Gilmour Cynthia C, Soren Ally Bullock, Gionfriddo Caitlin M, Podar Mircea, Wall Judy D, Brown Steven D, Michener Joshua K, Urriza Maria Soledad Goñi, Elias Dwayne A
Smithsonian Environmental Research Center, Edgewater, Maryland, USA.
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.
Int J Syst Evol Microbiol. 2019 Jun;71(3). doi: 10.1099/ijsem.0.004697. Epub 2021 Feb 11.
The sulfate-reducing, mercury-methylating strain ND132 was isolated from the brackish anaerobic bottom sediments of Chesapeake Bay, USA. Capable of high levels of mercury (Hg) methylation, ND132 has been widely used as a model strain to study the process and to determine the genetic basis of Hg methylation. Originally called ND132 on the basis of an early partial 16S rRNA sequence, the strain has never been formally described. Phylogenetic and physiological traits place this strain within the genus in the recently reclassified phylum (formerly ). ND132 is most closely related to BerOc1 and J2. Analysis of average nucleotide identity (ANI) of whole-genome sequences showed roughly 88 % ANI between BerOc1 and ND132, and 84 % similarity between ND132 and J2. These cut-off scores <95 %, along with a multi-gene phylogenetic analysis of members of the family and differences in physiology indicate that all three strains represent separate species. The Gram-stain-negative cells are vibrio-shaped, motile and not sporulated. ND132 is a salt-tolerant mesophile with optimal growth in the laboratory at 32 °C, 2 % salinity, and pH 7.8. The DNA G+C content of the genomic DNA is 65.2 %. It is an incomplete oxidizer of short chain fatty acids, using lactate, pyruvate and fumarate with sulfate or sulfite as the terminal electron acceptors. ND132 can respire fumarate using pyruvate as an electron donor. The major fatty acids are iso-C, anteiso-C, iso-C, iso-Cω9 and anteiso-C. We propose the classification of strain ND132 (DSM 110689, ATCC TSD-224) as the type strain sp. nov.
硫酸盐还原汞甲基化菌株ND132从美国切萨皮克湾的微咸厌氧底部沉积物中分离得到。ND132能够进行高水平的汞（Hg）甲基化，已被广泛用作研究该过程及确定汞甲基化遗传基础的模式菌株。该菌株最初基于早期的部分16S rRNA序列被命名为ND132，但从未被正式描述过。系统发育和生理特征将该菌株归入最近重新分类的门（以前的）中的属。ND132与BerOc1和J2关系最为密切。全基因组序列的平均核苷酸同一性（ANI）分析表明，BerOc1和ND132之间的ANI约为88%，ND132和J2之间的相似性为84%。这些截断分数<95%，以及对该科成员的多基因系统发育分析和生理差异表明，这三个菌株代表不同的物种。革兰氏染色阴性细胞呈弧菌状，具运动性，不产芽孢。ND132是一种耐盐嗜温菌，在实验室中32°C、盐度2%和pH 7.8条件下生长最佳。基因组DNA的DNA G+C含量为65.2%。它是短链脂肪酸的不完全氧化菌，利用乳酸、丙酮酸和富马酸，以硫酸盐或亚硫酸盐作为末端电子受体。ND132可以利用丙酮酸作为电子供体来呼吸富马酸。主要脂肪酸为异-C、anteiso-C、异-C、异-Cω9和anteiso-C。我们建议将菌株ND132（DSM 110689，ATCC TSD-224）分类为新种sp. nov.的模式菌株。
