Study On The GLA Production By Cunninghamella Growing In Potato Starch Waste Water

For potential functional roles in therapeutics and nutriology,gamma linolenic acid (GLA) have attracted much attention of researchers.Nowadays,it tended to produce GLA by microbial fermentation at home and abroad.However,expensive cost of synthetic medium was the bottleneck of large-scale production.To supply and develop cheaper oil resource for producing PUFAs have been becoming a studying area of massive focus.This paper studied on microbial oils production by fungi(F3) growing in potato starch processing waste water for GLA with low cost.Firstly an efficient oils-extracting method was obtained after the traditional acid-heating extraction technique was revised by use absoring filtration,n-hexanea and ethanol with a proportion of 2:1,two times acid-heating treatment,the effectiveness of producing oils then inhanced with 20.71% and reached 95% through the means of soxhlet extraction;It could be drew out that the utilization of saccharide derived from the liquefaction and saccharification of the potato starch residue could be a better complementarity to the carbon source.By using of starch waste water for seed medium and conclusion from the results of ion orthogonal experiments,the optimum seed medium was obtained:Cane Suger40g/L,(NH4)2SO41g/L,MgSO4﹒7H2O0.3g/L,NaAc2g/L,pH5.5.This study found that the best proportion of initial waste water and tap water was 1:4,then the oils content and GLA% reached 5.034 g/L and 11.04%;By studing the concentration of carbon source,nitrogen source,some effective ions,C/N and culture time,the optimum oils-producing conditions in the diluting waste water for strain F3 in the flask have acquired: (NH4)2SO40.5g/L,MgSO4·7H2O2g/L,Citric Acid3g/L,Corn Syrup10mL/L,KH2PO41g/L,NaAc5g/L, (NH4)2SO42g/L,pH6.0,cultivating period 6days,and the GLA% and GLA content were 13.95% and 0.867g/L ; Finally , in the 10L fermentor with high stirrer-rate and ventilate-rate,the biomass reached 20.09g/L and GLA% was 10.73%.This paper pointed out and adopted producing GLA from potato starch processing waste water for the first time,including the research of oils-extracting methods,using starch waste water for seeds culture , fermentation conditions in flask and 10L fermentor.This paper provides a theoretical and practical possibility for GLA production in the modern industry with a cheap way.