Purification of SRB growth inhibitor from BP bacterium

Abstract

The inhibition of sulfate reducing bacteria (SRB) is of academic and biotechnological interests due to their involvement in corrosion, hydrocarbon degradation and reservoir souring. The purification of SRB Growth Inhibitor (SGI) from BP bacterium is reported in this study. The growth inhibitor was purified by ion exchange chromatography. Gel filtration was used to fractionate the cell free supernatants (CFS) in the range of 100-7000 Da. Vitamin B12 and Blue Dextran were used as molecular weight markers. The chromatograms obtained revealed the molecular weight of SGI to be in the range of 1800-2000 Da. The purified inhibitor was tested against Desulfovibrio indonesiensis NCIMB 13468, Desulfovibrio vulgaris and Desulfovibrio alaskensis NCIMB 13491, revealing growth prevention that was 100 times the order of magnitude compared to normal growth after 72 hours of incubation. The test organisms were grown in VMR medium containing glass coupons and tested with the inhibitor. The coupons with the inhibitor showed a stunted growth compared with the control when viewed using scanning electron microscope. Confocal microscope revealed dead cells with the SGI when coupons were treated with live/dead stains. The results of this study suggest that SGI can be used as a possible treatment strategy against SRB