Biodegradation of chlorphyrifos byKlebsiella sp. isolated from an activated sludge sample of waste water treatment plant in damascus

Abstract

A chlorpyrifos (CPY)-degrading bacterial strain was isolated from an activated sludge sample collected from the Damascus Wastewater Treatment Plant, Syria. The isolation of Klebsiella sp. was facilitated by the addition of CPY at a rate of 3.84 g/L of sludge weekly (selection pressure). Identification of Klebsiella sp. was done using major staining and biochemical differentiation tests (Gram stain, cytochrome oxidase and some relevant saccharide fermentation tests using biochemical assays). Klebsiella sp. was maintained by culturing in a poor medium consisting of mineral salts and CPY as the sole carbon source. When 3 activated sludge samples were incubated in the presence of CPY (13.9 g/L sludge), 46% of added CPY were degraded within 4 d. By comparison, within 4 d the isolated Klebsiella sp. was found to break down 92% of CPY when co-incubated in a poor mineral medium in which CPY was the sole carbon source (13.9 g/L poor medium). Isolated Klebsiella sp. was able to tolerate up to 17.3 g of CPY in the poor medium.

Chlorpyrifos: pollution and remediation

“…Klebsiella sp. obtained from activated sludge sample of wastewater treatment plant in Damascus was reported to degrade 92 % chlorpyrifos in 4 days (Ghanem et al 2007). 100 % degradation of 100 mg L -1 chlorpyrifos has been observed using different bacteria including Sphingomonas, Stenotrophomonas, Bacillus sp., Brevundimonas, and Pseudomonas sp.…”

Biodegradation of chlorpyrifos by bacterial consortium isolated from agriculture soil

“…was isolated. The isolate was able to utilize chlorpyrifos as a sole source of carbon (Ghanem et al 2007). A bacterial consortium was developed from pesticide-contaminated soil of Punjab consisting of Pseudomonas aeruginosa, Bacillus cereus, Klebsiella sp and Serratia marscecens, that could successfully degrade chlorpyrifos (Lakshmi et al 2009).…”

Biodegradation of chlorpyrifos and its hydrolysis product 3,5,6-trichloro-2-pyridinol using a novel bacterium Ochrobactrum sp. JAS2: A proposal of its metabolic pathway

“…The bacterial species capable of degrading chlorpyrifos in liquid media belong to the genera Enterobacter, Klebsiella, Providencia, Pseudomonas, Leuconostoc, Lactobacillus, Serratia and Synechocystis [26][27][28][29][30][31]. To our knowledge, this is the first report for biodegradation of chlorpyrifos by Ochrobactrum sp.…”