Sulfurospirillum diekertiae sp. nov., a tetrachloroethene-respiring bacterium isolated from contaminated soil

Journal Article · Thu Mar 02 00:00:00 EST 2023 · International Journal of Systematic and Evolutionary Microbiology

DOI:https://doi.org/10.1099/ijsem.0.005693· OSTI ID:1965235

Jin, Huijuan ^[1]; Huo, Leitao ^[1]; Yang, Yi  ^[2]; Lv, Yan ^[1]; Wang, Jingjing ^[2]; Maillard, Julien ^[3]; Holliger, Christof ^[3]; Löffler, Frank E.  ^[4]; Yan, Jun  ^[2]

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1. Chinese Academy of Sciences (CAS), Shenyang (China). Institute of Applied Ecology; University of Chinese Academy of Sciences, Beijing (China)
2. Chinese Academy of Sciences (CAS), Shenyang (China). Institute of Applied Ecology
3. Ecole Polytechnique Federale Lausanne (EPFL) (Switzerland)
4. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Two anaerobic, tetrachloroethene- (PCE-) respiring bacterial isolates, designated strain ACS_DCE ^T and strain ACS_TCE, were characterized using a polyphasic approach. Cells were Gram-stain-negative, motile, non-spore-forming and shared a vibrioid- to spirillum-shaped morphology. Optimum growth occurred at 30°C and 0.1–0.4% salinity. The pH range for growth was pH 5.5–7.5, with an optimum at pH 7.2. Hydrogen, formate, pyruvate and lactate as electron donors supported respiratory reductive dechlorination of PCE to cis-1,2-dichloroethene (cDCE) in strain ACS_DCE ^T and of PCE to trichloroethene (TCE) in strain ACS_TCE. Both strains were able to grow with pyruvate under microaerobic conditions. Nitrate, elemental sulphur, and thiosulphate were alternative electron acceptors. Autotrophic growth was not observed and acetate served as carbon source for both strains. The major cellular fatty acids were C_16:1 ω7c, C_16:0, C_14:0 and C_18:1 ω7c. Both genomes feature a circular plasmid. Strains ACS_DCE ^T and ACS_TCE were previously assigned to the candidate species 'Sulfurospirillum acididehalogenans'. Here, based on key genomic features and pairwise comparisons of whole-genome sequences, including average nucleotide identity, digital DNA–DNA hybridization and average amino acid identity, strains ACS_DCE ^T and ACS_TCE, 'Ca. Sulfurospirillum diekertiae' strains SL2-1 and SL2-2, and the unclassified Sulfurospirillum sp. strain SPD-1 are grouped into one distinct species separate from previously described Sulfurospirillum species. Compared to Sulfurospirillum multivorans and Sulfurospirillum halorespirans, which dechlorinate PCE to cDCE without substantial TCE accumulation, these five strains produce TCE or cDCE as the end product. In addition, some cellular fatty acids (e.g., C_16:0 3OH, C_17:0 iso 3OH, C_17:0 2OH) were detected in strains ACS_DCE ^T and ACS_TCE but not in other Sulfurospirillum species. On the basis of phylogenetic, physiological and phenotypic characteristics, 'Ca. Sulfurospirillum acididehalogenans' and 'Ca. Sulfurospirillum diekertiae' are proposed to be merged into one novel species within the genus Sulfurospirillum, for which the name Sulfurospirillum diekertiae sp. nov. is proposed. Finally, the type strain is ACS_DCE ^T (=JCM 33349^T= KCTC 15819^T=CGMCC 1.5292^T).

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; Natural Science Foundation of China; Chinese Academy of Sciences (CAS)
• Grant/Contract Number: AC05-00OR22725; 41977295; 41907220; 41907287; ZDBS-LY-DQC038
• OSTI ID: 1965235
• Journal Information: International Journal of Systematic and Evolutionary Microbiology, Vol. 73, Issue 2; ISSN 1466-5026
• Publisher: International Union of Microbiological Societies
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
anaerobic bacteria
organohalide respiration
reductive dechlorination
Sulfurospirillum and tetrachloroethene