前端好氧预处理对油菜秸秆黄贮发酵品质的影响

Effects of aerobiotic pre-treatment on fermentation quality of rape straw yellow storage

油菜秸秆具有较高的营养成分,但较高的木质纤维素含量极大限制了其的饲料化应用。本研究提供了一种好氧预处理黄贮油菜秸秆饲料方法,期望在好氧条件下利用秸秆腐熟剂打破油菜秸秆中木质素、半纤维素和纤维素三者之间紧密连接的结构,促进后期的厌氧黄贮过程。研究结果显示:好氧预处理黄贮油菜秸秆饲料的干物质(DM)含量和酸性洗涤纤维(ADF)含量分别为32.62%和53.40%,均显著低于常规黄贮油菜秸秆饲料(35.14%和55.1%)(P<0.05),好氧预处理黄贮油菜秸秆饲料的可溶性碳水化合物(WSC)含量为0.54%,显著高于常规黄贮油菜秸秆饲料(0.35%)(P<0.05),好氧预处理有助于提高油菜秸秆黄贮饲料品质。对油菜秸秆结构进行表征,扫描电子显微镜显示,好氧预处理后的油菜秸秆相比原样表面出现塌陷,并且细胞壁有褶皱和破损,出现孔洞,比表面积增加;红外光谱图显示,好氧预处理明显降低了油菜秸秆羟基峰强度,但并未改变芳香族骨架振动吸收峰;X-射线衍射显示,好氧预处理明显降低了油菜秸秆在15~20°和22.5°处的纤维素结晶衍射峰。油菜秸秆结构表征说明,好氧预处理并未降解木质纤维素,但通过破坏油菜秸秆纤维的内部结构促进了后续厌氧发酵,进而提高油菜秸秆黄贮品质。结果表明,本研究提供的好氧预处理黄贮技术在不增加总体处理时间的前提下,能够有效提高油菜秸秆黄贮品质。

Rape straw could be considered as a good source of roughage due to its high nutritional content.However,its high lignocellulose content has greatly limits the application of rape straw as fodder.The present study provided an aerobiotic pre-treatment method for rape straw yellow storage,which can break the tight connection structure of lignin,hemicellulose and cellulose in rape straw by straw decomposition agent,and promote the flowing anaerobic yellow storage process.The results showed that the dry matter(DM)and acid detergent fiber(ADF)content of rape straw obtained from aerobic pre-treatment was 32.62%and 53.04%,respectively,which were significantly lower than those of conventional yellow storage(35.14%,55.1%)(P<0.05).The water-soluble cabohydrate content(WSC)of rape straw obtained from aerobic pre-treatment was 0.54%,which was significantly higher than those of conventional yellow storage(0.35%)(P<0.05).The structure of rape straw was characterized by scanning electron microscope(SEM)diagram,infrared spectra and diffraction of x-rays(XRD)patterns.Compared with the original materials,the surface of rape straw after aerobic pre-treatment was collapsed,the cell wall was damaged,and the specific surface area was increased.The intensity of hydroxyl peak of aerobic pre-treatment straw was significantly reduced,but no obvious change was detected on the vibration absorption peak of aromatic skeleton.In addition,the diffraction peaks of cellulose crystal at 15~20°and 22.5°were significantly reduced in rape straw after aerobic pre-treatment.The structure characterization of rape straw showed that aerobic pre-treatment did not degrade lignocellulose,but improved subsequent anaerobic fermentation by changing the internal structure of rape straw fiber,and led to a higher yellow storage quality of rape straw.Therefore,the aerobic pre-treatment yellow storage technology provided in the present study was a effective method to improve yellow storage quality of rape straw without increasing the overall treatment time.