ANTAGONISMAND SEASONAL FLUCTUATIONS OF SOME MARINE ISOLATES OF BACILLACEAE IN PORT SAED HARBOUR, EGYPT.

ANTAGONISMAND SEASONAL FLUCTUATIONS OF SOME MARINE
ISOLATES OF BACILLACEAE IN PORT SAED HARBOUR, EGYPT.
BY
M4NAL, M A. EL-1VA.GGAR
Miaobiology lab., Marine environmenla1 dept., NIOF, Alexandria, Egypt.
Key words: Antagonism- Bacillus sp.- Distribution-Diffusion- Inhibition.
ABSTRACT
Eighty-nine bacterial isolates related to Bacillaceae were collected from
Port Saed harbour during 200/. These isolates were examined for
bacterium bacterium antagonism using tooth picking technique and
Bulkholder diffi..ision technique. It was found that, more than 50% ofthese
tested isolates showed positive antagonism and the most potential
producers for antagonistic agents in such marine environments were
Bacillus cereus, B. megaterium, B. lichenijormis, B. lentus and B.
amyloliquefaciens. Moreover, the effect ofthe antagonistic activity on the.
ecological distribution of these bacteria was investigated using agar well
difJilsion technique. The results indicated that, the presence of B.
megaterium highly afjected the presence ofB. circulans, B. cereus and B.
lichenijormis specially in winter and autumn (193.7, 134 end 207 af;;solute
activity unit (Au)/ml, respectively), also the appearance of B.
amyloliquejacenies in spring showed a great inhibition activity against B.
cereus, B. lichenijormis, B. lentus and B. raegaterium (198.0, 126.3, 143.7
and 207.0 Azural, respectively). While B. lichenijormis affected in a clear
vision the presence ofB. subtilis (286 Au/ral).