Culturable bacteria from a full-scale desalination plant: Identification methods, bacterial diversity and selection of models based on membrane-biofilm community

Abstract

Bacterial models representative of a full-scale system are important requisites of biofouling studies. In this study, bacteria from upstream locations and from RO membranes were cultured and compared, using three identification methods, mainly to determine species-similarities and furthermore, to assess biochemical similarities between organisms from the upstream planktonic community and RO membranes, even if their taxonomy was not identical.Sixty-four bacterial strains from different locations of the Perth Seawater Desalination Plant, were isolated. There were similarities in species as well as carbon-source utilisation abilities of key models between cultures from upstream locations and membrane-biofilms. Pseudoalteromonas and Microbacterium were the most versatile in their metabolic abilities.Isolates were compared with the genetic biofilm communities on fourteen RO membrane units fouled over 7 years, from the full-scale plant [1]. Model fouling bacteria were selected based on their relative abundance in both culture and community profiles, phylogenetic and biochemical diversity. Bacteria from thirteen different genera were selected as models for exopolysaccharide-characterisation and biofouling studies, among which Pseudomonas and Bacillus were the most prevalent in both cultures and genetic biofilm community.