Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain.
Nestlé Research, Société des Produits Nestlé S.A, Route du Jorat 57, 1000 Lausanne, Switzerland.
Bioresour Technol. 2022 Sep;360:127655. doi: 10.1016/j.biortech.2022.127655. Epub 2022 Jul 20.
The feasibility of producing volatile fatty acids (VFAs) from five commercial bioplastics via acidogenic fermentation by a non-pretreated anaerobic sludge was investigated. Mesophilic, anaerobic, acidogenic batch assays at 1, 10 and 20 g/L feed concentrations revealed the feasibility of producing VFAs from polyhydroxyalkanoates (PHA), i.e., PHB and PHBV, but not from PBS, PCL and PLA under the test conditions and time. However, only high PHA substrate concentrations (10-20 g/L) resulted in organic overloading and decreasing the pH of the culture broth down to 4-5, which in turn induced the accumulation of VFAs via kinetic imbalance between acidogenesis and methanogenesis. Gaseous carbon (C-CO and C-CH) accounted for 8-35% of the total initial carbon, while C-VFAs represented 10-18%, mainly as acetate and butyrate. This study represents the first systematically assessed proof-of-concept to produce VFAs from PHA, which is key for the design of bioplastic-to-bioplastic recycling (bio)technologies.
研究了未经预处理的厌氧污泥通过产酸发酵从五种商业生物塑料生产挥发性脂肪酸（VFAs）的可行性。在 1、10 和 20 g/L 进料浓度下进行的中温、厌氧、产酸分批实验表明，聚羟基链烷酸酯（PHA），即 PHB 和 PHBV，可以从这些生物塑料中生产 VFAs，但 PBS、PCL 和 PLA 则不行。然而，只有高 PHA 基质浓度（10-20 g/L）会导致有机负荷过高，并将培养液的 pH 值降低到 4-5，这反过来又通过产酸和产甲烷之间的动力学失衡导致 VFAs 的积累。气态碳（C-CO 和 C-CH）占总初始碳的 8-35%，而 C-VFAs 则占 10-18%，主要为乙酸和丁酸。本研究首次系统评估了从 PHA 生产 VFAs 的概念验证，这是设计生物塑料到生物塑料回收（生物）技术的关键。
