Jin-Wei Zheng

Biodegradation of chloroacetamide herbicides by Paracoccus sp. FLY-8 in vitro.

A butachlor-degrading strain, designated FLY-8, was isolated from rice field soil and was identified as Paracoccus sp. Strain FLY-8 could degrade and utilize six chloroacetamide herbicides as carbon sources for growth, and the degradation rates followed the order alachlor > acetochlor > propisochlor > butachlor > pretilachlor > metolachlor. The influence of molecular structure of the chloroacetamide herbicides on the microbial degradation rate was first analyzed; the results indicated that the substitutions of alkoxymethyl side chain with alkoxyethyl side chain greatly reduced the degradation efficiencies; the length of amide nitrogens alkoxymethyl significantly affected the biodegradability of these herbicides: the longer the alkyl was, the slower the degradation efficiencies occurred. The phenyl alkyl substituents have no obvious influence on the degradation efficiency. The pathway of butachlor complete mineralization was elucidated on the basis of the results of metabolite identification and enzyme assays. Butachlor was degraded to alachlor by partial C-dealkylation and then converted to 2-chloro-N-(2,6-dimethylphenyl)acetamide by N-dealkylation, which subsequently transformed to 2,6-diethylaniline, which was further degraded via the metabolites aniline and catechol, and catechol was oxidized through an ortho-cleavage pathway. This study highlights an important potential use of strain FLY-8 for the in situ bioremediation of chloroacetamide herbicides and their metabolite-contaminated environment.

Sphingobacterium wenxiniae sp. nov., a cypermethrin-degrading species from activated sludge.

A Gram-negative, non-motile, non-spore-forming, non-flagellated rod capable of degrading cypermethrin, designated LQY-18(T), was isolated from activated sludge of a wastewater treatment plant in China. Strain LQY-18(T) grew at 8-40 °C (optimum 30 °C), at pH 5.0-10.0 (optimum pH 7.0) and with 0-5% (w/v) NaCl (optimum 1%). The predominant menaquinone was MK-7 (97%) and the major fatty acids were summed feature 3 (comprising C(16:1)ω6c and/or C(16:1)ω7c), iso-C(15:0) and iso-C(17:0) 3-OH. The DNA G+C content was 40.3 mol%. Phylogenetic analysis revealed that the isolate belonged to the genus Sphingobacterium of the phylum Bacteroidetes and showed low 16S rRNA gene sequence similarity with recognized members of the genus Sphingobacterium. The closest neighbour was Sphingobacterium mizutaii ATCC 33299(T) (92.9% 16S rRNA gene sequence similarity). On the basis of phenotypic, genetic and phylogenetic data, strain LQY-18(T) (=ACCC 05410(T)=CCTCC AB 2010005(T)=KCTC 23009(T)) should be classified as a representative of a novel species of the genus Sphingobacterium, for which the name Sphingobacterium wenxiniae sp. nov. is proposed.

Sphingobium wenxiniae sp. nov., a synthetic pyrethroid (SP)-degrading bacterium isolated from activated sludge in an SP-manufacturing wastewater treatment facility.

A synthetic pyrethroid (SP)-degrading bacterial strain, designated JZ-1(T), was isolated from activated sludge of a SP-manufacturing wastewater treatment facility and studied using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JZ-1(T) belonged to the genus Sphingobium, showing highest sequence similarities to Sphingobium faniae DSM 21829(T) (98.6 %), Sphingobium cloacae JCM 10874(T) (98.5 %), Sphingobium vermicomposti DSM 21299(T) (97.4 %) and Sphingobium ummariense CCM 7431(T) (96.9 %). The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of the cellular fatty acids C(18 : 1)ω7c, C(19 : 0) cyclo ω8c, 11 methyl C(18 : 1)ω7c, C(16 : 0) and C(14 : 0) 2-OH, and the G+C content of the genomic DNA also supported the affiliation of the strain with the genus Sphingobium. Strain JZ-1(T) showed low DNA-DNA relatedness values with S. faniae DSM 21829(T) (30.2 %), S. cloacae JCM 10874(T) (23.3 %), S. vermicomposti DSM 21299(T) (10.9 %) and S. ummariense CCM 7431(T) (7.9 %). Based on its phylogenetic position and its phenotypic and genotypic properties, strain JZ-1(T) represents a novel species of the genus Sphingobium, for which the name Sphingobium wenxiniae sp. nov. is proposed. The type strain is JZ-1(T) ( = CGMCC 1.7748(T)  = DSM 21828(T)).

Comamonas zonglianii sp. nov., isolated from phenol-contaminated soil

A bacterial strain, designated BF-3(T), was isolated from phenol-contaminated soil and investigated using a polyphasic taxonomic approach. Cells were Gram-reaction-negative, non-sporulating, non-motile, short rods. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BF-3(T) formed a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Comamonas; it showed highest sequence similarities to Comamonas aquatica LMG 2370(T) (96.8 %), C. nitrativorans DSM 13191(T) (96.4 %), C. odontotermitis LMG 23579(T) (96.4 %), C. kerstersii LMG 3475(T) (96.3 %), C. koreensis KCTC 12005(T) (96.1 %) and C. terrigena LMG 1253(T) (96.0 %). The major cellular fatty acids were C(16 : 0), C(18 : 1)/C(18 : 1)ω7c, C(17 : 0) cyclo and summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH). Based on the phylogenetic analysis, DNA-DNA hybridization, whole-cell fatty acid composition and biochemical characteristics, strain BF-3(T) was clearly distinct from type strains of other recognized species of the genus Comamonas and, as such, represents a novel species of the genus Comamonas, for which the name Comamonas zonglianii sp. nov. is proposed. The type strain is BF-3(T) (=CCTCC AB 209170(T) =DSM 22523(T)).

Catellibacterium nanjingense sp. nov., a propanil-degrading bacterium isolated from activated sludge, and emended description of the genus Catellibacterium

A novel facultatively anaerobic, non-spore-forming, non-motile, catalase- and oxidase-positive, Gram-negative and rod-shaped bacterial strain, designated Y12(T), was isolated from activated sludge of a wastewater bio-treatment facility. The strain was able to degrade about 90% of added propanil (100 mg l(-1)) within 3 days of incubation. Growth occurred in the presence of 0-4.5% (w/v) NaCl (optimum 0.5%), at 10-40 °C (optimum 28 °C) and at pH 5.5-10.0 (optimum pH 7.0). Vesicular internal membrane structures and photoheterotrophic growth were not observed. The major respiratory quinone was ubiquinone-10 and the major cellular fatty acid was summed feature 8 (C(18:1)ω6c and/or C(18:1)ω7c). The genomic DNA G+C content of strain Y12(T) was 63.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain Y12(T) was a member of the genus Catellibacterium, as it showed highest sequence similarities to Catellibacterium caeni DCA-1(T) (99.1%) and <96.0% similarities with other species of the genus Catellibacterium. Strain Y12(T) showed low DNA-DNA relatedness values with C. caeni DCA-1(T). Based on phenotypic, genotypic and phylogenetic properties, strain Y12(T) represents a novel species of the genus Catellibacterium, for which the name Catellibacterium nanjingense sp. nov. is proposed. The type strain is Y12(T) (=CCTCC AB 2010218(T) =KCTC 23298(T)). An emended description of the genus Catellibacterium is also presented.

Description of Catellibacterium caeni sp. nov., reclassification of Rhodobacter changlensis Anil Kumar et al. 2007 as Catellibacterium changlense comb. nov. and emended description of the genus Catellibacterium

A novel non-sporulating, non-motile, catalase- and oxidase-positive, strictly aerobic, Gram-negative, rod-shaped bacterial strain, designated DCA-1(T), was isolated from activated sludge collected from a butachlor wastewater treatment facility. The strain was able to degrade about 85 % of 100 mg butachlor l(-1) within 5 days of incubation. Growth occurred in the presence of 0-6 % (w/v) NaCl [optimum, 1 % (w/v) NaCl] and at pH 5.5-9.0 (optimum, pH 7.0) and 15-35 °C (optimum, 25-30 °C). Vesicular internal membrane structures and photoheterotrophic growth were not observed. The major respiratory quinone was ubiquinone 10 (Q-10) and the major cellular fatty acids were C(18 : 1)ω7c and 11-methyl C(18 : 1)ω7c. The genomic DNA G+C content of strain DCA-1(T) was 62.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain DCA-1(T) was a member of the family Rhodobacteraceae and was related most closely to the type strain of Catellibacterium aquatile (96.5 % sequence similarity). The combination of phylogenetic analysis, phenotypic characteristics and chemotaxonomic data supports the suggestion that strain DCA-1(T) represents a novel species of the genus Catellibacterium, for which the name Catellibacterium caeni sp. nov. is proposed. The type strain is DCA-1(T) ( = CGMCC 1.7745(T)  = DSM 21823(T)). In addition, based on the characterization data obtained in this study, it is proposed that Rhodobacter changlensis should be reclassified as Catellibacterium changlense comb. nov. (type strain JA139(T)  = DSM 18774(T)  = CCUG 53722(T)  = JCM 14338(T)). An emended description of the genus Catellibacterium is also presented.

Candida mengyuniae sp. nov., a metsulfuron-methyl-resistant yeast.

A metsulfuron-methyl-resistant yeast strain, JHL(T), was isolated from metsulfuron-methyl-contaminated soil collected in Jiangsu Province, China. Through morphological and physiological analysis as well as a molecular phylogenetic analysis based on the 26S rRNA gene D1/D2 region and internal transcribed spacer (ITS), this strain, which forms a clade with Candida vartiovaarae and a teleomorphic species, Williopsis saturnus, was revealed to represent a novel species in the genus Candida. The name Candida mengyuniae sp. nov. (type strain JHL(T)=CGMCC 2.3681(T)=CBS 10845(T)) is proposed for this novel species.

Sphingobium jiangsuense sp. nov., a 3-phenoxybenzoic acid-degrading bacterium isolated from a wastewater treatment system.

A non-sporulating, non-motile, catalase- and oxidase-positive, Gram-negative, rod-shaped bacterial strain, designated BA-3T, was isolated from activated sludge of a wastewater treatment facility. The strain was able to degrade about 95 % of 100 mg 3-phenoxybenzoic acid l(-1) within 2 days of incubation. Growth occurred in the presence of 0-2 % (w/v) NaCl [optimum, 0.5 % (w/v) NaCl], at pH 5.5-9.0 (optimum, pH 7.0) and at 10-37 °C (optimum, 28 °C). Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain BA-3T was a member of the genus Sphingobium; it showed highest gene sequence similarity to Sphingobium qiguonii X23T (98.2 %), and similarities of <97.0 % with strains of other Sphingobium species. The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of summed feature 8 (C18:1ω6c and/or C18:1ω7c) in the cellular fatty acid profile and the DNA G+C content also supported affiliation of the isolate to the genus Sphingobium. Strain BA-3T showed low DNA-DNA relatedness values (21.3±0.8 %) with Sphingobium qiguonii X23(T). Based on phenotypic, genotypic and phylogenetic data, strain BA-3T represents a novel species of the genus Sphingobium, for which the name Sphingobium jiangsuense sp. nov. is proposed; the type strain is BA-3T (=CCTCC AB 2010217T= KCTC 23196T=KACC 16433T).

Methylopila jiangsuensis sp. nov., an aerobic, facultatively methylotrophic bacterium

The taxonomic status was determined of an aerobic, facultatively methylotrophic strain, JZL-4(T), isolated from activated sludge. The cells were gram-negative, asporogenous, colourless, motile, short rods. The strain utilized methanol, methylamine, formate and a variety of polycarbon compounds, but not methane, dichloromethane or CO(2)/H(2), as carbon and energy sources. C(1) compounds were assimilated via the isocitrate lyase-negative serine pathway. Optimal growth occurred at 30 °C, pH 6.5-7.5 and 0.5 % (w/v) NaCl. The major cellular fatty acids were C(18 : 1)ω7c and C(18 : 0). The major phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and phosphatidylmonomethylethanolamine (PME); PME, the main phospholipid of strain JZL-4(T), was absent or present in only minor amounts in Methylopila capsulata IM1(T), Methylopila helvetica DM9(T) and Albibacter methylovorans DM10(T). The major ubiquinone was Q-10. The DNA G+C content of strain JZL-4(T) was 70.4 mol% (T(m)). Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain showed high sequence similarities to M. capsulata IM1(T) (97.2 %), A. methylovorans DM10(T) (94.9 %) and M. helvetica DM9(T) (94.1 %), and showed less than 94 % similarity to strains of other species with validly published names. Strain JZL-4(T) had a low level of DNA-DNA relatedness (34 %) with M. capsulata IM1(T). On the basis of phenotypic, genetic and phylogenetic data, strain JZL-4(T) is proposed to represent a novel species of the genus Methylopila, with the name Methylopila jiangsuensis sp. nov. The type strain is strain JZL-4(T) ( = ACCC 05406(T)  = DSM 22718(T)  = VKM B-2555(T)).