Production and fate of extracellular polymeric substances produced by benthic diatoms and bacteria: A laboratory study
详细信息    查看全文
文摘
It is well known that benthic diatoms and bacteria are able to affect the stability of cohesive sediments. Their production of new extracellular polymeric substances (EPS) increases the erosion threshold and decreases the erosion rate. To predict this build up of biostability in cohesive sediments, it is therefore vital to understand the EPS production rates for both diatoms and bacteria under different ecological conditions. The present study examined the production of EPS as function of light intensity and linked this to biostabilisation. Microbenthos was sampled from a Danish marine embayment at 5-m depth. A 10-day comparison of EPS production under light and under dark conditions showed that the bacterial EPS production hardly changed during the experiment, while the algal EPS production was significantly high already from day 1 and reached a maximum production on day 10. Erosion threshold of natural cohesive sediments was determined in annular flumes after variable consolidation periods under similar light/dark conditions. The evolutions of erosion threshold and EPS concentration correlated well under light conditions, while the development in dark conditions showed no significant correlation, indicating that diatoms are more efficient in sediment stabilisation than bacteria. Further it seems, that the studied biological-sedimentary system needs 2–3 days of acclimatisation before the production of EPS can be well correlated with the increase of sediment stability.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700