Localization of HCH catabolic genes (lin genes) in Sphingobium indicum B90A

Abstract

The locations of hexachlorocyclohexane (HCH) catabolic (lin) genes were investigated in HCH degrading sphingomonad, Sphingobium indicum B90A (that was isolated from India). Southern blot analysis revealed the presence of linA1, linC, linDER and linX (linX1 and linX2) on the plasmid DNA in Sphingobium indicum B90A.

Pseudomonas sp. to Sphingobium indicum: a journey of microbial degradation and bioremediation of Hexachlorocyclohexane

“…Purifi ed preparation of LinB of B90A not only transformed β-HCH in the fi rst step almost 50 times faster than that of UT26 but it also transformed δ-HCH to corresponding mono and dihydroxylated metabolites that were identifi ed as respective pentachlorocyclohexanols and tetrachlorocyclohexandiols [62]. This is in contrast to LinB of UT26 [60] and Sp+ [62] that did not transform pentachlorocyclohenaols. Until this time it was not clear why the β-and δ-HCH degradation differed so markedly among B90A, Sp+ and UT26.…”

“…However, it became clear from subsequent studies [60] that UT26 also degrades β-HCH albeit at lower rates. This was perhaps one of the reasons that the degradation of β-HCH by UT26 and Sp+ could not be initially noticed.…”

“…This was perhaps one of the reasons that the degradation of β-HCH by UT26 and Sp+ could not be initially noticed. It was the Japanese group [60] who for the fi rst time reported that LinB (haloalkane dehalogenase) encoded by linB of UT26 is responsible for the initial transformation of β-HCH to pentachlorocyclohexanol (PCCH), a product that was not degraded further. Although purifi ed preparation of LinB of strain UT26 transformed β-HCH to PCCH, crude cell incubation with strain UT26 had no affect on β-HCH transformation [60].…”

“…It was the Japanese group [60] who for the fi rst time reported that LinB (haloalkane dehalogenase) encoded by linB of UT26 is responsible for the initial transformation of β-HCH to pentachlorocyclohexanol (PCCH), a product that was not degraded further. Although purifi ed preparation of LinB of strain UT26 transformed β-HCH to PCCH, crude cell incubation with strain UT26 had no affect on β-HCH transformation [60]. However, this was in contrast to B90A that was repeatedly found to degrade β-HCH [7,8,46,61].…”

Genomic tools in bioremediation

“…A large number of bacteria/biodegradation by sludge, have been reported for degradation of different industrial wastes, such as dyes [7], hydrocarbons, especially related to petrochemical wastes [8][9][10], tanneries [11], chlorinated aromatics [12], distillery [13], pesticides [14][15][16][17][18], heavy metals [19]. Similarly, there are phenomenon such as chemotaxis and its relevance in bioremediation has been reported using pure culture system in a model study [20].…”