Kim Hyung Soo, Park Young In
Department of Biotechnology, School of Life Science and Biotechnology, Korea University, Seoul, Korea.
J Microbiol Biotechnol. 2007 Oct;17(10):1638-44.
The effect of carbon sources on tacrolimus production by a mutant strain of Streptomyces clavuligerus CKD 1119, an isolate from soil, was examined. Among the carbohydrates and oils tested in this work, a mixed carbon source of soluble starch and corn oil was the best. An analysis of the culture kinetics also showed that, in contrast to the carbohydrates, the corn oil was consumed later in the antibiotic production phase, implying that the oil substrate was the principal carbon source for the biosynthesis of tacrolimus, and this was directly proven by experiments using 14C-glucose and 14C-oleate substrates. Furthermore, corn oil induced the formation of lipase by the mutant strain, whereas the addition of glucose significantly repressed lipase activity. The lipase activity exhibited by the FK-506-overproducing mutants was also observed to be directly proportional to their tacrolimus yield, indicating that a high lipase activity is itself a crucial factor for tacrolimus production. A feasibility study with a 200-l pilot-scale fermentor and the best strain (Tc-XII- 15322) identified in this work revealed a high volumetric and specific productivity of about 495 mg/l and 0.34 mg/mg dry mycelium, respectively.
研究了碳源对从土壤中分离得到的克拉维链霉菌CKD 1119突变株生产他克莫司的影响。在这项工作中测试的碳水化合物和油类中，可溶性淀粉和玉米油的混合碳源是最佳的。培养动力学分析还表明，与碳水化合物不同，玉米油在抗生素生产阶段后期才被消耗，这意味着油底物是他克莫司生物合成的主要碳源，使用14C-葡萄糖和14C-油酸底物的实验直接证明了这一点。此外，玉米油诱导突变株形成脂肪酶，而添加葡萄糖则显著抑制脂肪酶活性。还观察到过量生产FK-506的突变株所表现出的脂肪酶活性与其他克莫司产量成正比，表明高脂肪酶活性本身是他克莫司生产的关键因素。使用200升中试规模发酵罐以及在这项工作中鉴定出的最佳菌株（Tc-XII-15322）进行的可行性研究表明，体积产率和比生产率分别约为495毫克/升和0.34毫克/毫克干菌丝体。
