Genome-based functional analyses in Corynebacterium glutamicum
The soil-inhabiting microorganism Corynebacterium glutamicum was discovered in the 1950ies in Japan as a natural producer of L-glutamic acid. Since 1985 our group is engaged in developing cloning systems and later genomics and post-genomics techniques for a systems understanding and its application in biotechnology.
Prof. Dr. Jörn Kalinowski
Previous and Current Research
Today C. glutamicum is dominant in the global market for the production of various amino acids used in nutrition and health applications. Due to its simple nutritional requirements, fast growth, and its easy handling both in genetic engineering and in fermentation, it is considered today as an ideal basis for the further development to a universal host for production of a large number of different products derived from primary metabolism or as producer of proteins.
The research group is working on C. glutamicum for more than 25 years now, starting with the development of tools and techniques for genetic engineering. Major achievements of the group were the initial development of electroporation and conjugal transfer of genetic material from E. coli donor strains. In addition, gene-disruption and gene-replacement techniques for C. glutamicum and related organisms were introduced by our group in the year 1991. By using these techniques together with gene cloning and functional analyses, initial insights into metabolism and hints for the more rational construction of amino acid producer strains were obtained in the following years. However, the main focus of industrial strain development was still the classical mutation and selection process.
The year 2003 brought a major breakthrough, since two groups working independently published the complete genome sequence of the type strain C. glutamicum ATCC 13032. As being one of these we were able to bring functional analyses to the next, the genome-wide level. Transcriptomics and proteomics were developed on the basis of the genome sequence and research on gene functions and especially regulation of genetic and metabolic networks in C. glutamicum flourished since then. Today, C. glutamicum can be considered a model organism for industrial production of metabolites derived from primary metabolism and also for closely related organisms from the Actinobacteria, some of them important pathogens (C. diphtheriae, Mycobacterium tuberculosis).
The research group is actually working on the following subjects
- genomics of the species C. glutamicum, its pan-genome and a minimal genome
- transcriptional regulatory networks including sigma factor networks involved in stress reponse
- advanced transcriptomics including transcriptome sequencing and small RNAs
- proteomics including post-translational modification and the surface-layer protein
- metabolic networks and metabolome analysis for amino acid production
The fast progress in C. glutamicum research that we experienced in the “genome age” would not be possible without a large national research network now existing since the 1980ies and with essential contributions by our in-house bioinformatics.
Future Projects and Aims
Our goals for the next years is to advance the knowledge on this organism, its gene functions and regulations for the in-depth understanding of its functional and regulatory systems as well as the application of this knowledge for biotechnological processes.