Studies On Fermentation Technique Of Fumaric Acid By Rhizopus Arrhizus

Fumaric acid occurs naturally in many plants and is named after fumaric officinalis,and it is a promising candidate in the manufacture of polymer and a sizing resin in paper factory. A systematic investigation was carried out to improve the productivity of fumaric acid producing strain by UV irritation and bioprocess optimization. During the selection procedure, a simple way of screening for high-yield fumaric acid producing stain was develop and evaluated, in which, area ratio of area of colored ring to that of colony was designed as an indicator.Fermentation medium of the Parent strain was optimized as follows: Glucose120g/L, urea0.5g/L, KH2PO40.6g/L, ZnSO4·7H2O0.088g/L, MgSO4·7H2O0.4g/L, CaCO31.5g/L, methnol60μL/50mL, corn oil3.0g/L,when the cultures were grown in the optimized fermentation medium, the fumaric acid yield26.22g/L,10.6%higher than the original fermentation medium.Fumaric acid over producting mutants were derived from rhizopus arrhizus,by means of mutations with UV and LiCl. The mutants were selected directionally from the agar plates containing bromocresol green and plastic tube. According the diameter of the color ring we can quickly detect the high producticity rhizopus.This new method enhance the efficiency of selection enormously. The mutant Rhizopus arrhizus3#produced55.02g/L fumaric acid in shaking--flask fermentation which were109%higher than that of the Parent strain Produced..By keeping the morphology of Rhizopus arrihzus in Pellet-formduring fermentation, the self-immobilization of Rhizopus arrihzus was aehieved. After that, the repeated intermittent fermentation by self-immobilized Rhizopus arrihzus exploited.