Development of a genetic system for the anaerobic gram-type positive thermophile Thermoanaerobacterium strain JW/SL-YS485

Anaerobic Gram-type positive thermophiles have been of particular research interest because of their reducing powers which enable a variety of fermentation products including ethanol, acetate, lactate, butyrate and butanol from various polymeric substrates such as starch, hemicellulose and cellulose. Low heating costs and easy product recovery are other promising aspects in the development of biotechnological processes utilizing the above mentioned microorganisms. However, besides traditional microbiological methods such as strain selection and process optimization, genetic engineering of such microorganisms is required for the molecular manipulation towards more economical fermentations.;This dissertation reports on the beginnings of the development of a genetic system for Thermoanaerobacterium JW/SL-YS485 and the directed manipulation towards more efficient substrate utilization.;Chapter 1 of this thesis will review various advances in our knowledge of anaerobic Gram-type positive thermophiles with an emphasis on Thermoanaerobacter/Thermoanaerobacterium species. The isolation and description of new species belonging to this group as well as the characterization of enzymes and the cloning and expression of their respective genes and other advances in our knowledge about their molecular biology will be elaborated on.;Chapter 2 reviews "Recombinant DNA applications in thermophiles" with an emphasis on newly available techniques including the development of various vectors and selective markers for the use in thermophiles.;Chapters 3, 4 and 5 describe the development of a first shuttle vector, the transfer and expression of heterologous genes and further developments in the genetic system for Thermoanaerobacterium JW/SL-YS485.