title: Hydrogen and polyhydroxybutyrate producing abilities of microbes from diverse habitats by dark fermentative process.
abstract: Thirty five bacterial isolates from diverse environmental sources such as contaminated food, nitrogen rich soil, activated sludges from pesticide and oil refineries effluent treatment plants were found to belong to Bacillus, Bordetella, Enterobacter, Proteus, and Pseudomonas sp. on the basis of 16S rRNA gene sequence analysis. Under dark fermentative conditions, maximum hydrogen (H(2)) yields (mol/mol of glucose added) were recorded to be 0.68 with Enterobacter aerogenes EGU16 followed by 0.63 with Bacillus cereus EGU43 and Bacillus thuringiensis EGU45. H(2) constituted 63-69% of the total biogas evolved. Out of these 35 microbes, 18 isolates had the ability to produce polyhydroxybutyrate (PHB), which varied up to 500 mg/l of medium, equivalent to a yield of 66.6%. The highest PHB yield was recorded with B. cereus strain EGU3. Nine strains had high hydrolytic activities (zone of hydrolysis): lipase (34-38 mm) -Bacillus sphaericus strains EGU385, EGU399 and EGU542; protease (56-62 mm) -Bacillus sp. strains EGU444, EGU447 and EGU445; amylase (23 mm) -B. thuringiensis EGU378, marine bacterium strain EGU409 and Pseudomonas sp. strain EGU448. These strains with high hydrolytic activities had relatively low H(2) producing abilities in the range of 0.26-0.42 mol/mol of glucose added and only B. thuringiensis strain EGU378 had the ability to produce PHB. This is the first report among the non-photosynthetic microbes, where the same organism(s) -B. cereus strain EGU43 and B. thuringiensis strain EGU45, have been shown to produce H(2) - 0.63 mol/mol of glucose added and PHB - 420-435 mg/l medium.
authors: Microbial Biotechnology and Genomics, Institute of Genomics and Integrative Biology (IGIB), CSIR, Delhi University Campus, Mall Road, Delhi 110007, India.
authors: Shalini
authors: S
authors: Porwal
authors: Tarika
authors: T
authors: Kumar
authors: Sadhana
authors: S
authors: Lal
authors: Asha
authors: A
authors: Rani
authors: Sushil
authors: S
authors: Kumar
authors: Simrita
authors: S
authors: Cheema
authors: Hemant J
authors: HJ
authors: Purohit
authors: Rakesh
authors: R
authors: Sharma
authors: Sanjay Kumar
authors: SK
authors: Singh Patel
authors: Vipin Chandra
authors: VC
authors: Kalia
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D017753:Ecosystem; D021902:Enterobacter aerogenes / Q000235:genetics / Q000378:metabolism*; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism*; D007700:Kinetics; D016133:Polymerase Chain Reaction; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012242:Rhodobacter sphaeroides / Q000235:genetics / Q000378:metabolism; D012722:Sewage
chemical_list: D006885:Hydroxybutyrates; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D006859:Hydrogen