An excellent baker's yeast strain ZLTH-58 (MATa/α,leu-,FLO1) with hi gh biomass, high-sugar-tolerance and good flocculation was constructed by primar y screening, isolation of haploid, mutagenesis, cloning and expression of FLO1 gen e and hybridization.
A high biomass production, high-sugar-tolerance and high flocculation triploid baker's yeast strain ZLFH-121(MATa/a/a, FLO1) was constructed by protoplast fusion combined with mass-mating. Study on the biomass production, high-sugar-tolerance and flocculation of the triploid strain ZLFH-121showed that this strain had improved qualities.
The ability of high-sugar-tolerance o f st rain ZLTH-58 was higher than the parental strain BL61.The ability of flocculati o n of strain ZLTH-58 was better than the parental strains BL56 and BL61.The fact o rs that affected the biomass of strain ZLTH-58 were also detected.
The results of determination of 8 strains' tolerance trait of alcohol, SO2, CO2, high concentration of glucose and wine brewing test showed mat strain A, B, C, F, H have good fermentation characters.
2.A strain LB1-1D which tolerated high concentration of lactic acid and sugar was obtained by taming and cultivating in the circumstance with high concentration of sugar and lactic acid. The strain's critical growth concentration of lactic acid and sugar were 24 g/L and 150 g/L respectively.
However,all the yeasts had satisfactory SO 2 resistant capability and high molecular sugar resis-tant capability and residual sugar content in final fermentation liquid was below4g /L.
A mutant FML8611, derived from Brevibacterium flavum FM84-415, was not only a homoserine auxotroph but also a resistant to s-(2-aminoethyl)-L-cysteine (AEC) and rifampin.With the adaptbility to high concentration of glucose,FML8011 can produce 78.9mg/ml L-lysine (as HCI salt) in shaking flask with 46.2 grams L-lysine from per 100 grams glucose. The characteristics of FML8611 mentioned above were stable. Some properties of FML8611 investigated.
TG≡866 Was breeded from TG-3 as parent mutagenized by ultraviolet and DES. The mutant has characteristics of high glucose resistance, high glutamate, resistance, monofluorine acetate resistance, litter grouth with only glutamate as C source and good grouth with only sucinate as C source. In 4 continuous batchs shaker experiments, average yield of gluta mate and convertion rate of glucose were 8.37% and 55.1%, respectively. In 500L fermentor, the result was achieved that the yield of glntamate was over 7.5% ...
A new strain of bacterium S9114, is bud from Brev. tianjin T_(6-13)by induced mutagenesis of the protoplasts with ultraviolet and NTG, etc.The strain S9114 shows the charaCteristic of enduring higher sucroseconcentration and higher glutamic acid concentration, non-glutamic acidconsumed and higher acid yield. The. highest glutandc add yield by shaking flask is up .to 96.99/L, 50% higher than that of the original strain.In 20m ̄3 fermentor, the highest acid yield is 92.3g/L and the highest inversion rate is 56...