利用啤酒废弃物培养Bt的条件与补料优化

Optimization of Fermentation Conditions and Feed Batch Modes of Bt Using Brewery Waste Medium

以污水源分离菌株Bt BRC-WLY1为供试菌,以啤酒废弃物为培养基,单因素实验优化发酵条件,并探讨补麦芽糖、预处理后的新鲜啤酒酵母液(下称酵母液)和KH2PO4的不同补料成分和补料时间对发酵水平的影响。结果显示,优化的最佳发酵条件是初始pH7.5～8.0、装液量80 mL、发酵温度30℃、接种量5%。最佳补料方式为发酵8 h,加入10%的酵母液,与未补料对比,芽胞数、晶体干重、生产强度和单位糖产量分别提高了8、1.78、0.98、3.07倍。

Bt BRC-WLY1 isolated from wastewater-digestive plants was cultivated in brewery-waste-medium by submerged fermentation with the single factor study to optimize the fermentation conditions in the experiment and the affection of fermentation of Bt by different feeding modes and feeding composition of material, pretreatmented brewery yeast fluid （yeast fluid）, KH2PO4 and feeding time on fermentation were also explored . The results showed that the optimal conditions comprised initial pH at 7.5-8.0, 80 mL of liquid volume in the 500 mL flask, fermentation temperature at 30℃ and 5% of inoculation volume. The optimal fed batch mode was fedding 10% （V/V） of yeast fluid after cultured for 8 hr, which resulted in spores yield, crystal weightiness, production intensity and yield of units sugar increased 8, 1.78, 0.98 and 3.07 times than those of fermentation without fed batched.