, 1995; Kominkova et al., 2000). Most works reveal fungi, especially aquatic Selleck Natural Product Library hyphomycetes, as the dominant players, in terms of activity

and biomass increase, during early decomposition of leaf litter in aquatic ecosystems (Baldy et al., 1995; Romaní et al., 2006). However, phenol-degrading bacteria may also be involved in decomposition of recalcitrant plant material in aquatic environments, although their potential role is much less investigated. Phenol-degrading bacteria are highly adaptive, as observed through the analysis of key functional genes in communities growing in biological wastewater treatment plants (Futamata et al., 2003; Basile & Erijman, 2010). Phenol hydroxylases, which convert phenol into catechol derivatives via hydroxylation, are specific phenol oxidases generally involved in the degradation of organic compounds. These enzymes have been extensively studied at the molecular level, and they can now be detected in natural samples by high-throughput analytical methods. Multicomponent phenol hydroxylases (mPHs) are considered to be predominant in nature (Nordlund et al., 1993; Watanabe et al., 2002). The largest subunit of multicomponent phenol hydroxylases (LmPHs) has been used as a molecular marker to assess the functional

and genetic diversities of biotechnologically relevant phenol-degrading bacteria (Futamata et al., 2005; Viggor et al., 2008). Moreover, phenol-degrading Adriamycin bacteria have been isolated and characterized from the phyllosphere of trees showing that leaves may contain a significant bacterial diversity with respect to LmPH sequence similarities (Sandhu et al., 2009). However, to the best Protirelin of our knowledge, no experimental report exists describing the change in the bacterial phenol-degrading community during leaf litter by the use of selected molecular markers targeting to functional genes. In this study, we have used the LmpH gene as a molecular proxy to analyze the changes in the phenol-degrading bacterial community during the decomposition of submersed

Platanus acerifolia [Aiton] Willd. leaves in a forested stream. We hypothesize that phenol-degrading bacteria might contribute to leaf litter breakdown and that their community structure might change throughout the decomposition process as higher amounts of free phenolic compounds are available. To test this hypothesis, three discrete sampling dates were chosen according to mass weight and enzymatic activity data from a previous experiment of leaf litter decomposition. Selected samples covered the main observed changes in microbial activity and biomass. The observed changes of the bacterial community indicate that a specialization of potential phenol-degrading bacteria exists during the decomposition of leaves.