青藏高原木孜塔格冰川、玉珠峰冰川及扎当冰川可培养细菌的生理特征

The physiological characteristics of culturable bacteria in Muztag、Yuzhufeng and Zadang Glaciers on Tibetan Plateau,China

为了解冰川微生物生长特点,分析了青藏高原木孜塔格冰川、玉珠峰冰川和扎当冰川可培养细菌在不同温度,及木孜塔格冰川可培养细菌在不同盐度和p H下的生长特性.木孜塔格冰川52%的可培养细菌不耐盐,只能在0%盐度下生长,38%的细菌可以在0%~4%/6%盐度培养基中生长,其余细菌可以在0%~1%/2%的盐度培养基中生长,且62%的细菌具有较广的p H值生长范围（p H 5~9）;另外,38%的细菌只能在弱酸性（5%）或者只能在弱碱性（33%）培养基中生长.3个冰川可培养细菌生长温度范围均为0~35℃,木孜塔格冰川最适生长温度≤20℃的细菌占其细菌总数的86%,而玉珠峰冰川和扎当冰川最适生长温度≤20℃的细菌则分别占其细菌总数的69%和53%.不同冰川具有不同最适生长温度的细菌的比例不同,同一冰川不同深度相同属类的细菌有相近的生长温度特征、耐盐度和耐酸碱特征.

In order to reveal the characteristics of glacier-microorganism,we assayed the culturable bacteria iso-lated from Muztag Glacier,Yuzhufeng Glacier and Zadang Glacier at different temperatures. Besides,culturable bacteria isolated from Muztag Glacier was observed at different salinity and pH. Salinity endurance of 52% of Muztag Glacier culturable bacteria was 0%,and 38%bacteria could grow in the medium of NaCl density with 0%~4%/6%,while the other bacterial salinity tolerance range was 0%~1%/2%. Muztag Glacier culturable bac-teria had wide range pH tolerance（5~9）occurring 62%,while bacteria only grew in weak acid（5%）or weak alkaline（33%）medium accounting for 38%. Growth-temperature range of bacteria in these three glaciers was 0~ 35 ℃. The Muztag bacterial optimum temperature which was below 20 ℃（including 20 ℃）accounted for 86%,while Yuzhufeng Glacier and Zadang Glacier were 69%and 53%,respectively. The percent of different op-timum temperatures in different glaciers were different. Culturable bacteria belonged to one genus isolated from same glacier had similar growth-temperature range,salinity and pH tolerance in different depths.