无黑色素普鲁兰多糖出芽短梗霉的选育

Breeding of a pigment-free pullulan production mutant strain of Aureobasidium pullulans

摘要: 为选育一株高产无黑色素普鲁兰多糖的出芽短梗霉（Aureobasidium pullulans）,以A.pullulans As.40329和A.pullulans As.3#为出发菌株,通过紫外诱变（15 W）筛选出三株正突变菌株作为亲本。在此基础上,对三株亲本制备原生质体并采用35%的PEG4000介导进行全基因重组（Genome shuffling,GS）。随后,经双亲灭活筛选后获得A.pullulans的全基因重组菌F2-6。结果表明,菌株F2-6遗传性状稳定且发酵多糖产物中近乎无黑色素（OD654维持在0.02左右）,多糖产量提高至（19.53±0.39）g/L,比原始菌As.3#提高119.69%,表明重组菌F2-6具有工业化生产普鲁兰多糖的潜能。

Abstract: To screen an Aureobasidium pullulans that could be used for the production of pigment-free pullulan, A. pullulans As.40329 and A.pullulans As.3 # were used as hosts in the present study. Three positive mutants were obtained as parents after ultraviolet ( 15 W) induced mutation of the two hosts, followed with genome shuffling ( GS) that mediated by 35% PEG 4000, and a stable A. pullulans strain F2-6 was obtained after parental inactivation. Nearly no pigment was detected in the culture of A.pullulans F2-6, and pullulan production reached to ( 19.53 ± 0.39) g/L, 119.69% higher than that of A. pullulans As.3 #. The results indicated that A.pullulans F2-6 could be used as a potential strain in industrial production process.