Das A, Roy P
Can J Microbiol. 1978 May;24(5):622-5. doi: 10.1139/m78-102.
Aspergillus niger strain CGU 87 was treated with UV radiation and some auxotrophic mutants were obtained. These mutants were less productive than CGU 87, which produced an average of 7.4% citric acid. All possible crosses in pair wise combinations were carried out between these auxotrophs, and three heterokaryons were synthesised. Finally, one heterozygous diploid was isolated from each of them. These heterokaryons and diploids showed improved productivity when compared with their component parents, but except in one diploid D5, all others produced less citric acid than CGU 87. The yield of D5 exceeded that of CGU 87 by 1.2 times and it produced 9% citric acid. This is a significant improvement and the increased productivity seems to be the result of successful adaptation of D5 to its fermentation environment.
黑曲霉CGU 87菌株经紫外线辐射处理后获得了一些营养缺陷型突变体。这些突变体的产量低于CGU 87，后者平均产柠檬酸7.4%。对这些营养缺陷型突变体进行了所有可能的两两组合杂交，合成了三个异核体。最后，从每个异核体中分离出一个杂合二倍体。与它们的亲本相比，这些异核体和二倍体的产量有所提高，但除了一个二倍体D5外，其他所有二倍体产生的柠檬酸都比CGU 87少。D5的产量比CGU 87高出1.2倍，产柠檬酸9%。这是一个显著的提高，产量增加似乎是D5成功适应其发酵环境的结果。
