Sophorolipids as protein inducers and inhibitors in fermentation medium

1. A method for inducing the production of a protein, comprising:

a) synthesizing sophorolipids by fermentation of Candida bombicola in a fermentation medium;

b) after 7 days of fermentation, extracting the sophorolipids produced from the fermentation medium;

c) washing the extracted sophorolipids to remove residual fatty acids to form a natural mixture of lactonic sophorolipids and non-lactonic sophorolipids; and

d) adding an effective amount of the natural mixture of lactonic sophorolipids and non-lactonic sophorolipids as protein inducing agent to a microbial culture medium during protein production by Bacillus subtilis cells in said culture medium,

wherein the protein is amylase, and

whereby the production of the amylase protein is significantly increased.

2. A method for inducing the production of amylase protein, comprising:

a) synthesizing sophorolipids by fermentation of Candida bombicola in a fermentation medium;

b) after 7 days of fermentation, extracting the sophorolipids thrice using ethyl acetate as a solvent;

c) pooling the extracted sophorolipids and removing the solvent;

d) washing the extracted sophorolipids with hexane to remove residual fatty acids to form a natural mixture of lactonic sophorolipids and non-lactonic sophorolipids; and

e) adding an effective amount of the natural mixture of lactonic sophorolipids and non-lactonic sophorolipids as protein inducing agent to a microbial culture medium during protein production by Bacillus subtilis cells in said culture medium,

wherein said fermentation medium comprises 100 g of glucose, 10 g of yeast extract, 1 g of urea, and 40 g of oleic acid in 1000 ml of water, and whereby the production of the amylase protein is significantly increased.

3. The method as claimed in claim 2 , further comprising:

a) growing the Bacillus subtilis cells in the culture medium comprising 5 gm/L peptone, 3 gm/L beef extract, and 2 gm/L starch;

b) inoculating the Bacillus subtilis cells in 10 ml of the culture medium and allowing the Bacillus subtilis cells to grow for 12 hours; and

c) after the Bacillus subtilis reaches the log phase, inoculating 1 ml of the log phase Bacillus subtilis cells in 100 ml of the culture medium.

4. The method as claimed in claim 3 , further comprising adding the natural mixture of sophorolipids to the culture medium as a fine powder.

5. The method as claimed in claim 3 , further comprising adding the natural mixture of sophorolipids to the culture medium in the form of a solution prepared in DMSO, alkaline sucrose solution, chloroform, methanol, or ethyl acetate.