title: Enhanced biosurfactant production through cloning of three genes and role of esterase in biosurfactant release.
abstract: BACKGROUND
  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 Bacillus species and its recombinants is a relatively novel approach.
  
  
  RESULTS
  Bacillus 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 Bacillus subtilis SK320 into E.coli. 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 Bacillus subtilis SK320 and recombinant strains BioS a, BioS b, BioS c were found to be effective emulsifiers, reducing the surface tension of water from 72 dynes/cm to as low as 30.7 dynes/cm.
  
  
  CONCLUSIONS
  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 Bacillus species. Biosurfactant-esterase complex has been found to have powerful emulsification properties, which shows promising bioremediation, hydrocarbon biodegradation and pharmaceutical applications.
authors.affiliation: Department of Biotechnology and Environmental Sciences, Thapar University, Patiala-147001, Punjab, India. kamalsekhon80@yahoo.com
authors.forename: Kamaljeet Kaur
authors.initials: KK
authors.lastname: Sekhon
authors.forename: Sunil
authors.initials: S
authors.lastname: Khanna
authors.forename: Swaranjit Singh
authors.initials: SS
authors.lastname: Cameotra
mesh_terms: D001407:Bacillus / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001673:Biodegradation, Environmental; D003001:Cloning, Molecular; D045703:Emulsifying Agents / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D004950:Esterases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000069463:Olive Oil; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism; D010938:Plant Oils / Q000737:chemistry; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D045703:Emulsifying Agents; D000069463:Olive Oil; D010938:Plant Oils; D011994:Recombinant Proteins; D013501:Surface-Active Agents; D004950:Esterases; D010453:Peptide Synthases; C069542:surfactin synthetase