| Totally 63 halophilic, strictly anaerobic bacteria were isolated from the sediments of Xiaokule salt lake and Balikun salt lake in Xinjiang China, the methanogenic sediment of South China sea and the sediment of Northeast Pacific deep-sea nodule province using Hungate roll-tube technique. The analysis of 16S rRNA gene sequence showed that they belong to three genus of Halanaerobium, Alkaliphilus, Virgibacillus. The strains E2r and S191 were isolated mainly from the sediment of Xiaokule salt lake and the sediment of Northeast Pacific nodule province. A phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains E2r and S191 had the highest sequence similarity with respect to type strains of Alkaliphilus crotonatoxidans (93.7%) and Halanaerobium saccharoly- ticum (98.6%), respectively.The strain E2r was straight to slight curved, Gram-positive rods that were motile with flagella and formed endospores. Growth was observed in the NaCl concentration between 0.5～15% (optimum 7.5%), pH range 5.5～9.1 (optimum 8.0) and the temperature range 15～42℃(optimum 32℃). The doubling time was about 14h when grown in Medium 210 at optimal condition. The isolate was strictly anaerobic, and capable of utilizing some substrates like fructose, maltose, methanol and n-butanol. Element sulfur and thiosulfate was used as electron acceptors. Phylogenetic analysis based on the 16S rDNA sequence indicated that strain E2r is a member of cluster XI within the low G+C Gram-positive bacteria. The G+C mol% of strain E2r was about 39.4%. The strain S191 was a strictly anaerobic, moderately halophilic, Gram-negative, rod-shaped bacterium. Growth was observed in the NaCl concentration between 5～25% (optimum 7.5～10%), pH range 6.0～8.9 (optimum 7.8～8.0) and the temperature range 15～42℃(optimum 32～37℃). The doubling time was about 3.43h when grown anaerobically in Medium 210 at optimal condition. Primary analysis indicated that the isolate is a new member of Halanaerobium. More taxonomy study of two strains will be performed. |
