Effects of starvation on aggregate colonization and motility of marine bacteria

Aquatic Microbial Ecology

Kam W. Tang¹  Emily M. Yam¹ 

关键词: Bacterial colonization;    Detachment;    Motility;    Image analyses;    Aggregates;    Starvation;   

DOI  :  10.3354/ame048207

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Fluxes of particulate matter to depth and dynamics of dissolved organic matter in the water column are influenced by microbial processes associated with organic aggregates like marine snow. These microscale processes include the encounter between bacteria and aggregates, which has been previously modeled and tested with well-fed and actively growing bacteria. In the present study, we investigated the effects of starvation on initial bacterial colonization of aggregates by measuring colonization and detachment of 6 isolates in different physiological states (fed vs. starved) using model aggregates. Because aggregate encounter depends on motility, the motility behaviors of fed and starved bacteria of 3 selected strains were also compared using image analysis. All 6 fed isolates colonized faster and achieved significantly higher steady-state abundances on model aggregates than those that were starved. However, there was no difference in detachment rates between fed and starved bacteria. The 3 selected strains had significantly lower average swimming speeds when starved. Diffusivities calculated from motilities of 2 starved isolates were more than 6 times lower than those of their fed counterparts. Our results show that starvation significantly affects bacterial behavior and bacteria–aggregate interactions, which may lead to differences in particulate and dissolved organic matter fluxes and cycling under different productivity regimes.

【 授权许可】

Unknown