Abstract:

The facultative anaerobic strain, H-2, was screened and isolated form the soil 80 cm depth from the surface layer at Zoige alpine wetland in Qinghai-Tibetan Plateau. It was identified as a Bacillus cereus by its morphological, physiological and biochemical characters and 16S rDNA sequence analysis. The results of cellulose producing research showed that the optimum carbon resource was 1.5% CMC-Na, the optimum temperature was 30℃ and rotating speed was 180 rpm. H-2 retained 80% enzyme producing activity at 15℃. Enzymology properties showed that the optimum pH and temperature were 7.0 and 40℃, and the highest cellulose activity was 15.443 U.

Key words: Alpine wetland in Qinghai-Tibetan Plateau, cellulase decomposing bacteria, enzymatic characteristics

摘要：

自青藏高原若尔盖高寒湿地距离表层80 cm深处的土壤中分离筛选到一株具有高纤维素分解活性的兼性厌氧菌株H-2。根据形态学、生理生化特征和16S rDNA分子生物学手段鉴定其为蜡样芽孢杆菌（Bacillus cereus）。对H-2菌株的产酶条件研究表明，羧甲基纤维素钠（sodium carboxymethyl cellulose-Na，CMC-Na）为最佳碳源；在1.5% CMC-Na，30℃、180 rpm振荡培养24 h，H-2产酶活性最高；15℃时，H-2仍保持80%产酶活性。对H-2菌株的纤维素酶活性条件进行初步研究表明，pH 7.0、温度40℃时，该菌株所产纤维素酶的活力最高，可达15.443 U。

关键词: 青藏高原高寒湿地;纤维素分解菌;酶学性质