Dominance of candidate Saccharibacteria in a membrane bioreactor treating medium age landfill leachate: Effects of organic load on microbial communities, hydrolytic potential and extracellular polymeric substances. (August 2017)

• Record Type: Journal Article
• Authors: Remmas, Nikolaos; Melidis, Paraschos; Zerva, Ioanna; Kristoffersen, Jon Bent; Nikolaki, Sofia; Tsiamis, George; Ntougias, Spyridon
• Is Part Of: Bioresource technology. Volume 238(2017)
• Page Start: 48
• Page End: 56
• Publication Date: 2017-08
• Subjects: Candidate phylum Saccharibacteria (candidate division TM7) -- Cryptomycota (Rozellomycota) -- Candidate phylum Dojkabacteria (candidate division WS6) -- β-glucosidase -- Membrane fouling; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2017.04.019
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Organic load, salinity and NH4 + -N influenced EPS and SMP during leachate treatment. Exceptionally high β -glucosidase activities were determined during MBR operation. Candidate Saccharibacteria were dominant at any landfill leachate concentration. A massive shift in other bacterial taxa was observed at high organic loading rate. The new fungal phylum Cryptomycota was predominant at high organic loading rate. Abstract: A membrane bioreactor (MBR), accomplishing high nitrogen removal efficiencies, was evaluated under various landfill leachate concentrations (50, 75 and 100% v/v). Proteinous and carbohydrate extracellular polymeric substances (EPS) and soluble microbial product (SMP) were strongly correlated ( p < 0.01 ) with organic load, salinity and NH4 + -N. Exceptionally high β- glucosidase activities (6700–10, 100 U g −1 ) were determined during MBR operation with 50% v/v leachate, as a result of the low organic carbon availability that extendedly induced β- glucosidases to breakdown the least biodegradable organic fraction. Illumina sequencing revealed that candidate Saccharibacteria were dominant, independently of the leachate concentration applied, whereas other microbiota (21.2% of total reads) disappeared when undiluted leachate was used. Fungal taxa shifted from a Saccharomyces - to a newly-described Cryptomycota-based community with increasing leachate concentration. Indeed, this is the first report on the dominance of candidate Saccharibacteria and on the examination of their metabolic behavior in a bioreactor treating real wastewater.