Optimization of Solid-state Fermentation Process and Development of Biocontrol Agent Based on Cassava Residue from Streptomyces Microflavus

Abstract

In this article, solid-state fermentation of low-cost Streptomyces microflavus is studied by using cassava residue, rice husk and other agricultural solid waste resources as the substrate to prepare biopharmaceuticals [1]. The experiment results showed that the Streptomyces microflavus’ optimum solid-state fermentation medium and conditions includes the following components: cassava residue 89.85%, rice husk 10%, KH2PO4 0.05%, NaCl 0.05%, MgSO4 0.05%. The fermentation temperature is controlled at about 30 °C, the initial water content is around 50%, initial pH is 6.6-7, the material thickness is 5cm, the inoculation amount is 7.5%, the cultivation time is 4 days, and the spore yield is 4.8*109 cfu/g. The survival rate of Streptomyces microflavus’ spores is 75%, which compared with blank conditions increased by 30% after low temperature vacuum drying. The work of this paper provides some theoretical guidance for the large-scale industrial production of Streptomyces, which has valuable application in agricultural field.