Long-term operation of a two-stage polyhydroxyalkanoates production process from hardwood sulphite spent liquor

authors	Queiros, D; Fonseca, A; Lemos, PC; Serafim, LS
nationality	International
journal	JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
author keywords	polyhydroxyalkanoates; mixed microbial cultures; waste treatment; aerobic process; bioconversion; kinetic parameters
keywords	MIXED MICROBIAL CULTURES; SEQUENCING BATCH REACTOR; MILL WASTE-WATER; ACTIVATED-SLUDGE; PHA PRODUCTION; BIODEGRADABLE POLYMERS; STRATEGIES; BIOSYNTHESIS; FEEDSTOCK; MOLASSES
abstract	BACKGROUNDThe development of sustainable industrial processes demands the recovery and transformation of their by-products. The production of polyhydroxyalkanoates (PHAs) by mixed microbial cultures (MMC) is one of the available routes. This study evaluated the possibility of applying a two-step PHAs production process using an industrial by-product, hardwood sulphite spent liquor (HSSL), as feedstock for a MMC. The first step consisted in the selection of PHAs-storing microorganisms using an aerobic dynamic feeding strategy followed by a second step, accumulation. RESULTSThe selected MMC, despite not being able to use the main carbon source of HSSL, lignosulphonates, revealed the capacity to consume acetate and xylose to accumulate poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and glucose biopolymer. The maximum PHAs content was relatively low, 6.6%, with a maximum production yield of 0.49 C-mmol HA C-mmol S-1 during the selection stage. CONCLUSIONA MMC was able to adapt to HSSL by consuming acetate and xylose. The imposed operational conditions resulted in a partial selection of the culture, since only acetate-consuming organisms experienced a real feast/famine regime, resulting in low PHAs production. (c) 2015 Society of Chemical Industry
publisher	WILEY-BLACKWELL
issn	0268-2575
year published	2016
volume	91
issue	9
beginning page	2480
ending page	2487
digital object identifier (doi)	10.1002/jctb.4841
web of science category	Biotechnology & Applied Microbiology; Chemistry, Multidisciplinary; Engineering, Environmental; Engineering, Chemical
subject category	Biotechnology & Applied Microbiology; Chemistry; Engineering
unique article identifier	WOS:000380044800013