The Effect Of COD Component On Oil Production By Rhodotorula Glutinis Growing In Starch Wastewater

In this paper, the COD component of starch wastewater and theeffect of COD component on biomass, oil production by Rhodotorulaglutinis growing in the wastewater were studied. The experimental starchwastewater comprised the soak solution the corn gluten water and thewastewater which was made up of certain proportion of starchwastewater.The organic pollutants in starch wastewater were detected byGC-MS, GC technique and conventional laboratory analysis. The resultsshowed that the COD of amino acid respectively reached119345.50mg/L12994.51mg/L and43954.61mg/L in the three kinds ofwastewater and the proportion of COD respectively reached22.8%娟个7.92%and10.43%. The amino acid promoted the growth of microorganismnoteworthily. The maximum biomass个increased from6.23g/L to13.63g/L and the maximum lipid content dropped from26.90%to18.16%.The protein in wastewater could be used as nitrogen source for thegrowth of yeast. The COD of protein separately achieved11204.71mg/L2119.50mg/L and5589.71mg/L. The COD proportion were9.39%16.31%and9.81%. During the fermentation process, most of protein could be consumed by Rhodotorula glutinis. The degradation rate ofprotein COD was5.48%. After120h fermentation, the concentration andCOD proportion of protein reached0.17g/L and10.45%.The carbon source in starch wastewater contained glucose, organicacids and short-chain alcohol. The proportion of organic acid CODrespectively reached10.95%,11.39%and18.62%in the three kinds ofwastewater.个The organic acids were conducive to Rhodotorula glutinislipid accumulation and the maximum lipid content reached27.49%at72h. During the fermentation process Rhodotorula glutinis could use largeof glucose, organic acids and ethanol. In mixed starch wastewater, thepercentage of carbon source COD was47.61%. After120h cultivation,the carbon source COD contributed nearly50%to the descent of the totalCOD.