Ecological Distribution and Bio degradational Activities of Oil-Degrading Marine Bacteria in the Arabian Gulf Water at Kuwait PDF

Keywords

oil degrading bacteria, Arabian Gulf, Kuwait

Abstract

The distribution of oil-degrading bacteria in the Arabian Gulf water at Kuwait during the year January-December 1995 was studied. This group of microorganisms ranged from 0.3 - 15.2 x 10³ CFU/l in Shuwaikh Station (a commercial harbour) and 0.1 - 5.8 x 10³ CFU/l in Salmiya (a relatively unpolluted control). Their percentages among total heterotrophic bacteria were in the range of 0.2-22.8% in Shuwaikh water and 0.1- 8.8% in Salmiya water. The rations of CFU/I of oil-degrading bacteria obtained from Shuwaikh to that obtained from Salmiya are in the range of 1.5-57.0. Autumn and winter were suitable seasons for obtaining high proportions of oil-degrading bacteria, while spring and summer were suitable for the development of large counts of total viable heterotrophic bacteria. The total number of viable fungi was greater during spring and autumn. Out of 180 bacterial cultures able to grow in the presence of crude oil, 28 cultures showed good growth. They were Pseudomonas spp. (32.1%), Arthrobacter spp. (23.1%), Corynebacterium spp. (17.8%), Acinetobacter spp. (10.7%), and Flavobacterium spp. (7.1%). Six of the 28 species were selected and inoculated singly and as mixtures into natural sea water. Arthrobacter sp. A(1) and Pseudomonas sp. P(6) degraded 64% and 60% of the saturates fraction respectively, which were 15.5% and 11.5% above those degraded in presence and in absence of the mixed inoculum of the six species. On the other hand Pseudomonas sp. P(8) and Arthrobacter sp. A(2) degraded 30% and 29% of the aromatic fractions, which was 10-12% more than the amounts degraded in the presence and absence of the mixed inoculum.