布氏乳杆菌、黑曲霉、热带假丝酵母、枯草芽孢杆菌与植物乳杆菌3菌组合对木薯渣发酵品质的影响

本试验旨在研究布氏乳杆菌（LAB）、黑曲霉（AN）、热带假丝酵母（CT）、枯草芽孢杆菌（BS）与植物乳杆菌（LAP） 3菌组合对木薯渣发酵品质的影响。以木薯渣为发酵原料，取LAB、AN、CT、BS与LAP中3种菌液以1∶1∶1体积比组合，共设5个不同组合：组合1：LAB+AN+LAP；组合2：LAB+CT+LAP；组合3：LAB+BS+LAP；组合4：AN+CT+LAP；组合5：CT+BS+LAP；空白组不添加任何添加剂，对照组Ⅰ添加1%尿素；对照组Ⅱ添加1%尿素+0.6%红糖，试验组Ⅰ为对照组Ⅰ+不同菌种组合（1~5），试验组Ⅱ为对照组Ⅱ+不同菌种组合（1~5）。各组均用生理盐水调制含水量为65%左右，于聚乙烯薄膜袋中真空发酵10 d。结果显示：①各试验组的pH均显著低于空白组和对照组（P < 0.05），试验Ⅱ1组（即LAB+AN+LAP+尿素+红糖）能提高木薯渣的乙酸含量，降解木薯渣中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）效果最好，其NDF和ADF含量均为最低，显著低于空白组和对照组（P < 0.05）；②试验Ⅱ5组（即CT+BS+LAP+尿素+红糖）提高木薯渣粗蛋白质（CP）含量效果最好，其CP含量最高，显著高于空白组和对照组（P < 0.05）；③添加相应的菌种+尿素+红糖发酵木薯渣有利于产生丙酸；④在木薯渣发酵过程中添加尿素+红糖比只添加尿素对木薯渣营养成分改善效果好；⑤在发酵培养基中添加尿素，能显著提高木薯渣CP含量；以乙酸和丁酸含量评价木薯渣品质，发现各组发酵木薯渣品质均达到1级水平。综上所述，LAB+AN+LAP+尿素+红糖或CT+BS+LAP+尿素+红糖固态发酵木薯渣后，均可有效改善木薯渣品质。

Effects of Three Strains Combinations of Lactobasillus buchneri,Aspergillus niger,Candida tropicalis,Bacillus subtilis and Lactobacillus plantarum on Fermentation Quality of Cassava Residue

The experiment was carried out to investigate effects of three strains combinations of Lactobasillus buchneri (LAB),Aspergillus niger (AN),Candida tropicalis (CT),Bacillus subtilis (BS) and Lactobacillus plantarum (LAP) on fermentation quality of cassava residue.In this study,cassava residue were used as fermentative raw material,three strains were combined by 1∶1∶1 chosen from LAB,AN,CT,BS and LAP,getting five different combination.Combination 1:LAB+AN+LAP;Combination 2:LAB+CT+LAP;Combination 3:LAB+BS+LAP;Combination 4:AN+CT+LAP;Combination 5:CT+BS+LAP;1% urea or 1% urea+0.6% brown sugar was added to each combination;Blank group was without any additives;1% urea was added to control group Ⅰ and 1% urea+0.6% brown sugar were added to control groupⅡ.Experimental group Ⅰ was consisted of control group Ⅰ+different combination (1-5) while experimental group Ⅱ was consisted of control group Ⅱ+different combination (1-5).Water content in each group was about 65% by modulating with normal saline,each group was fermented in the vacuum of polyethylene film bag for 10 days.The results showed as follows:①pH of each experimental group was significantly lower than that of blank group and control group (P < 0.05),experimental group Ⅱ1 (LAB+AN+LAP+urea+brown sugar) could improve acetic acid content of cassava residue and reduce the NDF and ADF contents,and which were the lowest and were significantly lower than that of blank group and the control groups (P < 0.05);②Experimental group Ⅱ5 (CT+BS+LAP+urea+brown sugar) could improve the crude protein content in the cassava residue which was significantly higher than that of blank group and the control groups (P < 0.05);③It was favorable to propionic acid production by adding the corresponding strains+urea+brown sugar to the cassava residue fermentation;④Urea and brown sugar were added into cassava residue for improving the nutrition composition during the fermentation process was better than that only urea was added;⑤When the urea was added into the fermentation medium,the crude protein content in cassava residue was significantly increased,when cassava residue fermented quality was evaluate by butyric acid and acetic acid contents,all the groups got to the top of grade.In conclusion,solid-state fermentation using LAB+AN+LAP+urea+brown sugar or CT+BS+LAP+urea+brown sugar could offer an effective alternative to improve the fermentation quality of cassava residue.