Interspecific interactions drive chitin and cellulose degradation by aquatic microorganisms

Aquatic Microbial Ecology

Hans-Peter Grossart¹  Alex R. Hall¹  Ivette Salka¹  Kirsten Pohlmann¹  Gianluca Corno¹ 

关键词: Aggregation;    Flagellate grazing;    Ecological interactions;    Microbial carbon transfer;    Polymer degradation;    System ecology;   

DOI  :  10.3354/ame01765

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Complex biopolymers (BPs) such as chitin and cellulose provide the majority of organic carbon in aquatic ecosystems, but the mechanisms by which communities of bacteria in natural systems exploit them are unclear. Previous degradation experiments in artificial systems predominantly used microcosms containing a single bacterial species, neglecting effects of interspecific interactions. By constructing simplified aquatic microbial communities, we tested how the addition of other bacterial species, of a nanoflagellate protist capable of consuming bacteria, or of both, affect utilization of BPs. Surprisingly, total abundance of resident bacteria in mixed communities increased upon addition of the protist. Concomitantly, bacteria shifted from free-living to aggregated morphotypes that seemed to promote utilization of BPs. In our model system, these interactions significantly increased productivity in terms of overall bacterial numbers and carbon transfer efficiency. This indicates that interactions on microbial aggregates may be crucial for chitin and cellulose degradation. We therefore suggest that interspecific microbial interactions must be considered when attempting to model the turnover of the vast pool of complex biopolymers in aquatic ecosystems.

【 授权许可】

Unknown