Optimization of the fermentation process of actinomycete strain Hhs.015(T)

Abstract

Strain Hhs.0 15 T (Saccharothrix yanglingensis sp. nov.), an antagonistic endophytic Saccharothrix actinomycete isolated from roots of cucumber plants, exhibited a broad antimicrobial spectrum in vitro and was active as a biocontrol against plant diseases in field trials. The SSY medium was used for production of antimicrobial metabolites by strain Hhs.0 15 T. However, this medium is too expensive for large-scale production. In this study, an alternative culture medium, based on agricultural waste products (e.g., apple pomace), was optimized. The results showed that the alternative medium contained 15g apple pomace, 4g rapeseed meal, 0.1g KH 2 PO 4, and 0.6g MgSO 4 7 H 2 O in 1L distilled water. This medium reduced the material costs by 91.5 compared to SSY medium. Response surface methodology (RSM) was used to investigate the influence of environmental variables on production of compounds of antimicrobial metabolites. The optimal conditions achieved were initial pH 7.0, medium volume of 90mL in 250mL flasks, rotary speed of 100 rpm, temperature 25 C , and inoculation volume of 15.8. The antimicrobial activity was increased by 20 by optimizing the environmental parameters. The results obtained allow an efficient production of components with antimicrobial activity by strain Hhs.0 15 T on a large scale at low costs. Copyright © 2010 XinxuanWang et al.