Choi J, Lee S Y
Department of Chemical Engineering and BioProcess Engineering Research Center, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701, Korea.
Biotechnol Bioeng. 1999 Mar 5;62(5):546-53. doi: 10.1002/(sici)1097-0290(19990305)62:5<546::aid-bit6>3.0.co;2-0.
A simple method for the recovery of microbial poly(3-hydroxybutyrate) [P(3HB)] from recombinant Escherichia coli harboring the Ralstonia eutropha PHA biosynthesis genes was developed. Various acids (HCl, H2SO4), alkalies (NaOH, KOH, and NH4OH), and surfactants (dioctylsulfosuccinate sodium salt [AOT], hexadecyltrimethylammonium bromide [CTAB], sodium dodecylsulfate [SDS], polyoxyethylene-p-tert-octylphenol [Triton X-100], and polyoxyethylene(20)sorbitan monolaurate [Tween 20]) were examined for their ability to digest non-P(3HB) cellular materials (NPCM). Even though SDS was an efficient chemical for P(3HB) recovery from recombinant E. coli, it is expensive and has waste disposal problem. NaOH and KOH were also efficient and economical for the recovery of P(3HB), and therefore, were used to optimize digestion condition. When 50 g DCW/L of recombinant E. coli cells having the P(3HB) content of 77% was treated with 0.2 N NaOH at 30 degrees C for 1 h, P(3HB) was recovered with purity of 98.5%. Using this simple recovery method, the effect of recovery method on the final production cost of P(3HB) was examined. Processes for the production of P(3HB) by recombinant E. coli from glucose with two different recovery methods, surfactant-hypochlorite digestion and simple digestion with NaOH, were designed and analyzed. By employing the fermentation process that resulted in P(3HB) concentration, P(3HB) content and P(3HB) productivity of 157 g/L, 77%, and 3.2 P(3HB) g/L-h, respectively, coupled with the recovery method of NaOH digestion, the production cost of P(3HB) was US$ 3.66/kg P(3HB), which was 25% less than that obtained by employing the surfactant-hypochlorite digestion method.
开发了一种从携带真养产碱菌PHA生物合成基因的重组大肠杆菌中回收微生物聚（3-羟基丁酸酯）[P(3HB)]的简单方法。研究了各种酸（盐酸、硫酸）、碱（氢氧化钠、氢氧化钾和氢氧化铵）和表面活性剂（二辛基磺基琥珀酸钠[AOT]、十六烷基三甲基溴化铵[CTAB]、十二烷基硫酸钠[SDS]、聚氧乙烯对叔辛基苯酚[Triton X-100]和聚氧乙烯（20）山梨醇单月桂酸酯[Tween 20]）消化非P(3HB)细胞物质（NPCM）的能力。尽管SDS是从重组大肠杆菌中回收P(3HB)的有效化学试剂，但它价格昂贵且存在废物处理问题。氢氧化钠和氢氧化钾对P(3HB)的回收也有效且经济，因此用于优化消化条件。当50 g DCW/L含77% P(3HB)的重组大肠杆菌细胞在30℃下用0.2 N氢氧化钠处理1小时时，回收的P(3HB)纯度为98.5%。使用这种简单的回收方法，研究了回收方法对P(3HB)最终生产成本的影响。设计并分析了重组大肠杆菌从葡萄糖生产P(3HB)的两种不同回收方法的工艺，即表面活性剂-次氯酸盐消化法和氢氧化钠简单消化法。通过采用发酵工艺，分别得到P(3HB)浓度、P(3HB)含量和P(3HB)生产率为157 g/L、77%和3.2 P(3HB) g/L·h，再结合氢氧化钠消化回收方法，P(3HB)的生产成本为3.66美元/kg P(3HB)，比采用表面活性剂-次氯酸盐消化法低25%。
