Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA.
Department of Biology, University of North Carolina,Chapel Hill, NC, 27599-3280, USA.
Syst Appl Microbiol. 2018 Sep;41(5):460-472. doi: 10.1016/j.syapm.2018.06.001. Epub 2018 Jun 8.
Four bacterial strains identified as members of the Acidovorax genus were isolated from two geographically distinct but similarly contaminated soils in North Carolina, USA, characterized, and their genomes sequenced. Their 16S rRNA genes were highly similar to those previously recovered during stable-isotope probing (SIP) of one of the soils with the polycyclic aromatic hydrocarbon (PAH) phenanthrene. Heterotrophic growth of all strains occurred with a number of organic acids, as well as phenanthrene, but no other tested PAHs. Optimal growth occurred aerobically under mesophilic temperature, neutral pH, and low salinity conditions. Predominant fatty acids were Cω7c/Cω6c, C, and Cω7c, and were consistent with the genus. Genomic G+C contents ranged from 63.6 to 64.2%. A combination of whole genome comparisons and physiological analyses indicated that these four strains likely represent a single species within the Acidovorax genus. Chromosomal genes for phenanthrene degradation to phthalate were nearly identical to highly conserved regions in phenanthrene-degrading Delftia, Burkholderia, Alcaligenes, and Massilia species in regions flanked by transposable or extrachromosomal elements. The lower degradation pathway for phenanthrene metabolism was inferred by comparisons to described genes and proteins. The novel species Acidovorax carolinensis sp. nov. is proposed, comprising the four strains described in this study with strain NA3 as the type strain (=LMG 30136, =DSM 105008).
从美国北卡罗来纳州两个地理位置不同但受到类似污染的土壤中分离到了 4 株菌，鉴定为 Acidovorax 属的成员，并对它们的基因组进行了测序。它们的 16S rRNA 基因与先前在其中一种土壤中用多环芳烃（PAH）菲进行稳定同位素探测（SIP）时回收的基因高度相似。所有菌株都能以多种有机酸以及菲为碳源进行异养生长，但不能以其他测试的 PAH 为碳源。所有菌株在中温、中性 pH 值和低盐条件下有氧生长最佳。优势脂肪酸为 Cω7c/Cω6c、C 和 Cω7c，与属一致。基因组 G+C 含量范围为 63.6%至 64.2%。全基因组比较和生理分析的组合表明，这 4 株菌可能代表 Acidovorax 属中的一个单一物种。到邻苯二甲酸的菲降解基因与菲降解的 Delftia、Burkholderia、Alcaligenes 和 Massilia 物种的高度保守区域几乎相同，这些区域位于可转座或染色体外元件侧翼。通过与描述的基因和蛋白质进行比较，推断出菲代谢的较低降解途径。提出了一种新的物种，即卡罗来纳 Acidovorax 新种，由本研究中描述的 4 株菌组成，其中 NA3 株为模式株（=LMG 30136，=DSM 105008）。
