以Aspergillus terreus生產降膽固醇化合物Lovastatin

Hypocholesterolemic Compound Lovastatin Production with Aspergillus terreus

劉秋幸(Chiu-Hsing Liu) ； 蘇遠志(Yuan-Chi Su) ； 劉俊民(Chung-Ming Liou)

《中華生質能源學會會誌》 26卷3&4期 (2007/12) Pp. 79-91

https://doi.org/10.6385/JBESC.200712.0079

摘要

本研究中檢討以人工突變提高土黴菌Aspergillus terreus生產之降膽固醇化合物Lovastatin。以紫外線（UV）及NTG（N-Methyl-N’-nitro-N-nitrosoguanidine）為誘變原人工誘變。經測定誘變之條件以15W之UV、45 cm距離處理10分鐘，使致死率在99%之條件誘變，可得較高之變異率。在以NTG誘變時，以2.5mg/mL NTG處理10分鐘，再經冰浴處理30分鐘，使致死率為99%之條件，可得較高之變異率。供試菌株重覆上述條件以UV照射或NTG處理，所得之菌株再以50mg/L之Nystatin篩選，再經單細胞分離得突變株UV-906，其Lovastatin之產量為原菌株之3倍。突變後之菌株，其孢子器（Conidium）構造並無改變但較小，且菌絲變細。以5% Glycerol為碳源，0.25% NaNo_3，或2.4% Peptonized milk為氮源，添加0.25% Yeast extract為生長因子、0.25 mL/L Tween 60為界面活性劑，且以NaOH調節pH至7.0培養，可得較高菌體量，其Lovastatin生産量於培養第10天達最高429.5 mg/L。此外褐變反應產物及發酵過程中pH之控制皆可提升Lovastatin生合成。

關鍵字

Aspergillus terreus ； Lovastatin ； UV照射 ； NTG處理 ； 界面活性劑

並列摘要

To investigate the optimal conditions for lovastatin production with Aspergillus terreus, the tested strain was improved by mutagenic methods including UV irradiation and N-methyl- N'-nitro-N-nitrosoguanidine (NTG) treatment following by random screening or monospore isolation by nystatin-resistant mutants to enhance the yield of lovastatin. Among the isolated mutants, isolate UN-906 produced 3 times of lovastatin higher than the parent strain. The optimal culture medium for lovastatin production was 5% glycerol as carbon source, 0.25% NaN0_3 or 2.4% peptonized milk as nitrogen source, 0.25% yeast extract as growth factor, 0.25 mL/L Tween 60 as surfactant, and adjusted the culture pH to 7.0 with NaOH. The optimal culture conditions were after seed culture for two days, A. terreus UN-906 was transferred to production medium with 45% inoculumn size and shaked for 10 days at 28°C, 130 rpm. Each liter of culture medium produced 429.5 mg of lovastatin.

並列關鍵字

Aspergillus terreus ； Lovastatin ； UV Irradiation ； NTG Treatment ； Surfactant