Effect of alkanes on the production of a solvent-stable extracellular protease by the organic solvent tolerant bacterium Bacillus licheniformis YP1

Abstract:

In this paper, the effect of 5% (V/V) n-alkanes (e.g, n-Heptane, n-Octane, n-Decane, n-Dodecane, n-Tetradecane and n-Hexadecane) on the growth and protease production of organic-solvent-tolerant- bacterium Bacillus licheniformis YP1 was studied. 5%(V/V) n-alkanes had no effect on the stability of YP1 protease. 5% (V/V) n-alkanes had no notable influence on the yield of strain YP1 but dramatically affected the protease production. The presence of n-Heptane, n-Octane and n-Decane deeply repressed the protease production; however n-Dodecane, n-Tetradecane and n-Hexadecane enhanced the protease production prominencely. The concentration of n-Tetradecane (1%-8%, V/V) had a direct ration with the protease production. The detailed experiments showed that the notable increase of protease activity appeared at the late logarithm of cultivation compared with the blank. The cell shape of YP1 strain remarkably decreased when grown in the presence of n-Tetradecane. This is the first report about the effect of n-alkanes on the protease production by the solvent tolerant bacterium.