Influence of removal of microbial inhibitors on PHA production from spent coffee grounds employing Halomonas halophila. Issue 2 (April 2018)

• Record Type: Journal Article
• Authors: Kovalcik, Adriana; Kucera, Dan; Matouskova, Petra; Pernicova, Iva; Obruca, Stanislav; Kalina, Michal; Enev, Vojtěch; Marova, Ivana
• Is Part Of: Journal of environmental chemical engineering. Volume 6:Issue 2(2018)
• Page Start: 3495
• Page End: 3501
• Publication Date: 2018-04
• Subjects: Antioxidants -- Phenolics -- Polyhydroxyalkanoates -- Resource recovery -- Spent coffee grounds -- Waste minimization; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2018.05.028
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Abstract: The valorization of food waste is the sustainable way how to handle resources wisely. Spent coffee grounds (SCGs) are waste products of the instant coffee production and coffee brewing. The potential of Halomonas halophila to produce polyhydroxyalkanoates (PHA) from fermentable sugars derived from SCGs has been studied. This organism was able to process SCG hydrolysates as a carbon source for its growth. Diluted acid hydrolysis (4.0 vol.% sulfuric acid, 120 min, 100 °C) has been employed, and three different SCG hydrolysates from non-modified SCGs, defatted SCGs and defatted SCGs with the eliminated phenolics have been prepared. However, in shake flask fermentation cultures, the growth of H. halophila was entirely inhibited on all the hydrolysates. Therefore, the hydrolysates have been detoxified using sorbent based on styrene-divinylbenzene based resins. When H. halophila was grown on detoxified hydrolysates, poly(3-hydroxybutyrate) (P3HB) was accumulated during 72 h. The biopolymer was characterized by gas chromatography, and size exclusion chromatography coupled with multiangle light scattering and differential refractometry. PHB titers reached 0.95 g/L with PHB content in bacteria cell dry mass 27% (wt/wt), the molecular weight of the produced polymer was about 440–825 kDa. This study demonstrates that at least the detoxification of SCG hydrolysates with sorbent was necessary to promote the fermentation of H. halophila . Moreover, the extraction of coffee oil and phenolics from SCG as a detoxification pretreatment step contributes to the increase of economic and environmental values of spent coffee grounds in the case of the cascading utilization and resource recovery.