Limpon Bora

Optimization of extracellular thermophilic highly alkaline lipase from thermophilic Bacillus sp isolated from Hotspring of Arunachal Pradesh, India

Studies on lipase production were carried out with a bacterial strain (Bacillus sp LBN 2) isolated from soil sample of hotspring of Arunachal Pradesh, India. The cells were cultivated in a mineral medium with maximum production at 1% groundnut oil. The optimum temperature and initial medium pH for lipase production by the organism were 500C and 9.0 respectively. The molecular mass was found to be 33KDa by SDS PAGE. The optimal pH and temperature for activity were 10 and 600C respectively. The enzyme was found to be stable in the pH range of 8–11 with 90% retention of activity at pH 11. The enzyme retained 90% activity at 600C and 70% of activity at 700C for 1h. The lipase was found to be stable in acetone followed by ethanol. The present findings suggested the enzyme to be thermophilic alkaline lipase.

Characterization of novel phospholipase C from Bacillus licheniformis MTCC 7445 and its application in degumming of vegetable oils

A novel microbial phospholipase C (PLC) from Bacillus licheniformis MTCC 7445 was purified to homogeneity by ammonium sulphate fractionation, dialysis, anion exchange chromatography and gel exclusion chromatography. The bacteria growing on vegetable oils secreted significantly high amount of PLC. The enzyme was purified to 23.4-fold with 46% recovery and specific activity 398 U/mg. It exhibited optimum activity at 70°C and pH 10.0. Using diphosphatidylglycerol as substrate the PLC of B. licheniformis MTCC 7445 had a Vmax and Km of 0.68 mM/min and 32 mM, respectively. It hydrolyzed phosphatidylinositol and phosphatidylserine as well as phosphatidylcholine but not other glycerophospholipids. Its activity was enhanced by 113% with Mn2+ and 110% with Mg2+. During degumming of vegetable oils with this enzyme preparation, the phosphorus content of the oil became lower than 4 mg/kg after 5 h of enzyme treatment at 40°C. The novel PLC from B. licheniformis MTCC 7445 is potentially useful for the refining of high quality oils with 95% removal of phospholipids with attractive yield.

Anticandidal activity of medicinal plants and Pseudomonas aeruginosa strains of clinical specimens

This study was designed to investigate the in vitro anticandidal activity of some medicinal plants and Pseudomonas aeruginosa strains against Candida species. The antifungal activity of methanolic extracts of five medicinal plants, namely, Cinnamomum porrectum, Lippia nudiflora, Cestrum nocturnum, Trachyspermum ammi, and Sida carpinifolia were studied. The medicinal characteristics of these plants were compared with commercially used antibiotics. The antimicrobial assay was done by agar well diffusion and the broth dilution method. Among the plants used, T. ammi and C. nocturnum were found to be more potent than the others. Twenty P. aeruginosa strains were isolated from various clinical specimens. The total inhibitions obtained were found to be 47%, 38%, and 36% in blood agar, whereas in Sabouraud dextrose agar (SDA) the inhibitions were 57%, 48%, and 37%, respectively.

A novel melt stable and high tensile strength biopolymer (polyhydroxyalkanoates) from Bacillus megaterium (MTCC10086) and its characterization

In the present investigation, we have defined a novel biopolymer from Bacillus megaterium strain with novel melt stability, high tensile strength, and elongation to break properties higher to polypropylene and similar to polyethylene the polymers available commercially. The polymer was characterized with FTIR and XRD. The percent crystalinity was found to 44.09% with tensile strength 42 (Mpa) and elongation to break (%) 142 higher than polypropylene. The polymeric properties were confirmed by differential scanning calorimeter and universal testing.