Hybridization dominance of kinetics in recombinant ATH-1376 obtained via protoplast fusion between Aspergillus niger and Trichoderma reesei.
Comparisons of the kinetics of mycelium growth, cellulase biosynthesis, and the degradation of filter paper to accumulate reducing-sugar by the filtrates of cultures were carried out among the recombinant strain ATH-1376 and its two parents, Aspergillus niger AMS11 and Trichoderma reesei QM9414. The results showed that both the specific mycelium growth rate and the cellulase biosynthesis rate of the recombinant were dramatically dominant over those of the two parents. In addition, the negative correlation between the specific mycelium growth rate and the cellulase biosynthesis rate of the recombinant ATH-1376 was much lower than those of its parents. In terms of the amount of reducing-sugar accumulated from the hydrolysis of filter paper by culture filtrates, there were great differences among the three different treatments, i.e., fermentation filtrate of single parental strain, mixture of the fermentation filtrates from two parental strains with different ratios (v:v), and filtrate from the mixed culture of the two parental strains. Out of these, the second approach, particularly with the ratio of 1:1, was best for the accumulation of reducing sugar. Within various tested periods of enzymic hydrolysis, the amounts of reducing-sugar produced by the recombinant were 1.19 to 2.26 times as much as the maximum amounts produced in parallel by the mixture of filtrates (1:1) from separate fermentations of the two parental strains. These results suggested that constructing the engineered strains with hybridization dominance of these two typical genera of far-heredity could be effective to overcome the great deficiencies of routine mixculture, single-strain fermentation, or double fed-batch fermentations.
Ai
Y
Y
School of Life Sciences, Zhongshan University, Guangzhou, China.
Meng
F
F
Xu
Y
Y
D001234:Aspergillus niger / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism*; D011523:Protoplasts; D011995:Recombination, Genetic; D014242:Trichoderma / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
D002480:Cellulase