a Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
Can J Microbiol. 2014 Jul;60(7):461-8. doi: 10.1139/cjm-2014-0108. Epub 2014 Jun 5.
Medium-chain-length polyhydroxyalkanoate (mcl-PHA) production by Pseudomonas putida LS46 was analyzed in shake-flask-based batch reactions, using pure chemical-grade glycerol (PG), biodiesel-derived "waste" glycerol (WG), and biodiesel-derived "waste" free fatty acids (WFA). Cell growth, substrate consumption, mcl-PHA accumulation within the cells, and the monomer composition of the synthesized biopolymers were monitored. The patterns of mcl-PHA synthesis in P. putida LS46 cells grown on PG and WG were similar but differed from that of cells grown with WFA. Polymer accumulation in glycerol-based cultures was stimulated by nitrogen limitation and plateaued after 48 h in both PG and WG cultures, with a total accumulation of 17.9% cell dry mass and 16.3% cell dry mass, respectively. In contrast, mcl-PHA synthesis was independent of nitrogen concentration in P. putida LS46 cells cultured with WFA, which accumulated to 29% cell dry mass. In all cases, the mcl-PHAs synthesized consisted primarily of 3-hydroxyoctanoate (C(8)) and 3-hydroxydecanoate (C(10)). WG and WFA supported similar or greater cell growth and mcl-PHA accumulation than PG under the experimental conditions used. These results suggest that biodiesel by-product streams could be used as low-cost carbon sources for sustainable mcl-PHA production.
采用摇瓶分批反应，分析了恶臭假单胞菌 LS46 利用纯化学级甘油 (PG)、生物柴油衍生的“废”甘油 (WG) 和生物柴油衍生的“废”游离脂肪酸 (WFA) 生产中链长度聚羟基烷酸酯 (mcl-PHA)。监测了细胞生长、底物消耗、细胞内 mcl-PHA 积累以及合成生物聚合物的单体组成。在 PG 和 WG 上生长的 LS46 细胞中 mcl-PHA 合成的模式相似，但与用 WFA 生长的细胞不同。在 PG 和 WG 培养物中，氮限制刺激了基于甘油的培养物中的聚合物积累，48 小时后达到平台期，分别积累了 17.9%的细胞干重和 16.3%的细胞干重。相比之下，在含有 WFA 的 LS46 细胞中，mcl-PHA 的合成与氮浓度无关，其积累到 29%的细胞干重。在所有情况下，合成的 mcl-PHA 主要由 3-羟基辛酸 (C(8)) 和 3-羟基癸酸 (C(10)) 组成。在所用的实验条件下，WG 和 WFA 支持的细胞生长和 mcl-PHA 积累与 PG 相似或更高。这些结果表明，生物柴油副产物流可以用作可持续 mcl-PHA 生产的低成本碳源。
