Granulicella sibirica sp. nov., a psychrotolerant acidobacterium isolated from an organic soil layer in forested tundra, West Siberia

An isolate of strictly aerobic, pale-pink pigmented bacteria, strain AF10^T, was obtained from an organic soil layer in forested tundra, Nadym region, West Siberia. Cells of strain AF10^T were Gram-negative, non-motile rods that produced an amorphous extracellular polysaccharide-like substance and formed large cell aggregates in old cultures. These bacteria were chemoorganotrophic, mildly acidophilic and psychrotolerant, and grew between pH 3.5 and 7.0 (optimum, pH 4.5-5.0) and at temperatures between 2 and 30 °C. The preferred growth substrates were sugars and some polysaccharides. The major fatty acids were iso-C15 : 0, C16 : 0, C16 : 1∆9 c and 13,16-dimethyl octacosanedioic acid. The genome of strain AF10^T was 6.14 Mbp in size and encoded a wide repertoire of carbohydrate active enzymes. The genomic DNA G+C content was 59.8 mol%. Phylogenetic analysis indicated that strain AF10^T is a member of the genus Granulicella, family Acidobacteriaceae, but displays 94.4-98.0 % 16S rRNA gene sequence similarity to currently described members of this genus. On the basis of phenotypic, chemotaxonomic, phylogenetic and genomic analyses, we propose to classify this bacterium as representing a novel species of the genus Granulicella, Granulicellasibirica sp. nov. Strain AF10^T (=DSM 104461^T=VKM B-3276^T) is the type strain.

Complete genome sequence of Granulicella tundricola type strain MP5ACTX9(T), an Acidobacteria from tundra soil

Granulicella tundricola strain MP5ACTX9(T) is a novel species of the genus Granulicella in subdivision 1 Acidobacteria. G. tundricola is a predominant member of soil bacterial communities, active at low temperatures and nutrient limiting conditions in Arctic alpine tundra. The organism is a cold-adapted acidophile and a versatile heterotroph that hydrolyzes a suite of sugars and complex polysaccharides. Genome analysis revealed metabolic versatility with genes involved in metabolism and transport of carbohydrates, including gene modules encoding for the carbohydrate-active enzyme (CAZy) families for the breakdown, utilization and biosynthesis of diverse structural and storage polysaccharides such as plant based carbon polymers. The genome of G. tundricola strain MP5ACTX9(T) consists of 4,309,151 bp of a circular chromosome and five mega plasmids with a total genome content of 5,503,984 bp. The genome comprises 4,705 protein-coding genes and 52 RNA genes.

Complete genome sequence of Granulicella mallensis type strain MP5ACTX8(T), an acidobacterium from tundra soil

Granulicella mallensis MP5ACTX8(T) is a novel species of the genus Granulicella in subdivision 1of Acidobacteria. G. mallensis is of ecological interest being a member of the dominant soil bacterial community active at low temperatures and nutrient limiting conditions in Arctic alpine tundra. G. mallensis is a cold-adapted acidophile and a versatile heterotroph that hydrolyzes a suite of sugars and complex polysaccharides. Genome analysis revealed metabolic versatility with genes involved in metabolism and transport of carbohydrates. These include gene modules encoding the carbohydrate-active enzyme (CAZyme) family involved in breakdown, utilization and biosynthesis of diverse structural and storage polysaccharides including plant based carbon polymers. The genome of Granulicella mallensis MP5ACTX8(T) consists of a single replicon of 6,237,577 base pairs (bp) with 4,907 protein-coding genes and 53 RNA genes.

Complete genome sequence of Terriglobus saanensis type strain SP1PR4(T), an Acidobacteria from tundra soil

Terriglobus saanensis SP1PR4(T) is a novel species of the genus Terriglobus. T. saanensis is of ecological interest because it is a representative of the phylum Acidobacteria, which are dominant members of bacterial soil microbiota in Arctic ecosystems. T. saanensis is a cold-adapted acidophile and a versatile heterotroph utilizing a suite of simple sugars and complex polysaccharides. The genome contained an abundance of genes assigned to metabolism and transport of carbohydrates including gene modules encoding for carbohydrate-active enzyme (CAZyme) family involved in breakdown, utilization and biosynthesis of diverse structural and storage polysaccharides. T. saanensis SP1PR4(T) represents the first member of genus Terriglobus with a completed genome sequence, consisting of a single replicon of 5,095,226 base pairs (bp), 54 RNA genes and 4,279 protein-coding genes. We infer that the physiology and metabolic potential of T. saanensis is adapted to allow for resilience to the nutrient-deficient conditions and fluctuating temperatures of Arctic tundra soils.