Bacteria associated with copepods: abundance, activity and community composition

Abstract

We measured abundance, activity and community composition of bacteria associated with Calanus spp. in the North Sea in late July and compared it to the free living bacteria. Both the local density and production of bacteria associated with Calanus spp. were magnitudes higher than the average in a comparable volume of water. As analyzed by denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene sequencing, the bacterial community associated with Calanus spp. consisted of members of the Roseobacter lineage (Alphaproteobacteria), whereas the free living bacteria were more diverse. Discovery of an identical bacterial phylotype on Calanus spp. and in the free living community at the specific depth with the highest Calanus spp. biomass suggested an active exchange of bacteria between copepods and the free living state.

The microbiome of North Sea copepods

“…5a, b), which is widely distributed and observed frequently in marine environments (Wagner-Döbler and Biebl 2006). Hence, it is not surprising that this group was already identified to be associated with copepods in recent studies (Grossart et al 2009;Tang et al 2009a, b;Møller 2007Møller et al 2007Peter and Sommaruga 2008). Rhodobacterales are known to be rapid and successful primary surface colonisers (Porsby et al 2008;Dang et al 2008;Jones et al 2007).…”

“…Dimethylsulfoniumpropionate (DMSP)-consuming bacteria were already found to be associated with the marine calanoid copepod Acartia tonsa by Tang et al (2001). Møller et al (2007), who first investigated the bacterial community associated with Calanus helgolandicus (North Sea) using culture-independent methods (DGGE and subsequent sequencing), found that all of the three obtained bacterial sequences belonged to the Roseobacter lineage. Their phylotype NS17 (DQ839262) clusters with 13 sequences of the present study (Fig.…”

“…To date, it is not known whether copepods exhibit a distinct bacterial community related to their lifestyle or metabolism or whether they simply represent polymeric chitinous surfaces in the marine environment. Bacteria located on the copepod exterior, in the gut, on faecal pellets and carcasses have been investigated with different methods in a number of previous studies (Sochard et al 1979;Brandt et al 2010;Carman 1994;Nagasawa et al 1985;Nagasawa and Nemoto 1988;Delille and Razouls 1994;Hansen and Bech 1996;Carman and Dobbs 1997;Tang 2005;Møller et al 2007;Tang et al 2009b;Harding 1973;Nagasawa 1992;Kirchner 1995). However, these studies were only snap shots investigating geographically different marine sites and several copepod genera by applying a vast variety of methods.…”

Comparison of different DNA-extraction techniques to investigate the bacterial community of marine copepods

“…These studies showed that the bacterial community of freshly dispatched copepods was different from that of copepods which were incubated for some days. Møller et al (2007) first investigated the bacterial community associated with Calanus sp. using PCR-DGGE and compared it with the community of the surrounding water.…”

“…5) Møller et al (2007). Phylotype Aca_104/1 clusters with a bacterium detected in a Taiwanese mangrove ecosystem (DQ234217) (Liao et al 2007), while sequence Tem_104/37 is related to a surface water bacterium from the German Bight (DQ911789).…”