Clostridium fungisolvens sp. nov., a new β-1,3-glucan-decomposing bacterium isolated from anoxic soil subjected to biological soil disinfestation

Biological soil disinfestation (BSD) or reductive soil disinfestation (RSD) is a bioremediation method used to suppress or eliminate soil-borne plant pathogens by stimulating activities of indigenous anaerobic bacteria of the soil. An anaerobic bacterial strain (TW1 T ) was isolated from an anoxic soil sample subjected to the BSD treatment and comprehensively characterized. Cells of the strain were Gram-stain-positive, slightly curved and motile rods producing terminal spores. The strain was aerotolerant. Strain TW1 T was saccharolytic and produced acetate, butyrate, H 2 and CO 2 as fermentation end products. Strain TW1 T decomposed β-1,3-glucan (curdlan and laminarin) and degraded mycelial cells of an ascomycete Fusarium plant pathogen. Major cellular fatty acids of strain TW1 T were C 14 : 0 , C 14 : 0 dimethylacetal (DMA), C 16 : 0 aldehyde and C 16 : 0 DMA. Strain TW1 T made a group on the phylogenetic tree constructed based on 16S rRNA gene sequences with species such as Clostridium fallax (96.3 %) and Clostridium polyendosporum (96.0 %). Whole genome analysis of strain TW1 T showed that the total length of the genome was 5.28 Mb with the DNA G+C content of 31.3 mol%. The average nucleotide identity (ANIb) between strain TW1 T and C. fallax was 71.2 %. Presence of the genes encoding laminarinase or GH16 β-glucosidase was confirmed from the genome analysis of strain TW1 T . Based on the genomic, phylogenetic and phenotypic properties obtained, we propose strain TW1 T should be assigned in the genus Clostridium in the family Clostridiaceae as Clostridium fungisolvens sp. nov. The type strain TW1 T (=NBRC 112097 T =DSM 110791 T ).