Effects of resource supplements on mature ciliate biofilms: an empirical test using a new type of flow cell

Abstract

Biofilm-dwelling consumer communities play an important role in the matter flux of many aquatic ecosystems. Due to their poor accessibility, little is as yet known about the regulation of natural biofilms. Here, a new type of flow cell is presented which facilitates both experimental manipulation and live observation of natural, pre-grown biofilms. These flow cells were used to study the dynamics of mature ciliate biofilms in response to supplementation of planktonic bacteria. The results suggest that enhanced ciliate productivity could be quickly transferred to micrometazoans (ciliate grazers), making the effects on the standing stock of the ciliates detectable only for a short time. Likewise, no effect on ciliates appeared when micrometazoan consumers were ab initio abundant. This indicates the importance of 'top-down' control of natural ciliate biofilms. The flow cells used here offer great potential for experimentally testing such control mechanisms within naturally cultivated biofilms.

Aquatic protists modulate the microbial activity associated with mineral surfaces and leaf litter

“…To gain their required carbon, microbial communities on organic substrates utilize the organic substances of the wood or leaf tissue itself. The carbon fixed in bacteria and algae is then transferred by grazing protists to the meio-and macrofauna (Augspurger et al 2008, Norf et al 2009). The nutrients released from grazing protists can be directly available to the local biofilm community or lost to downstream sites due to water flow.…”

An approach to determination of optimal species pool of periphytic microfauna in colonization surveys for marine bioassessment

“…Periphytic microfauna is an important component of benthic communities and plays necessary roles in energy transfer from bacteria and microalgae to the high trophic levels in microbial food webs (Azovsky 1988;Norf et al 2009;Xu et al 2011aXu et al , 2014a. With rapid responses to environmental changes, ease of sampling, and standardized methodologies for determining water quality status, microperiphyton has been considered as a useful bioindicator for monitoring programs to date (Cairns and Henebry 1982;Coppellotti and Matarazzo 2000;Xu et al 2009Xu et al , 2014b.…”

An approach to determining functional parameters of microperiphyton fauna in colonization surveys for marine bioassessment based on rarefaction curves

“…As consumers, the heterotrophic and mixotrophic components of the microperiphyton transfer the flow of both matter and energy from plankton to benthos (Kathol et al 2009;Norf et al 2009;Xu et al 2011Xu et al , 2014. With their rapid response to environmental changes, ease of sampling, and amenity to standardization for spatial and/or temporal evaluation, microperiphyton communities have widely been used as indicators of water quality in both freshwater and marine environments (Khatoon et al 2007;Risse-Buhl and Küsel 2009;Morin et al 2010;Xu et al 2014).…”