Candida parapsilosis as a potent biocontrol agent against growth and aflatoxin production by aspergillus species

Aflatoxin contamination of food and feed stuff is a serious health problem and significant economic concerns. In the present study, the inhibitory effect of Candida parapsilosis IP1698 on mycelial growth and aflatoxin production in aflatoxigenic strains of Aspergillus species was investigated. Mycelial growth inhibitions of nine strains of aflatoxigenic and non-aflatoxigenic Aspergillus species in the presence of C. parapsilosis investigated by pour plate technique at different pH, temperature and time of incubation. Reduction of aflatoxin was evaluated in co-cultured fungi in yeast extract sucrose broth after seven days of incubation using HPLC method. The data were analyzed by SPSS 11.5. The presence of the C. parapsilosis at different pH did not affect significantly the growth rate of Aspergillm isolates. On the other hand, temperature and time of incubation showed to be significantly effective when compared to controls without C. parapsilosis [P<0.05]. In aflatoxigenic strains, minimum percentage of reductions in total aflatoxin and BI, 62, Gi, G2 fractions were 92.98, 92.54, 77.48, 54.54 and 72.22 and maximum percentage of reductions were 99.59, not detectable, 94.42, and not detectable in both GI and G2, respectively. C parapsilosis might employ as a good biocontrol agent against growth and aflatoxin production by aflatoxigenic Aspergillus species

[Zebra fish: technology for natural product discovery]

Rising challenges in the present drug discovery model are prompting Prompt a renewed interest in natural products as a source of novel, bioactive small molecules. With the current validation of zebra fish as a biomedical appropriate model for functional genomics and in vivo drug discovery, the zebra fish bioassay-guided identification of natural products may be an attractive tactic to generate new lead compounds in a number of indication regions. Here, we review recent natural product research using zebra fish and evaluate the potential of this vertebrate model as a discovery platform for the systematic identification of bioactive natural products

[Antimicrobial activity of total extract and fractions of geum kokanicum]

Geum kokanicum Regel et schmath, a member of Rosaceae family, is an endemic perennial rhizomatous plant of Iran. This plant has a consideration attention in the treatment of diarrhea and other gastrointestinal disorders. In this study, the anti bacterial effects of total extract and fractions of rhizome of plant were investigated. Rhizomes of G. Kokanicum were collected in June 2006 from Bojnourd [khorasan province]. The dried rhizomes were extracted with ethanol to prepare the total extract. Another part of the rhizomes was separately extracted with petrolium ether, dichloromethane, methanol and water successively in order to obtain different fractions. The antibacterial effects of total extract and fractions were investigated with disc diffusion method. The results shows Staphylococcus aureus were susceptible against total extract and methanol fraction. This fraction [10mg/disc] was indicated the largest zone diameters [19mm]. The MIC Values of total extract was investigated. Among the bacterial strains, Staphylococcus epidermitus demonstrated high sensitivity to the total extract of G. kokanicum [0.125mg/ml]. The zone diameters of total extract was 18 mm on S. aureus in 10 mg/disc. Phytochemical analysis of total extract was shown the large amounts of tanan compounds. We suspect the antibacterial effect is for tanan compounds. This was demonstrated by bioautography method analysis of tanan part isolated form methanol fraction