甘露聚糖酶在发酵棕榈粕中的应用及仿生消化研究

Application of mannanase in fermented palm meal and study on biomimetic digestion

为提高棕榈粕的饲用价值,本研究评估了12种不同甘露聚糖酶对棕榈粕中甘露聚糖的酶解效果,筛选酶的最适添加量,对比研究了直接发酵组(对照组)、甘露聚糖酶组、发酵菌剂组和甘露聚糖酶+发酵菌剂组的固态发酵效果及在禽和反刍上的体外仿生消化率。结果表明:在甘露聚糖酶添加量2‰时,8#酶的还原糖含量最高为6.46%(对照组1.9%),还原糖占甘露聚糖的比例由4%提升至14%;对0‰~10‰甘露聚糖酶添加量处理棕榈粕结果表明,在酶添加量8‰时,8#酶的还原糖含量最高为9.9%(对照组2.1%),还原糖占甘露聚糖的比例由4%提升到21%;四种方式处理棕榈粕发酵72 h,结果表明甘露聚糖酶+发酵菌剂组在pH、粗蛋白质(CP)、乳酸、还原糖、酸溶蛋白/粗蛋白质均显著高于其他各组(P<0.001);禽和反刍体外仿生消化结果表明,甘露聚糖酶+发酵菌剂组禽的干物质消化率(DDM)显著高于其他各组(P<0.001),反刍体外总产气量相比对照组从20 mL提升至70 m L左右,反刍体外发酵菌体蛋白(MCP)(P<0.001)、NH3-N(P=0.002)均显著高于对照组。综上,8#甘露聚糖酶在添加8‰,发酵菌剂添加2‰获得的发酵棕榈粕在气味和指标上较棕榈粕均有明显提升,同时在单胃动物和反刍动物仿生消化评估上均表现出明显优势。

To improve the feeding value of palm meal,this study evaluated the enzymolysis effect of 12different mannanases on mannan in palm meal,screened the optimal addition amount of enzyme,and compared the solid fermentation effect of direct fermentation group(control group),mannanase group,fermentation agent group and mannanase+fermentation agent group and the in vitro biomimetic digestibility on poultry and ruminant.The results showed that when the mannanase supplemental level was 2‰,the reducing sugar content of 8#enzyme was up to 6.46%(1.9%in the control group),and the proportion of reducing sugar in mannan increased from 4%to 14%.The results of treating palm meal with 0‰to 10‰mannanase showed that the reducing sugar content of 8#enzyme was the highest of 9.9%(2.1%in control group)at 8‰,and the proportion of reducing sugar in mannan increased from 4%to 21%.The results showed that pH,crude protein(CP),lactic acid,reducing sugar and acid-soluble protein/crude protein in mannanase+fermentant group were significantly higher than those in other groups(P<0.001).The results of in vitro biomimetic digestion of poultry and ruminant showed that dry matter digestibility(DDM)of poultry in mannanase+fermentant group was significantly higher than that in other groups(P<0.001),total gas production of ruminant in vitro increased from 20 mL to about 70 mL compared with control group,and MCP(P<0.001)and NH3-N(P=0.002)of ruminant fermentation in vitro were significantly higher than those in control group.In conclusion,when 8#mannanase was added with 8‰and fermentation agent with 2‰,the fermented palm meal had significantly improved in odor and index compared with palm meal,and also had obvious advantages in bionic digestion evaluation of monogastric animals and ruminants.