Greses Silvia, De Bernardini Nicola, Treu Laura, Campanaro Stefano, González-Fernández Cristina
Biotechnological Processes Unit, IMDEA Energy, Avda. Ramón de la Sagra 3, 28935 Móstoles, Madrid, Spain.
Department of Biology, University of Padova, Via U. Bassi 58/b, 35121 Padova, Italy.
Bioresour Technol. 2023 Jun;377:128920. doi: 10.1016/j.biortech.2023.128920. Epub 2023 Mar 18.
Added-value chemicals production via food waste (FWs) valorization using open-mixed cultures is an emerging approach to replace petrochemical-based compounds. Nevertheless, the effects of operational parameters on the product spectrum remain uncertain given the wide number of co-occurring species and metabolisms. In this study, the identification of 58 metagenome-assembled genomes and their investigation assessed the effect of slight pH variations on microbial dynamics and the corresponding functions when FWs were subjected to anaerobic fermentation (AF) in 1-L continuous stirred tank reactors at 25 °C. The initial pH of 6.5 promoted a microbial community involved in acetate, butyrate and ethanol production, mediated by Bifidobacterium subtile IE007 and Eubacteriaceae IE027 as main species. A slight pH decrease to 6.1 shaped microbial functions that resulted in caproate and H production, increasing the relevance of Eubacteriaceae IE037 role. This study elucidated the strong pH effect on product outputs when minimal variations take place in AF.
利用开放混合培养物对食品废弃物（FWs）进行增值处理以生产增值化学品，是一种替代石化基化合物的新兴方法。然而，鉴于同时存在的物种和代谢种类繁多，操作参数对产物谱的影响仍不确定。在本研究中，通过鉴定58个宏基因组组装基因组并对其进行研究，评估了在25℃下1升连续搅拌釜式反应器中对FWs进行厌氧发酵（AF）时，轻微pH变化对微生物动态及相应功能的影响。初始pH为6.5时，以微妙双歧杆菌IE007和真杆菌科IE027为主要菌种，促进了参与乙酸、丁酸和乙醇生产的微生物群落的形成。pH轻微降至6.1时，塑造了导致己酸和氢气产生的微生物功能，增加了真杆菌科IE037的作用相关性。本研究阐明了在厌氧发酵过程中，当pH发生微小变化时，其对产物产量有强烈影响。
