abstract
Mixed microbial cultures (MMC) and waste/surplus substrates, as hardwood spent sulfite liquor, are being used to decrease polyhydroxyalkanoates' (PHA) production costs. The process involves two or three steps, being the selection step a crucial one. For the industrial implementation of this strategy, reactor stability in terms of both performance and microbial community presence has to be considered. A long-term operation of a sequencing batch reactor under feast/famine conditions was performed along with microbial community identification/quantification using FISH and DGGE. The community was found to be extremely dynamic, dominated by Alphaproteobacteria, with Paracoccus and Rhodobacter present, both PHA-storing microorganisms. 16S rRNA gene clone library further revealed that side populations' non-PHA accumulators were able to strive (Agrobacterium, Flavobacteria, and Brachymonas). Nevertheless, reactor performance in terms of PHA storage was stable during operation time. The monitoring of the MMC population evolution provided information on the relation between community structure and process operation.
keywords
SEQUENCING BATCH REACTOR; POLY-BETA-HYDROXYBUTYRATE; MIXED MICROBIAL CULTURE; ACTIVATED-SLUDGE; PHA PRODUCTION; BIODEGRADABLE POLYMERS; WASTE-WATER; ENRICHMENT; ACCUMULATION; CULTIVATION
subject category
Biotechnology & Applied Microbiology
authors
Queiros, D; Fonseca, A; Rossetti, S; Serafim, LS; Lemos, PC
our authors
Alexandre Miguel Alves Fonseca
PhD Student
Diogo Cerqueira Queirós
PhD Student
Luísa Seuanes Serafim
Assistant Professoracknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013) and LAQV-REQUIMTE (FCT UID/QUI/50006/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007265). Authors acknowledge Eng. A. Prates from CAIMA, Industria de Celulose S.A., Constancia, Portugal for HSSL. Diogo Queiros thanks FCT for his PhD Grant (SFRH/BD/87758/2012).