Document Details
Document Type |
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Thesis |
Document Title |
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MOLECULAR CHARACTERIZATION OF MICROORGANISMS CONTAMINATING DRIED FRUITS التوصيف الجزيئي لبعض الكائنات الحية الدقيقة الملوثة للفواكه المجففة |
Subject |
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Faculty of Science |
Document Language |
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Arabic |
Abstract |
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Fruits are an essential source of nutrients for human requirements. They contain many carbohydrates, minerals, vitamins, and amino acids making them desirable for fungal and bacterial growth. Dried fruits can be contaminated with fungi and bacteria which pose dangerous health problems. A total of 180 dried fruits samples including (raisin, date, and apricot) were purchased from markets in Jeddah Governorate, Saudi Arabia. Morphological fungal isolation of dried fruits was carried out by cutting each fruit into small segments (5x5 mm) and then inoculated on potato dextrose agar and incubated at 25°C for 7-14 days. The molecular analysis of fungal isolates was confirmed by sequencing the ITS region of the rRNA gene. The results revealed the isolation of 17 different species belonging to 13 genera of fungi including Alternaria sp., Aspergillus sp., Cladosporium sp., Curvularia sp., Eurotium sp., Lecythophora sp., Mucor sp., Paecilomyces sp., Penicillium sp., Rhizopus sp., Talaromyces sp., Ulocladium sp., Zygosaccharomyces sp. The most dominant genera isolated from two dried fruit including raisins and dates were Aspergillus sp. (367 CFU), Penicillium sp. (74 CFU), and Rhizopus sp. (27 CFU). In dried apricot Zygosaccharomyces sp. (2932 CFU) was the only detected isolated fungus. Morphological bacterial isolation of dried fruits was carried out by adding 5 g of each dried fruits sample to 5 ml of diluent (distilled water). A 0.1 ml volume of each dilution was used to make a series of pour plates. The plates were incubated at 30°C for 48 hr. In addition, the molecular identification analysis of bacterial isolates was confirmed by sequencing the 16S rRNA gene. The results revealed the isolation of 31 different species belonging to 3 genera of bacteria which are Bacillus, Micrococcus, and Staphylococcus. The most dominant genus is Bacillus sp. (739 CFU) isolated from dried fruits. Furthermore, the toxicity activity assay was carried out for some selected fungal extracts against the brine shrimp larvae. In conclusion, good manufacturing practices (GMPs) must be applied to maintain healthy dried fruits and reduce dried fruits contamination during and after harvest. |
Supervisor |
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Dr. Nidal Mohammed Omar Zabermawi |
Thesis Type |
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Master Thesis |
Publishing Year |
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1445 AH
2023 AD |
Added Date |
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Wednesday, October 25, 2023 |
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Researchers
رنا غرم الله الغامدي | Alghamdi, Rana GhormAllah | Researcher | Master | |
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