Breeding And Study On The Mortierella Alpina Saltant With A Higher Arachidonic Acid Production

The article takes Mortierella alpina200012201-12（12for short,the same below）as theoriginal strain．Get a Mortierella alpina saltant200012201-12-2-2（12-2-2for short，thesame below）with a higher arachidonic acid（ARA for short，the same below） productionthrough60Co-γ ray mutation breeding．Through PDA plate and scanning electronmicroscope observation，comparatively study mycelial growth，colonial morphology andsporulation of the original strain and the saltant．Study the influence of starch toMortierella alpina saltant producing ARA．By single factor test and orthogonal test，studythe culture medium and culture condition of the saltant producing arachidonic acid．Themain experimental results are as follows：1.Breeding saltant with a higher ARA production through60Co-γ ray mutation．Afterfiltering，get the saltant12-2-2finally．Its biomass is29.73g/L，oil length is35.15%，ARA production is3.75g/L．Its ARA production is2.09times of the original strain．Thereis a good commercial application prospect．2.There is a morphological difference between12-2-2and12：12-2-2grows in closeproximity to medium on the PDA plate．Its hypha is faint yellow．12bacterial colony is asa wavy，which dosen’t grows in close proximity to medium．Its hypha is white．Under theSEM observation，12-2-2hypha is thicker and denser than12hypha．Conidium andzygospore of12-2-2are less and observed hardly．3.Starch has acceleration on ARA production of the saltant．After adding2%starch intofermentation medium，biomass，oil length and ARA production is30.57g/L，37.23%and4.48g/L，which is1.09，1.06and1.21times of the control group respectively．The role ofstarch as carbon source is very weak，not obvious as glucose．But starch plays a function asthe attachment of mycelial growth．4.The primary and secondary order of the medium factors influencing the saltantproducing oil and ARA is：glucose＞starch＞yeast cream＞inorganic salt．The best culturemedium is：glucose70g/L,starch20g/L，yeast cream15g/L and inorganic salt0.5 g/L．Under the best condition，biomass is31.62g/L，oil production is12.84g/L，ARAproduction is5.31g/L．5.The primary and secondary order of the culture condition factors influencing thesaltant producing oil and ARA is：temperature＞culturing time＞shaking speed＞pH．Thebest culture condition is:temperature26℃，culturing time7days，shaking speed160r/minand pH8．Under the best condition，biomass is33.31g/L，oil production is13.98g/L，ARA production is5.81g/L．...