| Abstract | New technologies development and renewable source exploitation are key tools to realize the European Green Deal and to boost the bio-based economy. In this context, fermentation of organic residues as food waste is an efficient method to obtain marketable products such as carboxylic acids widely applied in industrial production. Under favourable thermodynamic conditions, short chain fatty acids deriving from primary fermentation could be biologically converted into medium-chain fatty acids as caproate via chain elongation (CE) process, by using ethanol or lactate as electron donors. This study evaluates the effectivity of producing caproate from Food Waste extract rich in organics with in situ electron donor production. The test carried out at OLR 15 gCOD Ld showed high Volatile Fatty Acids (from acetic to caproic acid) yields (0.37 g gCOD), with a maximum caproate concentration of 8 g L. The associated microbiome was composed by lactate-producing bacteria (Corynebacterium, Lactobacillus, and Olsenella) and by chain elongators (Clostridiaceae and Caproiciproducens). By stressing the system with OLR increase up to 20 gCOD Ld, the CE process was inhibited by the high concentration of caproate (low occurrence of Clostridiaceae and Caproiciproducens). Nevertheless, after few days of stop-feeding regime imposed to the system, the microbiome restored its capability to proceed with lactate-based CE pathways. Different batch tests carried out with the inhibited biomass at increasing initial caproate concentration confirmed its impact on lactate utilization kinetics. |
| Text | 471119 2022 10.1016/j.wasman.2022.07.031 Scopus 2 s2.0 85134893120 Fermentation Chain elongation Lactate Food Waste Carboxylic acids Caproiciproducens Biorefining food waste through the anaerobic conversion of endogenous lactate into caproate A fragile balance between microbial substrate utilization and product inhibition Gazzola G.; Maria Braguglia C.; Crognale S.; Gallipoli A.; Mininni G.; Piemonte V.; Rossetti S.; Tonanzi B.; Gianico A. Water Research Institute, National Research Council of Italy, CNR IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Water Research Institute, National Research Council of Italy, CNR IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy, , , Italy; Water Research Institute, National Research Council of Italy, CNR IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Water Research Institute, National Research Council of Italy, CNR IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy, , , Italy; Faculty of Engineering, University Campus Bio Medico, Via Alvaro del Portillo, 21, Roma, 00128, Faculty of Engineering, University Campus Bio Medico, Via Alvaro del Portillo, 21, 00128 Roma, Italy, , Italy New technologies development and renewable source exploitation are key tools to realize the European Green Deal and to boost the bio based economy. In this context, fermentation of organic residues as food waste is an efficient method to obtain marketable products such as carboxylic acids widely applied in industrial production. Under favourable thermodynamic conditions, short chain fatty acids deriving from primary fermentation could be biologically converted into medium chain fatty acids as caproate via chain elongation CE process, by using ethanol or lactate as electron donors. This study evaluates the effectivity of producing caproate from Food Waste extract rich in organics with in situ electron donor production. The test carried out at OLR 15 gCOD Ld showed high Volatile Fatty Acids from acetic to caproic acid yields 0.37 g gCOD , with a maximum caproate concentration of 8 g L. The associated microbiome was composed by lactate producing bacteria Corynebacterium, Lactobacillus, and Olsenella and by chain elongators Clostridiaceae and Caproiciproducens . By stressing the system with OLR increase up to 20 gCOD Ld, the CE process was inhibited by the high concentration of caproate low occurrence of Clostridiaceae and Caproiciproducens . Nevertheless, after few days of stop feeding regime imposed to the system, the microbiome restored its capability to proceed with lactate based CE pathways. Different batch tests carried out with the inhibited biomass at increasing initial caproate concentration confirmed its impact on lactate utilization kinetics. 150 Published version http //www.scopus.com/record/display.url eid=2 s2.0 85134893120 origin=inward Articolo in rivista Pergamon Press, 0956 053X Waste management Elmsford Waste management Elmsford Waste management. Elmsford TONANZI BARBARA giuseppe.mininni MININNI GIUSEPPE GAZZOLA GIULIO simona.rossetti ROSSETTI SIMONA camillamaria.braguglia BRAGUGLIA CAMILLA MARIA andrea.gianico GIANICO ANDREA agata.gallipoli GALLIPOLI AGATA simona.crognale CROGNALE SIMONA |
