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Jia C, Chai R, Zhang M, Guo X, Zhou X, Ding N, Lei C, Dong Z, Zhao J, Ren H, Lu D. Improvement of Saccharomyces cerevisiae strain tolerance to vanillin through heavy ion radiation combined with adaptive laboratory evolution. J Biotechnol 2024; 394:112-124. [PMID: 39197754 DOI: 10.1016/j.jbiotec.2024.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 08/12/2024] [Accepted: 08/23/2024] [Indexed: 09/01/2024]
Abstract
Vanillin is an inhibitor of lignocellulose hydrolysate, which can reduce the ability of Saccharomyces cerevisiae to utilize lignocellulose, which is an important factor limiting the development of the ethanol fermentation industry. In this study, mutants of vanillin-tolerant yeast named H6, H7, X3, and X8 were bred by heavy ion irradiation (HIR) combined with adaptive laboratory evolution (ALE). Phenotypic tests revealed that the mutants outperformed the original strain WT in tolerance, growth rate, genetic stability and fermentation ability. At 1.6 g/L vanillin concentration, the average OD600 value obtained for mutant strains was 0.95 and thus about 3.4-fold higher than for the wild-type. When the concentration of vanillin was 2.0 g/L, the glucose utilization rate of the mutant was 86.3 % within 96 h, while that of the original strain was only 70.0 %. At this concentration of vanillin, the mitochondrial membrane potential of the mutant strain recovered faster than that of the original strain, and the ROS scavenging ability was stronger. We analyzed the whole transcriptome sequencing map and the whole genome resequencing of the mutant, and found that DEGs such as FLO9, GRC3, PSP2 and SWF1, which have large differential expression multiples and obvious mutation characteristics, play an important role in cell flocculation, rDNA transcription, inhibition of DNA polymerase mutation and protein palmitoylation. These functions can help cells resist vanillin stress. The results show that combining HIR with ALE is an effective mutagenesis strategy. This approach can efficiently obtain Saccharomyces cerevisiae mutants with improved vanillin tolerance, and provide reference for obtaining robust yeast strains with lignocellulose inhibitor tolerance.
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Affiliation(s)
- Chenglin Jia
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ran Chai
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Miaomiao Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaopeng Guo
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
| | - Xiang Zhou
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nan Ding
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cairong Lei
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ziyi Dong
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingru Zhao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haiwei Ren
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Dong Lu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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2
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Guo X, Ren J, Zhou X, Zhang M, Lei C, Chai R, Zhang L, Lu D. Strategies to improve the efficiency and quality of mutant breeding using heavy-ion beam irradiation. Crit Rev Biotechnol 2024; 44:735-752. [PMID: 37455421 DOI: 10.1080/07388551.2023.2226339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 04/15/2023] [Indexed: 07/18/2023]
Abstract
Heavy-ion beam irradiation (HIBI) is useful for generating new germplasm in plants and microorganisms due to its ability to induce high mutagenesis rate, broad mutagenesis spectrum, and excellent stability of mutants. However, due to the random mutagenesis and associated mutant breeding modalities, it is imperative to improve HIBI-based mutant breeding efficiency and quality. This review discusses and summarizes the findings of existing theoretical and technical studies and presents a set of tandem strategies to enable efficient and high-quality HIBI-based mutant breeding practices. These strategies: adjust the mutation-inducing techniques, regulate cellular response states, formulate high-throughput screening schemes, and apply the generated superior genetic elements to genetic engineering approaches, thereby, improving the implications and expanding the scope of HIBI-based mutant breeding. These strategies aim to improve the mutagenesis rate, screening efficiency, and utilization of positive mutations. Here, we propose a model based on the integration of these strategies that would leverage the advantages of HIBI while compensating for its present shortcomings. Owing to the unique advantages of HIBI in creating high-quality genetic resources, we believe this review will contribute toward improving HIBI-based breeding.
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Affiliation(s)
- Xiaopeng Guo
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
| | - Junle Ren
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiang Zhou
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Miaomiao Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Cairong Lei
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ran Chai
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
| | - Lingxi Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
| | - Dong Lu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
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Noguchi T, Nishiyama R, Shimokawa T, Yamada K, Kagawa Y. Simultaneous production of cellobiose and xylobiose from alkali-treated bagasse using cellulase secreted by Fe-ion-irradiated Trichoderma reesei mutant. J Biosci Bioeng 2022; 134:491-495. [PMID: 36220721 DOI: 10.1016/j.jbiosc.2022.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 11/05/2022]
Abstract
Cellobiose and xylobiose are disaccharides composed of two glucose or xylose units with β-1,4 linkages. This study aimed to isolate a Trichoderma reesei mutant that lacks β-glucosidase and β-xylosidase activities for the simultaneous production of these disaccharides. Mutagenesis using Fe-ion beam resulted in a mutant strain, T. reesei T1640; the cellulase production in this strain was as high as that in the parent strain. Genomic analysis revealed that T1640 lost both the β-glucosidase and β-xylosidase activities owing to the translocation of the responsible genes. Hydrolysis of alkali-treated bagasse using the enzymes from T1640 leads to high yields (365 mg/g-biomass) and ratios (72.7% of the total sugars) of cellobiose and xylobiose.
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Affiliation(s)
- Takuya Noguchi
- New Frontiers Research Laboratory, Toray Industries, Inc., 6-10-1 Tebiro, Kamakura, Kanagawa 248-8555, Japan
| | - Ryuji Nishiyama
- New Frontiers Research Laboratory, Toray Industries, Inc., 6-10-1 Tebiro, Kamakura, Kanagawa 248-8555, Japan
| | - Takashi Shimokawa
- National Institutes of Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan
| | - Katsushige Yamada
- New Frontiers Research Laboratory, Toray Industries, Inc., 6-10-1 Tebiro, Kamakura, Kanagawa 248-8555, Japan
| | - Yusuke Kagawa
- New Frontiers Research Laboratory, Toray Industries, Inc., 6-10-1 Tebiro, Kamakura, Kanagawa 248-8555, Japan.
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Cao L, Gao Y, Wang XZ, Shu GY, Hu YN, Xie ZP, Cui W, Guo XP, Zhou X. A Series of Efficient Umbrella Modeling Strategies to Track Irradiation-Mutation Strains Improving Butyric Acid Production From the Pre-development Earlier Stage Point of View. Front Bioeng Biotechnol 2021; 9:609345. [PMID: 34222207 PMCID: PMC8242359 DOI: 10.3389/fbioe.2021.609345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Clostridium tyrobutyricum (C. tyrobutyricum) is a fermentation strain used to produce butyric acid. A promising new biofuel, n-butanol, can be produced by catalysis of butyrate, which can be obtained through microbial fermentation. Butyric acid has various uses in food additives and flavor agents, antiseptic substances, drug formulations, and fragrances. Its use as a food flavoring has been approved by the European Union, and it has therefore been listed on the EU Lists of Flavorings. As butyric acid fermentation is a cost-efficient process, butyric acid is an attractive feedstock for various biofuels and food commercialization products. 12C6+ irradiation has advantages over conventional mutation methods for fermentation production due to its dosage conformity and excellent biological availability. Nevertheless, the effects of these heavy-ion irradiations on the specific productiveness of C. tyrobutyricum are still uncertain. We developed non-structured mathematical models to represent the heavy-ion irradiation of C. tyrobutyricum in biofermentation reactors. The kinetic models reflect various fermentation features of the mutants, including the mutant strain growth model, butyric acid formation model, and medium consumption model. The models were constructed based on the Markov chain Monte Carlo model and logistic regression. Models were verified using experimental data in response to different initial glucose concentrations (0-180 g/L). The parameters of fixed proposals are applied in the various fermentation stages. Predictions of these models were in accordance well with the results of fermentation assays. The maximum butyric acid production was 56.3 g/L. Our study provides reliable information for increasing butyric acid production and for evaluating the feasibility of using mutant strains of C. tyrobutyricum at the pre-development phase.
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Affiliation(s)
- Li Cao
- College of Life Sciences and Engineering, Hexi University, Zhangye, China
| | - Yue Gao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Xue-Zhen Wang
- College of Life Sciences and Engineering, Hexi University, Zhangye, China
| | - Guang-Yuan Shu
- College of Life Sciences and Engineering, Hexi University, Zhangye, China
| | - Ya-Nan Hu
- College of Life Sciences and Engineering, Hexi University, Zhangye, China
| | - Zong-Ping Xie
- College of Life Sciences and Engineering, Hexi University, Zhangye, China
| | - Wei Cui
- College of Life Sciences and Engineering, Hexi University, Zhangye, China
| | - Xiao-Peng Guo
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Xiang Zhou
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,College of Life Science, University of Chinese Academy of Sciences, Beijing, China
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Jiang A, Hu W, Li W, Liu L, Tian X, Liu J, Wang S, Lu D, Chen J. Enhanced production of l-lactic acid by Lactobacillus thermophilus SRZ50 mutant generated by high-linear energy transfer heavy ion mutagenesis. Eng Life Sci 2018; 18:626-634. [PMID: 32624942 PMCID: PMC6999237 DOI: 10.1002/elsc.201800052] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/11/2018] [Accepted: 05/02/2018] [Indexed: 12/17/2022] Open
Abstract
The aim of this study was to improve l-lactic acid production of Lactobacillus thermophilus SRZ50. For this purpose, high efficient heavy-ion mutagenesis technique was performed using SRZ50 as the original strain. To enhance the screening efficiency for high yield l-lactic acid producers, a scale-down from shake flask to microtiter plate was developed. The results showed that 24-well U-bottom MTPs could well alternate shake flasks for L. thermophilus cultivation as a scale-down tool due to its a very good comparability to the shake flasks. Based on this microtiter plate screening method, two high l-lactic acid productivity mutants, A59 and A69, were successfully screened out, which presented, respectively, 15.8 and 16.2% higher productivities than that of the original strain. Based on fed-batch fermentation, the A69 mutant can accumulate 114.2 g/L l-lactic acid at 96 h. Hence, the proposed traditional microbial breeding method with efficient high-throughput screening assay was proved to be an appropriate strategy to obtain lactic acid-overproducing strain.
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Affiliation(s)
- Ai‐lian Jiang
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
- University of Chinese Academy of SciencesBeijingP. R. China
| | - Wei Hu
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
| | - Wen‐jian Li
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
| | - Lu Liu
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
- University of Chinese Academy of SciencesBeijingP. R. China
| | - Xue‐jiao Tian
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
- University of Chinese Academy of SciencesBeijingP. R. China
| | - Jing Liu
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
| | - Shu‐yang Wang
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
| | - Dong Lu
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
| | - Ji‐hong Chen
- Department of BiophysicsInstitute of Modern PhysicsChinese Academy of SciencesLanzhouP. R. China
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Amorim C, Silvério SC, Rodrigues LR. One-step process for producing prebiotic arabino-xylooligosaccharides from brewer's spent grain employing Trichoderma species. Food Chem 2018; 270:86-94. [PMID: 30174095 DOI: 10.1016/j.foodchem.2018.07.080] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/06/2018] [Accepted: 07/11/2018] [Indexed: 12/21/2022]
Abstract
Xylooligosaccharides (XOS) are prebiotic nutraceuticals that can be sourced from lignocellulosic biomass, such as agro-residues. This study reports for the first time an optimization study of XOS production from agro-residues by direct fermentation using two Trichoderma species. A total of 13 residues were evaluated as potential substrates for single-step production. The best results were found for Trichoderma reesei using brewers' spent grain (BSG) as substrate. Under optimal conditions (3 days, pH 7.0, 30 °C and 20 g/L of BSG), a production yield of 38.3 ± 1.8 mg/g (xylose equivalents/g of BSG) was achieved. The obtained oligosaccharides were identified as arabino-xylooligosacharides (AXOS) with degree of polymerization from 2 to 5. One-step fermentation proved to be a promising strategy for AXOS production from BSG, presenting a performance comparable with the use of commercial enzymes. This study provides new insights towards the bioprocess integration, enabling further developments of low-cost bioprocesses for the production of these valuable compounds.
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Affiliation(s)
- Cláudia Amorim
- CEB-Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Sara C Silvério
- CEB-Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Lígia R Rodrigues
- CEB-Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
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Zhang H, Lu D, Li X, Feng Y, Cui Q, Song X. Heavy ion mutagenesis combined with triclosan screening provides a new strategy for improving the arachidonic acid yield in Mortierella alpina. BMC Biotechnol 2018; 18:23. [PMID: 29716562 PMCID: PMC5930740 DOI: 10.1186/s12896-018-0437-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 04/18/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Arachidonic acid (ARA), which is a ω-6 polyunsaturated fatty acid, has a wide range of biological activities and is an essential component of cellular membranes in some human tissues. Mortierella alpina is the best strain for industrial production of ARA. To increase its yield of arachidonic acid, heavy ion beam irradiation mutagenesis of Mortierella alpina was carried out in combination with triclosan and octyl gallate treatment. RESULTS The obtained mutant strain F-23 ultimately achieved an ARA yield of 5.26 g L- 1, which is 3.24 times higher than that of the wild-type strain. In addition, quantitative real-time PCR confirmed that the expression levels of fatty acid synthase (FAS), Δ5-desaturase, Δ6-desaturase, and Δ9-desaturase were all significantly up-regulated in the mutant F-23 strain, especially Δ6- and Δ9-desaturase, which were up-regulated 3- and 2-fold, respectively. CONCLUSIONS This study confirmed a feasible mutagenesis breeding strategy for improving ARA production and provided a mutant of Mortierella alpina with high ARA yield.
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Affiliation(s)
- Huidan Zhang
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, Shandong, China.,Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dong Lu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
| | - Xin Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
| | - Yingang Feng
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, Shandong, China.,Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China
| | - Qiu Cui
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, Shandong, China.,Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, Shandong, China.,Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China
| | - Xiaojin Song
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, Shandong, China. .,Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China.
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Hu W, Li W, Chen J. Recent advances of microbial breeding via heavy-ion mutagenesis at IMP. Lett Appl Microbiol 2017; 65:274-280. [PMID: 28741678 DOI: 10.1111/lam.12780] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/11/2017] [Accepted: 07/17/2017] [Indexed: 12/12/2022]
Abstract
Nowadays, the value of heavy-ion mutagenesis has been accepted as a novel powerful mutagen technique to generate new microbial mutants due to its high linear energy transfer and high relative biological effectiveness. This paper briefly reviews recent progress in developing a more efficient mutagenesis technique for microbial breeding using heavy-ion mutagenesis, and also presents the outline of the beam line for microbial breeding in Heavy Ion Research Facility of Lanzhou. Then, new insights into microbial biotechnology via heavy-ion mutagenesis are also further explored. We hope that our concerns will give deep insight into microbial breeding biotechnology via heavy-ion mutagenesis. We also believe that heavy-ion mutagenesis breeding will greatly contribute to the progress of a comprehensive study industrial strain engineering for bioindustry in the future. SIGNIFICANCE AND IMPACT OF THE STUDY There is currently a great interest in developing rapid and diverse microbial mutation tool for strain modification. Heavy-ion mutagenesis has been proved as a powerful technology for microbial breeding due to its broad spectrum of mutation phenotypes with high efficiency. In order to deeply understand heavy-ion mutagenesis technology, this paper briefly reviews recent progress in microbial breeding using heavy-ion mutagenesis at IMP, and also presents the outline of the beam line for microbial breeding in Heavy Ion Research Facility of Lanzhou (HIRFL) as well as new insights into microbial biotechnology via heavy-ion mutagenesis. Thus, this work can provide the guidelines to promote the development of novel microbial biotechnology cross-linking heavy-ion mutagenesis breeding that could make breeding process more efficiently in the future.
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Affiliation(s)
- W Hu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
| | - W Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
| | - J Chen
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
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Hu W, Li W, Chen H, Liu J, Wang S, Chen J. Changes in transcript levels of starch hydrolysis genes and raising citric acid production via carbon ion irradiation mutagenesis of Aspergillus niger. PLoS One 2017. [PMID: 28650980 PMCID: PMC5484496 DOI: 10.1371/journal.pone.0180120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The filamentous ascomycete Aspergillus niger is well known for its ability to accumulate citric acid for the hydrolysis of starchy materials. To improve citric acid productivity, heavy ion beam mutagenesis was utilized to produce mutant A.niger strains with enhanced production of citric acid in this work. It was demonstrated that a mutant HW2 with high concentration of citric acid was isolated after carbon ion irradiation with the energy of 80Mev/μ, which was obvious increase higher than the original strain from liquefied corn starch as a feedstock. More importantly, with the evidence from the expression profiles of key genes and enzyme activity involved in the starch hydrolysis process between original strain and various phenotype mutants, our results confirmed that different transcript levels of key genes involving in starch hydrolysis process between original strain and mutants could be a significant contributor to different citric acid concentration in A.niger, such as, amyR and glaA, which therefore opened a new avenue for constructing genetically engineered A.niger mutants for high-yield citric acid accumulation in the future. As such, this work demonstrated that heavy ion beam mutagenesis presented an efficient alternative strategy to be developed to generate various phenotype microbe species mutants for functional genes research.
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Affiliation(s)
- Wei Hu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou city, Gansu Province, China
- * E-mail: (WH); (JC)
| | - Wenjian Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou city, Gansu Province, China
| | - Hao Chen
- College of food science and engineering, Gansu Agricultural University, Lanzhou city, Gansu Province, China
| | - Jing Liu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou city, Gansu Province, China
| | - Shuyang Wang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou city, Gansu Province, China
| | - Jihong Chen
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou city, Gansu Province, China
- * E-mail: (WH); (JC)
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