The prevalence and population density of the mycobiota of 50 samples belonging to 10 kinds of spices (anise, black pepper, red pepper, black cumin, peppermint, cardamom, clove, cumin, ginger and marjoram) which collected from different places in Jeddah Governorate were studied. The natural occurrence of mycotoxins in those samples was also investigated. Fifteen genera and thirty - one species of fungi in addition to one species variety were isolated and identified during this study. The most common genera were Aspergillus, Penicillium and Fusarium. Aflatoxins (12~40 µg/kg) were detected in the extract of 5 samples of each of anise seeds and black pepper fruits; three samples of black cumin seeds and on sample only of each of peppermint and marjoram leaves out of 5 samples tested of each. Sterigmatocystin (15~20 µg/kg) was detected in some samples of red pepper, cumin and marjoram. The inhibitory effects of 10 kinds of powdered spices were tested against 3 toxigenic isolates of fungi (Aspergillus flavus, A. versicolor and Penicillium citrinum). Clove proved to be antimycotic compounds. It inhibited the growth of the tested toxigenic fungi. Black pepper, peppermint, cardamom, cumin and marjoram completely inhibited aflatoxins production, while black pepper and cardamom also completely inhibited sterigmatocystin production.

Natural feed ingredients (corn, barley and wheat bran) and compound feed (manufactured pellet) are two types of fodder used for animal feeding, especially camel in Saudi Arabia. Twenty samples of each type of fodder were collected from seven different regions and screened for the presence of fungi, aflatoxins, ochratoxin and zearalenone. Fungal isolation of natural feed ingredients yielded 10 genera and 38 species of different fungi. Compound fodder samples were contaminated with 16 genera and 32 species of fungi. Total counts of Aspergillus, Penicillium and Fusarium in the animal feed samples were ranged from 54 to 223 × 10(3), 31.9 to 60 × 10(3) and 18 to 29 × 10(3) CFU/g, respectively. These isolates when tested for aflatoxin, ochratoxin and zearalenone producing ability, revealed this property in only four isolate, identified as Aspergillus flavus, A. parasiticus, A. ochraceus and Fusarium graminaerum. The percentage of toxigenic fungi was ranged from 5.5% to 30% for natural feed ingredients and from 4.5% to 20% for compound feed. The incidence of aflatoxins (AFT) in samples of natural feed ingredients was found to be ranged from 1 to 24.8 ppb, ochratoxin A (OTA) ranged from 1 to 44 ppb and zearalenone (ZON) ranged from 1 to 23 ppb. Contamination of compound feed with aflatoxin and ochratoxin A was ranged from 1 to 6.4 ppb and 1 to 4.7 ppb, respectively. All samples collected were found contaminated with fungi or their toxins and natural feed samples were more contaminated compared to compound feed samples. The concentrations detected were in the allowed limit (<20 ppb) except four samples of natural feed ingredients which were above the allowed limit of the tested mycotoxins. In conclusion, feed samples were contaminated with fungi and some toxigenic isolates which were responsible about mycotoxin production. Some samples had exceeded amount of AFT, OTA and ZON and may be contaminated with other mycotoxins which mean implication of fungi in camel health problems and death in Saudi Arabia.

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Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) analysis was used to detect the patulin-producing potential among seven different strains of Paecilomyces variotii isolated from air samples collected in Jeddah City, Saudi Arabia. Using five different primers, the strains showed some similarities and distinct RAPD patterns. A correlation between isolation source and clustering was noted in the constructed dendrogram. Patulin-producing strains showed identical RAPD patterns. Primer M13 produced a distinct fragment with toxin-producing strains.

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In this work, sequential optimization strategy, based on statistical designs, was employed to enhance the degradation of PHB by Trichoderma asperellum through the measurement of PHB depolymerase specific activity. For PHB degradation screening, two-level Plackett-Burman design was used. Result of study revealed that fermentation medium composition significantly influencing the PHB depolymerase specific activity. Further, it was reported that time of incubation, levels of PHB and concentration of glucose were found to be the major factors influencing the enzyme specific activity. A second threelevel Box-Behnken design was applied to acquire the best process conditions for PHB depolymerase specific activity. In this study, the initial basal medium showed a PHB depolymerase specific activity of 40 ng / l / hr / g dry wt and through the two successive statistical design, the final level of PHB depolymerase specific activity was 3230 ng / l / hr / g drywt, this means a nearly of 80 fold increase.