Journal of The School of Marine Science and Technology,Vol.9 No.3
Study on reduction of formaldehyde in SMM-7 marine bacterial strain
Hiroshi ISHII, Takafumi MAEDA, Ryoichi INOUE and Hiroshi SAITO
Abstract
Based on our results on the growth of marine bacterial strain, SMM-7 in nutrient broth medium with the high con-centration （750 ppm） formaldehyde （FAD）, as presented in another paper, we inferred that this bacterial strain is capable of bioremediation in ocean. There is a possibility that the bacteria possess enzyme against the effect of FAD. In this study, we investigated the cellular location of such enzyme to understand the degradation pathway of FAD in the SMM-7 strain.
The SMM-7 strain was cultured in nutrient broth medium with FAD, the culture was centrifuged, and the cell supernatant and subnatant was recovered. The cell subnatant was treated with phosphate buffer （pH7.0） 3 times, and recovered after 3rd treatment. After treatment, the cell homogenate was centrifuged, supernatant was filtered through Millipore filter （0.45μm）, and the cell extract was recovered. Finally, 10 ppm FAD was added to cell supernatant, subnatant with phosphate buffer and cell extract, and conc0entration of FAD was measured using Nash method. Furthermore, heat treatment was applied to the cell supernatant and cell extract. Reduction of FAD was clearly noticed in cell extract. In contrast there was no reduction of FAD in the cell extract after applying the heat treatment. The results indicate 1） that SMM-7 strain might resist to FAD intracellularly 2） that the reduction effect of FAD in the cell could be due to enzyme.