Reduced and minimal cell factories in bioprocesses: Towards a streamlined chassis

Abstract

The rapid advances in molecular genome engineering, systems biology and synthetic biology over the past decade have laid the ground for extensive engineering of bacterial and fungal genomes and the rational setup of synthetic biological systems. In order to optimize the production host for biotechnical processes, the genomes of many industrial workhorse microorganisms such as Escherichia coli, Bacillus subtilis, Corynebacterium glutamicum, Streptomyces species, Pseudomonas species, Saccharomyces cerevisiae, and Lactococcus lactis have been successfully reduced. Here, we evaluate this progress in the context of biotechnical application for the production of industrially attractive products. Based on the view of microbial cells as factories, we discuss the concept of relevant genes. We attempt to estimate the theoretical benefits of genome reduction which form the basis of target selection. Subsequently, we comprehensively discuss existing studies on genome-reduced strains. The current limits of beneficial genome reduction and potential future developments in both prokaryotic and eukaryotic systems are considered.