Bacterial microflora associated with two species of corals in the gulf of Aqaba

الملخص EN

The abundance and seasonal variation of aerobic heterotrophic bacteria in the interstitial space of two scleractinian coral species, Stylophora pistillata and Acropora valida, were investigated and compared with ambient water at three stations along the coast of the Gulf of Aqaba.

Higher bacterial counts (in the ratio 6:2:1) were obtained from the two stations subject to industrial pollution, Jordan Fertilizers Industries (JFI) and Phosphate Loading Berth (PLB), compared to the Marine Science Station (MSS), as clean water.

Highly significant temporal variations were obtained (P<0.01), with maximal mean numbers observed in February.

Furthermore, highly significant variations were obtained from various depths (P<0.01), which ranged between 898±153 CFU.

ml-1 and 116±23 CFU.

ml-1, being maximal in surface waters.

The mean bacterial density was slightly higher in ambient waters, followed by samples from the interstitial space of S.

pistillata and A.

valida, but the differences were not significant (P>0.1).

The higher nutritive value of the coral's interstitial space is indicated in this study by 2 times higher proteolytic, lipolytic, and amylolytic bacterial activities than in ambient waters,.

Several strains of agarolytic bacteria belonging mainly to the genera Pseudomonas and Flavobacterium were isolated.