title: Community-Level Physiological Profiling of Microbial Communities in Constructed Wetlands: Effects of Sample Preparation.
abstract: Community-level physiological profiling (CLPP) using BIOLOG® EcoPlates™ has become a popular method for characterizing and comparing the functional diversity, functional potential, and metabolic activity of heterotrophic microbial communities. The method was originally developed for profiling soil communities; however, its usage has expanded into the fields of ecotoxicology, agronomy, and the monitoring and profiling of microbial communities in various wastewater treatment systems, including constructed wetlands for water pollution control. When performing CLPP on aqueous samples from constructed wetlands, a wide variety of sample characteristics can be encountered and challenges may arise due to excessive solids, color, or turbidity. The aim of this study was to investigate the impacts of different sample preparation methods on CLPP performed on a variety of aqueous samples covering a broad range of physical and chemical characteristics. The results show that using filter paper, centrifugation, or settling helped clarify samples for subsequent CLPP analysis, however did not do so as effectively as dilution for the darkest samples. Dilution was able to provide suitable clarity for the darkest samples; however, 100-fold dilution significantly affected the carbon source utilization patterns (CSUPs), particularly with samples that were already partially or fully clear. Ten-fold dilution also had some effect on the CSUPs of samples which were originally clear; however, the effect was minimal. Based on these findings, for this specific set of samples, a 10-fold dilution provided a good balance between ease of use, sufficient clarity (for dark samples), and limited effect on CSUPs. The process and findings outlined here can hopefully serve future studies looking to utilize CLPP for functional analysis of microbial communities and also assist in comparing data from studies where different sample preparation methods were utilized.
authors.affiliation: Environmental Sciences Group, Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, K7K 7B4, Canada. Mark.Button@rmc.ca.
authors.forename: Mark
authors.initials: M
authors.lastname: Button
authors.affiliation: Environmental Sciences Group, Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, K7K 7B4, Canada.
authors.forename: Kela
authors.initials: K
authors.lastname: Weber
authors.affiliation: Helmholtz Center for Environmental Research (UFZ), Environmental and Biotechnology Center (UBZ), Permoserstrasse 15, Leipzig, 04318, Germany.
authors.forename: Jaime
authors.initials: J
authors.lastname: Nivala
authors.affiliation: Helmholtz Center for Environmental Research (UFZ), Environmental and Biotechnology Center (UBZ), Permoserstrasse 15, Leipzig, 04318, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Aubron
authors.affiliation: Helmholtz Center for Environmental Research (UFZ), Environmental and Biotechnology Center (UBZ), Permoserstrasse 15, Leipzig, 04318, Germany.
authors.forename: Roland Arno
authors.initials: RA
authors.lastname: Müller
mesh_terms: D005858:Germany; D007700:Kinetics; D064307:Microbiota; D015999:Multivariate Analysis; D010865:Pilot Projects; D014871:Water Microbiology; D053833:Wetlands
keywords: CLPP; Domestic wastewater; Horizontal flow; Microbial activity; Treatment wetland