高产酵母菌株(Rhodotorula bacarum)产普鲁兰多糖过程中搅拌和通气条件的优化

Optimization of Agitation and Aeration Conditions for High Pullulan-producing Strain of Rhodotorula bacarum

在过去的研究中发现普鲁兰多糖高产酵母菌株摇瓶发酵的最佳条件是 180r/min ,2 8℃ ,6 0h ,在此条件下该菌株可以产生质量体积分数为 5 9%的普鲁兰多糖。本文研究发现在 5L发酵罐中通气量和搅拌速度对该酵母菌株的普鲁兰多糖产量有很明显的影响。研究结果表明产普鲁兰多糖的最适通气量和搅拌速度分别是6 . 5L/min和 30 .0r/min。相应的 ,用每升含 80g的葡萄糖做发酵培养基 ,在 2 8℃条件下培养 72h ,其普鲁兰多糖的产量质量体积分数为达到 7. 5 % ,这是迄今为止所报道的产普鲁兰多糖酵母中产量最高的菌株。作者发现这株酵母菌产普鲁兰多糖高效合成过程的原因是其有很高的葡萄糖转化率。

In the previous studies,we found that Rhodotorula bacarum could produce 5.9% pullulan within 60 h at 28℃ under the optimal conditions in shaking flasks at 180 r/min. In this study,effects of agitation and aeration levels on pullulan production in 5 L fermentor by the strain were examined. The optimal agitation and aeration levels for pullulan production were found to be 300 r/min and 6.5 L/min,respectively. Under these conditions,7.5% pullulan was obtained from the fermentation medium with 80 g/L glucose within 72 h at 28℃. This was the highest yield of pullulan produced by the yeast strain reported so far. The synthetic process for pullulan production by this strain was very efficient because of a high conversion rate from glucose.