下脚料制备生物菌肥的工艺优化及养分测定

以游离氨基酸态氮为评价指标,研究了转速、料液比、接种量、发酵温度和发酵时间5个因素对发酵效果的影响,在单因素实验基础上,对转速、接种量和温度3个因素用Box-ehnken 设计及响应面分析方法,确定了最佳发酵工艺参数为:转速203 r/min、接种量5%、温度30 ℃。在此条件下,发酵液中游离氨基酸态氮含量达到13.891 g/L,较优化前(12.365 g/L)提高了12.34%。另对初步放大实验所得的菌肥产品质量进行评价,结果显示,菌肥总氮含量约为15.8%,总有机质含量约为37%,两者指标均优于国家相关标准。

Optimum fermentation conditions of fermenting residues of aquatic products by mixed strains with response surface methodology

With the free-amino-acid nitrogen content as an examining index, we conducted a single-factor experiment for shaker speed and material liquid, then inoculation, fermentation temperature, and fermentation time. Response surface methodology was used to design an experiment on the basis of the single-factor experiment results; a quadratic regression model of shaker speed, inoculation, and fermentation temperature was established by Design Expert 7.0. The optimal conditions were as follows: shaker speed of 203 r/min, inoculum size of 5%, and temperature of 30 ℃. Under these conditions, the free-amino-acid nitrogen content was 13.891 g/L, representing an increase of 12.34% over the previous value (12.365 g/L). The optimized process caused the bacterial manure product quality to exceed the national standard; the total nitrogen content was approximately 15.8% and the total organic matter content was approximately 37%.