The present study was designed to investigate the possibility of exploiting the interspecies interaction of microbial cells in order to enhance the production of prodigiosin by local isolate S. marcescens S23. Prodigiosin is a promising drug owing to its characteristics of antibacterial, antifungal, immunosuppressive and anticancer activities. S. marcescens S23 was isolated from soil sample and already recognized via morphological, biochemical and molecular identification process. The first step was to detect the optimal conditions for maximum prodigiosin production using chemically defined liquid medium. The results revealed that the optimal conditions for prodigiosin production were sucrose as carbon source; peptone as nitrogen source; 60/40% optimum C/N ratio, 2% inoculum size containing 2×109 cells/ml, which increased the production of prodigiosin from 1.72 to 416 mg/L. Elicitation experiments were carried out by introducing live and dead cells of E. coli, Bacillus subtilis and Saccharomyces cerevisiae, separately, to the S. marcescens culture at zero time. Based on the results obtained in this study, S. marcescens increased its production of prodigiosin as a result of interaction with microbial elicitor cells. The maximum enhancement was achieved in the culture elicited with the heat killed cells of E. coli at an inoculation level of 3% with an increase of approximately 9-fold, whereas the minimum enhancement was upon elicitation with live cells of E. coli and S. cerevisiae. Based on the results obtained in this study, elicitation strategy of exploiting interspecies interactions with microbial cells is successful and useful for enhancing the production of antibiotics.
It is noted in the title that the paper studies the viewpoint in the novel The Dog and the Long Night by the Iranian novelist Shahranoush Parsi Pour and in the novel Alibaba's Sad Night by the Iraqi novelist Abdulkhaliq Ar-Rikabi. Both are well known novelists, and about whose stories and novels many critical books, MA theses, and Ph.D. dissertations have been written. Also, some of their literary works have won prizes. Here, the researcher shed light on the concept of viewpoint, its types, and its importance in novels in general. This was done along with tackling the two viewpoints in both novels, where similarities and differences were identified. For this end, the researcher has adopted the analytic-descriptive appro
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In this article four samples of HgBa2Ca2Cu2.4Ag0.6O8+δ were prepared and irradiated with different doses of gamma radiation 6, 8 and 10 Mrad. The effects of gamma irradiation on structure of HgBa2Ca2Cu2.4Ag0.6O8+δ samples were characterized using X-ray diffraction. It was concluded that there effect on structure by gamma irradiation. Scherrer, crystallization, and Williamson equations were applied based on the X-ray diffraction diagram and for all gamma doses, to calculate crystal size, strain, and degree of crystallinity. I
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