木薯渣生产菌体蛋白的研究

[目的]研究利用固态发酵技术生产菌体蛋白的适宜菌种及条件。[方法]以木薯渣为主要原料,选用霉菌单菌种、酵母菌单菌种及二者混菌种为供试菌种,通过固态发酵生产菌体蛋白,并以混合菌为菌种进行4因素正交试验。[结果]混菌种发酵所得蛋白含量高于单菌种;在混菌发酵培养基中添加无机氮源,产物中蛋白含量显著提高;正交试验表明,各因素对生产菌体蛋白影响顺序为:发酵温度>接种比例>培养基含水量>发酵时间;最佳发酵条件组合为:温度30℃,时间5 d,培养基含水量60%,酵母菌和霉菌接种比2∶1,其蛋白质含量可达15.68%,较原料有明显的提高。[结论]木薯渣混菌固态发酵后蛋白质含量明显增高,作为饲料有较高的应用价值。

Study on Bacterial Protein Produced from Cassava Residue

[Objective] The aim to study the suitable strain and condition for producing the bacterial protein by solid state fermentation technique.[Method] The cassava residue was used as raw material and the single strain of mildew and microzymes and their mixed bacterium were taken as tested strains to produce bacterial protein through solid fermentation and the orthogonal test with 4 factors was conducted.[Result] The protein content obtained by mixed bacterium fermentation was higher than that by single bacteria fermentation.When the inorganic nitrogen source was added into the fermentation medium with mixed bacterium the protein content in fermentation product was significantly increased.The orthogonal test showed that the effect of each factor on producing bacterial protein in order was fermentation temperature > inoculation ratio > moisture content of medium > fermentation time.The best combination for fermentation conditions were: fermentation temperature of 30 ℃,fermentation time of 5 days,60% moisture content of medium,the inoculation ratio of mildew and microzymes being 2∶1,under which,15.68% of protein content could be obtained,being increased noticeably compared with the raw material.[Conclusion] The cassava residue with mixed bacterium through solid state fermentation could increase the protein content significantly,so it had higher application value when it was taken as the feed.