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