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oai:uvadoc.uva.es:10324/467512022-07-18T09:33:09Zcom_10324_35294com_10324_952com_10324_894col_10324_35295

Elucidating the influence of environmental factors on biogas-based polyhydroxybutyrate production by Methylocystis hirsuta CSC1 Rodríguez Muñoz, Yadira Firmino, Paulo Igor Milen Arnáiz, Esther Lebrero Fernández, Raquel Muñoz Torre, Raúl Biogás Biogas Conversión de metano 23 Química Producción Científica The valorization of biogas as a feedstock for the generation of added-value bioproducts will play a key role on the sustainability of anaerobic digestion. The present work assessed the influence of key environmental parameters (O2:CH4 ratio, temperature and nitrogen source) on the growth and polyhydroxybutyrate (PHB) synthesis under nitrogen limiting conditions of the type II methanotroph Methylocystis hirsuta CSC1 using biogas as a feedstock. The O2:CH4 ratios tested (1:1, 1.5:1 and 2:1) did not affect significantly M. hirsuta CSC1 growth yields (~5 g TSS mol−1 CH4), although lower CH4 removal rates were reached under O2-limiting conditions (ratio 1:1). The highest PHB content (45 wt%) was achieved at a ratio 2:1 and was threefold higher than those obtained at lower ratios (~15 wt%). The increase in temperature from 15 to 25 °C resulted in increases in the growth yield (from 5 to 6 g TSS mol−1 CH4) and PHB content (from 32 to 40 wt%). Conversely, the lowest PHB content (30 wt%) was reached at 37 °C, together with a negligible growth under nutrient sufficient conditions. The nitrogen source also played a key role on both M. hirsuta CSC1 growth and PHB synthesis. Thus, ammonium resulted in the highest growth yield (7 g TSS mol−1 CH4), although the maximum PHB content was achieved when biomass was previously grown in nitrate as the nitrogen source (41 wt%). Nitrite exerted an inhibitory effect on M. hirsuta CSC1 growth. Ministerio de Economía y Competitividad (BES-2016-077160) y (proyecto CTM2015-70442-R) Junta de Castilla y León y EU-FEDER (CLU 2017-09), (VA281P18) y (UIC 071) 2021-06-04T12:01:56Z 2021-06-04T12:01:56Z 2020 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Science of The Total Environment, 2020, vol. 706, n. 1, p. 135136 0048-9697 https://uvadoc.uva.es/handle/10324/46751 10.1016/j.scitotenv.2019.135136 135136 Science of The Total Environment 706 eng https://www.sciencedirect.com/science/article/abs/pii/S0048969719351289 Attribution-NonCommercial-NoDerivatives 4.0 Internacional info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/4.0/ © 2020 Elsevier application/pdf Elsevier https://uvadoc.uva.es/bitstream/10324/46751/4/Elucidating-influence-environmental.pdf.jpg Hispana TEXT http://creativecommons.org/licenses/by-nc-nd/4.0/ UVaDOC. Repositorio Documental de la Universidad de Valladolid https://uvadoc.uva.es/handle/10324/46751