Hydrolytic dehalogenation of the chlorothalonil isomer o-tetrachlorophthalonitrile by Pseudochrobactrum sp. BSQ-1

Abstract

Microbial dehalogenation plays key roles in the biodegradation and detoxification of halogenated aromatics. Although the hydrolytic dehalogenation of halogenated aliphatic hydrocarbons and carboxylic acids has been extensively studied, there are few reports on the hydrolytic dehalogenation of halogenated aromatics. In this study, the aerobic strain BSQ-1, isolated from soils contaminated with halogenated aromatics in Jiangsu, China, was able to completely degrade 0.12 mM o-tetrachlorophthalonitrile in 84 hours in the presence of 2 mM sodium acetate trihydrate and released one equivalent of chlorine ions. MS-MS and NMR analysis revealed that o-tetrachlorophthalonitrile was dehalogenated to 4-hydroxyl-o-trichlorophthalonitrile. The dehalogenation of o-tetrachlorophthalonitrile could occur under both aerobic and anaerobic conditions, showing that the observed dehalogenation was a hydrolytic process. The optimal temperature and pH for o-tetrachlorophthalonitrile dehalogenation by strain BSQ-1 were 30°C and 8, respectively. It was found that 0.2 mM Zn 2+ , Mg 2+ or Co 2+ enhanced dehalogenation activity, whereas 0.2 mM Fe 3+ , Ni 2+ , Cu 2+ , Ca 2+ , or Pb 2+ inhibited dehalogenation activity. Strain BSQ-1 was able to dehalogenate not only

Biotransformation of chlorothalonil by strain Stenotrophomonas acidaminiphila BJ1 isolated from farmland soil

“…The main metabolites mainly include hydroxy chlorohydrin, 3-methoxycarbonyl-2,4,5,6tetrachlorobenzeneacetamide, methyl-2,5,6-trichloro-3-cyano-4-methoxy-benzoate, methyl-3-cyano-2,4,5,6-tetrachlorobenzoate, 4-sulfydryl-2,5,6-trichloroisophthalonitrile, 2-chloro-4,6-disulfydryl-5chloromethylisophthalonitrile, 2-chloro-4-sulfydryl-5-chloromethylisophthalonitril, etc. [20,23,37]. Here in this study, two degradation products were found in the microcosms after 4 days of incubation.…”

Combined Microbial Consortium Inoculation and Black Locust Planting Is Effective in the Bioremediation of Waste Drill Cuttings

“…The dominant taxa that characterized the differences between bioremediation treatments and control included bacterial genera Pseudochrobactrum , Brevundimonas , and Bacillus and fungal genera Scedosporium , Stachybotrys , Microascus , and Acremonium . Pseudochrobactrum can degrade phenols ( Mao et al, 2015 ), halogenated aromatics ( Liu et al, 2016 ), and lignin ( Shannon et al, 2017 ), and Brevundimonas has the ability to degrade phenols ( Zhang et al, 2018 ). The dominant fungal genera have the ability to degrade lignin, cellulose, and PAHs ( Santos et al, 2006 ; López-González et al, 2015 ).…”

Biodegradation of Atrazine by the NovelKlebsiella variicolaStrain FH-1

“…These compounds were first weighed and dissolved in sterile water. The concentration of trace metal ions in the inorganic salt medium was set to 0.2 mM based on a previous study in order for bacteria to maintain their normal growth [25]. The pH value was adjusted to 7.0 in the inorganic salt medium with both FH-1 bacterial suspension (5%) and Atrazine (50 mg L –1 ) added.…”