Isolation and characterization of Sporobacter termitidis gen nov sp nov, from the digestive tract of the wood-feeding termite Nasutitermes lujae

A new chemoorganotrophic bacterium, strain SYR(T) (T = type strain), was isolated from the digestive tract of the wood-feeding termite Nasutitermes lujae. This organism was a slightly curved spore-forming rod-shaped bacterium. It had a gram-positive-type cell wall and was obligately anaerobic. It grew exclusively on a limited range of methylated aromatic compounds including 3,4,5-trimethoxycinnamate (TMC), sinapate (3,5-dimethoxy-3-hydroxycinnamate), 3,4-dimethoxycinnamate, 3,4,5-trimethoxybenzoate, ferulate, syringate (3,5-dimethoxy-4-hydroxybenzoate), and vanillate (4-hydroxy-3-methoxybenzoate) but not on carbohydrates, alcohols, or fatty acids. The isolate required yeast extract for growth. Strain SYR(T) grew optimally between 32 and 35 degrees C and at pH values between 6.7 and 7.2, with NaCl concentrations from 0 to 5 g . liter(-1), on TMC with a doubling time of about 25 h. During growth on TMC in the presence of sulfide or cysteine, dimethyl sulfide and acetate were produced, whereas methanethiol was an intermediary product of metabolism. The ring of the methoxylated aromatic compound was cleaved. The DNA base composition was 57 mol% guanine plus cytosine. Comparative 16S rRNA sequence analysis indicated that strain SYR(T) was distantly related to Eubacterium desmolans and Eubacterium plautii. On the basis of its distinct phylogenetic position and physiological properties, strain SYRT has been designated a new species of a new genus, Sporobacter termitidis gen. nov., sp. nov. (= DSM 10068(T)).