Ribosome Engineering and Secondary Metabolite Production

Current methods of improving the productivity of industrial micro-organisms range from the classical random approach to using highly rational methods—for example, metabolic engineering. This chapter outlines ribosome engineering and its applicability, especially focusing on strain improvement for antibiotic overproduction in Streptomyces and Bacillus and for enhancement of tolerance to organic chemicals in Pseudomonas. It is demonstrated that a cell's function can be altered dramatically by modulating the ribosome using a drug-resistance mutation technique. Our approach is characterized by focusing on ribosomal function at late growth phase. The novel breeding approach discussed in this chapter is based on two different aspects, modulation of the translational apparatus by induction of str and gen mutations, and modulation of the transcriptional apparatus by induction of a rif mutation. Modulation of these two mechanisms may function co-operatively to increase antibiotic productivity. The chapter focuses on several important facts, which might be useful in eliciting the cell's ability. These facts encourage constructing more elegantly designed and more widely applicable ribosome engineering in the near future.