竹笋加工废弃物发酵菌种的筛选及其发酵工艺优化

Screening and optimization of fermentation process of bamboo shoot processing wastes

为提高竹笋加工废弃物的饲用价值,扩大动物饲料原料来源,本试验采用平板分离法从腐烂稻草中分离1株能降解纤维素的菌株HYH-1。通过形态学观察、生理生化试验和16S rDNA序列分析对分离菌株进行鉴定。以纤维素降解率为指标,通过单因素试验探究了葡萄糖添加量、KH_(2)PO_(4)添加量、MgSO_(4)·7H_(2)O添加量、固水比、接种量、发酵时间、发酵温度等对纤维素降解率的影响。在单因素试验结果基础上,采用响应面法对纤维素降解率影响较大的因素如葡萄糖添加量、KH_(2)PO_(4)添加量、固水比和接种量进行了优化。结果表明:纤维素降解菌HYH-1被鉴定为耐盐芽孢杆菌(Bacillus halodurans)。建立了竹笋加工废弃物固体发酵条件的二次回归模型,该模型极显著,拟合度良好。适宜的发酵工艺为葡萄糖2.9%,KH_(2)PO_(4)2.9%,MgSO_(4)·7H_(2)O 0.15%,固水比1:1,接种量11.50%,发酵时间8 d,发酵温度37℃。此条件下,竹笋加工废弃物中纤维素降解率达到54.85%。研究结果为竹笋加工废弃物的资源化利用提供了理论参考依据。

To improve the feeding value of bamboo shoots processing waste and to expand the source of animal feed materials.A cellulose degrading strain HYH-1 was isolated from decaying rice straw by plate isolation method,and the isolate was identified by morphological observation,physiological and biochemical tests and 16S rDNA sequence analysis.The effects of glucose addition,KH_(2)PO_(4) addition,MgSO_(4)·7H_(2)O addition,solid water ratio,inoculum amount,fermentation time and fermentation temperature on the cellulose degradation rate were investigated by single-factor test using cellulose degradation rate as the index.Based on the results of the single-factor test,the factors that had a significant effect on the cellulose degradation rate,such as glucose addition,KH_(2)PO_(4) addition,solid water ratio and inoculum,were optimized using the response surface method.The results showed that the cellulose degrading bacteria HYH-1 was identified as salt-tolerant Bacillus halodurans.A quadratic regression model for the solid fermentation conditions of bamboo shoot processing waste was established,which was highly significant with good fit.The suitable fermentation process was 2.9% glucose,2.9%KH_(2)PO_(4),0.15% MgSO_(4)·7H_(2)O,1:1 solid to water ratio,11.50% inoculum,8 d fermentation time and 37℃.Under these conditions,the cellulose degradation rate in bamboo shoot processing waste reached 54.85%.The results of the study provide a theoretical reference for the resource utilization of bamboo shoots processing waste.