A novel cyhalothrin-degrading strain, designated as LM-6T, was isolated from a cyhalothrin contaminated wastewater sample. The bacterium was found to be Gram stain-negative, non-spore-forming, vibrio-shaped, and motile with a single polar flagellum. Strain LM-6T was observed to grow optimally at 28–30 °C, pH 6.0 and in the absence of NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain LM-6T is a member of the genus Ferrovibrio, and showed the highest sequence similarity with Ferrovibrio denitrificans Sp-1T (97.7 %), followed by Taonella mepensis H1T (93.3 %). The major fatty acids of strain LM-6T (>5 %) were determined to be C18:1ω7c and/or C18:1ω6c, C16:0, C18:1 2–OH and C17:1 iso I and/or anteiso B. The major polar lipids were identified to be phosphatidylglycerol, phosphatidylethanolamine and phosphatidylmethylethanolamine. The major respiratory quinone was determined to be ubiquinone-10. The genomic DNA G+C content of strain LM-6T is 66.5 mol %. Strain LM-6T showed low DNA–DNA relatedness with F. denitrificans Sp-1T (53.1 ± 0.5 %). On the basis of phylogenetic, genomic, phenotypic and chemotaxonomic data, strain LM-6T is considered to represent a novel species of the genus Ferrovibrio, for which the name Ferrovibrio xuzhouensis sp. nov. is proposed. The type strain is Ferrovibrio xuzhouensis LM-6T (=KCTC 42182T = ACCC 19710T).

A novel Gram-positive, fluoroglycofen-degrading bacterium, designated cmg86T, was isolated from herbicide contaminated soil collected from Tongjing, Jiangsu province, China. Strain cmg86T was found to be aerobic, motile, endospore-forming rods. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain cmg86T belongs to the genus Lysinibacillus and showed the highest sequence similarity to Lysinibacillus meyeri DSM 25057T (97.9 %) and Lysinibacillus odysseyi KCTC 3961T (96.6 %). The cell-wall peptidoglycan type was determined to be A4α (l-Lys-d-Asp), which is consistent with the cell-wall characteristics of the genus Lysinibacillus. The predominant respiratory quinones were identified as menaquinone-7 (MK-7, 89.5 %) and meanaquinone-6 (MK-6, 8.9 %), and the major fatty acids were identified as iso-C15:0, anteiso-C15:0 and antesio-C17:0. The major polar lipids were found to be phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The genomic DNA G+C content of strain cmg86T was determined to be 37.6 mol%. The results of this study support the conclusion that strain cmg86T represents a novel species of the genus Lysinibacillus for which the name and Lysinibacillus fluoroglycofenilyticus sp. nov. is proposed. The type strain is cmg86T (=KCTC 33183T = CCTCC AB 2013247T).

Fomesafen is a diphenyl ether herbicide used to control the growth of broadleaf weeds in bean fields. Although the degradation of fomesafen in soils was thought to occur primarily by microbial activity, little was known about the kinetic and metabolic behaviors of this herbicide. This paper reported the capability of the newly isolated strain Pseudomonas zeshuii BY-1 to use fomesafen as the sole source of carbon in pure culture for its growth. Up to 88.7% of 50 mg of L–1 fomesafen was degraded by this bacterium in mineral medium within 3 days. Strain BY-1 could also degrade other diphenyl ethers, including lactofen, acifluorfen, and fluoroglycofen. During the fomesafen degradation, five metabolites were detected and identified by liquid chromatography–mass spectrometry and tandem mass spectrometry. The primary degradation pathway of fomesafen might be the reduction of the nitro group to an amino group, followed by the acetylation of the amino derivative, dechlorination, and cleavage of the S–N bond. The addition of the BY-1 stain into soils treated with fomesafen resulted in a higher degradation rate than that observed in uninoculated soils, and the bacteria community in contaminated soil recovered after inoculation of the BY-1 stain. On the basis of these results, strain P. zeshuii BY-1 has the potential to be used in the bioremediation of fomesafen-contaminated soils.

Ancylobacter sp. XJ-412-1, capable of degrading metsulfuron-methyl, was isolated from sulfonylurea-contaminated soil. When metsulfuron-methyl was provided as the sole carbon source, more than 90.5% of metsulfuron-methyl at concentration of 50 mg l−1 was degraded by strain XJ-412-1 after incubation at 30°C for 7 days. The initial degradation products of metsulfuron-methyl (MSM), thifensulfuron-methyl (TSM), and bensulfuron-methyl (BSM) by XJ-412-1 were identified as corresponding deesterified derivatives by liquid chromatography-mass spectrometry, which indicated a primary pathway of the deesterification of these three sulfonylurea herbicides. The carboxyesterase activity of the cell-free extracts was assayed and strongly inhibited by 4-chloromercuribenzoic acid (PCMB), diethyl pyrocarbonate (DEPC), phenylmethylsulfonyl fluoride (PMSF), and malathion.

The diphenyl ether herbicide lactofen is commonly used to control broadleaf weeds. Once released into the environment, this herbicide is subject to microbial reactions. This study describes the biotransformation of lactofen by Brevundimonas sp. LY-2 isolated from enrichment cultures inoculated with soil sample. This strain degraded about 80% of 50 mg L−1 lactofen in 5 days of incubation in flasks. The metabolic behaviors of the herbicide in the media are described. The results show a transformation pathway of lactofen by the bacterium leading to the formation of 1-(carboxy)ethyl-5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoate and ethanol. An esterase, which could cleave the right ester bond of the alkanoic side chain of lactofen, was purified 113.3-fold to homogeneity with 6.83% recovery. The current results suggested that Brevundimonas sp. LY-2 degraded lactofen via the ester bond cleavage catalyzed by esterase.

The fomesafen degrading bacterium ZB-1 was isolated from contaminated agricultural soil, and identified as Lysinibacillus sp. based on the comparative analysis of 16S rRNA gene. The strain could utilize fomesafen as the sole carbon source for growth, and the total degradation rate was 81.32% after 7 d of inoculation in mineral salts medium. Strain ZB-1 could also degrade other diphenyl ethers including lactofen and fluoroglycofen. The optimum temperature for fomesafen degradation by strain ZB-1 was 30 °C. The effect of fomesafen concentration on degradation was also examined. Cell-free extract of strain ZB-1 was able to degrade fomesafen and other diphenyl ethers. Metabolism of fomesafen was accompanied by a transient accumulation of a metabolite identified as [N-[4-{4-(trifluoromethyl)phenoxy}-2-methanamidephenyl]acetamide] using liquid chromatography–mass spectrometry, thus indicating a metabolic pathway involving reduction, acetylation of nitro groups and dechlorination. The inoculation of strain ZB-1 to soil treated with fomesafen resulted in a higher degradation rate than in noninoculated soil regardless of the soil sterilized or nonsterilized.