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), w as isolated from the digestive tract of the wood-feeding termite Nasut itermes lujae. This organism was a slightly curved spore-forming rod-s haped bacterium. It had a gram-positive-type cell wall and was obligat ely anaerobic. It grew exclusively on a limited range of methylated ar omatic compounds including 3,4,5-trimethoxycinnamate (TMC), sinapate ( 3,5-dimethoxy-3-hydroxycinnamate), 3,4-dimethoxycinnamate, 3,4,5-trime thoxybenzoate, 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 growt h. 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 . l iter(-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 aceta te 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. Comparat ive 16S rRNA sequence analysis indicated that strain SYR(T) was distan tly related to Eubacterium desmolans and Eubacterium plautii. On the b asis of its distinct phylogenetic position and physiological propertie s, strain SYRT has been designated a new species of a new genus, Sporo bacter termitidis gen. nov., sp. nov. (= DSM 10068(T)).