研究报告
熊惠磊,张晓聪,杨海洋,张志强,段双妮,刘海涛,陈选平,施汉昌.碳同位素解析厌氧产酸过程挥发性有机酸来源[J].环境科学学报,2022,42(8):337-346
碳同位素解析厌氧产酸过程挥发性有机酸来源
- Sources of volatile organic acids in anaerobic acidification process by carbon isotope tracer technique
- 基金项目:国家重点研发计划政府间国际科技创新合作项目(No.2019YFE0109000);国家水体污染控制与治理科技重大专项(No.2009ZX07313-003)
- 熊惠磊
- 北京协同创新研究院,北京 100094;湘南学院,郴州 423099
- 张志强
- 农业农村部规划设计研究院,北京 100125
- 陈选平
- 湖南大自然环保科技有限公司,郴州 423099
- 施汉昌
- 北京协同创新研究院,北京 100094;清华大学环境学院,北京 100084
- 摘要:针对厌氧产酸条件下挥发性有机酸(VFAs)来源不明确及定向合成无依据的问题,基于同位素示踪技术对VFAs来源与合成比例进行研究.构建完全的厌氧产酸体系,采用牛血清蛋白、植物油和稳定同位素型葡萄糖(碳13丰度99%)作为反应底物,利用碳同位素示踪原理,定量分析VFAs的来源及其比例.结果表明:碳水化合物(碳13丰度99%)主要贡献偶数型短链脂肪酸的生成,其中对乙酸(HAc)和丁酸(HBu)的 贡献率分别为77%和86%;而蛋白质(碳12)主要贡献奇数型短链脂肪酸的生成,其中对丙酸(HPr)和戊酸(HVa)的贡献率分别为85%和99%.通过改变发酵底物中碳水化合物和蛋白质比例,可以有效调节水解液中奇数型与偶数型短链脂肪酸的浓度和比例,为后期微生物合成高品质聚羟基脂肪酸酯(PHA)提供物质基础.
- Abstract:The source and synthesis ratio of VFAs were studied in this paper using isotope tracer technology in view of the unclear source of volatile organic acids (VFAs) under anaerobic acid production and the lack of basis for directional synthesis. A complete anaerobic acid production system was constructed, in which bovine serum protein, vegetable oil and stable isotope glucose (99% abundance of C-13) were used as reaction substrates, and the source and proportion of VFAs were quantitatively analyzed by using the principle of carbon isotope tracing. The results showed that the carbohydrate (13C) would mainly promote the formation of even type short-chain fatty acids, with 77% and 86% contributions to acetic acid (HAc) and butyric acid (HBu), respectively. However, the protein (12C) could be more conducive to the synthesis of odd type short-chain fatty acids, in which the contribution rates to propionic acid (HPr) and valeric acid (HVa) were 85% and 99%, respectively. The concentration and ratio of odd and even short chain fatty acids in the hydrolysate can be effectively adjusted by changing the ratio of carbohydrate and protein in the fermentation substrate, so as to provide a material basis for the later microbial synthesis of high-quality polyhydroxyfatty acid esters (PHA).