Community structure of microbial biofilms associated with membrane-based water purification processes as revealed using a polyphasic approach

Abstract

The microbial communities of membrane biofilms occurring in two full-scale water purification processes employing microfiltration (MF) and reverse osmosis (RO) membranes were characterized using a polyphasic approach that employed bacterial cultivation, 16S rDNA clone library and fluorescence in situ hybridization techniques. All methods showed that the alpha-Proteobacteria was the largest microbial fraction in the samples, followed by the gamma-Proteobacteria. This suggested that members of these two groups could be responsible for the biofouling on the membranes studied. Furthermore, the microbial community structures between the MF and RO samples were considerably different in composition of the most predominant 16S rDNA clones and bacterial isolates from the alpha-Proteobacteria and only shared two common groups ( Bradyrhizobium, Bosea) out of more than 17 different bacterial groups observed. The MF and RO samples further contained Planctomycetes and Fibroacter/ Acidobacteria as the second predominant bacterial clones, respectively, and differed in minor bacterial clones and isolates. The community structure differences were mainly attributed to differences in feed water, process configurations and operating environments, such as the pressure and hydrodynamic conditions present in the water purification systems.

Technical Note: Community of bacteria attached on the PVDF MF membrane surface fouled from drinking water treatment, in Seoul, Korea

“…The α-proteobacteria was found to be the most predominant group on the MF membrane surface, which was in agreement with a previous study (Chen et al, 2004). The α-proteobacteria groups became the most dominant biofoulant under pressurized oligotrophic conditions.…”

“…The development of such characterization techniques are especially important for the identification of microbial communities in fouled membrane, which may provide a better understanding of biofouling formation mechanisms including microorganisms and EPS. Bacterial community structure analyses have recently been performed for membranes that were fouled during wastewater and effluent treatment (Ivnitsky et al, 2007;Miura et al, 2007;Pang and Liu, 2007;Chen et al, 2004). The bacterial community was identified using both polymerase chain reaction (PCR)-denaturing gradient Correspondence to: J. Cho (jwcho@gist.ac.kr) gel electrophoresis (DGGE) and 16S rDNA gene clone library methods, in conjunction with providing phylogenetic tree information.…”

A sequencing approach targeting the 16S rRNA gene unravels the biofilm composition of spiral-wound membranes used in the dairy industry

“…The short read lengths (400-440 bp) enabled a thorough taxonomic assignment for all samples at the genus level, with an overall low abundance of 1% of unclassified phyla. In comparison to many studies previously conducted on biofouling in water treatment plants (including desalination and waste water treatment plants), biofilm composition in the dairy industry is different, most notably because of the high proportion of Firmicutes, which are absent from water treatment plants (Chen et al 2004;Ivnitsky et al 2007;Huang et al 2008;Matin et al 2011;Khan et al 2013;Levi et al 2016).…”

Pyrosequencing analysis of roof-harvested rainwater and river water used for domestic purposes in Luthengele village in the Eastern Cape Province of South Africa

“…Alphaproteobacteria in freshwater systems (Chen et al 2004;Eichler et al 2006). The dominance of Betaproteobacteria and Alphaproteobacteria demonstrated the likelihood that fresh water ecosystems provided a conducive environment for enriching members within Betaproteobacteria and Alphaproteobacteria.…”

“…Freshwater habitats comprise a specific bacterial community in which Proteobacteria (mostly alpha-, beta-and gamma Proteobacteria) are dominant, although Actinobacteria, Bacteroidetes, Nitrospira, Chloroflexi, Cyanobacteria, and Verrucomicrobia are also frequently present (Zwart et al 2002). The dominance of Proteobacteria in drinking water has been demonstrated by a number of researchers (Zwart et al 2002;Chen et al 2004;Bricheux et al 2013). However the presence of other bacteria phylum will depend on the immediate sources of contamination or the fresh water ecosystem (Eichler et al 2006).…”