Labuzek S, Radecka I
Department of Biochemistry, Faculty of Biology and Environmental Protection, University of Silesia, Katowice, Poland.
J Appl Microbiol. 2001 Mar;90(3):353-7. doi: 10.1046/j.1365-2672.2001.01253.x.
The study was attempted to determine the ability of a Gram-positive Bacillus cereus UW85 strain to biosynthesize poly (3-hydroxybutyrate) copolymers when epsilon-caprolactone, or epsilon-caprolactone and glucose, were used as carbon sources.
Bacillus cereus was grown for 24 h under nitrogen-limited conditions in a mineral salts medium. Growth was monitored by measurement of turbidity. Glucose level was determined by the colorimetric anthrone
The epsilon-caprolactone concentration was determined by gas chromatography. The bacterial biopolymers were extracted with chloroform in a Soxhlet extractor and then characterized by nuclear magnetic resonance and gel permeation chromatography. When epsilon-caprolactone was used as a carbon substrate, the bacterial strain produced tercopolymer with 3-hydroxybutyrate, 3-hydroxyvalerate and 6-hydroxyhexanoate units. However, when caprolactone and glucose were supplied together, only homopolymer of poly (3-hydroxybutyrate) was produced.
All tercopolymers isolated from B. cereus UW85 cells were obtained with yields up to 9% (w/w) and low number-average molecular weight compared with the homopolymer PHB.
Bacillus cereus UW85 produced tercopolymer with a low molecular weight from one substrate (epsilon-caprolactone) used as a carbon source. The results are significant for the potential future application of Bacillus biopolymers to bioplastics production.
本研究旨在确定革兰氏阳性蜡样芽孢杆菌 UW85 菌株在以 ε-己内酯或 ε-己内酯与葡萄糖作为碳源时生物合成聚（3-羟基丁酸酯）共聚物的能力。
蜡样芽孢杆菌在氮限制条件下于无机盐培养基中培养 24 小时。通过测量浊度监测生长情况。葡萄糖水平通过比色法蒽酮法测定。ε-己内酯浓度通过气相色谱法测定。细菌生物聚合物在索氏提取器中用氯仿提取，然后通过核磁共振和凝胶渗透色谱法进行表征。当以 ε-己内酯作为碳底物时，该细菌菌株产生了含有 3-羟基丁酸酯、3-羟基戊酸酯和 6-羟基己酸酯单元的三元共聚物。然而，当同时提供己内酯和葡萄糖时，仅产生了聚（3-羟基丁酸酯）均聚物。
从蜡样芽孢杆菌 UW85 细胞中分离得到的所有三元共聚物产量高达 9%（w/w），与聚（3-羟基丁酸酯）均聚物相比，数均分子量较低。
蜡样芽孢杆菌 UW85 以一种用作碳源的底物（ε-己内酯）产生了低分子量的三元共聚物。这些结果对于蜡样芽孢杆菌生物聚合物未来在生物塑料生产中的潜在应用具有重要意义。
