PG-091:

A novel bacterial species of yet unidentified genus isolated from thermophilic compost prepared from marine animal resources material

A Gram-negative strain (Cory-14), motile, facultative anaerobic, endospores-forming rod-shaped bacterium was isolated on Corynebacterium agar from the compost in Japan. The 16S rRNA gene sequences of strain Cory-14 showed the highest similarity to that of Paenibacillus elgii NBRC 100335^T with only 89.87%. The phylogenetic tree showed strain Cory-14 is separated into different subline that did not clustered with Paenibacillus species. Strain Cory-14 grew at temperature between 18.3_46.2°C, at 0.5_7.0 % NaCl and at pH 5.0_9.5. It is a fast growing (μ_max: 0.4055 h^-1) bacterium on the conditions at 40°C, 0.5 % NaCl and at pH 7.2. Strain Cory-14 forms small colonies that are raised, entire, circular, mucoid, opaque and slightly yellowish on Trypticase soy agar. Terminal non-bulging endospores are formed after 1 d of cultivation as revealed by malachite green spore stain. In addition, strain Cory-14 grew well on MacConkey agar without lactose utilization. Strain Cory-14 exhibits enzyme activities of oxidase and catalase but no reaction for deaminase, β-galactosidase, arginine dihydrolase, lysine decarboxylase, ornithine decarboxylase and nitrate reductase. Gelatin, casein, tween-80, tween-20 and starch were hydrolyzed but not carboxymethyl cellulose and tyrosine. Acetoin was produced but indole and hydrogen sulfide were not detected. Strain Cory-14 utilizes N-acetyl-glucosamine, gluconate, malate and citrate as sole carbon sources, but not glucose, arabinose, mannose, mannitol, maltose, caprate, adipate or phenyl acetate as determined with the API 20E and 20NE system (Biomerieux). Acid was not produced from sugars as determined with the methyl red test in API 50CH at 48 h, except N-acetyl-glucosamine at 72 h and glycerol after 96 h. Based on some distinct taxonomic features, strain Cory-14 is proposed as a novel bacterium belonging to unidentified genus.

keywords:Novel bacterium,Compost,Taxonomic characterization