纯种米根霉种曲的制备及工艺条件优化

Preparation of Pure-species Rhizopus oryzae Starter and Its Technical Optimization

从米根霉的生长特性出发,采用纯种培养技术,对米饭含水量、NH4NO3添加量、翻曲次数、培养温度、接种量、培养时间、装料量等7个可能影响米根霉种曲质量的因素分别进行了考察,从中筛选出了3个重要因素(培养温度、接种量、培养时间)及其优化水平范围,然后再结合正交试验作进一步优化。结果表明,最佳的组合方案为培养温度35℃、接种量0.1 mL/瓶、培养时间7 d,其中温度、接种量是影响试验结果的主要因素,培养时间是次要因素。在最优条件下,种曲孢子数可达2.79×108个/g,高于正交试验中所有的结果,说明优化试验是成功的。

Based on the growth properties of Rhizopus oryzae, seven factors probably influencing the quality of Rhizopus oryzae starter, including steamed rice moisture content, the addition level of NH4NO3, turning times of the starter, culture temperature, inoculating quantity, culture time, and charge amount, were investigated respectively by pure-species culture technology. Then 3 most important influencing factors （culture temper-ature, inoculating quantity and culture time） were screened out and used for orthogonal test to obtain the optimum technical conditions as follows：culture temperature was at 35℃, the inoculating quantity was 0.1 mL/flask, and culture time was 7 days. Among the three factors, culture temper-ature and the inoculating quality were the superior influencing factors than culture time. Under the optimum technical conditions, the spore num-ber of the starter could reach up to 2.79í108 particle/g, higher than all the results in the orthogonal test, which proved the success of the optimiza-tion test.