CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal.
LABBELS - Associate Laboratory, Braga/Guimarães, Portugal.
Appl Microbiol Biotechnol. 2024 Jul 16;108(1):419. doi: 10.1007/s00253-024-13248-6.
Waste glycerol is produced in excess by several industries, such as during biodiesel production. In this work, the metabolic versatility of anaerobic sludge was explored towards waste glycerol valorization. By applying different environmental (methanogenic and sulfate-reducing) conditions, three distinct microbial cultures were obtained from the same inoculum (anaerobic granular sludge), with high microbial specialization, within three different phyla (Thermodesulfobacteriota, Euryarchaeota and Pseudomonadota). The cultures are capable of glycerol conversion through different pathways: (i) glycerol conversion to methane by a bacterium closely related to Solidesulfovibrio alcoholivorans (99.8% 16S rRNA gene identity), in syntrophic relationship with Methanofollis liminatans (98.8% identity), (ii) fermentation to propionate by Propionivibrio pelophilus strain asp66 (98.6% identity), with a propionate yield of 0.88 mmol mmol (0.71 mg mg) and a propionate purity of 80-97% and (iii) acetate production coupled to sulfate reduction by Desulfolutivibrio sulfoxidireducens (98.3% identity). In conclusion, starting from the same inoculum, we could drive the metabolic and functional potential of the microbiota towards the formation of several valuable products that can be used in industrial applications or as energy carriers. KEY POINTS: Versatility of anaerobic cultures was explored for waste glycerol valorization Different environmental conditions lead to metabolic specialization Biocommodities such as propionate, acetate and methane were produced.
废弃甘油是由多个行业产生的过剩产物，如生物柴油生产过程中。在这项工作中，探索了厌氧污泥的代谢多功能性，以实现废弃甘油的增值利用。通过应用不同的环境（产甲烷和硫酸盐还原）条件，从相同的接种物（厌氧颗粒污泥）中获得了三种不同的微生物培养物，具有高度的微生物特异性，分属于三个不同的门（Thermodesulfobacteriota、Euryarchaeota 和 Pseudomonadota）。这些培养物能够通过不同的途径将甘油转化为：（i）与 Solidesulfovibrio alcoholivorans 密切相关的细菌（99.8% 16S rRNA 基因同一性）将甘油转化为甲烷，与 Methanofollis liminatans （98.8%同一性）形成共生关系，（ii）丙酸发酵为丙酸的丙酸杆菌属菌株 asp66（98.6%同一性），丙酸产率为 0.88mmolmmol（0.71mgmg），丙酸纯度为 80-97%，（iii）脱硫脱硫杆菌属通过硫酸盐还原偶联生成乙酸（98.3%同一性）。总之，从相同的接种物开始，我们可以驱动微生物群落的代谢和功能潜力，形成几种可用于工业应用或作为能源载体的有价值的产品。关键点：探索了厌氧培养物的多功能性，以实现废弃甘油的增值利用不同的环境条件导致代谢专业化产生了生物商品，如丙酸、乙酸和甲烷。
