http://192.168.1.40:8080/xmlui/handle/123456789/1149 2026-05-31T13:44:03Z http://192.168.1.40:8080/xmlui/handle/123456789/2413 Origin, occurrence, and biodegradation of long-side-chain alkyl compounds in the environment: A review Dutta, Tapan K. Long-side-chain alkyl compounds, such as those present in oil and oil products, either of natural or of anthropogenic origin or released by industrial activities, are a ubiquitous group of chemicals in the environment. Among them, long-side-chain alkylmonocycloalkanes, alkylbenzenes, and alkyl organic sulfur compounds are largely found in fossil fuels while long-side-chain alkylbenzene sulfonates and alkylphenols are released into the environment primarily due to domestic activities. The present article briefly summarizes the advances that have occurred in this field in terms of the identity, abundance, possible origin and significance of these long-side-chain alkyl compounds found in the environment. In addition, the susceptibility to biodegradation and the fate of these chemicals in the environment are discussed. DOI: 10.1007/s10653-004-0158-0 2005-09-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2412 Pathways in the degradation of hydrolyzed alcohols of butyl benzyl phthalate in metabolically diverse Gordonia sp. strain MTCC 4818 Chatterjee, S.; Mallick, S.; Dutta, Tapan K. In the present study, the metabolic pathways involved in the degradation of benzyl alcohol and 1-butanol, the hydrolyzed products of butyl benzyl phthalate, were investigated by the Gordonia sp. strain MTCC 4818. The strain can utilize both benzyl alcohol and 1-butanol individually as sole carbon sources, where benzyl alcohol was found to be metabolized via benzaldehyde, benzoic acid and catechol, which was further degraded by ortho cleavage dioxygenase to cis,cis-muconic acid and subsequently to muconolactone leading to tricarboxylic acid cycle. On the other hand, 1-butanol was metabolized via butyraldehyde and butyric acid, which was channeled into the tricarboxylic acid cycle via the beta-oxidation pathway. Numbers of dehydrogenases, both NAD(+)-dependent and NAD(+)-independent, were found to be involved in the degradation of benzyl alcohol and 1-butanol, where several dehydrogenases exhibited relaxed substrate specificity. Both 2,3- and 3,4-dihydroxybenzoic acids were utilized by the test organism for growth and metabolized by the ortho-cleavage pathway by the cell-free extract of benzoate-grown cells, similar to catechol, suggesting possible broad substrate specificity of the ring cleavage dioxygenase. Moreover, the test organism can utilize various primary and secondary alcohols, aliphatic aldehydes and acids in the C-2-C-5 range besides n-hexadecane, 1,4-butanediol and cyclohexanol individually as the sole carbon sources indicating metabolic diversity in the Gordonia sp. strain MTCC 4818. DOI: 10.1159/000088841 2005-01-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2169 Isolation of a Pseudomonas sp capable of utilizing 4-nonylphenol in the presence of phenol Chakraborty, Joydeep; Dutta, Tapan K. Enrichment techniques led to the isolation of a Pseudomonas sp. strain P2 from municipal waste-contaminated soil sample, which could utilize different isomers of a commercial mixture of 4-nonylphenol when grown in the presence of phenol. The isolate was identified as Pseudomonas sp., based on the morphological, nutritional, and biochemical characteristics and 16S rDNA sequence analysis. The beta-ketoadipate pathway was found to be involved in the degradation of phenol by Pseudomonas sp. strain P2. Gas chromatography-mass spectrometric analysis of the culture media indicated degradation of various major isomers of 4-nonylphenol in the range of 29-50%. However, the selected ion monitoring mode of analysis of biodegraded products of 4-nonylphenol indicated the absence of any aromatic compounds other than those of the isomers of 4-nonylphenol. Moreover, Pseudomonas sp. strain P2 was incapable of utilizing various alkanes individually as sole carbon source, whereas the degradation of 4-nonylphenol was observed only when the test organism was induced with phenol, suggesting that the degradation of 4-nonylphenol was possibly initiated from the phenolic moiety of the molecule, but not from the alkyl side-chain. 2006-11-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2153 A novel degradation pathway in the assimilation of phenanthrene by Staphylococcus sp strain PN/Y via meta-cleavage of 2-hydroxy-1-naphthoic acid: formation of trans-2,3-dioxo-5-(2 '-hydroxyphenyl)pent-4-enoic acid Mallick, S.; Chatterjee, S.; Dutta, Tapan K. Staphylococcus sp. strain PN/Y, capable of utilizing phenanthrene as a sole source of carbon and energy, was isolated from petroleum-contaminated soil. In the degradation of phenanthrene by strain PN/Y, various metabolites, isolated and identified by a combination of chromatographic and spectrometric analyses, revealed a novel phenanthrene assimilation pathway involving 2-hydroxy- 1-naphthoic acid. Metabolism of phenanthrene was initiated by the dioxygenation on the 1,2-position of phenanthrene followed by meta-cleavage of phenanthrene-1,2-diol, leading to 2-hydroxy-1-naphthoic acid, which was then processed via a novel meta-cleavage pathway, leading to the formation of trans-2,3-dioxo-5-(2′-hydroxyphenyl)-pent-4-enoic acid and subsequently to salicylic acid. In the lower pathway, salicylic acid was transformed to catechol, which was then metabolized by catechol-2,3-dioxygenase to 2-hydroxymuconaldehyde acid, ultimately forming TCA cycle intermediates. The catabolic genes involved in phenanthrene degradation were found to be plasmid-encoded. This detailed study of polycyclic aromatic hydrocarbon (PAH) metabolism by a Gram-positive species involving a unique ring-cleavage dioxygenase in a novel phenanthrene degradation pathway provides a new insight into the microbial degradation of PAHs. DOI: 10.1099/mic.0.2006/004218-0 2007-07-01T00:00:00Z