Enhanced biosurfactant production through cloning of three genes and role of esterase in biosurfactant release

<p>Abstract</p> <p>Background</p> <p>Biosurfactants have been reported to utilize a number of immiscible substrates and thereby facilitate the biodegradation of panoply of polyaromatic hydrocarbons. Olive oil is one such carbon source which has been explored by many researchers. However, studying the concomitant production of biosurfactant and esterase enzyme in the presence of olive oil in the <it>Bacillus </it>species and its recombinants is a relatively novel approach.</p> <p>Results</p> <p><it>Bacillus </it>species isolated from endosulfan sprayed cashew plantation soil was cultivated on a number of hydrophobic substrates. Olive oil was found to be the best inducer of biosurfactant activity. The protein associated with the release of the biosurfactant was found to be an esterase. There was a twofold increase in the biosurfactant and esterase activities after the successful cloning of the biosurfactant genes from <it>Bacillus subtilis </it>SK320 into <it>E.coli. </it>Multiple sequence alignment showed regions of similarity and conserved sequences between biosurfactant and esterase genes, further confirming the symbiotic correlation between the two. Biosurfactants produced by <it>Bacillus subtilis </it>SK320 and recombinant strains <it>BioS a, BioS b, BioS c </it>were found to be effective emulsifiers, reducing the surface tension of water from 72 dynes/cm to as low as 30.7 dynes/cm.</p> <p>Conclusion</p> <p>The attributes of enhanced biosurfactant and esterase production by hyper-producing recombinant strains have many utilities from industrial viewpoint. This study for the first time has shown a possible association between biosurfactant production and esterase activity in any <it>Bacillus </it>species. Biosurfactant-esterase complex has been found to have powerful emulsification properties, which shows promising bioremediation, hydrocarbon biodegradation and pharmaceutical applications.</p

Environmental Applications of Biosurfactants: Recent Advances

Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as hydrocarbons and metals. An alternative and eco-friendly method of remediation technology of environments contaminated with these pollutants is the use of biosurfactants and biosurfactant-producing microorganisms. The diversity of biosurfactants makes them an attractive group of compounds for potential use in a wide variety of industrial and biotechnological applications. The purpose of this review is to provide a comprehensive overview of advances in the applications of biosurfactants and biosurfactant-producing microorganisms in hydrocarbon and metal remediation technologies

Emulsification and Hydrolysis of Oil by Syncephalastrum racemosum

A fungal strain, Syncephalastrum racemosum, was isolated from oil-leak contaminated soils from Kanpur, India. The strain was examined for potential to emulsify soybean oil using a 18 per cent oil supplement as carbon source in minimal salt medium. On 72 h growth of the fungus in oil and salt medium, the cellfree supernatant (CFS) showed presence of mono- and di-glycerides indicating degradation of oils to free fatty acids (FFAs). Increasing concentration of oil resulted in enhanced formation of FFAs. The degradation process was observed to be related to the emulsification activity in CFS which was observed to increase with time. The study reports the emulsification and hydrolytic activity of S. racemosum, an activity that can be exploited for increasing the accessibility and treatment of hazardous substance including hydrophobic explosives.Defence Science Journal, 2010, 60(3), pp.251-254, DOI:http://dx.doi.org/10.14429/dsj.60.35

Biogenic selenium nanoparticles induce ROS-mediated necroptosis in PC-3 cancer cells through TNF activation

Abstract Background Selenium is well documented to inhibit cancer at higher doses; however, the mechanism behind this inhibition varies widely depending on the cell type and selenium species. Previously, we have demonstrated that Bacillus licheniformis JS2 derived biogenic selenium nanoparticles (SeNPs) induce non-apoptotic cell death in prostate adenocarcinoma cell line, PC-3, at a minimal concentration of 2 µg Se/ml, without causing toxicity to the primary cells. However, the mechanism behind its anticancer activity was elusive. Results Our results have shown that these SeNPs at a concentration of 2 µg Se/ml were able to induce reactive oxygen species (ROS) mediated necroptosis in PC-3 cells by gaining cellular internalization. Real-time qPCR analysis showed increased expression of necroptosis associated tumor necrotic factor (TNF) and interferon regulatory factor 1 (IRF1). An increased expression of RIP1 protein was also observed at the translational level upon SeNP treatment. Moreover, the cell viability was significantly increased in the presence of necroptosis inhibitor, Necrostatin-1. Conclusion Data suggest that our biogenic SeNPs induce cell death in PC-3 cells by the ROS-mediated activation of necroptosis, independent to RIP3 and MLKL, regulated by a RIP1 kinase