title: Screening and isolation of halophilic bacteria producing industrially important enzymes.
abstract: Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of the study was to isolate and study the diversity among halophilic bacteria producing enzymes of industrial value. Screening of halophiles from various saline habitats of India led to isolation of 108 halophilic bacteria producing industrially important hydrolases (amylases, lipases and proteases). Characterization of 21 potential isolates by morphological, biochemical and 16S rRNA gene analysis found them related to Marinobacter, Virgibacillus, Halobacillus, Geomicrobium, Chromohalobacter, Oceanobacillus, Bacillus, Halomonas and Staphylococcus genera. They belonged to moderately halophilic group of bacteria exhibiting salt requirement in the range of 3-20%. There is significant diversity among halophiles from saline habitats of India. Preliminary characterization of crude hydrolases established them to be active and stable under more than one extreme condition of high salt, pH, temperature and presence of organic solvents. It is concluded that these halophilic isolates are not only diverse in phylogeny but also in their enzyme characteristics. Their enzymes may be potentially useful for catalysis under harsh operational conditions encountered in industrial processes. The solvent stability among halophilic enzymes seems a generic novel feature making them potentially useful in non-aqueous enzymology.
authors.affiliation: Department of Chemistry, Indian Institute of Technology , Delhi, New Delhi , India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Kumar
authors.forename: Ram
authors.initials: R
authors.lastname: Karan
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kapoor
authors.forename: Singh
authors.initials: S
authors.lastname: S P
authors.forename: Khare
authors.initials: K
authors.lastname: S K
keywords: Biodiversity; Halophiles; Halophilic enzymes; Hydrolases; Solvent-stable.
references.citation: Int J Syst Bacteriol. 1992 Oct;42(4):568-76
references.pmid: 1382536
references.citation: FEMS Microbiol Lett. 2001 Dec 18;205(2):291-7
references.pmid: 11750818
references.citation: Microb Ecol. 2008 Feb;55(2):163-72
references.pmid: 17604989
references.citation: FEMS Microbiol Ecol. 2009 Apr;68(1):59-71
references.pmid: 19187212
references.citation: J Basic Microbiol. 2008 Jun;48(3):160-7
references.pmid: 18506896
references.citation: J Microbiol Methods. 2003 Mar;52(3):353-9
references.pmid: 12531504
references.citation: J Ind Microbiol Biotechnol. 2009 Mar;36(3):333-40
references.pmid: 19037673
references.citation: Nucleic Acids Res. 1997 Sep 1;25(17):3389-402
references.pmid: 9254694
references.citation: Agric Biol Chem. 1991 Sep;55(9):2251-8
references.pmid: 1368737
references.citation: J Appl Microbiol. 2003;94(2):295-300
references.pmid: 12534822
references.citation: Environ Technol. 2010 Sep;31(10):1061-72
references.pmid: 20718288
references.citation: Curr Microbiol. 2010 Mar;60(3):157-61
references.pmid: 19826862
references.citation: Biotechnol Bioeng. 1997 Aug 5;55(3):471-9
references.pmid: 18636512
references.citation: J Agric Food Chem. 2010 Jan 13;58(1):248-56
references.pmid: 19938835
references.citation: FEMS Microbiol Ecol. 2002 Jan 1;39(1):1-7
references.pmid: 19709178
references.citation: BMC Microbiol. 2007 Aug 10;7:77
references.pmid: 17692114
references.citation: Extremophiles. 2005 Feb;9(1):85-9
references.pmid: 15378403
references.citation: Int J Syst Evol Microbiol. 2010 Apr;60(Pt 4):990-995
references.pmid: 19666816
references.citation: J Comput Biol. 2000 Feb-Apr;7(1-2):203-14
references.pmid: 10890397
references.citation: Int J Syst Evol Microbiol. 2003 Sep;53(Pt 5):1383-1387
references.pmid: 13130022
references.citation: Int J Syst Evol Microbiol. 2007 Oct;57(Pt 10):2259-2261
references.pmid: 17911292
references.citation: FEMS Microbiol Lett. 2000 Feb 1;183(1):67-71
references.pmid: 10650204
references.citation: Crit Rev Biotechnol. 2009;29(1):44-54
references.pmid: 19514902
references.citation: Microbiol Mol Biol Rev. 1998 Jun;62(2):504-44
references.pmid: 9618450