Polyhydroxyalkanoates (PHAs) are naturally occurring biodegradable polymers with promising application in the formulation of plastic materials. PHAs are produced by numerous bacteria as energy/carbon storage materials from various substrates, including sugars and plant oils. Since these substrates compete as food sources, their use as raw material for industrial-scale production of PHA is limited. Therefore, efforts have been focused on seeking alternative sources for bacterial production of PHA. One substrate that seems to have great potential is the seed oil of Jatropha curcas plant. Among other favorable properties, J. curcas seed oil is non-edible, widely available, and can be cheaply produced. In this study, Pseudomonas oleovorans (ATCC 29347) was grown in a mineral salt medium supplemented with saponified J. curcas seed oil as the only carbon source under batch fermentation. Optimum PHA yield of 26.06% cell dry weight was achieved after 72 h. The PHA had a melting point (T(m)) between 150 and 160 degrees C. Results of polymer analyses by gas chromatography/mass spectrometry (GC/MS) identified only the methyl 3-hydroxybutanoate monomeric unit. However, electrospray ionization-time of flight mass spectroscopy (ESI-TOF MS) confirmed that the PHA was a copolymer with the characteristic HB/HV peaks at m/z 1155.49 (HB) and 1,169, 1,184-1,194 (HV). The data were further supported by 1H and 13C NMR analysis. Polymer analysis by gel permeation chromatography (GPC) indicated a peak molecular weight (MP) of 179,797, molecular weight (M(W)) of 166,838, weight number average mass (M(n)) of 131,847, and polydispersity (M(w)/M (n)) of 1.3. The data from this study indicate that J. curcas seed oil can be used as a substrate to produce the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3HB-co-3HV).

(R)-3-Hydroxycarboxylic acids, chiral enantiomers of bacterial polyhydroxyalkanoates (PHA), may be valuable synthons for the production of numerous industrial materials such as β-lactams, fungicides, flavors, pheromones and vitamins. In this study, (R)-3-hydroxycarboxylic acid [(R)-3HAs)] synthons were produced by Streptomyces sp. JM3 (JN166713) under batch fermentation. Initial confirmation of PHA production was achieved by matrix assisted laser desorption ionization-time of flight mass spectroscopy and gas chromatography/mass spectroscopy (GC/MS). Subsequently, (R)-3HAs were produced by in vivo depolymerization and the monomers were separated using acid precipitation and anion exchange chromatography. The (R)-3HAs were identified by GC/MS as 3-trimethylsiloxy esters of decanoic, octanoic and butanoic acids. This was further supported by (13)C nuclear magnetic resonance spectrometry. The (R)-3HAs exhibited antimicrobial activity against Escherichia coli O157:H7, Listeria monocytogenes (ATCC 7644) and Salmonella typhimurium (ATCC 14028) with minimum inhibitory concentration ranging from 12.5 to 25 mg ml(-1). However, the minimum bactericidal concentration data suggest that the (R)-3HAs may be bactericidal for E. coli O157:H7 and bacteriostatic for S. typhimurium and L. monocytogenes. Furthermore, the major purified synthon was shown to minimize the invasion of fibroblasts by S. typhimurium (ATCC 14028) [p < 0.05], using the MTT assay [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)].

Identification and characterization of viable culturable bacteria (VCB) associated with soils from Africa and the Americas are significant for environmental and battlefield security. Such analyses are scarce, and their evaluation using traditional microbiological methods does not fully elucidate the structure and chemotaxonomic characteristics of the microbial community. In this study, matrix-assisted laser desorption time of flight mass spectrometry (MALDI-TOF MS), spectrometry in addition to 16S rRNA sequencing, and diversity indices were employed to characterize VCB and their associated biomarkers. Nineteen genera were identified across all sample locations, but only four (Bacillus, Brevibacillus, Paenibacillus, and Terribacillus) confirmed by ClustalW2 as being 98-99 % similar among locations. Further evaluation of soils showed bacterial diversity (H) of (1.0-8.4), evenness (E H), (0.14-0.72), similarity (Sj), (0.0-0.38), and cfu/g soil (2.5 9 10 1-2.2 9 10 7). Analysis of representative bacteria using MALDI-TOF MS identified biomarkers for the genera Bacillus at m/z 6,778 (75 %), 9,437 (100 %);

Keywords: Lactobacillus parafarraginis, lactic acid bacteria (LAB), multi-drug resistant (MDR), extended spectrum beta-lactamase (ESBL), bacteriocin A new strain of Lactobacillus parafarraginis was isolated from a sample of commercial yogurt and identified by phenotypic and molecular methods. Phenotypic characterization showed bacilli sizes ~ 0.75-2.75 μm × 0.25-0.75 μm, a generation time of ~3.04 h under anaerobic conditions, halotolerance, lactose fermentation, production of hydrogen sulfide gas from Kliger iron agar, and the presence of an unusual fatty-acid methyl ester, cis-10-nonadecenoic acid. Based on 16S rRNA gene sequencing, the isolate was identified as Lactobacillus parafarraginis and given the GenBank accession number (KU495926). L. parafarraginis ((KU495926)) inhibited 14 multidrug-resistant (MDR) and extended spectrum β-lactamase (ESBL) Gram-negative clinical isolates, as well as 11 other pathogens by spot-test and well-diffusion assays. The MDR/ESBL clinical isolates and other pathogens included Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii/haemolyticus, Enterobacter aerogenes, Proteus mirabilis and Klebsiella pneumonia, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli (O157:H7), Bacillus cereus, Yersinia enterocolitica, Pseudomonas aeruginosa, Shigella sonnei, Streptococcus pyogenes and Enterococcus faecalis. Analyses of the semi-purified inhibitory fraction by SDS-PAGE, fast perfusion liquid chromatography (FPLC) inferred antimicrobial properties, characteristic of bacteriocins, with a protein band of ~75 kDa. Four bacteriocin structural genes which include sakT-β for sakacinT-β chain, sakT-α (sakacinT-α chain), acd T (acidocin), and plnc8A (plantaricin-α chain) were detected by PCR. The data suggest that L. parafarraginis (KU495926) may be a novel strain with potential therapeutic application. To our knowledge, this is the first report of the isolation of this strain from yogurt. ARTICLE INFO

Since the oil crisis of the 1970s much attempt has been made, albeit with varying degrees of success, to source the ideal substrate and bacteria for the production of PHA. The non-edible, naturally epoxidized seed oil from Vernonia galamensis and mixed cultures consisting of Alcaligenes latus (ATCC 29712), Cupriavidus necator (ATCC 17699), Escherichia coli (DH5α) and Pseudomonas oleovorans (ATCC 29347), were evaluated for PHA production under batch and fed-batch fermentations. PHA production, optimized by the mixed culture of E. coli and C. necator, was 0.4-19% (%wt/wt, cdw) for batch and fed-batch fermentations. Analyses of PHA by Matrix Assisted Laser Desorption IonizationTime of Flight Mass Spectrometry (MALDI-TOF MS) and Gas Chromatography Mass Spectrometry (GC/MS) identified the 3-hydroxybutyrate (3HB) monomeric unit. The PHA ester bond stretching vibration (C=O), was confirmed at absorption 1740.66 cm -1 , using Fourier Transform Infrared Spectroscopy (FTIR). Gel Permeation Chromatography (GPC) indicated peak molecular weights between 3.8×10 3 -1.12×10 6 Da with melting points (T m ), 60-90°C. The data further illustrates that inedible oils could be the ideal carbon source for the production of PHA.