Methods for the genetic manipulation of marine bacteria

Genetic manipulation of bacteria is a procedure necessary to obtain new strains that express peculiar and defined genetic determinants or to introduce genetic variants responsible for phenotypic modifications. This procedure can be applied to explore the biotechnological potential associated with environmental bacteria and to utilize the functional properties of specific genes when inserted into an appropriate host. In the past years, marine bacteria have received increasing attention because they represent a fascinating reservoir of genetic and functional diversity that can be utilized to fuel the bioeconomy sector. However, there is an urgent need for an in-depth investigation and improvement of the genetic manipulation tools applicable to marine strains because of the paucity of knowledge regarding this. This review aims to describe the genetic manipulation methods hitherto used in marine bacteria, thus highlighting the limiting factors of the different techniques available today to increase manipulation efficiency. In particular, we focus on methods of natural and artificial transformations (especially electroporation) and conjugation because they have been successfully applied to several marine strains. Finally, we emphasize that, to avoid failure, future work should be carried out to establish tailored methodologies for marine bacteria.

Mechanism and influencing factors of natural transformation in bacteria / 生物工程学报

Horizontal gene transfer contributes to the spread of antibiotic-resistance cassettes, the distribution of toxin-encoding phages and the transfer of pathogenicity islands. Natural transformation, which is the process of competent cells to uptake free DNA from environment and to recombine this DNA into the chromosome, is a mode of horizontal gene transfer. Natural transformation promotes the spread of antibiotic-resistance cassettes among different bacteria, resulting in the emergence of antibiotic resistant bacteria. The emergence of antibiotic resistant pathogens poses an enormous threat to the treatment of infections. Natural transformation could occur in many bacteria, but the mechanism many be different in different bacteria. Also, the inducer and efficiency of natural transformation in different bacteria are influenced by various factors. This review focuses on the mechanism and influencing factors of natural transformation in bacteria.