This study was focused on the polyhydroxybutyrate (PHB) accumulation property of Bacillus aryabhattai isolated from environment. Twenty-four polyhydroxyalkanoate (PHA) producers were screened out from sixty-two environmental bacterial isolates based on Sudan Black B colony staining. Based on their PHA accumulation property, six promising isolates were further screened out. The most productive isolate PHB10 was identified as B. aryabhattai PHB10. The polymer production maxima were 3.264 g/L, 2.181 g/L, 1.47 g/L, 1.742 g/L and 1.786 g/L in glucose, fructose, maltose, starch and glycerol respectively. The bacterial culture reached its stationary and declining phases at 18 h and 21 h respectively and indicated growth-associated PHB production. Nuclear Magnetic Resonance (NMR) spectra confirmed the material as PHB. The material has thermal stability between 30 and 140 °C, melting point at 170 °C and maximum thermal degradation at 287 °C. The molecular weight and poly dispersion index of the polymer were found as 199.7 kDa and 2.67 respectively. The bacterium B. aryabhattai accumulating PHB up to 75% of cell dry mass utilizing various carbon sources is a potential candidate for large scale production of bacterial polyhydroxybutyrate.

The soil metagenome derived L-asparaginase with enhanced activities could be a potential candidate to develop as a drug in Acute Lymphoblastic Leukemia (ALL) therapy.

L-Asparaginase, a therapeutic enzyme used in lymphoblastic leukemia and lymphosarcoma chemotherapy which is derived mostly from the bacterial sources Escherichia coli and Erwinia sp. The long term administration of the drug leads to the development of resistant tumours and anaphylactic shock in certain individuals. Hence serologically different L-Asparaginase from novel microbial sources with enhanced therapeutic potential and immunological characteristics is an essential requirement. The marine bacteria having diverse range of potential enzymes might be a source for L-Asparaginase with novel properties, which are still unexplored. In this study, we have screened marine bacteria isolated from the coastal regions of Kerala which showed both intra and extra cellular L-Asparaginase activity. Bacillus sp. (Accession no KF142395) was found to have the highest extracellular enzyme activity (2.31 IU/ml) while Shewanella sp. (Accession no KF142390) showed maximum intracellular Asparaginase activity (2.16 IU/ml).The crude extracellular enzyme preparation from Bacillus sp. had cytotoxic effect on HL60 cell line with an IC50 value of 12.5µg/ml.

Methylotrophs present in the soil play an important role in the regulation of one carbon compounds in the environment, and thereby aid in mitigating global warming. The study envisages the isolation and characterization of methanol-degrading bacteria from Kuttanad wetland ecosystem, India. Three methylotrophs, viz. Achromobacter spanius KUT14, Acinetobacter sp. KUT26 and Methylobacterium radiotolerans KUT39 were isolated and their phylogenetic positions were determined by constructing a phylogenetic tree based on 16S rDNA sequences. In vitro activity of methanol dehydrogenase enzyme, responsible for methanol oxidation was evaluated and the genes involved in methanol metabolism, mxaF and xoxF were partially amplified and sequenced. The specific activity of methanol dehydrogenase (451.9 nmol min mg) observed in KUT39 is the highest, reported ever to our knowledge from a soil bacterium. KUT14 recorded the least activity of 50.15 nmol min mg and is the first report on methylotrophy in A. spanius.