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Li Z, Yang S, Zhang Z, Wu Y, Tang J, Wang L, Chen S. Enhancement of acarbose production by genetic engineering and fed-batch fermentation strategy in Actinoplanes sp. SIPI12-34. Microb Cell Fact 2022; 21:240. [DOI: 10.1186/s12934-022-01969-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/11/2022] [Indexed: 11/25/2022] Open
Abstract
Abstract
Background
Acarbose, as an alpha-glucosidase inhibitor, is widely used clinically to treat type II diabetes. In its industrial production, Actinoplanes sp. SE50/110 is used as the production strain. Lack of research on its regulatory mechanisms and unexplored gene targets are major obstacles to rational strain design. Here, transcriptome sequencing was applied to uncover more gene targets and rational genetic engineering was performed to increase acarbose production.
Results
In this study, with the help of transcriptome information, a TetR family regulator (TetR1) was identified and confirmed to have a positive effect on the synthesis of acarbose by promoting the expression of acbB and acbD. Some genes with low expression levels in the acarbose biosynthesis gene cluster were overexpressed and this resulted in a significant increase in acarbose yield. In addition, the regulation of metabolic pathways was performed to retain more glucose-1-phosphate for acarbose synthesis by weakening the glycogen synthesis pathway and strengthening the glycogen degradation pathway. Eventually, with a combination of multiple strategies and fed-batch fermentation, the yield of acarbose in the engineered strain increased 58% compared to the parent strain, reaching 8.04 g/L, which is the highest fermentation titer reported.
Conclusions
In our research, acarbose production had been effectively and steadily improved through genetic engineering based on transcriptome analysis and fed-batch culture strategy.
Graphical Abstract
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Droste J, Rückert C, Kalinowski J, Hamed MB, Anné J, Simoens K, Bernaerts K, Economou A, Busche T. Extensive Reannotation of the Genome of the Model Streptomycete Streptomyces lividans TK24 Based on Transcriptome and Proteome Information. Front Microbiol 2021; 12:604034. [PMID: 33935985 PMCID: PMC8079986 DOI: 10.3389/fmicb.2021.604034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 03/12/2021] [Indexed: 01/04/2023] Open
Abstract
Streptomyces lividans TK24 is a relevant Gram-positive soil inhabiting bacterium and one of the model organisms of the genus Streptomyces. It is known for its potential to produce secondary metabolites, antibiotics, and other industrially relevant products. S. lividans TK24 is the plasmid-free derivative of S. lividans 66 and a close genetic relative of the strain Streptomyces coelicolor A3(2). In this study, we used transcriptome and proteome data to improve the annotation of the S. lividans TK24 genome. The RNA-seq data of primary 5'-ends of transcripts were used to determine transcription start sites (TSS) in the genome. We identified 5,424 TSS, of which 4,664 were assigned to annotated CDS and ncRNAs, 687 to antisense transcripts distributed between 606 CDS and their UTRs, 67 to tRNAs, and 108 to novel transcripts and CDS. Using the TSS data, the promoter regions and their motifs were analyzed in detail, revealing a conserved -10 (TAnnnT) and a weakly conserved -35 region (nTGACn). The analysis of the 5' untranslated region (UTRs) of S. lividans TK24 revealed 17% leaderless transcripts. Several cis-regulatory elements, like riboswitches or attenuator structures could be detected in the 5'-UTRs. The S. lividans TK24 transcriptome contains at least 929 operons. The genome harbors 27 secondary metabolite gene clusters of which 26 could be shown to be transcribed under at least one of the applied conditions. Comparison of the reannotated genome with that of the strain Streptomyces coelicolor A3(2) revealed a high degree of similarity. This study presents an extensive reannotation of the S. lividans TK24 genome based on transcriptome and proteome analyses. The analysis of TSS data revealed insights into the promoter structure, 5'-UTRs, cis-regulatory elements, attenuator structures and novel transcripts, like small RNAs. Finally, the repertoire of secondary metabolite gene clusters was examined. These data provide a basis for future studies regarding gene characterization, transcriptional regulatory networks, and usage as a secondary metabolite producing strain.
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Affiliation(s)
- Julian Droste
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Christian Rückert
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Mohamed Belal Hamed
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, KU Leuven, Rega Institute, Leuven, Belgium.,Molecular Biology Department, National Research Centre, Dokii, Egypt
| | - Jozef Anné
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, KU Leuven, Rega Institute, Leuven, Belgium
| | - Kenneth Simoens
- Bio- and Chemical Systems Technology, Reactor Engineering, and Safety (CREaS) Section, Department of Chemical Engineering, KU Leuven, Leuven, Belgium
| | - Kristel Bernaerts
- Bio- and Chemical Systems Technology, Reactor Engineering, and Safety (CREaS) Section, Department of Chemical Engineering, KU Leuven, Leuven, Belgium
| | - Anastassios Economou
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, KU Leuven, Rega Institute, Leuven, Belgium
| | - Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
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Droste J, Ortseifen V, Schaffert L, Persicke M, Schneiker-Bekel S, Pühler A, Kalinowski J. The expression of the acarbose biosynthesis gene cluster in Actinoplanes sp. SE50/110 is dependent on the growth phase. BMC Genomics 2020; 21:818. [PMID: 33225887 PMCID: PMC7682106 DOI: 10.1186/s12864-020-07194-6] [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: 07/02/2020] [Accepted: 10/26/2020] [Indexed: 11/26/2022] Open
Abstract
Background Actinoplanes sp. SE50/110 is the natural producer of the diabetes mellitus drug acarbose, which is highly produced during the growth phase and ceases during the stationary phase. In previous works, the growth-dependency of acarbose formation was assumed to be caused by a decreasing transcription of the acarbose biosynthesis genes during transition and stationary growth phase. Results In this study, transcriptomic data using RNA-seq and state-of-the-art proteomic data from seven time points of controlled bioreactor cultivations were used to analyze expression dynamics during growth of Actinoplanes sp. SE50/110. A hierarchical cluster analysis revealed co-regulated genes, which display similar transcription dynamics over the cultivation time. Aside from an expected metabolic switch from primary to secondary metabolism during transition phase, we observed a continuously decreasing transcript abundance of all acarbose biosynthetic genes from the early growth phase until stationary phase, with the strongest decrease for the monocistronically transcribed genes acbA, acbB, acbD and acbE. Our data confirm a similar trend for acb gene transcription and acarbose formation rate. Surprisingly, the proteome dynamics does not follow the respective transcription for all acb genes. This suggests different protein stabilities or post-transcriptional regulation of the Acb proteins, which in turn could indicate bottlenecks in the acarbose biosynthesis. Furthermore, several genes are co-expressed with the acb gene cluster over the course of the cultivation, including eleven transcriptional regulators (e.g. ACSP50_0424), two sigma factors (ACSP50_0644, ACSP50_6006) and further genes, which have not previously been in focus of acarbose research in Actinoplanes sp. SE50/110. Conclusion In conclusion, we have demonstrated, that a genome wide transcriptome and proteome analysis in a high temporal resolution is well suited to study the acarbose biosynthesis and the transcriptional and post-transcriptional regulation thereof. Supplementary Information Supplementary information accompanies this paper at 10.1186/s12864-020-07194-6.
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Affiliation(s)
- Julian Droste
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Sequenz 1, Bielefeld, 33615, Germany
| | - Vera Ortseifen
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Sequenz 1, 33615, Bielefeld, Germany
| | - Lena Schaffert
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Sequenz 1, Bielefeld, 33615, Germany
| | - Marcus Persicke
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Sequenz 1, Bielefeld, 33615, Germany
| | - Susanne Schneiker-Bekel
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Sequenz 1, 33615, Bielefeld, Germany
| | - Alfred Pühler
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Sequenz 1, 33615, Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Sequenz 1, Bielefeld, 33615, Germany.
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Droste J, Kulisch M, Wolf T, Schaffert L, Schneiker-Bekel S, Pühler A, Kalinowski J. A maltose-regulated large genomic region is activated by the transcriptional regulator MalT in Actinoplanes sp. SE50/110. Appl Microbiol Biotechnol 2020; 104:9283-9294. [PMID: 32989516 PMCID: PMC7567727 DOI: 10.1007/s00253-020-10923-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/15/2020] [Accepted: 09/21/2020] [Indexed: 11/25/2022]
Abstract
Actinoplanes sp. SE50/110 is the industrially relevant producer of acarbose, which is used in the treatment of diabetes mellitus. Recent studies elucidated the expression dynamics in Actinoplanes sp. SE50/110 during growth. From these data, we obtained a large genomic region (ACSP50_3900 to ACSP50_3950) containing 51 genes, of which 39 are transcribed in the same manner. These co-regulated genes were found to be stronger transcribed on maltose compared with glucose as a carbon source. The transcriptional regulator MalT was identified as an activator of this maltose-regulated large genomic region (MRLGR). Since most of the genes are poorly annotated, the function of this region is farther unclear. However, comprehensive BLAST analyses indicate similarities to enzymes involved in amino acid metabolism. We determined a conserved binding motif of MalT overlapping the -35 promoter region of 17 transcription start sites inside the MRLGR. The corresponding sequence motif 5'-TCATCC-5nt-GGATGA-3' displays high similarities to reported MalT binding sites in Escherichia coli and Klebsiella pneumoniae, in which MalT is the activator of mal genes. A malT deletion and an overexpression mutant were constructed. Differential transcriptome analyses revealed an activating effect of MalT on 40 of the 51 genes. Surprisingly, no gene of the maltose metabolism is affected. In contrast to many other bacteria, MalT is not the activator of mal genes in Actinoplanes sp. SE50/110. Finally, the MRLGR was found partly in other closely related bacteria of the family Micromonosporaceae. Even the conserved MalT binding site was found upstream of several genes inside of the corresponding regions. KEY POINTS : • MalT is the maltose-dependent activator of a large genomic region in ACSP50_WT. • The consensus binding motif is similar to MalT binding sites in other bacteria. • MalT is not the regulator of genes involved in maltose metabolism in ACSP50_WT.
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Affiliation(s)
- Julian Droste
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Martin Kulisch
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Timo Wolf
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Lena Schaffert
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Susanne Schneiker-Bekel
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Alfred Pühler
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany.
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Weng CY, Shi LZ, Wang YJ, Zheng YG. Transcriptome analysis of Actinoplanes utahensis reveals molecular signature of saccharide impact on acarbose biosynthesis. 3 Biotech 2020; 10:473. [PMID: 33088668 DOI: 10.1007/s13205-020-02466-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/03/2020] [Indexed: 01/21/2023] Open
Abstract
Different carbon sources lead to differential acarbose production in Actinoplanes. To uncover the underlying differentiation in the context of genes and pathways, we performed transcriptome sequencing of Actinoplanes utahensis ZJB-03852 grown on different saccharides, such as glucose, maltose, or the saccharide complex consisting of glucose plus maltose. The differentially expressed genes were classified into GO (gene ontology) terms and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways for functional annotations. Key enriched modules were uncovered. Our data revealed that both maltose and its complex with glucose gave improved acarbose titer. Sugar transportation, cytochrome oxidase, protein synthesis and amino acid metabolism modules were enriched under the saccharide complex condition, while ferritin metabolism gene expressions were enriched in the glucose medium. Our results provided the foundation for uncovering the mechanism of carbon source on acarbose production in A. utahensis.
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Affiliation(s)
- Chun-Yue Weng
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014 People's Republic of China
- Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014 Zhejiang People's Republic of China
| | - Li-Zhen Shi
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014 People's Republic of China
- Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014 Zhejiang People's Republic of China
| | - Ya-Jun Wang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014 People's Republic of China
- Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014 Zhejiang People's Republic of China
| | - Yu-Guo Zheng
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014 People's Republic of China
- Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014 Zhejiang People's Republic of China
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Absence of the highly expressed small carbohydrate-binding protein Cgt improves the acarbose formation in Actinoplanes sp. SE50/110. Appl Microbiol Biotechnol 2020; 104:5395-5408. [PMID: 32346757 PMCID: PMC7275007 DOI: 10.1007/s00253-020-10584-1] [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: 11/28/2019] [Revised: 03/06/2020] [Accepted: 03/24/2020] [Indexed: 11/17/2022]
Abstract
Actinoplanes sp. SE50/110 (ATCC 31044) is the wild type of industrial producer strains of acarbose. Acarbose has been used since the early 1990s as an inhibitor of intestinal human α-glucosidases in the medical treatment of type II diabetes mellitus. The small secreted protein Cgt, which consists of a single carbohydrate-binding module (CBM) 20-domain, was found to be highly expressed in Actinoplanes sp. SE50/110 in previous studies, but neither its function nor a possible role in the acarbose formation was explored, yet. Here, we demonstrated the starch-binding function of the Cgt protein in a binding assay. Transcription analysis showed that the cgt gene was strongly repressed in the presence of glucose or lactose. Due to this and its high abundance in the extracellular proteome of Actinoplanes, a functional role within the sugar metabolism or in the environmental stress protection was assumed. However, the gene deletion mutant ∆cgt, constructed by CRISPR/Cas9 technology, displayed no apparent phenotype in screening experiments testing for pH and osmolality stress, limited carbon source starch, and the excess of seven different sugars in liquid culture and further 97 carbon sources in the Omnilog Phenotypic Microarray System of Biolog. Therefore, a protective function as a surface protein or a function within the retainment and the utilization of carbon sources could not be experimentally validated. Remarkably, enhanced production of acarbose was determined yielding into 8–16% higher product titers when grown in maltose-containing medium.
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Schaffert L, Schneiker-Bekel S, Dymek S, Droste J, Persicke M, Busche T, Brandt D, Pühler A, Kalinowski J. Essentiality of the Maltase AmlE in Maltose Utilization and Its Transcriptional Regulation by the Repressor AmlR in the Acarbose-Producing Bacterium Actinoplanes sp. SE50/110. Front Microbiol 2019; 10:2448. [PMID: 31736895 PMCID: PMC6828939 DOI: 10.3389/fmicb.2019.02448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 10/11/2019] [Indexed: 11/13/2022] Open
Abstract
Actinoplanes sp. SE50/110 is the wild type of industrial production strains of the fine-chemical acarbose (acarviosyl-maltose), which is used as α-glucosidase inhibitor in the treatment of type II diabetes. Although maltose is an important building block of acarbose, the maltose/maltodextrin metabolism has not been studied in Actinoplanes sp. SE50/110 yet. Bioinformatic analysis located a putative maltase gene amlE (ACSP50_2474, previously named malL; Wendler et al., 2015a), in an operon with an upstream PurR/LacI-type transcriptional regulator gene, named amlR (ACSP50_2475), and a gene downstream (ACSP50_2473) encoding a GGDEF-EAL-domain-containing protein putatively involved in c-di-GMP signaling. Targeted gene deletion mutants of amlE and amlR were constructed by use of the CRISPR/Cas9 technology. By growth experiments and functional assays of ΔamlE, we could show that AmlE is essential for the maltose utilization in Actinoplanes sp. SE50/110. Neither a gene encoding a maltose phosphorylase (MalP) nor MalP enzyme activity were detected in the wild type. By this, the maltose/maltodextrin system appears to be fundamentally different from other described prokaryotic systems. By sequence similarity analysis and functional assays from the species Streptomyces lividans TK23, S. coelicolor A3(2) and S. glaucescens GLA.O, first hints for a widespread lack of MalP and presence of AmlE in the class Actinobacteria were given. Transcription of the aml operon is significantly repressed in the wild type when growing on glucose and repression is absent in an ΔamlR deletion mutant. Although AmlR apparently is a local transcriptional regulator of the aml operon, the ΔamlR strain shows severe growth inhibitions on glucose and – concomitantly – differential transcription of several genes of various functional classes. We ascribe these effects to ACSP50_2473, which is localized downstream of amlE and presumably involved in the metabolism of the second messenger c-di-GMP. It can be assumed, that maltose does not only represent the most important carbon source of Actinoplanes sp. SE50/110, but that its metabolism is coupled to the nucleotide messenger system of c-di-GMP.
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Affiliation(s)
- Lena Schaffert
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Susanne Schneiker-Bekel
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany.,Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Saskia Dymek
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Julian Droste
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Marcus Persicke
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - David Brandt
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Alfred Pühler
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
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Schaffert L, März C, Burkhardt L, Droste J, Brandt D, Busche T, Rosen W, Schneiker-Bekel S, Persicke M, Pühler A, Kalinowski J. Evaluation of vector systems and promoters for overexpression of the acarbose biosynthesis gene acbC in Actinoplanes sp. SE50/110. Microb Cell Fact 2019; 18:114. [PMID: 31253141 PMCID: PMC6599336 DOI: 10.1186/s12934-019-1162-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 06/19/2019] [Indexed: 02/05/2023] Open
Abstract
Background Actinoplanes sp. SE50/110 is a natural producer of acarbose. It has been extensively studied in the last decades, which has led to the comprehensive analysis of the whole genome, transcriptome and proteome. First genetic and microbial techniques have been successfully established allowing targeted genome editing by CRISPR/Cas9 and conjugal transfer. Still, a suitable system for the overexpression of singular genes does not exist for Actinoplanes sp. SE50/110. Here, we discuss, test and analyze different strategies by the example of the acarbose biosynthesis gene acbC. Results The integrative φC31-based vector pSET152 was chosen for the development of an expression system, as for the replicative pSG5-based vector pKC1139 unwanted vector integration by homologous recombination was observed. Since simple gene duplication by pSET152 integration under control of native promoters appeared to be insufficient for overexpression, a promoter screening experiment was carried out. We analyzed promoter strengths of five native and seven heterologous promoters using transcriptional fusion with the gusA gene and glucuronidase assays as well as reverse transcription quantitative PCR (RT-qPCR). Additionally, we mapped transcription starts and identified the promoter sequence motifs by 5′-RNAseq experiments. Promoters with medium to strong expression were included into the pSET152-system, leading to an overexpression of the acbC gene. AcbC catalyzes the first step of acarbose biosynthesis and connects primary to secondary metabolism. By overexpression, the acarbose formation was not enhanced, but slightly reduced in case of strongest overexpression. We assume either disturbance of substrate channeling or a negative feed-back inhibition by one of the intermediates, which accumulates in the acbC-overexpression mutant. According to LC–MS-analysis, we conclude, that this intermediate is valienol-7P. This points to a bottleneck in later steps of acarbose biosynthesis. Conclusion Development of an overexpression system for Actinoplanes sp. SE50/110 is an important step for future metabolic engineering. This system will help altering transcript amounts of singular genes, that can be used to unclench metabolic bottlenecks and to redirect metabolic resources. Furthermore, an essential tool is provided, that can be transferred to other subspecies of Actinoplanes and industrially relevant derivatives. Electronic supplementary material The online version of this article (10.1186/s12934-019-1162-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lena Schaffert
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Camilla März
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Lisa Burkhardt
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Julian Droste
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - David Brandt
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Winfried Rosen
- Product Supply, Bayer AG, Friedrich Ebert Str. 217-475, 42117, Wuppertal, Germany
| | - Susanne Schneiker-Bekel
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany.,Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Marcus Persicke
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Alfred Pühler
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany.
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Xie H, Zhao Q, Zhang X, Kang Q, Bai L. Comparative functional genomics of the acarbose producers reveals potential targets for metabolic engineering. Synth Syst Biotechnol 2019; 4:49-56. [PMID: 30723817 PMCID: PMC6350373 DOI: 10.1016/j.synbio.2019.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 12/31/2018] [Accepted: 01/10/2019] [Indexed: 12/20/2022] Open
Abstract
The α-glucosidase inhibitor acarbose is produced in large-scale by strains derived from Actinoplanes sp. SE50 and used widely for the treatment of type-2 diabetes. Compared with the wild-type SE50, a high-yield derivative Actinoplanes sp. SE50/110 shows 2-fold and 3–7-fold improvement of acarbose yield and acb cluster transcription, respectively. The genome of SE50 was fully sequenced and compared with that of SE50/110, and 11 SNVs and 4 InDels, affecting 8 CDSs, were identified in SE50/110. The 8 CDSs were individually inactivated in SE50. Deletions of ACWT_4325 (encoding alcohol dehydrogenase) resulted in increases of acarbose yield by 25% from 1.87 to 2.34 g/L, acetyl-CoA concentration by 52.7%, and PEP concentration by 22.7%. Meanwhile, deletion of ACWT_7629 (encoding elongation factor G) caused improvements of acarbose yield by 36% from 1.87 to 2.54 g/L, transcription of acb cluster, and ppGpp concentration to 2.2 folds. Combined deletions of ACWT_4325 and ACWT_7629 resulted in further improvement of acarbose to 2.83 g/L (i.e. 76% of SE50/110), suggesting that the metabolic perturbation and improved transcription of acb cluster caused by these two mutations contribute substantially to the acarbose overproduction. Enforced application of similar strategies was performed to manipulate SE50/110, resulting in a further increase of acarbose titer from 3.73 to 4.21 g/L. Therefore, the comparative genomics approach combined with functional verification not only revealed the acarbose overproduction mechanisms, but also guided further engineering of its high-yield producers.
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Affiliation(s)
- Huixin Xie
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qinqin Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xin Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qianjin Kang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Linquan Bai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
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Wolf T, Droste J, Gren T, Ortseifen V, Schneiker-Bekel S, Zemke T, Pühler A, Kalinowski J. The MalR type regulator AcrC is a transcriptional repressor of acarbose biosynthetic genes in Actinoplanes sp. SE50/110. BMC Genomics 2017; 18:562. [PMID: 28743243 PMCID: PMC5526262 DOI: 10.1186/s12864-017-3941-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 07/13/2017] [Indexed: 01/09/2023] Open
Abstract
Background Acarbose is used in the treatment of diabetes mellitus type II and is produced by Actinoplanes sp. SE50/110. Although the biosynthesis of acarbose has been intensively studied, profound knowledge about transcription factors involved in acarbose biosynthesis and their binding sites has been missing until now. In contrast to acarbose biosynthetic gene clusters in Streptomyces spp., the corresponding gene cluster of Actinoplanes sp. SE50/110 lacks genes for transcriptional regulators. Results The acarbose regulator C (AcrC) was identified through an in silico approach by aligning the LacI family regulators of acarbose biosynthetic gene clusters in Streptomyces spp. with the Actinoplanes sp. SE50/110 genome. The gene for acrC, located in a head-to-head arrangement with the maltose/maltodextrin ABC transporter malEFG operon, was deleted by introducing PCR targeting for Actinoplanes sp. SE50/110. Characterization was carried out through cultivation experiments, genome-wide microarray hybridizations, and RT-qPCR as well as electrophoretic mobility shift assays for the elucidation of binding motifs. The results show that AcrC binds to the intergenic region between acbE and acbD in Actinoplanes sp. SE50/110 and acts as a transcriptional repressor on these genes. The transcriptomic profile of the wild type was reconstituted through a complementation of the deleted acrC gene. Additionally, regulatory sequence motifs for the binding of AcrC were identified in the intergenic region of acbE and acbD. It was shown that AcrC expression influences acarbose formation in the early growth phase. Interestingly, AcrC does not regulate the malEFG operon. Conclusions This study characterizes the first known transcription factor of the acarbose biosynthetic gene cluster in Actinoplanes sp. SE50/110. It therefore represents an important step for understanding the regulatory network of this organism. Based on this work, rational strain design for improving the biotechnological production of acarbose can now be implemented. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3941-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Timo Wolf
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Julian Droste
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Tetiana Gren
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Vera Ortseifen
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Susanne Schneiker-Bekel
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Till Zemke
- Product Supply, Bayer Pharma AG, Friedrich Ebert Str. 217-475, 42117, Wuppertal, Germany
| | - Alfred Pühler
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany.
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