Isolation, identification and antimicrobial activities of some fungi associated with marine algae

Ninety four fungal isolates belonging to nineteen fungal genera and thirty seven species were isolated from different algae samples collected from Abou-keer, Alexandria, Egypt, during the four seasons of 2004. The marine fungal genera were Helicascus, Sigmoidea and Varicosporina, while the terrestrial fungal genera were Acremonium, AIternaria, Aspergillus, Chrysonilia, Cladosporium, Dendryphiopsis, Fusarium, Geotriclium, Helminthosporium, Moniliella, Mucor, Penicillium. Scopulariopsis, Trichoderma, Ulocladium and Verticillium. All fungal isolates were tested against some pathogenic bacteria, yeast and fungi. The results revealed that, Penicillium brevicompactum [APt] and Varicsporina ramulosa [SPa] were the most promising fungi which were active against gram positive, gram negative bacteria and fungi

Production of some biologically active secondary metabolites from marine-derived fungus Varicosporina ramulosa

In a screening of fungal isolates associated with marine algae collected from Abou-keer, Alexanderia during the four seasons of 2004, to obtain new biologically active compounds. Varicosporina ramulosa isolate was identified and selected as a producer of 13 compounds. Out of 13 pure compounds produced, compounds 3 and 10 were considered as antibacterial and antifungal compounds, respectively as they were active against gram positive, gram negative bacteria and a fungus. Optimization of conditions (fermentation media, incubation period, temperature, initial pH, aeration levels) which activate compounds 3 and 10 production were studied. Also the spectral properties (UV, MS, GC/MS, IR and 1H-NMR) of the purified compounds were determined. Compound 3 suggested to be dibutyl phthalate and compound 10 may be ergosterol or one of its isomers. Biological evaluation of the two compounds towards 6 different types of tumor cell lines showed weak effect of compound 3 at different concentrations on the viable cell count of the different tumor cell lines. While compound 10 showed different activities against the viable cell count of the 6 different tumor cell lines. It kills 50% of the viable infected liver and lung cells at concentrations equal to 99.7 μg/mL, 74.9μg/mL, respectively. Compound 10 can be recommended as new anticancer compounds.

Interaction between bacteria, fungi and aspergillus parasiticus on production of aflatoxin

The of Aspagiltus parasiticus spores was grown on yeast extract sucrose troth medium, into wild strains of either bacteria or fungi resulted in the reduction of aflatoxin concentration. Mixed culture of A. parasiticus was grown into Bacilluscereus, showed significantly reduction in total aflatoxin in the incubation periods 7 day and 14 days. However mixed culture of all molds and bacteria had lower affect than single culture of B. cereus on aflatoxin production in the incubation period 7 days. Pseudomonase aeruginosn stimulated aflatoxin B2 production by A. parauticus after 7 days but it inhibited after 14 days ittwbation. Fusarium moniliforme had little affect on total aflatoxin reduction from A. parasiticus. The production of aflatoxin by mixed of these molds with bacteria [B. cereus, P. aeruginosa or Sarcina sp.] decrease after 7 days incubation, and extension the incubation period to 14 days was associated with markedly reduction in aflatoxin concentration. There was astatistically significant change in levels of AFBI, AFB2, AFG1, and AFG2 when A. parasiticus incubated with other microorganisms. The four aflatoxins are not completely removed. There was apparently nodirect relationship between toxin production and dry weight of the mycelium

Study of antimicrobial activity by some medicinal plants

The whole parts of the random selection of medicinal plants contained antimicrobial activities, therefore, in the present study several extracts of the plants were prepared and tested for their antimicrobial potency to indicate in which solvent the principle was mostly included. It was found that most extracts showed marked activity against most the organisms tested. Beside Balanites aegyptiaca [fruits] showed marked activity against all microorganisms except Kluyveromyces lactis [Y-1118] and Candida utilis in ethyl alcohol extract, however beazeaoe, ether, chloroform and ethyl alcohol extract showed complete inhibition toward Salmonella typhi. The results disclosed the importance of such studies and call for further investigations. They also explained some commonplace folklore medicinal applications and practices. Correlation can be made with the use of some of the plants in herbal medicine

stability of aflatoxins under various pressures, heat treatment and time of exposure

The relationship between heat treatment under various pressures and time of exposure on aflatoxins destruction was investigated. The toxins were produced by Aspergillus flavus strains isolated from wheat, corn, and rice on [YES] medium. The results revealed that, heat treatment under pressure reduced the level of AFB[1], whereas induce complete destruction in the level of AFB[2] during the applied time under investigations The effect of pressure cooking with excess water on the deterioration of aflatoxins in different substrates [such as broad beans, cow peas, macaroni, rice and wheat] was also studied. The results indicated that there is no complete destruction of aflatoxins, and in- turn did not eliminate the hazards of aflatoxins produced by A. parasitic us NRRL 2999on the substrates. The destruction of aflatoxins depended on its type and the substrates

Effect of gamma irradiation on aflatoxin production by aspergillus parasiticus

Exposure of aflatoxins produced by A. parasiticus grown on sterile raw peanuts to specific gamma irradiation doses induced reduction in aflatoxins with increasing gamma irradiation dose than did aflatoxin from non-irradiated sterile raw peanuts [control]. The reduction of aflatoxins ranged from 9.3 to 29.7%, 13.9 to 37.3%, 0.96 to 16.8% and 0.72 to 60.3% for AFB1, AFB2, AFG1 and AFG2, when the culture was irradiated at 0.5 to KGY, respectively. On the other hand, non- sterile raw peanuts that was inoculated with conidia of the fungus and then incubated for 2 weeks at 30C following irradiation resulted in reduction in aflatoxins ranged from 18.2 to 89%, 26 to 96%, 35.4 to 85.2% and 17.3 to 76.4% for AFB1, AFB2, AFG1 and AFG2, respectively. Irradiated raw peanuts culture following inoculation with conidia of the fungus and then incubated for 2 weeks at 30C resulted in reduction of toxin [s] production ranged from 4.9 to 28.4%, 16.8 to 54.7%, 1.71 to 18.6% and from 9.13 to 30.4% in AFB1 AFB2, AFG1 and AFG2 when cultures irradiated at 0.5 to 5 KGY, respectively. Inoculation of either sterile or non-sterile raw peanuts cultures following irradiation resulted in completely degradation of aflatoxin [s] at higher doses between 2.5 to 5 KGy for sterile substrates and at 2.5 to 4 KGy for non-sterile raw peanuts

Effect of pesticides on total phospholipids of hansenula anomala

Cells of Hansenula anomala were found to contain an altered phospholipid when grown under aerobic or anaerobic conditions in the presence of a fungicide, tilt, insecticide, dimecron and acardicide, Neoron. Experimental results indicate that the level of phospholipids have a significant positive correlation with increasing the concentration of any of the three pesticides under test. Also the level of phospholipids for yeast cells grown aerobically were higher than those grown under anaerobic conditions

Effect of propiconazol on amino acid compositions of some yeasts

Amino acid pool was extracted from Hansenula anomala, Candida guilliermondii and Rhodotorula rubra grown under aerobic and anaerobic conditions in the presence of different concentrations of Propiconazol [Tilt] used as a fungicide. The levels of free amino acids in these yeasts showed remarkable fluctuations and decreases. Higher changes occurred in both quantitative and qualitative levels of the free amino acid pools when the yeasts under investigation were grown in increasing growth-inhibitory concentrations of Propiconazol. However, it was found that the concentrations of total free amino acids are lower when these yeasts are grown on medium containing a fungicide