下脚料制备生物菌肥的工艺优化及养分测定

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

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(12.365g/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。

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 of5%,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 approximately15. 8% and the total organic matter content was approximately 37%.