|Shakeel, Qaiser - Huazhong Agricultural University|
|Lyu, Ang - Huazhong Agricultural University|
|Zhang, Jing - Huazhong Agricultural University|
|Wu, M - Huazhong Agricultural University|
|Chen, Shouwen - Huazhong Agricultural University|
|Li, Guoqing - Huazhong Agricultural University|
|Yang, Long - Huazhong Agricultural University|
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2016
Publication Date: 6/24/2016
Citation: Shakeel, Q., Lyu, A., Zhang, J., Wu, M., Chen, S., Chen, W., Li, G., Yang, L. 2016. Optimization of medium composition and cultural conditions for production of antifungal substances by Streptomyces platensis 3-10 and evaluation of its efficacy in suppression of clubroot disease of oilseed rape. Biological Control. 101:59-68.
Interpretive Summary: Biological control of plant disease is an environmental friendly alternative in managing plant diseases. One of the important mechanisms in successful biological control is antibiosis through production of antifungal substances. A medium optimized for production of antifungal substances would be advantageous in production of inoculum of the biocontrol agents. This research was aimed at developing a medium composition and cultural conditions that are optimal for production of antifungal substance by the biocontrol agent Streptomyces sp. It was shown that solubale starch as carbon source and peptone and soymeal as nitrogen source are optimal medium composition and pH 6.5 and temperature at 28 C in shake culture are optimal conditions for production of antifungal substance by the biocontrol agent. Inoculum of the biocontrol agent Streptomyces sp. prepared this way was very effective in controlling a cabbage root disease caused by Plasmodiophora brassicae. The optimized medium composition and cultural conditions will facility utilization of Streptomyces sp. in managing plant diseases.
Technical Abstract: This study was conducted to optimize the medium composition and cultural conditions for improving production of antifungal substances (AFS) by Streptomyces 3-10 and for enhancing its efficacy in suppression of clubroot disease of oilseed rape caused by Plasmodiophora brassicae. Results showed that the optimum carbon source was soluble starch (3%, w/v) and the optimum nitrogen sources were peptone (0.75%, w/v) and soybean meal (1%, w/v). The optimum cultural conditions were: initial pH 6.5, temperature at 28oC and shaking speed at 150 rpm. Spores, cultural filtrates and crude extract of isolate 3-10 reduced the size and growth of club as well as root hair infection except when they were used to treat the seeds of oilseed rape. Interestingly, all the treatments stimulated root hair formation. Live cultures of isolate 3-10 controlled the clubroot disease by >80% while cultural filtrate and crude extract reduced clubroot by >70%. The information suggests that isolate 3-10 is a promising biocontrol agent of P. brassicae. The optimized medium will facilitate the use of this isolate 3-10 for mass production of the AFS by Streptomyces 3-10.