本文選題：棉籽餅粕 + 微生物降解�。� 參考：《湖南農(nóng)業(yè)大學(xué)》2015年碩士論文

【摘要】：本文以棉籽餅粕為原料,開(kāi)展了微生物法降棉酚以及利用蛋白酶水解棉籽蛋白制備棉籽多肽的工藝研究。本文從棉田土壤中分離得到以棉酚為唯一碳源的芽孢細(xì)菌菌株106株。經(jīng)過(guò)復(fù)篩,從中篩選得到了1株對(duì)棉酚降解性能較好的菌株,命名為菌株M57-1,通過(guò)初步鑒定該菌為芽孢桿菌屬(Bacillus)。其對(duì)棉籽餅中棉酚降解率高達(dá)67.52%,能有效降解棉籽餅中的游離棉酚,達(dá)到使棉籽餅脫毒的效果。通過(guò)優(yōu)化,確定了該菌最適生長(zhǎng)條件以及利用該菌制備種子發(fā)酵液和固態(tài)發(fā)酵的最優(yōu)條件。利用該菌作為種子液培養(yǎng)的時(shí)間為18h,種子液發(fā)酵培養(yǎng)基可采用營(yíng)養(yǎng)肉湯培養(yǎng)基。固態(tài)發(fā)酵時(shí),固態(tài)發(fā)酵培養(yǎng)基中的輔料可使用蔗糖渣,棉籽餅與蔗糖渣比例為4：1,加入棉籽餅與蔗糖渣總質(zhì)量的77%的水制成。接入至固態(tài)發(fā)酵培養(yǎng)基中種子發(fā)酵液的接種量為3%,發(fā)酵溫度為36℃,發(fā)酵時(shí)間為11d,對(duì)棉籽餅中棉酚降解率可達(dá)78.96%。經(jīng)發(fā)酵條件優(yōu)化后,其對(duì)棉酚的降解率得到了進(jìn)一步提高。本文還對(duì)降棉酚后的棉籽餅進(jìn)行了酶水解工藝條件優(yōu)化研究,利用其制備棉籽多肽。確定了酶解溶液的料液比為1：4(w/w),水解用酶為堿性蛋白酶。通過(guò)響應(yīng)面優(yōu)化,建立了酶解條件中加酶量、溫度、酶解時(shí)間3個(gè)因素對(duì)多肽轉(zhuǎn)化率影響的二次模型。通過(guò)優(yōu)化模型,最終得到堿性蛋白酶水解棉籽蛋白制備多肽的工藝條件為：料液比1：4、加酶量1.48%、溫度51.5℃、酶解時(shí)間8 h、pH值8.2,采用上述優(yōu)化的參數(shù)酶解棉籽蛋白,多肽轉(zhuǎn)化率可達(dá)84.52%,優(yōu)化效果明顯,可在實(shí)際生產(chǎn)中起到指導(dǎo)作用。
[Abstract]:In this paper, using cottonseed cake as raw material, the process of reducing gossypol by microorganism and hydrolyzing cottonseed protein with protease to prepare cottonseed polypeptide was studied. In this paper, 106 Bacillus strains with gossypol as the sole carbon source were isolated from cotton soil. After screening, a strain with good degradation of gossypol was obtained and named as strain M57-1. The strain was identified as Bacillus sp. The degradation rate of gossypol in cottonseed cake is as high as 67.52, which can effectively degrade free gossypol in cottonseed cake and detoxify cottonseed cake. Through optimization, the optimum growth conditions and the optimal conditions for the preparation of seed fermentation broth and solid state fermentation were determined. The culture time of the strain was 18 h, and the nutrient broth medium could be used in the fermentation medium of the seed liquid. During solid state fermentation, sucrose residue was used as auxiliary material in solid fermentation medium. The ratio of cottonseed cake to sucrose residue was 4: 1, and 77% of the total mass of cottonseed cake and sucrose residue was added. The inoculation amount of seed fermentation broth was 3, the fermentation temperature was 36 鈩，

本文編號(hào)：1808304