عنوان مقاله [English]
Aspergillus niger is one of the microorganisms utilized to produce single cell protein. This filamentous fungus can produce a wide range of enzymes and may be cultivated by lot of substrates. Aspergillus niger is able to produce high amount of extracellular protein, therefore it is possible to enrich the substrate and also extract the protein with a solvent. Its growth efficiency is higher on solid substrate because it can grow naturally on pectin substrate. Saffron petal is now one of the agricultural wastes while it could be used as substrate for solid state fermentation. In this research A. niger was cultivated on dried saffron petals in a 15 day period and its protein content was extracted with two solvents and assayed by Biuret and Modified Lowry methods. Highest amount of protein assayed by Biuret was 98.53 mg per gram of dry substrate when extracted with distilled water and reached up to 167 mg/g dry substrate when using a mixture of NaOH and Sodium carbonate-bicarbonat buffer.