Data_Sheet_7_Taxonomic Description and Genome Sequence of Christensenella intestinihominis sp. nov., a Novel Cholesterol-Lowering Bacterium Isolated From Human Gut.PDF

A Gram-staining-negative, non-spore-forming, short, straight rod, non-motile, and obligate anaerobic bacterial strain, AF73-05CM02T, was isolated from a fecal sample of a 30 years old healthy male living in Shenzhen, China. Colonies were approximately 0.2 mm in diameter, beige, and circular after 4 days of incubation on PYG agar under anaerobic conditions at 37°C. Strain AF73-05CM02T grew in a temperature range between 30 and 42°C and a pH range from 6.0 to 8.5, with optimum growth at 37–42°C and pH 7.0. 16S rRNA gene sequence analysis demonstrated that strain AF73-05CM02T belongs to the genus Christensenella and showed the highest level of sequence similarity (98.68%) with Christensenella minuta DSM 22607T. The predominant fatty acids of strain AF73-05CM02T were C10:0 (7.5%), iso-C11:0 (5.6%), C12:0 (7.2%), C14:0 (46.6%), iso-C15:0 (7.4%), C16:0 (9.7%), and C18:1 ω9c (6.9%). Acetic acid, formic acid, butyric acid, and lactic acid were the end products of glucose fermentation. The strain was negative for catalase, indole production, and hydrolysis of gelatin. Genomic relatedness analyses based on average nucleotide identity (ANI) indicated that strain AF73-05CM02T significantly differed from other species of the genus Christensenella, showing ANI values less than 82.89% with the phylogenetically closest species. The G + C content of the genomic DNA was 52.07 mol% from the genome sequence, which differs from that of Christensenella minuta. Several physiological, biochemical, and genotypic properties differentiated the novel bacterial strain from the related species, indicating that the strain represents a new species of the genus Christensenella for which the name Christensenella intestinihominis sp. nov. is proposed, with strain AF73-05CM02T ( = CGMCC 1.5207T = DSM 103477T ) being the type strain. The following study explored the cholesterol-lowering function of strains AF73-05CM02T and Christensenella minuta DSM 22067T and revealed that the two strains exhibit the capacity for removing cholesterol with efficiency rates of 36.6 and 54.3% and produce exopolysaccharide of 234 and 271 mg/L, respectively.

革兰氏阴性、无芽孢、短直杆状、无运动性的专性厌氧细菌菌株AF73-05CM02T，分离自中国深圳一名30岁健康男性的粪便样本。该菌株于37℃厌氧条件下在PYG琼脂平板培养4天后，菌落直径约0.2 mm，呈米色圆形。菌株AF73-05CM02T的生长温度范围为30~42℃，pH范围为6.0~8.5，最适生长温度为37~42℃、最适pH为7.0。16S rRNA基因序列分析显示，菌株AF73-05CM02T隶属于克里斯滕森菌属（Christensenella），与最小克里斯滕森菌（Christensenella minuta）DSM 22607T的序列相似性最高，达98.68%。菌株AF73-05CM02T的主要脂肪酸成分为C10:0（7.5%）、异-C11:0（5.6%）、C12:0（7.2%）、C14:0（46.6%）、异-C15:0（7.4%）、C16:0（9.7%）以及C18:1 ω9c（6.9%）。葡萄糖发酵的终产物为乙酸、甲酸、丁酸及乳酸。该菌株过氧化氢酶、吲哚试验及明胶水解试验均呈阴性。基于平均核苷酸同源性（average nucleotide identity, ANI）的基因组亲缘关系分析显示，菌株AF73-05CM02T与克里斯滕森菌属其他物种存在显著差异，与系统发育关系最近的物种的ANI值均低于82.89%。基因组序列分析表明，该菌株的基因组DNA G+C摩尔含量为52.07%，与最小克里斯滕森菌存在差异。多项生理、生化及基因型特征可将该新菌株与近缘物种区分开，表明其隶属于克里斯滕森菌属的一个新物种，故提议将其命名为Christensenella intestinihominis sp. nov.，模式菌株为AF73-05CM02T（= CGMCC 1.5207T = DSM 103477T）。后续研究对菌株AF73-05CM02T与最小克里斯滕森菌DSM 22067T的降胆固醇功能进行了探究，结果显示两菌株均具备胆固醇清除能力，清除效率分别为36.6%与54.3%，同时分别可产生234 mg/L与271 mg/L的胞外多糖。