Production of catalases byComamonas spp. and resistance to oxidative stress

Abstract

Bacterial isolates Comamonas terrigena N3H (from soil contaminated with crude oil) and C. testosteroni (isolated from the sludge of a wastewater treatment plant), exhibit much higher total catalase activity than the same species from laboratory collection cultures. Electrophoretic resolution of catalases revealed only one corresponding band in cell-free extracts of both C. testosteroni cultures. Isolates of C. terrigena N3H exhibited catalase-1 and catalase-2 activity, whereas in the collection culture C. terrigena ATCC 8461 only catalase-1 was detected. The environmental isolates exhibited much higher resistance to exogenous H2O2 (20, 40 mmol/L) than collection cultures, mainly in the middle and late exponential growth phases. The stepwise H2O2-adapted culture of C. terrigena N3H, which was more resistant to oxidative stress than the original isolate, exhibited an increase of catalase and peroxidase activity represented by catalase-1. Pretreatment of cells with 0.5 mmol/L H2O2 followed by an application of the oxidative agent in toxic concentrations (up to 40 mmol/L) increased the rate of cell survival in the original isolate, but not in the H2O2-adapted variant. The protection of bacteria caused by such pretreatment corresponded with stimulation of catalase activity in pretreated culture.

Permanent draft genome sequence of Comamonas testosteroni KF-1

“…Members of the genus Comamonas are able to cope with harsh environmental conditions such as high concentrations of arsenate [50,51], zinc [52], cobalt and nickel [53], or phenol [54], and can exhibit increased resistance to oxidative stress [55] or antibiotics [56]. Another C.…”

Efeito dos herbicidas ametrina e clomazone no sitema antioxidante bacteriano

“…Diversas bactérias quando expostas a xenobióticos aumentam a atividade de CAT para combater o estresse oxidativo. A bactéria Comamonas terrigena N3H é conhecida por sua ampla diversidade catabólica em degradar diferentes xenobióticos; isoladas de solos contaminados com hidrocarbonetos, Comamonas terrigena N3H apresentou alta atividade de catalase em relação a mesma espécie isolada de solos não contaminados(GODOCIKOVA et al, 2005).Entretanto, as catalases são essenciais não somente para a proteção contra o estresse oxidativo, mas também são importantes por participarem de alterações metabólicas sobre substâncias tóxicas por meio das suas reações peroxidativas(BUCKOVA et al, 2010). A espécie C. terrigena N3H não possui a enzima chave (fenolhidroxilase) para a degradação de fenóis, no…”