| Title | Structural composition and metabolic activities of the microbiome involved in the production of n-caproate from food waste |
| Abstract | Recent applications of anaerobic digestion technology are moving towards production of high value-added products, such as carboxylic acids, from renewable resources in order to achieve a sustainable and circular bio-economy by minimizing waste production. Among the possible high value-added chemicals, this work focused on the biological production of medium chain fatty acids (e.g., caproate) from real food waste (FW). The long-term performance of chain elongation process was thoroughly investigated in a single-stage fermentation process, without addition of external electron donor (e.g., ethanol,lactate). Different organic load rates (OLRs) (i.e. 5,15,20 gCOD L-1d-1) were tested by using two different feeding strategies (a feeding cycle of 4 days with stop feeding cycle of 3 days and a discontinuous feeding every 3/4 days) both with a hydraulic retention time of 4 days and pH controlled at 6±0.2. The use of FW extract provided bioavailable sugars essential for primary fermentation, fostering lactate production together with volatile fatty acids useful for the subsequent chain elongation (Fig.1). Caproic acid biological productions was influenced by the applied OLRs, reaching its highest value (5.8gL-1) with a significant COD conversion of 21% at OLR =15gCOD L-1d-1 with discontinuous feeding. A cutting-edge biomolecular approach was used for describing the structural composition and metabolic activities of chain-elongating microbiome. The application of in situ hybridization techniques and high-throughput 16S rRNA gene sequencing revealed a core microbiome composed of lactate-producing Actinomyces, Atopobium, Lactobacillus and Olsenella, and caproate-producing Pseudoramibacter or Caprociproducens. In agreement with
process data, the existence of a stable long-term lactate-based chain elongation process was fully supported by metagenomics analysis revealing the presence of key enzymes for the
production of lactate, as well as several enzymes for chain elongation involved in the reverse ?-oxidation pathway. |
| Source | MEWE2021, Delft, NL, 18-20/10/2021 |
| Keywords | microbiomefood wasten-caproate16S rRNA gene sequencing |
| Year | 2021 |
| Type | Presentazione |
| Authors | Crognale S, Gallipoli A, Gianico A, Gazzola G, Montecchio D, Rossetti S, Braguglia CM |
| Text | 474717 2021 microbiome food waste n caproate 16S rRNA gene sequencing Structural composition and metabolic activities of the microbiome involved in the production of n caproate from food waste Crognale S, Gallipoli A, Gianico A, Gazzola G, Montecchio D, Rossetti S, Braguglia CM CNR IRSA, National Research Council of Italy, Water Research Institute, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Rome, Italy Recent applications of anaerobic digestion technology are moving towards production of high value added products, such as carboxylic acids, from renewable resources in order to achieve a sustainable and circular bio economy by minimizing waste production. Among the possible high value added chemicals, this work focused on the biological production of medium chain fatty acids e.g., caproate from real food waste FW . The long term performance of chain elongation process was thoroughly investigated in a single stage fermentation process, without addition of external electron donor e.g., ethanol,lactate . Different organic load rates OLRs i.e. 5,15,20 gCOD L 1d 1 were tested by using two different feeding strategies a feeding cycle of 4 days with stop feeding cycle of 3 days and a discontinuous feeding every 3/4 days both with a hydraulic retention time of 4 days and pH controlled at 6±0.2. The use of FW extract provided bioavailable sugars essential for primary fermentation, fostering lactate production together with volatile fatty acids useful for the subsequent chain elongation Fig.1 . Caproic acid biological productions was influenced by the applied OLRs, reaching its highest value 5.8gL 1 with a significant COD conversion of 21% at OLR =15gCOD L 1d 1 with discontinuous feeding. A cutting edge biomolecular approach was used for describing the structural composition and metabolic activities of chain elongating microbiome. The application of in situ hybridization techniques and high throughput 16S rRNA gene sequencing revealed a core microbiome composed of lactate producing Actinomyces, Atopobium, Lactobacillus and Olsenella, and caproate producing Pseudoramibacter or Caprociproducens. In agreement with process data, the existence of a stable long term lactate based chain elongation process was fully supported by metagenomics analysis revealing the presence of key enzymes for the production of lactate, as well as several enzymes for chain elongation involved in the reverse oxidation pathway. Preprint MEWE2021 Delft, NL 18 20/10/2021 Internazionale Contributo Presentazione GAZZOLA GIULIO simona.rossetti ROSSETTI SIMONA camillamaria.braguglia BRAGUGLIA CAMILLA MARIA andrea.gianico GIANICO ANDREA daniele.montecchio MONTECCHIO DANIELE agata.gallipoli GALLIPOLI AGATA simona.crognale CROGNALE SIMONA |
