Vinasse, a recalcitrant waste of the ethanol industry was employed for the production of polyhydroxyalkanoate (PHA) by the extremely halophilic archaeon, Haloarcula marismortui in shake flasks. The PHA was recovered by osmotic lysis of the cells and subsequent purification by sodium hypochlorite and organic solvents. Through UV-vis spectroscopy, differential scanning calorimetry, Fourier transform infrared, and nuclear magnetic resonance spectroscopy, the PHA was found to have characteristics very similar to that of the standard polyhydroxybutyrate (PHB) from Sigma. Inhibitory effect of polyphenols contained in vinasse was assessed by a quick and reliable cup-plate agar-diffusion method. Raw vinasse (10%) was utilized leading to accumulation of 23% PHA (of cell dry weight) and following an efficacious pre-treatment process through adsorption on activated carbon, 100% pre-treated vinasse could be utilized leading to 30% accumulation of PHB by H. marismortui. Maximum specific growth rate, specific production rate, and volumetric productivity attained using 10% raw vinasse were comparable to that obtained using a previously reported nutrient deficient medium (NDM), while the values with 100% pre-treated vinasse were higher than that determined using NDM medium. This is the first report of polyhydroxybutyrate production by a halophilic microorganism utilizing vinasse.

A marine actinobacterium isolated from the Bay of Bengal, India and previously found to be producing an antimicrobial and cytotoxic terpenoid was further investigated for antimicrobial metabolites. The bacterium was preliminarily identified as a new species of the genus Streptomyces (strain MS1/7). The cell-free culture broth was extracted with n-butanol and purified using silica gel column chromatography and high-performance liquid chromatography. Molecular characterization was done using ESI mass, IR and 1H and 13C NMR spectrometry. 2-Allyloxyphenol (MW 150; C9H10O2), a synthetic drug and chemical intermediate, was obtained as a natural product for the first time. Serendipitous natural occurrence provided new insights into the synthetic molecule. 2-Allyloxyphenol was found to be inhibitory to 21 bacteria and three fungi in the minimum range 0.2-1.75 mg mL(-1) determined by agar dilution method. 2-Allyoxyphenol possesses strong antioxidant property (IC(50) 22 microg mL(-1), measured by 1, 1-diphenyl-2-picryl hydrazyl scavenging activity). Hydroxyl and allyloxy groups in 2-allyloxyphenol were responsible for antimicrobial and antioxidant activities. 2-Allyloxyphenol has marked resemblance to smoky aroma and is two to three times more active as an antimicrobial than some commercial smoke-flavour compounds. Absence of hemolytic toxicity, potential carcinogenicity, cytotoxicity and reports of toxic reactions in literature suggest possible application of 2-allyloxyphenol as a food preservative and an oral disinfectant.

This study investigates the in vitro antioxidant and antimicrobial activities of eight extracts obtained from the dried barks of Commiphora berryi and Commiphora caudata (Burseraceae). The radical scavenging activity was assessed by 1,1-diphenyl-2-picryl hydrazyl (DPPH) and nitric oxide assays. The methanolic extracts of C. berryi and C. caudata showed significant DPPH radical scavenging activity, with IC₅₀ values of 26.92 and 21.16 µg mL⁻¹, respectively, and low radical scavenging activity against the nitric oxide assay. The antimicrobial activity of the plants was tested against the Gram-positive and Gram-negative bacteria. The ethyl acetate, chloroform and petroleum ether extracts of C. berryi showed good antibacterial activity against Pseudomonas aeruginosa, with a minimum inhibitory concentration (MIC) of 0.26 mg mL⁻¹, whereas the ethyl acetate and methanol extracts of C. caudata showed moderate antimicrobial activity with an MIC of more than 2.0 mg mL⁻¹ against P. aeruginosa compared to the petroleum ether and chloroform extracts, which showed an MIC of 1.1 mg mL⁻¹. The methanolic extracts of C. berryi and C. caudata also showed moderate cytotoxic activity against a human mammary carcinoma cell line (MCF-7), with values IC₅₀ of 82.6 and 88.4 µg mL⁻¹, respectively.

A novel actinomycete producing 2-allyloxyphenol, designated strain MS1/7T , was isolated from sediments of the Sundarbans mangrove forest, India. Growth on International Streptomyces Project (ISP) media 2, 3, 4, 5 and 7 produced olive green to grey aerial hyphae that carried smooth-surfaced spores in a flexuous (Rectiflexibiles) arrangement. The strain contained LL-diaminopimelic acid, but no diagnostic sugars in whole-cell hydrolysates. Hexa-, octa-and a minor amount of tetra-hydrogenated menaquinones with nine isoprene units [MK-9 (H 4 , H 6 , H 8 and H 10 )] were present as isoprene analogues. Diagnostic phospholipids were phosphatidylethanolamine and diphosphatidylglycerol. The predominant fatty acids were anteiso-C 15 : 0 (34.80 %), iso-C 16 : 0 (16.45 %), C 16 (10.53 %) and anteiso-C 17 : 0 (10.92 %). The strain showed greater than 99 % 16S rRNA gene sequence similarity to the type strains of several recognized species of the genus Streptomyces, but in the phylogenetic tree based on 16S rRNA gene sequences it formed a distinct phyletic line and demonstrated closest relationships to viomycin-producers (Streptomyces californicus NRRL B-1221 T , Streptomyces floridae MTCC 2534 T and Streptomyces puniceus NRRL B-2895 T ). However, strain MS1/7 T could be distinguished from these and other closely related species based on low levels of DNA-DNA relatedness (,44 %) and disparate physiological features, principally amino acid utilization and growth in NaCl. Strain MS1/7 T is therefore suggested to represent a novel species of the genus Streptomyces, for which the name Streptomyces sundarbansensis sp. nov. is proposed. The type strain is MS1/7 T (5MTCC 10621 T 5DSM 42019 T ).Streptomycetes remain a rich source of novel bioactive compounds and, on the premise that poorly researched habitats can offer better prospects for discovering new natural products, actinomycetes from such habitats are currently the focus of considerable scientific interest. Poorly explored ecosystems such as estuarine mangroves have the potential to become a new resource for biological and chemical diversity, should salinity be a determinant of bacterial diversity (Hong et al., 2009). Our group (Saha et al., 2006) has described the purification of a bioactive compound (relative molecular weight 300.2 Da, predicted molecular formula C 20 H 28 O 2 ) from strain MS1/7 T isolated from the Sundarbans mangrove forest (the world's largest), India. To the authors' knowledge, the natural product 2-allyloxyphenol was obtained from this strain for the first time in any living organism (Arumugam et al., 2010). A study, based on a combination of genotypic and phenotypic methods, is reported here to determine the taxonomic position of strain MS1/7 T .Sediments from the Lothian Island of the Sundarbans mangrove forest (20 u 509 N 88 u 199 E) were collected in February 2001. Isolation was carried out by the standard dilution-plating technique on medium containing (per litre): 10.0 g starch, 3.0 g casein, 1.0 g peptone, 10.0 g malt extract, 0.5 g K 2 HPO 4 , 1...

No abstract

No abstract

An aqueous-methanolic [methanol:water (1:1)] extract of the whole plant of Artemisia pallens (Family: Asteraceae) has shown good antibacterial activity against Pseudomonas aeruginosa and Shigella flexneri at the concentration of 100 mg/mL. The activity-guided fractionation has led to isolation of compound 4-hydroxyphenyl-?-D-glucopyranoside (which is known as arbutin), as a major constituent and exhibited the same antibacterial activity at a concentration of 17 mg/mL. Both the crude extract and arbutin also showed 94% anticorrosive efficiency against mild steel in 1M HCl at concentration of 200 mg/L.

Iron (III) complexes of some smoke flavour compounds (2-allyloxyphenol, guaiacol, eugenol and 2-ethoxyphenol) were synthesised and characterised by UV-Vis spectroscopy and ESI mass spectrometry. The ligand metal binding ratio was found to be 1:1 by the Job plot method. Antimicrobial activity of the ligand iron complex was determined against Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. This activity was compared with that of the free ligand (four smoke flavour compounds). While enhanced antimicrobial activities of guaiacol and 2-ethoxyphenol iron complexes were observed, this effect was, however, limited for eugenol and 2-allyloxyphenol iron complexes. In this study, it was established for the first time that not only do smoke flavour compounds complex with iron which could potentially retard food spoilage, but also after complexation, some complexes attain antimicrobial activities compared to the inactive free ligands.