Extraction Of Ergosterol And Chitosan From Fermentation Mycelia, And The Utilization Of Extraction Wastewater

Ergosterol and chitosan have been widely used as pharmaceutical and chemical raw material. Chitosan is mainly extracted from shrimp and crab shell, ergosterol from fungi by means of fermentation. As the main by-product of pharmaceutical fermentation, Penicillium chrysongenum and Cephalosporium acremonium mycelia contains ergosterol and chitoan stimutanously, which provides a new low-cost means for the producton of ergosterol and chitosan. Extraction of ergosterol and chitosan from Penicillium chrysongenum and Cephalosporium acremonium mycelia not only has the considerable economic efficiency, but also is advantageous to the environmental protection.The extraction conditions of ergosterol from Penicillium chrysongenum were firstly studied, and the highest yield of ergosterol was gained at the optimal conditions——6%NaOH,20%alcohol,80℃,2h. The petroleum ether was used to extract ergosterol from the disrupted cell at50℃for three times. Three organic solutions (methylbenzene, methylbenzene-methanol, methylbenzene-acetone) were used for recrystallization, and methylbenzene-acetone was better than the others for recrystallization of ergosterol. Then the effects of different factors, including alkali concentration, ratio of solid and liquid, Extraction time and temperature, on efficiency of disrupting cell wall and removing protein were studied. At last the conclusion showed that the optimal conditions were12.5%NaOH,1:4(solid:liquid),2.6hour,93.5℃.Thirdly, the processing conditions of taking off acetyl in mycelia cell wall were researched. Through monofactorial experiments and central composite design, the effects of alkali concentration, ratio of solid to liquild, Extraction time, and temperature on chitosan yield were studied. The best conditions were42%NaOH,1:4(ratio of solid to liquid),3.5hour,78℃. Meanwhile, the conditions for extraction of chitosan using acid were studied, the chitosan yield was highest at5%acetate,80℃and2hour.Lots of saline wastewater was produced during the extraction of ergosterol and chitosan. The product of β-carotene by strains of Rhodotorula glutinis on the saline wastewater was investigated. Under the optimal growth conditions (the initial glucose concentration30g/L, pH6.5and30℃), the total carotenoids was217μg/g dry cell weight, the final COD removal efficiency and biomass were71.4%and7.21g/l, respectively.