ORIGINAL PAPER Isolation and characterization of potential aerobic bacteria capable for pyridine degradation in presence of picoline, phenol and formaldehyde as co-pollutants Ram Chandra Æ Ram Naresh Bharagava Æ Atya Kapley Æ Hemant J. Purohit Received: 23 April 2009 / Accepted: 2 July 2009 / Published online: 16 July 2009 Ó Springer Science+Business Media B.V. 2009 Abstract Pyridine, heterocyclic aromatic compound is known to be toxic, carcinogenic and teratogenic to several living organisms. In this study, two aerobic bacteria ITR- CEM1 and ITRCEM2 capable for pyridine degradation were isolated and characterized as Bacillus cereus (DQ435020) and Alcaligenes faecalis (DQ435021), respectively. For pyridine degradation, mixed bacterial culture was found more effective compared to axenic culture ITRCEM1 and ITRCEM2 degrading 94.23, 67.84, and 83.35% pyridine, respectively, at 144 h incubation period at pH 7.0 ± 0.1, temp 37 ± 2°C and shaking rate 125 rpm in MSM con- taining 1% glucose and 0.2% peptone as carbon and nitrogen source, respectively. The presence of phenol and formalde- hyde in MSM has shown inhibitory effect on pyridine deg- radation whereas picoline has favored the bacterial growths and pyridine degradation. Further, the HPLC analysis has shown the reduction in peaks compared to controls, indi- cating that reduction in peak area might be largely attributed to the bacterial degradation of pyridine by bacterial catabolic enzymes. Keywords Pyridine Á Phenol Á Formaldehyde Á Degradation Á Bacillus cereus Á Alcaligenes faecalis Introduction Pyridine is an N-heterocyclic aromatic compound and a weak organic base, with unpleasant odour, high water solubility and high volatility. It is used as an industrial solvent especially for dehydrochlorination reaction and has potential applications in manufacturing of dyes, explosives, pesticides and pharmaceuticals (Mudliar et al. 2008). Pyr- idine and its derivatives are known to be toxic, carcino- genic and teratogenic to several living organisms (Padoley et al. 2006; Jori et al. 1983). In environment, it is discharged with effluents from different industries such as pharmaceuticals, dyes, pesti- cides and herbicides manufacture, shale oil processing, food processing and coal carbonization and causes severe odour problems as well as exhibits moderate to acute toxicity (Padoley et al. 2006; Mohan et al. 2003). The United States Environmental Protection Agency (USEPA) has listed pyridine as one of the major organic pollutants (Richards and Shieth 1986). Therefore, industrial waste- waters containing pyridine must be treated before dis- charging into the environment to prevent the damage to natural ecosystems. Various physico-chemical methods such as activated carbon adsorption, chemical oxidation, incineration and aqueous oxidation are being used for the treatment of various types of industrial wastes, but these methods of treatment are energy intensive, require high capital and operating costs and also generate secondary waste streams (Padoley et al. 2006; Mudliar et al. 2008). Alternatively, biological treatment process has been accepted as one of the most feasible and eco-friendly methods requiring low capital and operating cost and also the treatment results information of innocuous products. Authors have reported the biodegradation of pyridine and its derivatives under aerobic, anaerobic and anoxic R. Chandra (&) Á R. N. Bharagava Environmental Microbiology Section, Indian Institute of Toxicology Research (CSIR), Post Box No. 80, M.G. Marg, Lucknow, Uttar Pradesh 226 001, India e-mail: ramchandra_env@indiatimes.com; rc_microitrc@yahoo.co.in A. Kapley Á H. J. Purohit Environmental Genomics Unit, National Environmental Engineering Research Institute (CSIR), Nehru Marg, Nagpur, Maharashtra 440020, India 123 World J Microbiol Biotechnol (2009) 25:2113–2119 DOI 10.1007/s11274-009-0114-3