Biology Department, Marine Biology, Ghent University, Campus Sterre, Krijgslaan 281-S8, 9000 Ghent, Belgium.
Microb Ecol. 2010 Oct;60(3):581-91. doi: 10.1007/s00248-010-9669-7. Epub 2010 May 4.
Fecal pellets make up a significant fraction of the global flux of organic matter in oceans, and the associated bacterial communities in particular are a potential food source for marine organisms. However, these communities remain largely unknown. In the present study, the bacterial communities on fecal pellets of the benthic copepod Paramphiascella fulvofasciata feeding on the diatoms Navicula phyllepta and Seminavis robusta were analyzed. The aim of this study was to characterize the bacterial communities associated with the diatoms and the fecal pellets by means of DGGE profiling. Furthermore, isolated bacteria were characterized by means of partial 16S rRNA gene sequencing. The composition of the bacterial microflora on fecal pellets was studied in terms of the effect of the original food source, the age of the fecal pellets and the copepod's identity. Alphaproteobacteria, Flavobacteria, and Bacilli were found on the fecal pellets; whereas on diatoms, exclusively Gammaproteobacteria were identified. Especially after eating N. phyllepta, there was an important increase in bacterial diversity, although the diatom N. phyllepta harbored a less diverse bacterial community than S. robusta. Our data suggest that the additional bacteria originate from the copepod's digestive tract and largely depends on the initial food source.
粪便颗粒构成了海洋中有机质全球通量的重要部分，特别是相关的细菌群落，是海洋生物的潜在食物来源。然而，这些群落仍然很大程度上不为人知。本研究分析了底栖桡足类 Paramphiascella fulvofasciata 摄食硅藻 Navicula phyllepta 和 Seminavis robusta 后粪便颗粒上的细菌群落。本研究的目的是通过 DGGE 分析来描述与硅藻和粪便颗粒相关的细菌群落。此外，还通过部分 16S rRNA 基因测序对分离的细菌进行了表征。通过研究原始食物来源、粪便颗粒的年龄和桡足类的身份对粪便颗粒上细菌微生物群组成的影响来研究细菌微菌群的组成。在粪便颗粒上发现了α变形菌门、黄杆菌门和芽孢杆菌门；而在硅藻上，则只鉴定出γ变形菌门。特别是在摄食 N. phyllepta 之后，细菌多样性有了重要的增加，尽管硅藻 N. phyllepta 拥有的细菌群落多样性比 S. robusta 少。我们的数据表明，额外的细菌来源于桡足类的消化道，并且在很大程度上取决于初始食物来源。
