豆粕混菌液体发酵制种技术试验研究

利用热带假丝酵母和枯草芽孢杆菌混菌发酵进行液体制种。结果表明:受接种量、豆粕含量和培养温度的影响,两株菌种菌数的增长速度具有相对一致的变化趋势;受培养时间的影响,热带假丝酵母菌先增后降,枯草芽孢杆菌先降后增;热带假丝酵母在pH3.5时菌数最大,枯草芽孢杆菌在pH4.5～7.5范围内适宜生长。在豆粕质量分数15%、葡萄糖质量分数1%、初始pH4.5的液体培养基上,两菌分别接种10%,在发酵温度28℃、摇床转速160r/min条件下培养5d,热带假丝酵母菌和枯草芽孢杆菌菌数达到最大,分别为752.5×106和264.2×107 cfu/ml。

Liquid state fermentation of soybean meal with mixed strains for seed strain preparation

Candida tropicalis and Bacillus subtilis mixed in liquid state fermentation was used for the seed strain preparation.The results showed that the growth rates of the strains had a relatively consistent trend with inoculation amount,soybean meal content and cultural temperature;The number of Candida tropicalis increased first and then decreased,and Bacillus subtilis down first and then increased as culture time increasing.Candida tropicalis at pH3.5 had the largest number,pH rang of appropriative growth of Bacillus subtilis was from 4.5 to 7.5.It was obtained that both 10% of two strains were added into liquid culture medium with soybean meal of 15%(W/W),glucose of 1% and initial pH of 9.0,cultured at 28℃ for 5 days with rotation speed of 160 r/min,the number of Candida tropicalis and Bacillus subtilis bacteria could reach maximum,being 752.5×106 cfu/ml and 264.2×107 cfu/ml,respectively.