Author(s)

Andrés Díaz-García^*, Jennifer García-Riaño, Jimmy Zapata-Narvaez

Biological Control Laboratory, Tibaitatá Research Center, Colombian Corporation for Agricultural Research (Corpoica), Bogotá, Colombia.

The desirable active ingredients for the development of bioproducts based in Bacillus sp. for the control of soil pathogens are the spores because these structures exhibit more resistance and stability to conditions present during the fermentation, formulation, and storage processes. To improve the sporulation of a native strain of Bacillus amyloliquefaciens (Bs006) using liquid fermentation, some modifications in the concentrations of the components in a previously standardized culture media were made. Subsequently, five sporulation inducers (iron nitrate, mixture of salts, peroxide hydrogen, temperature, and initial cell concentration) were evaluated. The treatment with a mixture of salts in combination with an initial cell concentration of 1 × 10⁸ cells/ml was selected because a final spore concentration of 1.05 × 10¹⁰ spores/ml after 66 hours with a fully substrate consumption and sporulation efficiency of 88.7% was obtained. To demonstrate the biological activity of B. amyloliquefaciens Bs006 in Cape gooseberry seedlings, a greenhouse bioassay was conducted, and statistical differences in plant growth-promoting parameters compared with previous media were not found. Additionally, the proposed modified media (coded as JM) presented a benefit-cost ratio 2.65 times higher compared with the baseline media.

Bacillus amyloliquefaciens, Sporulation Induction, Liquid Media Design, Cape Gooseberry, Plant Growth Promotion

Díaz-García, A. , García-Riaño, J. and Zapata-Narvaez, J. (2015) Improvement of Sporulation Conditions of a New Strain of Bacillus amyloliquefaciens in Liquid Fermentation. Advances in Bioscience and Biotechnology, 6, 302-310. doi: 10.4236/abb.2015.64029.