| The shortage of conventional protein feed resources in China.Therefore,the digestion utilization rate of plant-derived raw materials can be improved.Then optimizing the treatment process of feather resources.Disulfide bond reductase was isolated and purified from bacillus licheniformis CP-16,which was heterologous expressed by bacillus subtilis WB600.The protease with a wide range of pH and temperature adaptability,and the high reducing disulfide bond activity can destroy the disulfide bond structure of the raw protein.Disulfide reductase has great potential as an intestinal additive.Animal digestion is a process of coordination treatment.Firstly,the interaction effect and dose relationship between disulfide bond reductase activity and endogenous enzyme activity were studied.Secondly,the content of tyrosine in soybean meal,peanut meal,rapeseed meal,corn protein powder and cottonseed meal degraded by trypsin and chymotrypsin was determined.Thirdly,in vitro method was used to evaluate the change of soluble protein content,small peptide content and free sulfhydryl group in plant protein feed after adding disulfide bond reductase in 40 min,80 min,120 min and 160 min,and to speculate the possible mechanism of action.Finally,this study also studied the promotion of disulfide reductase diagonase,and carried out single factor analysis and further orthogonal test and optimization on the processing parameters of the by-products of down processing.The results are as follows:1.The relationship between disulfide reductase and trypsin and chymotrypsin in different doses was studied.The results showed that the enzyme activity loss rate of trypsin and chymotrypsin increased with the addition of disulfide reductase and the duration of action,and the loss rate of chymotrypsin activity(15.68%)was much higher than that of trypsin activity(2.96%)after the addition of disulfide reductase.Both trypsin and chymotrypsin degrade the disulfide bond reduction activity of disulfide bond reductase,respectively 67.03% and 72.52%,but disulfide bond reductase treated with trypsin and chymotrypsin showed enzyme activity within the 4h range.2.The dosage relationship of disulfide reductase on soybean meal,peanut meal,rapeseed meal,cottonseed meal and corn protein powder hydrolyzed by trypsin and chymotrypsin was studied.The results showed that disulfide reductase had the function of solubilization,which was beneficial to the full contact between feed protein and liquid and the binding of protease.The addition of disulfide reductase promoted the hydrolysis of feed materials by trypsin andchymotrypsin(P<0.05),which promoted the optimal dose and effect.The addition of disulfide reductase promoted the ability of trypsin and chymotrypsin to hydrolyze feathers.Combining with the parameter model of 31-day-old broilers,disulfide reductase was used as feed additive to hydrolyze soybean meal in the intestine in vitro.3.The relationship between dose and effect of adding disulfide reductase diagonal protease in feather degradation was studied.The concentration ratio of keratinase and disulfide bond reductase,the pressure treatment time of the feather,the final concentration of the added enzyme,and the enzymatic hydrolysis time all significantly affected the down processing waste(P<0.05).The results showed that when the final concentration ratio of ceratase and disulphase reductase was 80:1,the feather was treated with pressure for 2h,the final concentration of added enzyme was 90 u/mL,and the enzymatic hydrolysis time was 48 h,the soluble protein in supernatant solution was 640.26% higher than that in the control group after the same pressure treatment(P<0.05).In summary,the addition of disulfide bond reductase is beneficial to the hydrolysis of plant feed and down processing by-products by trypsin and chymotrypsin,which provides theoretical guidance for practical production and application. |
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