Sikandar I. Mulla

Publications (7) View all

• Article: Enhanced degradation of 3-nitrobenzoate by immobilized cells of Bacillus flexus strain XJU-4

  Sikandar I. Mulla, Manjunatha P. Talwar, Robertcyril S. Hoskeri, Harichandra Z. Ninnekar
  Biotechnology and Bioprocess Engineering 12/2012; · 1.28 Impact Factor
• Article: Enhanced degradation of 2-nitrotoluene by immobilized cells of Micrococcus sp. strain SMN-1.

  Sikandar I Mulla, Manjunatha P Talwar, Zabin K Bagewadi, Robertcyril S Hoskeri, Harichandra Z Ninnekar
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  ABSTRACT: Nitrotoluenes are the toxic pollutants of the environment because of their large scale use in the production of explosives. Biodegradation of such chemicals by microorganisms may provide an effective method for their detoxification. We have studied the degradation of 2-nitrotoluene by cells of Micrococcus sp. strain SMN-1 immobilized in various matrices such as polyurethane foam (PUF), sodium alginate (SA), sodium alginate-polyvinyl alcohol (SA-PVA), agar and polyacrylamide. The rate of degradation of 15 and 30mM 2-nitrotoluene by freely suspended cells and immobilized cells in batches and fed-batch with shaken cultures were compared. The PUF-immobilized cells achieved higher degradation of 15 and 30mM 2-nitrotoluene than freely suspended cells and the cells immobilized in SA-PVA, polyacrylamide, SA and agar. The PUF-immobilized cells could be reused more than 24cycles without loosing their degradation capacity and showed more tolerance to pH and temperature changes than freely suspended cells. These results revealed the enhanced rate of degradation of 2-nitrotoluene by PUF-immobilized cells of Micrococcus sp. strain SMN-1.
  Chemosphere 11/2012; · 3.21 Impact Factor
• Article: Biodegradation of 3-Nitrobenzoate by Bacillus flexus strain XJU-4

  Sikandar I. Mulla, T. P. Manjunatha, Robertcyril S. Hoskeri, Preeti N. Tallur, Harichandra Z. Ninnekar
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  ABSTRACT: Bacillus flexus strain XJU-4 utilized 3-nitrobenzoate at 12mM as a sole source of carbon and energy. This strain also utilized 4-nitrobenzoate, 2-nitrotoluene and nitrobenzene as growth substrates. The optimum conditions for degradation of 3-nitrobenzoate by the organism were found to be at pH 7.0 and temperature 30°C. Metabolite analysis, growth and enzymatic studies have revealed that the organism degraded 3-nitrobenzoate by oxidative mechanism through protocatechuate with the release of nitrite. The cells grown on 3-nitrobenzoate utilized protocatechuate but not 3-hydroxybenzoate, 3-aminobenzoate, 4-hydroxy-3-nitrobenzoate and 4-nitrocatechol. The cell-free extract of Bacillus flexus strain XJU-4 grown on 3-nitrobenzoate contained the activity of protocatechuate 2,3-dioxygenase, which suggest that protocatechuate was further degraded by a novel 2,3-dioxygenative meta-cleavage pathway. KeywordsDegradation– Bacillus flexus strain XJU-4–3-Nitrobenzoate–Protocatechuate
  World Journal of Microbiology and Biotechnology 04/2012; 27(7):1587-1592. · 1.53 Impact Factor
• Article: Biodegradation of 2-nitrotoluene by Micrococcus sp. strain SMN-1.

  Sikandar I Mulla, Robertcyril S Hoskeri, Yogesh S Shouche, Harichandra Z Ninnekar
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  ABSTRACT: A bacterial consortium capable of degrading nitroaromatic compounds was isolated from pesticide-contaminated soil samples by selective enrichment on 2-nitrotoluene as a sole source of carbon and energy. The three different bacterial isolates obtained from bacterial consortium were identified as Bacillus sp. (A and C), Bacillus flexus (B) and Micrococcus sp. (D) on the basis of their morphological and biochemical characteristics and by phylogenetic analysis based on 16S rRNA gene sequences. The pathway for the degradation of 2-nitrotoluene by Micrococcus sp. strain SMN-1 was elucidated by the isolation and identification of metabolites, growth and enzymatic studies. The organism degraded 2-nitrotoluene through 3-methylcatechol by a meta-cleavage pathway, with release of nitrite.
  Biodegradation 02/2011; 22(1):95-102. · 2.02 Impact Factor
• Article: Bacterial degradation of fungicide captan.

  Veena B Megadi, Preeti N Tallur, Sikandar I Mulla, Harichandra Z Ninnekar
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  ABSTRACT: The phthalimide fungicide captan has been widely used to control plant pathogenic fungi. A strain of Bacillus circulans utilized the fungicide captan as sole source of carbon and energy. The organism degraded captan by a pathway involving its initial hydrolysis to yield cis-1,2,3,6-tetrahydrophthalimide, a compound without fungicidal activity. The formation of this compound was confirmed by HPLC, IR, NMR, and mass spectral analysis. The results also revealed that cis-1,2,3,6-tetrahydrophthalimide was further degraded to o-phthalic acid by a protocatechuate pathway. These findings indicated that there was a complete mineralization of fungicide captan by B. circulans.
  Journal of Agricultural and Food Chemistry 12/2010; 58(24):12863-8. · 2.82 Impact Factor