Do bacteria influence the sensitivity of phytoplankton to allelochemicals from submerged macrophytes?

摘要

The inhibition of phytoplankton by allelochemicals released from submerged macrophytes has been demonstrated in numerous studies, but the relevance of this process at ecosystem level is still debated because in situ evidence is difficult to achieve (Gross et al. 2007, Hilt & Gross 2008). An unsolved question is whether microorganisms interfere with this process by transforming allelopathically active substances (Gross et al. 1996, Nakai et al. 1999) or otherwise modifying the effect of allelochemicals on phytoplankton. Bacteria suspended in the surrounding water as well as those in biofilms attached to the exuding submerged macrophytes and the target phytoplankton species may potentially have an impact. Muller et al. (2007) were the first to isolate bacteria associated with the surrounding water column and the attached biofilm of an allelopathically active submerged macrophyte species {Myriophyllum spicatum L.) that were able to degrade polyphenols, the main allelopathically active compounds.