加拿大海盆与楚科奇海沉积物岩芯中好气异养细菌的分布

DISTRIBUTION OF GAB IN SEDIMENT CORES COLLECTED FROM THE CANADIAN BASIN AND THE CHUKCHI SEA

本文用MPN法测定了两种培养温度下加拿大海盆与楚科奇海10根沉积物岩芯中182份样品的好气异养细菌(GAB)的检出率和含量。结果发现沉积物中GAB检出率高,GAB平均值为4.46×107个·g-1(4℃)和5.47×107个·g-1(25℃)。最高GAB含量出现于20—22cm层,GAB含量在沉积物各层位间波动,总体上呈现中下层沉积物GAB含量低于表层之势。25℃培养时能提高GAB检出率和含量。温度的提高将可能改变测区沉积物GAB的生存环境和生存状况。纬度区间的差异似显出测区中部GAB检出率和含量高于高、低纬度区间之状(4℃培养明显于25℃)。浅水区沉积物中的GAB含量较低,而水越深则GAB含量似越高,以25℃为明显。

The occurrence percentage and content of General Aerobic Heterotrophic Bacteria （GAB） were determined by using the method of MPN for 182 subsamples from 10 sediment cores taken from Canadian basin and Chukchi sea at two different culturing temperatures. The results showed that the general occurrence percentage of GAB was quite high, average contents of GAB at cultured temperatures of 4℃ and 25 ℃ were 4.46 × 10^7 and 5.47 × 10^7 ceils · g （wt）^-1 respectively. The highest GAB content occurred at 20-22 cm layer in the sediment. GAB contents waved among the strata of sediments, but a trend appeared that： contents in the middle or lower strata were lower than those of upper stratum. Cultivation at 25 ℃ could improve the occurrence percentage and contents of GAB, which suggests that the increasing of temperature may change the living circumstances and conditions of GAB. The differences of GAB among the latitudes areas indicated that occurrence percentage and contents of GAB in middle latitude are- as were higher than those in the higher or lower latitude areas, and were more obvious at 4 ℃ than those at 25 ℃. The GAB contents in sediment under the shallower water seemed to be lower than those in sediments under the deeper water and this status was more obvious at 25 ℃ than that at 4 ℃.