الفهرس 
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Abstract
The present work has been devoted to study the effect of different parameters on lovastatin production by the local isolated strain of M. purpureus, in an attempt to maximize the production, and also to develop a potential fermentation process for the production of lovastatin using milk permeate as cheap production medium.The results can be summarized in the following points:1-local Out of 12 local fungal isolates tested, only 5 isolates showed the ability to produce lovastatin in the broth medium, with Monascus purpureus isolate the most producer strain (82 mg/L).
2- The most promising medium for lovastatin production by this strain was MPIII medium, which contains glucose and ammonium chloride as carbon and nitrogen sources, respectively.
3- For improving lovastatin production by Monascus purpureus, optimization of environmental and cultural fermentation conditions were carried out: a- The incubation period of 10 days was the best period for lovastatin production.b- The maximum production of lovastatin (140 mg/L) occurred at incubation temperature 28 ºC and initial pH 6.c- Lactose was the best carbon source for lovastatin production by this strain, and 8% of lactose was the best concentration for the optimum lovastatin secretion (245 mg/L).d- Supplementation of the production medium with mycological peptone (0.4%) as nitrogen source was superior for the production of lovastatin (262 mg/L) by this fungus.
e- Addition of KH2PO4 (0.2%), MgSO4 (0.09%) and MnSO4 (0.02%) to the modified MPIII medium (which contains lactose and mycological peptone as carbon and nitrogen sources, respectively) increased the yield of lovastatin production (285 mg/L).f- The inoculum type, 48 h aged seed culture, at a size 10% (v/v) gave the highest yield in lovastatin (330 mg/L).g Lovastatin production increased by increasing agitation speed up to 200 rpm, at which the fungus produced 358 mg/L.h- Addition of amino acid methionine to the production medium at concentration 0.1 g/L after 72 h of fungus inoculation increased the yield of lovastatin (436 mg/L).