微生物发酵对木薯渣营养成分的影响

Effect of microbial fermentation on nutrient composition of cassava residues

【背景】将木薯渣作为饲料资源进行开发和利用能够减轻环境污染,实现资源就地转化,已成为国内外研究热点。微生物发酵可降低木薯渣的粗纤维含量,改善适口性,提高饲料转化率。【目的】筛选对木薯渣发酵效果较好的微生物发酵剂及其发酵时长。【方法】试验选用A(芽孢菌+乳酸菌+酿酒酵母菌)、B(戊糖片球菌+酿酒酵母菌)和C(植物乳杆菌+枯草芽孢杆菌+酿酒酵母菌)这3种复合微生物发酵剂与新鲜木薯渣混合,随机分为7组,每组5个重复,分别于发酵的第0、1、3、7、14、28和56天取样,测定其常规营养成分。【结果】与发酵前相比,发酵剂A和B可显著增加木薯渣的粗灰分含量(P<0.05),发酵剂C可显著增加木薯渣的粗蛋白质含量(P<0.05);3种发酵剂均可显著降低木薯渣的中性洗涤纤维含量、显著增加粗脂肪含量(P<0.05)。【结论】微生物发酵可有效改善木薯渣的营养价值,其中利用发酵剂C进行短期发酵对其营养价值,尤其是粗蛋白质和粗脂肪含量的提高最明显。

[Background]The development and utilization of cassava residues(CR)as feed resources can reduce environmental pollution and realize the local transformation of these resources.Microbial fermentation can reduce the crude fiber content of CR,improve their palatability,and increase feed conversion efficiency.[Objective]This study was conducted to screen microbial starter cultures with better fermentation effects on CR and their fermentation duration.[Methods]Three kinds of complex microbial starter cultures,including A(Bacillus,Lactobacillus,and Saccharomyces cerevisiae),B(Pediococcus pentosaceus,and Saccharomyces cerevisiae),and C(Lactobacillus plantarum,Saccharomyces cerevisiae,and Bacillus subtilis)were selected and mixed with fresh CR.Then,they were randomly divided into seven groups with five replicates per group.Samples were collected on days 0,1,3,7,14,28,and 56 of the fermentation,respectively,to determine the nutritional composition.[Results]Compared with fresh CR,starter culture A and B increased(P<0.05)the crude ash content of CR;Starter culture C increased(P<0.05)the crude protein content of CR;The three kinds of starter cultures decreased(P<0.05)the neutral detergent fiber content of CR and increased(P<0.05)the crude fat content.[Conclusion]Microbial fermentation can effectively improve the nutritional value of CR,of which the use of starter culture C for short-term fermentation has the most significant increase in their nutritional value,especially crude protein and crude fat contents.