Formation of autodiploid strains in Aspergillus niger and their application to citric acid production from starch |
| |
| Affiliation: | 1. Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Jagiellonian University Medical College, Kraków, Poland;2. Microbiological Laboratory, Department of Laboratory Diagnostics, Ludwik Rydygier Memorial Hospital, Kraków, Poland;3. Department of Cranio-Maxillofacial, Oncological and Reconstructive Surgery, Institute of Stomatology, Jagiellonian University Medical College, Kraków, Poland;1. Development and Research Laboratory, Niigata Meijo Co., Ltd., 1-8-39 Toei, Ojiya, Niigata 947-0004, Japan;2. Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata, Niigata 950-2181, Japan;3. Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata, Niigata 950-2181, Japan;4. Department of Materials Engineering, National Institute of Technology, Nagaoka College, 888 Nishikatagai, Nagaoka, Niigata 940-8532, Japan;1. Section for Medical Statistics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University Vienna, A-1090 Vienna, Austria;2. Division Cardiac-, Thoracic-, Vascular Anaesthesia and Intensive Care, Medical University Vienna, A-1090 Vienna, Austria;3. Medical Clinic III, Division Endocrinology, Medical University Vienna, A-1090 Vienna, Austria;1. Department of Microbiology, University College of Medical Sciences (University of Delhi) and Guru Teg Bahadur Hospital, Delhi 110095, India;2. Department of Dermatology, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi 110095, India;3. Department of Biochemistry, B.N. College of Engineering & Technology, Lucknow 226201, U.P., India;4. Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan 45142, Saudi Arabia |
| |
| Abstract: | Autodiploid strains were induced by colchicine treatment of Aspergillus niger WU-2223L, a citric acid-producing strain. In shaking culture, a representative autodiploid strain, L-d1, yielded higher citric acid than the parental strain, WU-2223L. When glucose was used as a carbon source, L-d1 and WU-2223L produced 67.2 g/l and 62.0 g/l of citric acid, respectively, from 120 g/l of glucose in 9 d-cultivation. Furthermore, the autodiploid strain L-d1 produced 49.6 g/l of citric acid, 1.4 times as much as that produced by WU-2223L from 120 g/l of soluble starch. During the whole period of cultivation with starch, the extracellular glucoamylase activity of L-d1 was on the same level as that of WU-2223L, but the extracellular acid-protease activity of L-d1 was much higher. The addition of pepstatin, an inhibitor of acid protease, to the culture broth at 2 d greatly increased the extracellular glucoamylase activity, and citric acid production by L-d1 reached a level of 59.0 g/l. During several subcultivations on both minimal and complete agar media, the autodiploid strains were genetically stable since they formed diploid conidia in their uniform colonies without producing sectors, and maintained citric acid productivity. However, when cultivated on minimal and complete agar media containing benomyl as a haploidizing reagent, the autodiploid strains readily formed sectors of haploid segregants. The properties of the haploid strains obtained by the benomyl treatment of the autodiploid strains were similar in morphology and citric acid productivity to those of the parental strain, WU-2223L. These results indicated that the enhanced production of citric acid from soluble starch by the autodiploid strains was due to autodiploid formation but not to gene mutation caused by the colchicine treatment. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
