title: Biodegradation of 2-hydroxyquinoxaline (2-HQ) by Bacillus sp.
abstract: An aerobic Gram +ve bacterial strain capable of utilizing 2-Hydroxyquinoxaline (2-HQ) as sole source of carbon and energy was isolated from Chrysanthemum indicum Indian agricultural soil and named as HQ2. On the basis of morphology, physico-biochemical characteristics and 16S rRNA sequence analysis, strain HQ2 was identified as Bacillus sp. The generation time of Bacillus sp. in log phase during growth on 2-HQ is 0.79 h or 47.4 min. The optimal conditions for 2-HQ degradation by Bacillus sp. were inoculum density of 1.0 OD, pH of 6-8, temperature of 37-45 °C and 2-HQ concentration of 500 ppm. Among the additional carbon and nitrogen sources, carbon sources did not influence the degradation rate of 2-HQ, but nitrogen sources-yeast extract marginally enhanced the rate of degradation of 2-HQ. GC-MS analysis of the culture Bacillus sp. grown on 2-HQ indicated the formation of dimers from 2 molecules of 2-hydroxyquinoxaline. The formation of dimer for degradation of 2-HQ by the culture appears to be the first report to our scientific knowledge.
authors: Department of Microbiology, Sri Krishnadevaraya University, Anantapuram - 515 003, A.P., India; Faculty of Science, Department of Biochemistry, University of Johannesburg, PO Box-524, APK Campus, Johannesburg 2006, South Africa. Electronic address: visitsubbu@gmail.com.
authors: G V Subba
authors: GV
authors: Reddy
authors: Department of Microbiology, Sri Krishnadevaraya University, Anantapuram - 515 003, A.P., India.
authors: B R
authors: BR
authors: Reddy
authors: Faculty of Science, Department of Biochemistry, University of Johannesburg, PO Box-524, APK Campus, Johannesburg 2006, South Africa.
authors: M G
authors: MG
authors: Tlou
mesh_terms: D001407:Bacillus / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001483:Base Sequence; D001673:Biodegradation, Environmental; D019281:Dimerization; D008969:Molecular Sequence Data; D010802:Phylogeny; D011810:Quinoxalines / Q000737:chemistry / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D011810:Quinoxalines; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; C098565:2-hydroxyquinoxaline
keywords: 16S rRNA sequence analysis; 2-Hydroxyquinoxaline; Bacillus sp.; GC-MS analysis