Characterization of bacterial flora in some oil exploration fields of Egypt

Several soil samples were collected from Abou-Rudies and Balayim fields, South Sinai, Egypt, at different intervals and depths during the period 1986-1989. Twenty-two different isolates were prepared and purified. The identification process revealed that the major isolates belong to three genera and six species; namely, Micrococcus halobius, Pseudomonas [including two species, Ps. fluorescens and Ps. pseudomallei], Bacillus [including three species, B. Firmus, B. megaterium and B. pumilus]. Unexpectedly, the genus Bacillus was predominating, since it included ten species, while the genus Pseudomonas or Micrococcus included only six species of each

Activity of some intracellular enzymes of three virulent erwinia sp in presence of some heavy metal salts

Based on equal number of cells, supplementation of 10-6 M cadmium highly stimulated the intracellular amylase, GGT, LDH as well as the glucose and urea content of E. carotovora var. carotovora cells. This was coupled with initiation of highly active GOT, CPK as well as accumulation of cholesterol in the cells. Lanthanum was less active and unable to initiate GOT or CPK. Nickel was almost without effect though reduced LDH activity without initiating either enzyme or cholesterol production. Similar stimulations and/or initiations were observed, though to variable extents, when the same concentration of the three elements were supplied to E. carotovora var. citrullis or E. toxica. In the meantime, lanthanum arrested GPT whereas nickel arrested GOT activity of E. toxica. The highest yield of amylase, GPT, GGT or glucose was obtained when E. Carotovora var. Carotovora was supplemented with Cd + Ni. The highest urea level was recorded in Erwinia carotovora var. citrullis, amended with Cd + La

Role of antibiosis in antagonism of streptomyces spp to soft rot bacteria in soil

In pot experiments, young melon seedlings were artificially infected with Erwinia carotovora var. carotovora under various conditions of amendment of Streptomyces venezuelae [S1], S. rubiginosus [S2] and S. recifensis [S3]. The three organisms were equally effective when appplied singly to the soil simultaneously with seed sowing. Their early application [one week before seed sowing] or spraying their broth before infection seemed less effective if not promoting pathogenecity. The mixed Streptomyces species were also potent [with few exceptions] when their spores were early prevailing in the soil before sowing or when their culture filtrates were sprayed on the seedlings before infection. The growth of melon plants drastically reduced the total bacterial count with lesser effect on the mycoflora. This was highly furthered in soils amended with the Streptomyces species on the day of seed sowing. Soil mycoflora was also drasticallt reduced when Streptomyces spores were amended to the soil before or accompanying melon seed sowing

Influence of vanadium salts on growth and antagonistic potentiality of three virulent plant pathogenic bacteria

vanadium, at 10-6 - 5 x 10-5 M, severely attenuated the rate of growth of Erwinia carotovora var. carotovora, Erwinia caroto-vora var. citrullis and Erwinia toxica; the penta-valent [vanadate] ion was more toxic than the tetravalent [vanadyl] form. Vanadate ion abolished the resistance of E. carotovora var. citrullis and Micrococcus luteus toward E. toxica filtrate; the resistance of E. carotovora var. carotovora, E. carotovora var. citrullis, E. toxica, Bacillus subtilis, Bacillus lichenoformis and Serratia marcescence toward E. carotovora var. citrullis broth and the resistance of E. toxica, Escherichia coli, E. subtilis and M. luteus against E. carotovora var. carotovora filtrate. Vanadyl ion broke the resistance of Proteus vulgaris, Bacillus cereus, Mycobacterium phlei and M. luteus to E. carotovora var. citrullis and that of E. carotovora var. carotovora, E. coli, B. subtilis, B. lichenoformis and M. phlei to E. carotovora var. carotovora toxins. Both forms of vanadium could break the resistance of E. toxica and E. carotovora var. citrullis to the antibiotics of Streptomyces venezuelae and S. rubiginosus whereas the vanadyl ion was able to do so for E. carotovora var. carotovora. Both forms of vanadium abolished the activity of S. reclfencis against both varieties of E. carotovora