Sorokin Dimitry Y, Khijniak Tatiana V, Elcheninov Alexander G, Toshchakov Stepan V, Kostrikina Nadezhda A, Bale Nicole J, Sinninghe Damsté Jaap S, Kublanov Ilya V
1Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia.
2Department of Biotechnology, TU Delft, Delft, The Netherlands.
Int J Syst Evol Microbiol. 2019 May;69(5):1327-1335. doi: 10.1099/ijsem.0.003312. Epub 2019 Feb 25.
An extremely halophilic euryarchaeon, strain HArcel1, was enriched and isolated in pure culture from the surface brines and sediments of hypersaline athalassic lakes in the Kulunda Steppe (Altai region, Russia) using amorphous cellulose as the growth substrate. The colonies of HArcel1 are pale-orange, and form large zones of cellulose hydrolysis around them. The cells are non-motile cocci of variable size with a thin monolayer cell wall. The isolate is an obligate aerobic heterotroph capable of growth with only three substrates: various forms of insoluble cellulose, xylan and cellobiose. Strain HArcel1 is an extremely halophilic neutrophile, growing within the salinity range from 2.5 to 5 M NaCl (optimum at 3.5-4 M). The core archaeal lipids are dominated by C20-C20 and C25-C20 dialkyl glycerol ethers, in approximately 6:1 proportion. The 16S rRNA and rpoB' gene analysis indicated that HArcel1 forms a separate lineage within the family Haloarculaceae, order Halobacteriales, with the genera Halorhabdus and Halopricus as closest relatives. On the basis of the unique phenotypic properties and distinct phylogeny of the 16S rRNA and rpoB' genes, it is suggested that strain HArcel1 is classified into a new genus and species Halococcoides cellulosivorans gen. nov., sp. nov. (JCM 31941=UNIQEM U975).
一株极端嗜盐的广古菌HArcel1，从俄罗斯阿尔泰地区库伦达草原高盐无海迹湖泊的表层卤水和沉积物中，以无定形纤维素作为生长底物进行富集培养并分离得到纯培养物。HArcel1的菌落呈浅橙色，在其周围形成大片纤维素水解区域。细胞为大小可变的无运动性球菌，具薄的单层细胞壁。该分离株是专性需氧异养菌，仅能利用三种底物生长：各种形式的不溶性纤维素、木聚糖和纤维二糖。菌株HArcel1是极端嗜盐嗜中性菌，在2.5至5 M NaCl盐度范围内生长（最适盐度为3.5 - 4 M）。核心古菌脂质以C20 - C20和C25 - C20二烷基甘油醚为主，比例约为6:1。16S rRNA和rpoB'基因分析表明，HArcel1在嗜盐杆菌目盐弧菌科内形成一个独立的谱系，与盐嗜杆菌属和盐普里库斯属为近亲。基于16S rRNA和rpoB'基因独特的表型特性和明显的系统发育关系，建议将菌株HArcel1分类为一个新属新种，即嗜纤维素盐球菌属（Halococcoides cellulosivorans），新属，新种（模式菌株JCM 31941 = UNIQEM U975）。
