Study on the Mechanisms of Transportation and Accumulation of n-Hexadecane by Microorganism

Through indoor experiments, concentration changes of n-hexadecane in the cells of bacillus cereus DQ01 and bacillus sp.DQ02 with the time, inhibition effect of NaN3 on the transportation of n-hexadecane across the membrane, as well as the accumulated form of n-hexadecane in the cells of bacteria were studied. The results showed that the higher the content of n-hexadecane in the medium was, the more the n-hexadecane that accumulated in the cells of DQ01 and DQ02 was. The two strains could accumulate n-alkane against a concentration gradient. By adding 30 mmol·L^-1 sodium azide in the culture medium, the content of n-hexadecane that accumulated in the cells was apparently lower than that in the control group in which did not add inhibitor, which inferred that the transportation of n-hexadecane by DQ01 and DQ02 was an energy-dependent active transport process. Through electron microscopy, inclusions which did not appear when glucose served as the only carbon source, were observed in the cells of DQ01 and DQ02 when n-hexadecane was the only substrate, and inclusion bodies in DQ01, the number of which was more than that in DQ02, were transparent and smooth, while the inclusions of DQ02 were irregular and scattered in the cells.