, and bioavailability properties appropriate to accelerate wound closure before microbial biofilm formation. Antimicrobial activity of these wound dressings can be improved by incorporation of bioactive compounds extracted from medicinal plant species such as curcumin. Low water solubility and poor bioavailability are recognized as two main disadvantages of curcumin, lipophilic phytopolyphenol, which could be controlled by targeted polymeric micro and nano-scaffolds. Consequently, this review has discussed the capacity and challenges of these types of formulations according to recent investigations.

An endophytic bacterial strain, isolated from Fragaria × ananassa roots, and its antifungal activity against Colletotrichum nymphaeae were investigated under in vitro, in vivo, and greenhouse experiments. Bacterial isolate was identified as Bacillus atrophaeus strain DM6120 using phenotypic, biochemical, and molecular phylogenetic analysis of the 16S rDNA gene sequences. Bacterial strain DM6120 suppressed mycelial growth of C. nymphaeae (54.92%) using dual-culture method. The non-volatile compounds produced by DM6120 inhibited mycelial growth and conidial germination of C. nymphaeae by 74.12% and 80.80%, respectively. However, inhibition percentage of mycelial growth of the pathogen by volatile compounds of the strain DM6120 was lower (11.9%) than that for the two dual culture and non-volatile compound tests. The strain DM6120 produced protease, chitinase, pectinase, siderophore, IAA, gibberellin, and fixed nitrogen. The living cells of the strain DM6120 decreased anthracnose disease at post-harvest on fruit by 71.42%. Furthermore, disease severity of strawberry anthracnose was suppressed using soil drenching and foliar spray application methods 60 days after inoculation by 94.44% and 88.88%, respectively. PCR amplification confirmed the presence of iturin and surfactin genes in strain DM6120. The bioactive fractions produced by strain DM6120 were analyzed by gas chromatography-mass spectrometry. Six compounds from n-butanol extract and seven compounds from methanol extract were identified. 1,1-dibutoxyacetone (58.789%) and diethylene glycol, o,o-di(pivaloyl)- (29.922%) from n-butanol extract and acetic acid (39.923%) and 2-furanmethanol (30.305%) from methanol extract were determined as the main bioactive compounds produced by bacterial strain DM6120.

The biosynthesis of nanoparticles (NPs) has been proposed due to its fast, clean, safe, and cost-effective production and being efficient alternative to conventional physicochemical methods. This study aimed to isolate and identify aquatic yeast strains for their potential to form Zinc oxide nanoparticles (ZnONPs). A yeast strain, NS02, with high tolerance against zinc ion (5.25 mM) was isolated using the enrichment technique and was selected as efficient candidate for the biosynthesis of ZnONPs under cell-free extract (CFE) strategy. The preliminary evaluation on the formation of ZnONPs was performed by visual observation and UV-visible absorption spectra of the biosynthesized ZnONPs. The morphology, size and elemental distribution of the nanoparticles were determined by Field emission scanning electron microscopy (FESEM) equipped with energy-dispersive X-ray (EDX). X-ray diffractometer (XRD) was used to identify the crystalline phase of the ZnONPs. Antibacterial activity of ZnONPs against pathogenic bacteria isolated from the clinical specimens was investigated using agar well diffusion method. The isolate NS02 was characterized based on their morphological properties and amplification the ITS-5.8S-ITS2 rDNA regions. The present study pioneered the capabilities of the native aquatic strain Rhodotorula pacifica for the extracellular synthesis of ZnONPs with CFE strategy. The biosynthesized ZnONPs had a growth inhibitory effect all tested clinical isolates due to their nanometric size and well-defined dispersity. This investigation is attempted to indicate the novel microbial sources of aquatic yeasts as biological plant in the synthesis of ZnONPs with antimicrobial activity under cell-free extract strategy.

In this study, the extraction of rare metals from the spent automobile catalyst using Aspergillus niger (A. niger) was investigated. The effect of different factors including initial glucose, initial pH, inoculum percentage, and Solid to Liquid (S/L) ratio on the A.niger growth was done. Then in the condition of initial glucose of 100 g/L, initial pH of 5, inoculum percentage of 2.5 %, S/L ratio of 1 %(w/v), the extraction efficiency were 25.9 % of cerium (Ce), 43.0 % of aluminum (Al) for 240 h, and 23.9 % of lanthanum (La) for 48 h. After the bioleaching section, the spent residue was applied for platinum (Pt) and palladium (Pd) recovery using aqua regia, which results in a 100 % recovery of these metals. The shrinking core model results showed that both chemical reaction and diffusion on the surface controlled the overall reaction rate. Additionally, the characterization methods including SEM, FTIR, HPLC, and XRD before and after bioleaching were performed.

Ultrasound-assisted Fenton-like was utilized to leaching precious metals from spent automobile catalysts. The effect of different factors including solid to liquid (S/L) ratio, H2O2 percentage and initial Fe2+ concentration was done. Response surface methodology (RSM) was used to optimize the effective factors in the leaching of Al and Ce from the spent automobile catalyst. The optimum conditions for three effective factors were 0.01% (w/v) S/L ratio, 10.3% (v/v) H2O2 and 12.6% (w/v) Fe2+. The recovery efficiencies of Al and Ce in the optimum conditions were 81.7 and 47.2% in 4 h, respectively. In the absence of ultrasound, Al and Ce recoveries decreased to 69.5 and 13.4%, respectively. The residue after leaching was applied for Pt and Pd recovery using aqua regia, which results to 100% recovery. The modified shrinking core modeling results suggested that chemical reaction was the rate controlling step. The characterization methods including scanning electron microscopy (SEM) and X-ray diffraction (XRD) before and after bioleaching were performed.

Strawberry anthracnose, caused by Colletotrichum nymphaeae is an important disease of strawberry. In this study, an endophytic bacterium isolated from the stem of Fragaria × ananassa cv Paros and identified as Serratia rubidaea strain Mar61-01 based on phenotypic, biochemical characteristics and molecular phylogenetic analysis. Antagonistic activities of this endophytic bacterium against C. nymphaeae were investigated under in vitro, in vivo and greenhouse conditions. The strain Mar61-01 reduced mycelial growth and conidial germination of C. nymphaeae in in vitro tests. Furthermore, it reduced disease severity on inoculated strawberry fruits and seedlings compared with uninoculated control. In addition, the strain Mar61-01 produced prodigiosin pigment. The pigment was purified by thin layer chromatography and its chemical structure was characterized by FT-IR and NMR (400 MHz) spectra. The results indicated that prodigiosin is a key feature in biocontrol of C. nymphaeae. The inhibition growth of C. nymphaeae under in vitro, in vivo, and greenhouse conditions showed that S. rubidaea Mar61-01 has the potential for managing of strawberry anthracnose.

The aim of this study was to isolate and characterize marine bacterial strains capable of converting selenite to elemental selenium with the formation of Se nanoparticles (SeNPs). For the first time, a novel marine strain belonging to Bacillus amyloliquefaciens (GenBank accession no. MK392020) was isolated from the coast of the Caspian Sea and characterized based on its ability for transformation of selenite to SeNPs under aerobic conditions. The preliminary formation of SeNPs was confirmed via color changes and the products characterized by UV-Vis spectroscopy. The field-emission scanning electron microscopy (FESEM) together with energy-dispersive X-ray (EDX) analysis showed the presence of the spherical SeNPs on both the surface of the bacterial biomass and in the supernatant solution. Dynamic light scattering (DLS) analysis showed the SeNPs to have an average particle size (Z-average) around 45.4-68.3 nm. The X-ray diffraction (XRD) studies substantiated the amorphous nature of the biosynthesized SeNPs. Fourier-transform infrared spectroscopic (FTIR) studies of the SeNPs indicated typical proteinaceous and lipid-related bands as capping agents on the SeNPs. Different effective parameters corresponding the yield of SeNPs by B. amyloliquefaciens strain SRB04 were optimized under resting cell strategy. Results showed that the optimal process conditions for SeNP production were 2 mM of selenite oxyanion, 20 g/L of cell biomass, and 60 h reaction time. The synthesized SeNPs had a remarkable antibacterial activity on Staphylococcus aureus compared with chloramphenicol as a broad-spectrum antibiotic.

An environment-friendly, cheap method, biogenic synthesis of silver nanoparticles (AgNPs) is interesting as compared to physical and chemical synthesis methods. The aim of the present study was to utilize the inherent capability of Yarrowia lipolytica as a novel biocatalyst for green production of AgNPs using different strategies, including growing cells, resting cells, and cell-free extracts (CFE) under optimized reaction conditions. The produced AgNPs were evaluated with UV–vis spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, and Fourier transform infrared spectrometry. In the growing cells strategy, Y. lipolytica produced spherical AgNPs under the optimized conditions, 2.5 mM of silver ions, 7.5 g/l of yeast biomass, a temperature of 30 °C, a pH of 6, and a shaking rate of 50 rpm after 48 h. The sizes and monodispersity of the AgNPs in the resting cells strategy were better than those in the other two. However, the AgNPs were produced faster in the CFE strategy. The antibacterial activity and minimal inhibitory concentration of the AgNPs against certain Gram-positive and Gram-negative bacteria were determined by the agar well diffusion and broth microdilution methods. The AgNPs had a considerable antibacterial effect compared to chloramphenicol as a broad-spectrum antibiotic.

For the first time a novel aquatic bacterium belonging to strain of Pseudomonas chlororaphis was developed for the synthesis of cadmium sulfide quantum dots. The cadmium sulfate solution incubated with cell-free extract (CFE) of P. chlororaphis strain CHR05 to generate cadmium sulfide nanoparticles (CdSNps) which were characterized with combined spectroscopy and microscopy analyses. The preliminary confirmation on the formation of CdSNps was done by UV–vis and fluorescence analyses with the absorption and emission spectra at 435 and 475 nm, respectively. EDX pattern shows that the CdSNps are composed of the elementals Cd and S. Also, XRD analysis of the purified nanoparticles confirmed the formation of CdSNps. FE-SEM, TEM, and DLS analyzed the size and morphology of the CdSNps. The biosynthesis of CdSNps with the strategy of cell free extract was investigated under optimum conditions. After 24 h of incubation, the results showed that the novel isolated strain can produce spherical CdSNps with an average size of 6.7 ± 2.4 nm, after exposure to CdSO4 solution (2.5 mM) at pH 7.5 and 30 °C. The antibacterial activity CdSNps against some Gram-positive and -negative bacteria were determined using agar well diffusion method and microplate method which has growth-inhibitory effect all on tested bacteria.

Take-all caused by Gaeumannomyces graminis var. tritici (Ggt) is one of the most important root and crown diseases of wheat. In this research, four basidiomycetes isolates as fungal endophytes were isolated from healthy cereal plants and were identified as Coprinopsis urticicola M2, Rhizoctonia endophytica M9, Rhizoctonia zeae M32 and Fomes fomentarius M40 based on phenotypic characteristics and molecular phylogenetic analysis of the ITS rDNA sequences (ITS1-5.8S rDNA-ITS2). Then, their effects as potential biological control agents (BCAs) against Ggt were tested in vitro and greenhouse conditions. All isolates had inhibitory effects on the development of Ggt growth in vitro by dual-culture method with inhibition percentage ranging from 39.1% to 54.8%. Volatile antifungal effects were observed for M32 isolate with 23.7% inhibition, followed by the isolate M2 (18.7%). However, culture filtrates of M2 isolate showed maximum inhibition (29.8%) against Ggt. Only two of the four isolates (M2 and M32) had significant effects on controlling take-all in greenhouse conditions. M2 isolate produced IAA and gibberellin, which had the most effect on increasing of growth parameters of wheat plant in greenhouse conditions. M2 isolate was able to colonize the root cortex of wheat seedlings more rapidly compared to pathogen, as assessed by both cultural and microscopic methods. Therefore, its mode of action may depend on the internal root colonization of wheat by C. urticicola M2 and competition for space and nutrient with the Ggt. This is the first research which shows that the C. urticicola M2 could colonize the wheat roots and has great potential to be used as effective biocontrol agent of take-all. Additionally, it can improve growth parameters in wheat under greenhouse conditions. Therefore, the results of this research indicated that C. urticicola M2, due to its ability to colonize the root and crown internal tissues, may provide an advantage as biocontrol agents to be used in the field conditions.

Proton-transfer compounds were prepared by the reaction of pyridine-2,6-dicarboxylic acid (pydcH2) with 1-methylimidazole (1-mim) and 2-methyimidazole (2-mim) in 1:2 molar ratio. The reaction of ligands with antimony(III)chloride led to complexes formulated as [Sb(pydcH)(pydc)(H2O)] (1) and [Sb2(pydcH)2(H2O)2(Cl)2(OH)]2·2H2O (2). Both two of complexes were characterized by elemental analysis, IR, UV–Vis and NMR spectroscopy and also their structures were confirmed by X-ray crystallography. Cyclic voltammetry measurements on the complexes revealed one redox couple corresponding to Sb(III)/Sb(V) at E0′ of −0.184 to −0.052 V versus Ag/AgCl, under argon. Aeration proved the further interaction potent of complex (2) with oxygen compared to (1), within 5 min. In this study, the cytotoxic potential of each of three compounds were evaluated, using oxaliplatin as a standard, under MTT method, against MCF7 (a human breast cancer), H1299 (a human non-small cell lung carcinoma), HT29 (a human colon adenocarcinoma), HepG2 (a human liver hepatocellular carcinoma) and βTC (a mouse beta pancreatic) cell lines. Complex (2) with E0′ about three and a half times (1) exhibited more significant toxicity compared to (1). The strongest cytotoxic effect for (2) was indicated on HepG2 cell line (IC50 = 1 μM). Antibacterial activity of the compounds was evaluated against three Gram-positive bacteria namely Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis and also three Gram-negative bacteria namely Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris through the established antibacterial assays including broth microdilution method using 2,3,5-triphenyl tetrazolium chloride (TTC, as chromogenic marker) and agar well diffusion method. Both two complexes showed an enhanced antibacterial activity in comparison with the standard drug chloramphenicol.

Proteins have evolved in specific 3D structures and play different functions in cells and determine various reactions and pathways. The newly synthesized amino acid chains once depart ribosome must crumple into three-dimensional structures so can be biologically active. This process of protein that makes a functional molecule is called protein folding. The protein folding is both a biological and a physicochemical process that depends on the sequence of it. In fact, this process occurs more complicated and in some cases and in exposure to some molecules like glucose (glycation), mistaken folding leads to amyloid structures and fatal disorders called conformational diseases. Such conditions are detected by the quality control system of the cell and these abnormal proteins undergo renovation or degradation. This scenario takes place by the chaperones, chaperonins, and Ubiquitin-proteasome complex. Understanding of protein folding mechanisms from different views including experimental and computational approaches has revealed some intermediate ensembles such as molten globule and has been subjected to biophysical and molecular biology attempts to know more about prevalent conformational diseases.

Proteins have evolved in specific 3D structures and play different functions in cells and determine various reactions and pathways. The newly synthesized amino acid chains once depart ribosome must crumple into three-dimensional structures so can be biologically active. This process of protein that makes a functional molecule is called protein folding. The protein folding is both a biological and a physicochemical process that depends on the sequence of it. In fact, this process occurs more complicated and in some cases and in exposure to some molecules like glucose (glycation), mistaken folding leads to amyloid structures and fatal disorders called conformational diseases. Such conditions are detected by the quality control system of the cell and these abnormal proteins undergo renovation or degradation. This scenario takes place by the chaperones, chaperonins, and Ubiquitin-proteasome complex. Understanding of protein folding mechanisms from different views including experimental and computational approaches has revealed some intermediate ensembles such as molten globule and has been subjected to biophysical and molecular biology attempts to know more about prevalent conformational diseases.

Crown gall disease of grapevine, caused by Agrobacterium tumefaciens, often results in severe economic loss to grape production worldwide. This study demonstrated the ability of the endophytic bacteria Pseudomonas sp. Sn48 and Pantoea sp. Sa14 isolated from domesticated and wild grapevines to induce resistance in both above‐ and belowground tissues of grapevines infected with A. tumefaciens. Our results provide evidence that both strains can colonize roots and/or shoots. We showed that the strains Pseudomonas sp. Sn48 and Pantoea sp. Sa14 are capable of inducing stilbenic phytoalexin production in grapevine tissues and to further prime plantlets for enhanced phytoalexin production after A. tumefaciens inoculation. We also showed that in the majority of treatments, polyamine accumulation remained unchanged or slightly increased in plantlets treated with Pseudomonas sp. Sn48 and Pantoea sp. Sa14 compared with the control. Our findings indicated that the levels of polyamines remain unchanged or significantly decrease in plantlets treated with endophytic bacteria after A. tumefaciens challenge compared to the control and plantlets treated with individual endophytic bacterial strains. PR1, PR2, and PR4 gene expression levels of plantlets treated with Pseudomonas sp. Sn48 and Pantoea sp. Sa14 significantly increased after A. tumefaciens inoculation. The findings revealed the efficacy of the selected endophytic bacteria in triggering grapevine resistance against A. tumefaciens and the possible use of these strains as an alternative to chemical control methods in grapevine crown gall disease management.

Four coordination complexes, [2-mimH]2[Co(pydc)2][ClO4]. H2O (1), [2-mimH]2[Zr(pydc)3] (2), [imiH]2[Zr(pydc)3].4H2O (3) and [Ca(pydcH2)2(H2O)]2[Co(pydc)2]2·6H2O (4) have been prepared from the reaction between proton-transfer compounds containing pyridine-2,6-dicarboxylic acid (pydcH2) with 2-methylimidazole (2-mim) and imidazole (imi) in 1:2 M ratio and metal salts. These compounds have been characterized by spectroscopic methods and single crystal X-ray diffraction technique was used to determine their structures. Also, thermal analyses (TGA/DTA) were carried out on all the synthetic compounds. Then the agar dilution and diffusion methods were used to determine the antibacterial activity of the ligands and their complexes on the growth profile of two pathogenic Gram-positive bacteria namely Staphylococcus aureus and Bacillus cereus and also two Gram- negative bacteria namely Escherichia coli and Klebsiella oxytoca. The highest antibacterial activity was exhibited by (pydcH2) and complex (2) at MIC values between 75 and 175 μg/mL. These two compounds exhibited stronger effects than gentamicin as a standard drug toward Klebsiella oxytoca. The anti-proliferative activity of compounds was evaluated in vitro using oxaliplatin as a positive control against MCF7 (a human breast cancer), HL60 (a human lymphocyte) and HT29 (a human colon adenocarcinoma) cell lines. Selective and significant cytotoxic effect of complex (4) was observed on MCF7 cells (IC50 = 10 μM, Cell viability 62.12%).

The purpose of this research was to explore the control of common bean root rot disease caused by Fusarium solani by the bacterial strain CTA8689 under in vitro and greenhouse conditions. The strain CTA8689 was isolated from common bean root and identified as Achromobacter xylosoxidans using 16S rDNA sequence, morphological and physiological characteristics. The strain CTA8689 suppressed the mycelial growth of F. solani in dual-culture (58.67%) and culture filtrates (41.87%) methods. The volatile compounds (VOCs) produced by CTA8689 inhibited mycelial growth and conidial germination of F. solani by 42.26% and 59.12%, respectively. Also, this strain produced biofilm, lytic enzymes such as chitinase, protease and pectinase, siderophore, IAA and gibberellin, and it was able to phosphate solubilization. Furthermore, the disease severity of common bean root rot was reduced using soil and seed treatment by 83.89% and 87.60%, respectively, 60 days after inoculation. Additionally, the strain improved the plant growth parameters in common bean under greenhouse conditions. The VOCs produced by the strain CTA8689 were analyzed by Gas chromatography-mass spectroscopy (GC-MS). Out of 23 identified VOCs, 1,3-Dimethylbenzene (21.613%), Benzene, 1,3-bis (1,1-dimethylethyl)- (13.823%%), Ethylbenzene (8.636%), Dodecane, 4,6-dimethyl- (8.145%) and Decane (5.905%), were the major bioactive components. The mode of action of the strain CTA8689 on the F. solani was through the production of antifungal compounds (antibiosis) and lytic enzymes, which suppressed mycelial growth and conidial germination of the pathogen in vitro and greenhouse conditions. Overall, our results showed that A. xylosoxidans strain CTA8689 could be a promising biological control agent (BCAs) for common bean root rot.

In this study, four endophytic bacterial strains were isolated from healthy strawberry plant and were identified as Bacillus spp. strain YN8, Bacillus spp. strain LN57, Bacillus spp. strain MN17 and Pseudomonas aeruginosa strain EN18 based on phenotypic, biochemical characteristics and molecular phylogenetic analysis. Then, their effects as biocontrol agents against Colletotrichum nymphaeae causal agent of strawberry anthracnose were investigated under in vitro, in vivo and greenhouse conditions. All strains decreased growth of C. nymphaeae in vitro tests. Disease severity on inoculated strawberry fruits and seedlings were reduced significantly more than control which can be due to the secretion of enzymes and antifungal metabolites. In addition, the toxin produced by pathogen was extracted and purified by thin layer chromatography (TLC) and its chemical structure was characterized by Fourier transform infrared (FT-IR), H and C Nuclear magnetic resonance (NMR) spectra (400 and 100 MHz). The ability of detoxification of extracted toxin by endophytic bacterial strains was performed using bioassay tests and spectral analysis. Bioassay tests of fungal toxin treated with the strains MN17 and EN18 did not display any symptoms on strawberry leaves. Also, spectral analysis indicated various absorption coefficients by each bacterial strain that corresponds with bioassay tests.

A nonpathogenic endophytic bacterial isolate, recovered from Fragaria × ananassa stolon, and its antifungal activity against Colletotrichum nymphaeae was evaluated under in vitro, in vivo, and greenhouse conditions. Bacterial isolate was identified as Staphylococcus sciuri MarR44 (Strain ID: WDCM 891 = CCSM-B 00640) using phenotypic and biochemical properties and molecular phylogenetic analysis of the 16S rDNA gene sequences. The living cells of strain MarR44 inhibited mycelial growth of C. nymphaeae (52.46%) using dual-culture method. The volatile compounds (VOCs) produced by MarR44 inhibited mycelial growth and conidial germination of C. nymphaeae by 34.52% and 82.81%, respectively. However, inhibition percentage of mycelial growth of pathogen by culture filtrates of the strain MarR44 was lower (23.07%) than that for the two dual culture and volatile compounds assay tests. Moreover, the cell-free-culture filtrates of this strain reduced the biomass and conidial germination of pathogen by 91.89% and 41.10%, respectively. Also, the strain MarR44 was capable of producing protease, chitinase, HCN, siderophore, IAA, gibberellin, and biofilm. The living cells and volatile compounds of the strain MarR44 reduced anthracnose disease at post-harvest on fruit by 52.45% and 72.17%, respectively. Furthermore, disease severity of strawberry anthracnose was reduced using drenching soil and inoculated plants methods by 77.77 and 72.22%, respectively, 60 days after inoculation. The VOCs released by strain MarR44 were analyzed by Gas chromatography-mass spectroscopy (GC–MS). Out of 24 identified VOCs, Mesityl oxide (81.436%), Acetic acid, 2-methylpropyl ester (3.442%), 4-Methyldecane (1.837%), 4-Penten-2-one,4-methyl- (1.739%), Toluene (1.248%), and o-Xylene (1.24%) were the major components. The mode of action of S. sciuri MarR44 on the C. nymphaeae was through the production of antifungal volatile compounds (Antibiosis), which inhibited mycelial growth and conidial germination of pathogen in vitro and fruit decay development in vivo. To the best of our knowledge, this is the first report of S. sciuri having antifungal activity against causal agent strawberry anthracnose. These results indicated that the VOCs of S. sciuri strain MarR44 are promising biofumigant for management of strawberry anthracnose.

A major challenge for functional foods containing probiotics is to provide a sufficient number of probiotic microorganisms to survive the harsh environments during processing and storage so that they can confer their health benefits. Extensive studies have been carried out on the spray-drying of probiotics based on enhancing their survivability after drying and during storage. However, in this study, the production of spray-dried powder of L. rhamnosus was investigated based on maximizing the total CFU yield, which is a combination of the yields of survivability, powder production, and stability. The results suggested that although enhancing additives such as tragacanth to skim milk could significantly increase the survival of the cells during drying, it may significantly decrease the powder yield which could result in a low total CFU yield. Furthermore, good stability of cells micro-encapsulated in skim milk + sucrose could not compensate for their low survival during the drying. It was determined that bacterial adaptation to sodium chloride, micro-encapsulation of cells in 20% skim milk, and suitable spray-drying conditions (inlet air temperature of 150 °C and feed flow rate of 8 ml/min) could lead to the highest total CFU yield compared to other conditions. Using the micro-encapsulated cells in yogurt showed a 5-fold stability enhancement in the viable cells compared to the fresh cells without excessive acid production during 20 days of storage. These results confirmed the positive effects of micro-encapsulation on the shelf-life of probiotics.

In this study, about 112 isolates ofStreptomyceswere isolated from chickpea rhizospheric soils. Among the isolated strains, five showed strong inhibitory effects against chickpea Fusarium wilt caused byFusarium oxysporumf. sp.ciceris in vitrousing plate assay and selected for further studies. The selected strains were identified asStreptomycesspp. based on morphological and biochemical characterization as well as 16S rDNA sequences analysis. Our results assigned them to strains related to genus ofStreptomyces.In vitro, antagonistic effects ofStreptomycesstrains against the disease were evaluated through the dual-culture method, volatile and non-volatile metabolites, siderophore, protease and chitinase production. All bacterial strains inhibited mycelial growth of the pathogen ranging from 26 to 44.2% in dual culture assay. The non-volatile extract of five of theStreptomycesstrains inhibited more than 50% growth of the pathogen, whereas volatile compounds were less effective on mycelial growth inhibition (20.2 to 33.4%). The ability of the biocontrol agents to produce siderophore and protease were varied, whereas, production of chitinase was detected for all strains. Results of the greenhouse assay indicated that all biocontrol agents reduced disease severity (ranging from 38.7 to 54.8%). Accordingly, strain KS62 showed higher control efficacy (54.8%). In addition, the biomass of chickpea plants (plant height and dry weight) significantly increased in plants treated withStreptomycesstrains compared to non-bacterized control. The results of this study showed that it may be possible to manage chickpea Fusarium wilt disease effectively by usingStreptomycesspecies, as biocontrol agents. Therefore, evaluating their efficiency under field conditions is needed.

A novel endophytic bacterium, designated strain UN1512, was isolated from strawberry leaves, and its antifungal activity against Colletotrichum nymphaeae was estimated under in vitro, in vivo, and greenhouse conditions. The bacterial isolate was identified as Stenotrophomonas maltophilia via morphological, biochemical, and molecular traits. The strain UN1512 decreased the mycelial growth of C. nymphaeae (54.92%) in dual culture. The volatile and non-volatile compounds produced by strain UN1512 reduced mycelial growth of fungal pathogen by 17.85% and 30.06%, respectively. Also, the strain was able to secrete of protease, chitinase, pectinase, siderophore, IAA, and gibberellin. In addition, disease severity of strawberry anthracnose was inhibited via inoculating the bacterial suspension in phylloplane, rhizosphere, and healthy fruits. Also, the effect of volatile compounds (VOCs) produced by strain UN1512 on growth promotion of tomato plants was investigated under in vitro and growth chamber experiments. The results showed that, these compounds significantly enhance the fresh weight and length of roots and shoots. The VOCs produced by strain UN1512 were analyzed by GC-MS and 31 identified VOCs, that Benzothiazole (18.271%), 1,3,5,7-Cyclooctatetraene-1-carboxaldehyde (9.308%), Carbonic acid, octadecyl phenyl ester (5.203%), Benzaldehyde, 2,5-bis[(trimethylsilyl)oxy]- (4.086%), Estragole (3.557%), Benzaldehyde (3.506%) were the major components. Our studies report that strain UN1512 was capable to inhibit the causal agent strawberry anthracnose, and the VOCs produced by this strain increased the tomato seedlings growth.

40 isoeugenol-tolerant yeasts were isolated from the rhizosphere soil samples which in turn were collected from aromatic plants in different regions of Iran, and further tested for their ability to grow on a minimal medium containing isoeugenol as the sole carbon and energy source. Nine isolates which were able to grow on isoeugenol were examined for their ability to convert isoeugenol into vanillin under growing cell experiments. Of the tested yeasts, the highest conversion efficiency was observed in isolate MP24. The isolate was identified as Trichosporon asahii based on morphological, biochemical and molecular (ITS region) characters and tested to effectively convert isoeugenol into vanillin under resting cell system. A comparative analysis of thin layer chromatography (TLC), UV–Vis spectrometry, and high-performance liquid chromatography (HPLC) verified that vanillin and vanillic acid are accumulated as two major metabolites using T. asahii strain MP24 resting cells. In the presence of 7.5 g/l of wet weight cells of the strain MP24 pre-grown on isoeugenol and harvested at the end of the exponential growth phase, the optimal concentration of vanillin reached 2.4 g/l with a molar conversion of 52.5% in the potassium phosphate buffer (100 mM, pH 5.8) supplemented with 5 g/l of isoeugenol and 2% (v/v) N,N-dimethylformamide (DMF). The total concentration of vanillin and vanillic acid obtained from the bioconversion process was 4.2 g/l (total molar yield of 88.3%). Until now, no data has been published on the conversion of isoeugenol into vanillin by the strains of the genus Trichosporon.

A total of 40 fungal cultures were isolated for their ability to grow on caffeine as a sole source carbon and nitrogen, and further screened for theophylline-producing activities under the growing cell system. Based on thin-layer chromatography and high-performance liquid chromatography analyses, the potent strain Aureobasidium sp. TeO12 was chosen for its capability to generate theophylline via biotransformation of caffeine. It was identified based on phenotypic characteristics and its ITS1-5.8S-ITS2 rDNA sequencing data (GenBank accession number no. KT439072). To improve theophylline yield, the effects of various factors, such as resting cell density, Fe(II) concentration, and course of the transformation of caffeine, were studied in a biotransformation reaction containing 0.1 M sodium phosphate buffer (pH 7), Aureobasidium sp. TeO12 resting cells as the whole-cell catalyst and caffeine (2.5 g/L) as the substrate, and the reaction was incubated at 30 °C on an orbital shaker (200 rpm). The results indicated that optimal combination included resting cell density 6 g/L, Fe(II) concentration 75 mg/L, and the biotransformation time 72 h. Under these optimal reaction conditions, the highest theophylline concentration of 1.55 g/L (molar yield of 67%) with an average degradation yield of the substrate of about 83% was obtained in the biotransformation process. This is the first report on the biotransformation of caffeine into theophylline by a novel strain of the genus Aureobasidium.

The present study has been conducted towards isolation of moderately halophilic bacteria capable of transforming caffeine into theobromine. A total of 45 caffeine-degrading moderate halophiles were enriched from hypersaline lakes and examined for the biotransformation of caffeine to theobromine by thin-layer chromatography (TLC) and high-performance liquid chromatography analyses. Strain GL6, giving the highest yield of theobromine, was isolated from the Hoz Soltan Lake, 20 % w/v salinity, central Iran, and identified as Salinivibrio costicola based on morphological and biochemical features as well as its 16S rRNA gene sequence analysis (GeneBank Accession No. KT378066) and DNA–DNA relatedness. The biotransformation of caffeine with strain GL6 leads to the formation of two metabolites, identified as theobromine and paraxanthine, but the yield of paraxanthine was much lower. Further study on the production of theobromine from caffeine under resting cell experiment was carried out subsequently. The optimal yield of theobromine (56 %) was obtained after a 32-h incubation using 5 mM of caffeine and 15 g l−1 (wet weight) of biomass in 0.1 M saline phosphate buffer (pH 7.0 and 10 % w/v NaCl) under agitation 180 rpm at 30 °C. The biotransformed theobromine was purified by preparative TLC and subjected to FTIR and mass spectroscopy for chemical identification. This is the first evidence for biotransformation of caffeine into theobromine by strains of the genus Salinivibrio.

To screen strains of halotolerant or halophile bacteria which are able to convert isoeugenol to vanillin, 36 different strains of bacteria isolated from the salty environments in Iran were investigated. During growth on isoeugenol, a moderately halotolerant Gram-negative coccobacil showed capability of converting isoeugenol to vanillin. Based on morphological, physiological, and phylogenetic studies, strain CSW4 was classified as a bacterium belonging to the genus Psychrobacter. The bioconversion products were confirmed by thin-layer chromatography, high-performance liquid chromatography, and spectral data obtained from UV/Vis spectroscopy, FTIR, and mass-spectroscopy. Using growing cells, vanillin reached its maximum level of 88.18 mg L(-1) after 24 h of reaction time in the presence of 1 g L(-1) isoeugenol, resulting in a molar yield of 10.2%. The use of resting cells led to the optimal yield of vanillin (16.4%) which was obtained after 18-h reaction using 1 g L(-1) isoeugenol and 3.1 g of dry weight of cells per liter harvested at the end of the exponential growth phase. To improve vanillin yield, the effect of substrate concentration on vanillin production under resting cells conditions was also investigated. Using 10 g L(-1) isoeugenol, the maximal vanillin concentration (1.28 g L(-1)) was achieved after a 48-h reaction, without further optimization. The present study brings the first evidence for biotransformation of isoeugenol to vanillin in the genus Psychrobacter.

There is a growing interest in exploiting microbial bioconversions for the production of high value-added products such as vanillin and vanillic acid. We conducted this study to screen strains of bacteria which are able to degrade ferulic acid, and to evaluate the possibility of forming vanillic acid via conversion of ferulic acid under resting cell conditions. Twenty-seven different strains of bacteria were isolated from different samples which in turn were collected from a variety of sites in Iran and examined for bioconversion of ferulic acid into vanillic acid by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses. Based on TLC and HPLC analyses, the strain SHL1 giving highest vanillic acid yield was selected and identified as Bacillus licheniformis (GenBank accession number HQ111516) based on morphological and physiochemical characteristics and its 16S rDNA gene sequence. In the presence of 1 g/l ferulic acid, vanillic acid reached a maximum value of 494 mg/l (molar yield of 60%) after 45 h of reaction time using resting cells of strain SHL1 without further optimization. The present study gives the first evidence for ferulic acid biotransformation by B. licheniformis.

The popular demand for natural food additives has resulted in a number of processes for producing natural vanillin. Although there are chemical procedures and plant sources for vanillin production, microbial bioconversions are being sought as a suitable ‘natural’ alternative. The present paper describes the conversion of isoeugenol to vanillin by a novel bacterial strain isolated from soil. The strain was identified as Pseudomonas sp. strain KOB10 based on morphological and physiochemical characteristics and its 16S rDNA gene sequence. We optimized medium composition for vanillin production using a Taguchi experimental design. Eight factors, i.e. isoeugenol, glycerol, tryptone, K2HPO4, KH2PO4, Cu2+, Mg2+ and Ca2+ concentrations, were selected and experiments based on an orthogonal array layout of L18 (22 × 36) were performed. Analysis of the experimental data using the Taguchi method indicated that Cu2+ and glycerol concentrations had the highest impact on isoeugenol conversion into vanillin at a ...