球磨预处理和固态发酵对玉米秸秆饲用品质的影响

Effect of Ball Milling Pretreatment and Solid State Fermentation on the Feed Quality of Corn Straw

摘要:

玉米秸秆经球磨预处理后物理空间结构和化学物质结构改变, 更容易被相应的酶降解, 进而被微生物利用, 其饲用品质提高, 从而可能替代饲料中的部分粮食。研究表明, 球磨预处理后的玉米秸秆粒径大小均匀, 约90%的颗粒集中在10~100 μm, 酸性洗涤纤维下降3.5%, 可溶性总糖提高2.0倍, 对其单糖组成分析发现：可溶性总糖的增加主要来自半纤维素和纤维素的分子断裂。用木聚糖酶和纤维素酶酶解球磨预处理后的玉米秸秆, 可溶性总糖和还原糖含量比酶解前分别提高了3.3倍和9.7倍, 球磨预处理后酶解效率大大提高。球磨预处理的玉米秸秆经固态酶解、发酵后, 总酸质量分数达26.3 mg/g, 纤维素和半纤维素质量分数分别下降9.1%和4.9%, 乳酸菌含量达到1.5×109 CFU/g, 饲用品质显著提高。

Abstract:

Ball milling pretreatment can be used to change the physical and chemical structure of corn straw, making it much easier to be degraded by enzymes, which will enhance the microorganism utilization rate to improve its feed quality. This study indicated that the particle size of corn straw after ball milling mainly(90%) distributed in the range of 10~100 μm and ball mill crushed corn straw had a 3.5% decrease in Acid Detergent Fiber(ADF) content and a 200% increase in soluble sugar content due to the breaking of hemicellulose chain and cellulose chain. The total content of soluble sugar and reducing sugar of ball milling corn straw hydrolysed by xylanase and cellulase increased by 3.3 fold and 9.7 fold than that without treatment, separately. The total acid content reached 26.3 mg/g and the lactic acid bacteria population was about 1.5×109 CFU/g after corn straw solid state fermentation. Furthermore, the cellulose and hemicellulose separately decreased by 9.1 and 4.9 percentage points than before, which could significantly improve the quality of the feed.