The distribution characteristics of bacterial beta-glucosidase activity in Taiwan strait

Twenty stations were established in the near-shore regions of South Fujian Shoal (116 degrees 10'-119 degrees 00' E, 21 degrees 20'-24 degrees 10' N) on summer and winter cruises during the period from August 1997 and February to March 1998. The distribution pattern of marine bacterial beta-glucosidase activity (beta-GlcA) has been investigated by using fluorogenic model substrate (FMS) technique in order to have better understanding of the beta-GlcA, as well as its relation to marine bacterial biomass, productivity and environmental factors in Taiwan strait. The results showed that: (1) In summer, the average of beta-GlcA at the Southern stations of Taiwan strait was 1.94 nmol/l h. While in winter, the average of beta-GlcA at the Northern stations was 0.86 nmol/l h and the range of variation (0.34-1.89 nmol/l h) was much more narrow than that in summer (0.31-8.1 nmol/l h). (2) According to the carbon conversion factor, the beta-GlcA was 0.14 and 0.062 ugc/l h in summer and winter respectively. These beta-GlcA values were higher than the bacterial production of the two seasons respectively. (3) The beta-GlcA gradually rises from offshore water to near-shore water. (4) The correlation between the beta-GlcA and the bacterial secondary production was not so obvious. (5) The correlation between the section distributions, daily varying of the beta-GlcA and the bacterial production was not obvious. (6) In the surface water, the distribution character of free-state beta-GlcA from bacteria was equal to that of the total beta-GlcA in the whole sea area.