Abstract:Gene recombination through recombinases and auxiliary protein enzymes exists widely in bacteria and it has great significance to bacterial genetic diversity and evolution. At present, genetic recombinations in bacteria are classed into three types: homologous recombination, site-specific recombination and transposition recombination. In this article, recombinases, and related protein enzymes of bacterial recombination systems, the mechanisms of various recombinations, and applications of recombination systems to genetic manipulation were reviewed.