Cultivation of fungus Mortierella isabellina on corn cob hydrolysate

Oleaginozni mikroorganizmi poput plijesni Mortierella isabellina nakupljaju lipide u uvjetima limitacije rasta izvorom dušika u prisutnosti suviška izvora ugljika. Mikrobni lipidi su alternativna sirovina za proizvodnju biodizela druge generacije. Lignocelulozna biomasa je nusproizvod poljoprivredne i drvne industrije i može se koristiti kao jeftin izvor ugljika za rast mikroorganizama. Iako jeftina, lignocelulozna biomasa ima vrlo složen sastav zbog čega se podvrgava različitim postupcima predobrade koji povećavaju cijenu biogoriva. U ovom istraživanju Mortierella isabellina je uzgojena na hidrolizatu alkalno predobrađenih kukuruznih oklasaka uz limitaciju rasta izvorom dušika. Tijekom rasta dva najzastupljenija šećera u lignoceluloznom hidrolizatu, glukoza i ksiloza, su se trošila redoslijedno. Najveće vrijednosti koncentracije lipida od 10,614 gL-1 i produktivnosti sinteze lipida od 0,87115 gL-1dan-1 postignute su jedanaesti dan uzgoja.Oleaginous microorganisms such as fungus Mortierella isabellina accumulate lipids under nitrogen limited conditions in presence of a excess carbon source. The microbial lipids are alternative feedstock for the production of second generation biodiesel. Lignocellulose biomass is a by-product obtained from the agricultural and wood industry and can be used as a cheap carbon source for growth of microorganisms. Although inexpensive, lignocellulose biomass has a very complex composition due to which it has to be subjected to different pretreatment procedures that increase the price of biofuel. In this study, Mortierella isabellina was cultivated on the enzymatic hydrolysate of alkali-prepared corn cobs under nitrogen limited conditions. During the growth two main sugars in lignocellulosic hydrolysate, xylose and glucose, were consumed sequentially. The highest lipid productivity and lipid concentration of 0.87115 gL-1day-1 and 10.614 gL-1, respectively, was obtained at the eleventh day of cultivation