微生物在藻际环境中的物质循环作用

Roles of microbes in matter cycles in phycosphere niche

浮游植物作为海洋初级生产力的主要驱动者,其功能的发挥与共生微生物密不可分.藻类(甲藻、硅藻或蓝藻)的栖息环境中存在多样的共生细菌,各类细菌拥有不同的组成比例,但某些异养细菌在藻际环境中总是占据优势地位,如变形杆菌、黄杆菌及放线菌等.基于微生物在调节微食物网、促进物质循环和维持生态系统平衡中的重要意义,本文主要以赤潮事件的藻际环境为例,尝试梳理上述主导性"常驻微生物"在"藻-菌"共生体物质转化中的作用.特别是针对近些年来倍受关注的黄杆菌和玫瑰杆菌,着重例述了它们在物质代谢中的行为与生态策略,以更好地理解常驻物种在藻际生态位中的生态行为与协同进化.

Phytoplankton is the main driver of marine primary production and matter cycles. Their ecological functions have closely linked to the associated microbes. Although microbial biodiversity is high in all kinds of algal hosts（ such as dinoflagellate,diatoms and blue-green algae）,some heterotrophic bacteria（ Alphaproteobacteria,Gammaproteobacteria,Flavobacteria,and Actinobacteria） often appear as the dominant communities. In algae-bacteria symbiosis,microbes play important ecological roles,such as regulating microbial food web,mediating the energy flow nutrient cycling,and maintaining the balance of ecological system. In this review,we summarized the bacterial functions in phycosphere environment,and discussed their contribution to biogeochemical cycle and co-evolution. Particularly,we attempted to take Flavobacteria and Roseobacters as the examples to reveal the metabolic behavior and survive strategies,for better understanding the ecological characterization and co-evolution of ＂resident species＂in phycosphere niche.