Logan Mohanakrishnan, Zhu Fengyi, Lens Piet N L, Cetecioglu Zeynep
Department of Chemical Engineering, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm SE 100 44, Sweden.
Department of Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland, University Road, Galway H91 TK33, Ireland.
ACS Omega. 2023 Sep 14;8(38):34397-34409. doi: 10.1021/acsomega.2c06459. eCollection 2023 Sep 26.
Developing novel strategies to enhance volatile fatty acid (VFA) yield from abundant waste resources is imperative to improve the competitiveness of biobased VFAs over petrochemical-based VFAs. This study hypothesized to improve the VFA yield from food waste via three strategies, viz., pH adjustment (5 and 10), supplementation of selenium (Se) oxyanions, and heat treatment of the inoculum (at 85 °C for 1 h). The highest VFA yield of 0.516 g COD/g VS was achieved at alkaline pH, which was 45% higher than the maximum VFA production at acidic pH. Heat treatment resulted in VFA accumulation after day 10 upon alkaline pretreatment. Se oxyanions acted as chemical inhibitors to improve the VFA yield at pH 10 with non-heat-treated inoculum (NHT). Acetic and propionic acid production was dominant at alkaline pH (NHT); however, the VFA composition diversified under the other tested conditions. More than 95% Se removal was achieved on day 1 under all the conditions tested. However, the heat treatment was detrimental for selenate reduction, with less than 15% Se removal after 20 days. Biosynthesized Se nanoparticles were confirmed by transmission and scanning electron microscopy and and energy dispersive X-ray analyses. The heat treatment inhibited the presence of nonsporulating bacteria and methanogenic archaea (). High-throughput sequencing also revealed higher relative abundances of the bacterial families (such as , , and ) that are capable of VFA production and/or selenium reduction.
开发新策略以提高从丰富的废弃资源中产生挥发性脂肪酸（VFA）的产量，对于提高生物基VFA相对于石化基VFA的竞争力至关重要。本研究假设通过三种策略提高食物垃圾中VFA的产量，即pH调节（5和10）、补充硒（Se）含氧阴离子以及对接种物进行热处理（85°C处理1小时）。在碱性pH条件下实现了最高VFA产量0.516 g COD/g VS，比酸性pH下的最大VFA产量高45%。热处理导致碱性预处理10天后VFA积累。在接种未热处理（NHT）的情况下，Se含氧阴离子在pH 10时作为化学抑制剂提高了VFA产量。在碱性pH（NHT）条件下，乙酸和丙酸的产生占主导；然而，在其他测试条件下VFA组成多样化。在所有测试条件下，第1天实现了超过95%的Se去除。然而，热处理不利于硒酸盐还原，20天后Se去除率低于15%。通过透射和扫描电子显微镜以及能量色散X射线分析确认了生物合成的Se纳米颗粒。热处理抑制了非芽孢杆菌和产甲烷古菌的存在。高通量测序还揭示了能够产生VFA和/或还原硒的细菌家族（如 、 和 ）的相对丰度更高。
