Application Of Feruloyl Esterase In Brewers’ Spent Grain’ Enzymatic Feed

Brewers’ spent grain （BSG） was the abundant by-product in the beer brewing,which took up about85%. This article had done some research on producing feruloylesterase （FAE） by solid-state fermentation from Aspergillus niger based on BSG, andthen the combination of FAE and yiduoli enzyme was used to degradate BSG. Thezymolyte was applied to mix in feed for broiler. There was not any antibiotic additionin the whole feeding process, in order to discover the geern and safe fermented feed.The results were showed:（1） The single factor method was used to optimize the technoly of producing FAE bysolid-state fermentation from Aspergillus niger. The optimal conditions offermentation were as follows:2:8（g/g） of the ratio for wheat bran and BSG,2:4（g/g）of the ratio for peptone and yeast,0.25mm of wheat bran grain size, pH7,40%of water content,10%of inoculum,6days of incubation and33℃of incubationtemperature, the activity of the FAE was improved to five times compared tounoptimized and the maximum activity is29.49（U/g）.（2）The physicochemical propreties of FAE were showed: the optimum pH andtemperature was6and45℃respectively. FAE was quite stable when pH5and45°Cof temperature. Mg²⁺was the only ion could improve the FAE activity and increasedby1.13times, while other ions, such as Na⁺, Fe²⁺, Cu²⁺, Zn²⁺, Ca²⁺, Mn²⁺and K+all had inhibition on FAE.（3） FAE and yiduoli enzyme were combined to emzymatic hydrolysis BSG. Theoptimal conditions for enzymatic degradation of BSG were as follows:2.5days ofenzymatic degradation,40°C of operating temperature,50%BSG of water content,6.6-8.8U/g BSG of FAE dose and simultaneous addition of two kinds of enzymes.Ferulic acid, xylooligosaccharides, and reducing sugars released were increased by1.88,50, and19.37times, respectively, compared with the control group, whichcontained no enzyme. Then the BSG soft, track-free, no decay and weak acid, thequality identification was excellent.（4） BSG under enzymatic treatments was then added into the broiler feed. Thehygienic index of feed was all accorded with the standard. The results showed that BSG handled with （FAE+AF831） had a lower feed intake than did the control groupas weight gain increased by4.37%（P>0.05） and the feed conversion ratio wasreduced by7.63%（P <0.01）. The survival rates for four groups were all zero and nodifference was indicated between the groups.（5） The technology was conducted to investigate the effect of FAE and yiduolienzyme on nuitrent utilization. The results showed that FAE and yiduoli enzyme werehelp to improve the utilization of dry matter, crude protein, crude ash, acid detergentfiber, but the improvement was limited. For the neutral detergent fiber, the utilizationof AF831group, FAE group and （FAE+AF831） group would marked increased by7.43%，11.66%，15.85%（P<0.01）.