CAJ | 학술논문

从健康桑树根系中分离筛选得到一株内生产油脂真菌--菜豆壳球孢菌MOD-1(Macrophomina phaseolina,MOD-1).结合均匀设计和单因子筛选法得到该菌株产油脂发酵培养基最优配方为:可溶性淀粉105 g/L,蛋白胨1.1 g/L,磷酸二氢钾1.5 g/L,硫酸铵0.3 g/L,硫酸镁0.32 g/L,氯化锰4.9 nmol/L.在此基础上优化该菌株产油脂的摇瓶发酵条件为:发酵液初始pH 7.0,发酵温度26 ℃,摇瓶转速190 r/min,装液量100 mL.在优化后的培养基组分及摇瓶发酵条件下培养6 d,菌体生长量(干质量)高达41.852 g/L,油脂产量达到25.511 g/L.利用气相色谱-质谱法分别测定菌株在优化后的培养基或发酵条件下产生油脂的脂肪酸组成,前一种条件下检测出9种脂肪酸成分,其中单不饱和脂肪酸含量为67.92%;后一种条件下检测出7种脂肪酸成分,其中单不饱和脂肪酸含量为74.32%.结果表明,在优化培养基及摇瓶发酵条件下, MOD-1菌株的油脂产量增高,组成简单,易于纯化,且单不饱和脂肪酸含量较高.
종건강상수근계중분리사선득도일주내생산유지진균--채두각구포균MOD-1(Macrophomina phaseolina,MOD-1).결합균균설계화단인자사선법득도해균주산유지발효배양기최우배방위:가용성정분105 g/L,단백동1.1 g/L,린산이경갑1.5 g/L,류산안0.3 g/L,류산미0.32 g/L,록화맹4.9 nmol/L.재차기출상우화해균주산유지적요병발효조건위:발효액초시pH 7.0,발효온도26 ℃,요병전속190 r/min,장액량100 mL.재우화후적배양기조분급요병발효조건하배양6 d,균체생장량(간질량)고체41.852 g/L,유지산량체도25.511 g/L.이용기상색보-질보법분별측정균주재우화후적배양기혹발효조건하산생유지적지방산조성,전일충조건하검측출9충지방산성분,기중단불포화지방산함량위67.92%;후일충조건하검측출7충지방산성분,기중단불포화지방산함량위74.32%.결과표명,재우화배양기급요병발효조건하, MOD-1균주적유지산량증고,조성간단,역우순화,차단불포화지방산함량교고.
Macrophomina phaseolina MOD-1 is an endophytic oleaginous fungus isolated from the healthy mulberry root. To optimize medium composition and fermentation conditions for lipid production from MOD-1, the experiments with single factor and uniform design were conducted. The best medium composition was found with soluble starch 105 g/L, peptone 1.1 g/L, KH_2PO_4 1.5 g/L, (NH_4)_2SO_4 0.3 g/L, MgSO_4 0.32 g/L, and MnCl_2 4.9 nmol/L. Based on this culture medium, the optimal fermentation conditions were as follows: initial pH 7.0, temperature 26 ℃, rotation speed 190 r/min and medium volume 100 mL. After being cultured for 6 h under the optimized condition, the culture's dry cell weight was found as high as 41.852 g/L and lipid yield reached 25.511 g/L. Determination of fatty acid composition in the cultures obtained under optimized culture medium or fermentation condition by gas chromatography and mass spectrometry (GC-MS) revealed that there were 9 kinds of fatty acids in the lipids from the former condition, among which the content of monounsaturated fatty acids was 67.92%, and there were 7 kinds of fatty acids in the lipids from the latter condition, among which the content of monounsaturated fatty acids was 74.32%. The results indicate that, under optimized condition, lipid yield of MOD-1 is increased. Its lipid composition is simple and easy to be purified. Besides, it has a high content of monounsaturated fatty acids.