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DatoValore
TitleEffect of the organic loading rate on the PHA-storing microbiome in sequencing batch reactors operated with uncoupled carbon and nitrogen feeding
AbstractOver the last years, in a search for sustainable and biodegradable alternatives to petrol-based plastics, biotechnological applications turned to the potentialities of mixed microbial cultures (MMC) for producing polyhydroxyalkanoates (PHAs). Under a feast and famine regime, an uncoupled carbon (C) and nitrogen (N)-feeding strategy may be adopted by dosing the C-source at the beginning of the feast and the N-source at the beginning of the famine in order to stimulate a PHA storage response and microbial growth. Even though this strategy has been already successfully applied for the PHA production, very few information is to date available regarding the MMC operating in these systems and the influence of Organic Loading Rate (OLR) on their selection and enrichment. To fill the gap, this study investigated the effect of the OLR on the selection of PHA-accumulating microorganisms in a sequencing batch reactor (SBR) operated with an uncoupled C and N feeding strategy. The SBR cycle length was set at 12 h and four OLRs values (4.25, 8.50, 12.75 and 18 gCOD L d) were tested by changing the concentration of the feeding solution, made of a synthetic mixture of acetic (85% of the overall COD) and propionic (15%) acids. The PHA-storage yield increased by increasing the OLR (up to 0.69 COD/COD at 12.75 gCOD L d) but significantly decreased (0.27 COD/COD) at 18 gCOD L d concomitantly with a longer feast phase and a lower PHA content in the biomass at the end of the feast phase. The selective pressure induced by the applied OLRs strongly influenced the microbiome composition revealing a high content of putative PHA-storing bacteria, such as Rhodobacter, Thauera and Paracoccus, in the SBR operated at OLRs 4.25, 8.50 and 12.75 g COD L d (up to 97.4% of total reads) and a low content (5.4%) in the SBR at 18 g COD L dwhere the predominance of genus Nitrinicola was instead observed.
SourceScience of the total environment 825
KeywordsPolyhydroxyalkanoates (PHA)Mixed Microbial Culture (MMC)Feast and famine regimeUncoupled C/N feeding
JournalScience of the total environment
EditorElsevier, Lausanne ;, Paesi Bassi
Year2022
TypeArticolo in rivista
DOI10.1016/j.scitotenv.2022.153995
AuthorsCrognale S.; Lorini L.; Valentino F.; Villano M.; Marzo Gago C.; Tonanzi B.; Majone M.; Rossetti S.
Text464956 2022 10.1016/j.scitotenv.2022.153995 Scopus 2 s2.0 85125125586 Polyhydroxyalkanoates PHA Mixed Microbial Culture MMC Feast and famine regime Uncoupled C/N feeding Effect of the organic loading rate on the PHA storing microbiome in sequencing batch reactors operated with uncoupled carbon and nitrogen feeding Crognale S.; Lorini L.; Valentino F.; Villano M.; Marzo Gago C.; Tonanzi B.; Majone M.; Rossetti S. Water Research Institute, National Research Council IRSA CNR , Rome, Monterotondo, Water Research Institute, National Research Council IRSA CNR Monterotondo, Rome, Italy, , , Italy; Water Research Institute, National Research Council IRSA CNR , Rome, Monterotondo, Water Research Institute, National Research Council IRSA CNR Monterotondo, Rome, Italy, , , Italy; Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome, 00185, Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy, , Italy; Department of Environmental Sciences, Informatics and Statistics, Ca Foscari University of Venice, Via Torino 155, Mestre Venice, 30170, Department of Environmental Sciences, Informatics and Statistics, Ca Foscari University of Venice, Via Torino 155, 30170 Mestre Venice, Italy, , Italy; Department of Chemical Engineering and Food Technology, Faculty of Science, IVAGRO, University of Cadiz, Puerto Real, Department of Chemical Engineering and Food Technology, Faculty of Science, IVAGRO, University of Cadiz, Puerto Real, Spain, , Spain Over the last years, in a search for sustainable and biodegradable alternatives to petrol based plastics, biotechnological applications turned to the potentialities of mixed microbial cultures MMC for producing polyhydroxyalkanoates PHAs . Under a feast and famine regime, an uncoupled carbon C and nitrogen N feeding strategy may be adopted by dosing the C source at the beginning of the feast and the N source at the beginning of the famine in order to stimulate a PHA storage response and microbial growth. Even though this strategy has been already successfully applied for the PHA production, very few information is to date available regarding the MMC operating in these systems and the influence of Organic Loading Rate OLR on their selection and enrichment. To fill the gap, this study investigated the effect of the OLR on the selection of PHA accumulating microorganisms in a sequencing batch reactor SBR operated with an uncoupled C and N feeding strategy. The SBR cycle length was set at 12 h and four OLRs values 4.25, 8.50, 12.75 and 18 gCOD L d were tested by changing the concentration of the feeding solution, made of a synthetic mixture of acetic 85% of the overall COD and propionic 15% acids. The PHA storage yield increased by increasing the OLR up to 0.69 COD/COD at 12.75 gCOD L d but significantly decreased 0.27 COD/COD at 18 gCOD L d concomitantly with a longer feast phase and a lower PHA content in the biomass at the end of the feast phase. The selective pressure induced by the applied OLRs strongly influenced the microbiome composition revealing a high content of putative PHA storing bacteria, such as Rhodobacter, Thauera and Paracoccus, in the SBR operated at OLRs 4.25, 8.50 and 12.75 g COD L d up to 97.4% of total reads and a low content 5.4% in the SBR at 18 g COD L dwhere the predominance of genus Nitrinicola was instead observed. 825 Published version http //www.scopus.com/record/display.url eid=2 s2.0 85125125586 origin=inward Effect of the organic loading rate on the PHA storing microbiome in sequencing batch reactors operated with uncoupled carbon and nitrogen feeding Crognale_2022_STOTEN_PHA.pdf Articolo in rivista Elsevier 0048 9697 Science of the total environment Science of the total environment Sci. total environ. TONANZI BARBARA simona.rossetti ROSSETTI SIMONA simona.crognale CROGNALE SIMONA