Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Production of certain bioactive compounds of some microorganisms from wadi araba,egypt

Auteur : Hozzein, Wael Nabil Morsy.

Etablissement de soutenance : Beni-Suef University

Grade : Master of Science (MS) in Botany-Microbiology 2000

Résumé
The work in the present study began by collection of thirty soil lamples from different six localities representing Wadi Araba, Egypt. PVadi Araba is a big valley in the Eastern Desert of Egypt, and to our knowledge was not investigated microbiologically up till now. The geomorphology, climatic factors and soil analysis of the study area were given. The climatic parameters recorded revealed that this area Is located in the hyperarid zone of Egypt with a mean annual temperature of 21.4°C and mean annual rainfall of 1 mm/year. The physicochemical [characteristics of the collected soil samples showed that all of them were bandy soils. The soil samples varied from slightly to moderate alkaline and also from non-saline to slightly saline. We tend to isolate alkalophilic and alkaline-resistant microorganisms as a possible source of new antimicrobial compounds. Dilution plate technique was used for this purpose using Sato medium A recommended for isolating microorganisms on high alkaline medium. |The number of microbial colonies from the different soil samples varied from 102 to 104 CFU/g of soil. It was obvious that the viable microbial Runts were affected by the organic matter content and the pH of the soil. A total of 117 alkalophilic and alkaline-resistant microorganisms ;were isolated. Among them, 73 isolates were bacteria, 40 isolates were fctinomycetes and the remaining 4 isolates were fungi. The purified alkalophilic and alkaline-resistant microorganisms were then investigated for their antimicrobial activities using the classical diffusion method. Certain Gram-positive & Gram-negative bacteria and fungi were used as ■est organisms for such a purpose. The alkalophilic actinomycetes were -Jie most active group and so we choose to continue work with them. The diameter of inhibition zones of growth was used to select the working Isolate. The most potent isolate was the isolate WA52, which was ■elected for further studies. These included its identification to the species level ; the effect of different environmental and nutritional factors on the biosynthesis of the active metabolite ; and separation, purification and ■entification of the active compound.

Présentation étendue (EULC)