Currently, researchers have identified several bacteria that have excellent properties beyond those of E. coli, such as Pseudomonas taiwanensis, V. natriegens, and Paenibacillus polymyxa . Among them, V. natriegens is the most promising new chassis organism. In recent years, many papers have reported the potential of V. natriegensas a chassis organism. And at least five student teams have carried out relevant research in the International Genetically Engineered Machine Competition (iGEM) to develop the potential of V. natriegens as a novel chassis organism .
V. natriegens, which grow in large numbers in the ocean, are currently the fastest-growing non-pathogenic microorganisms in the world. It has a generation time of only 9.4-9.8 minutes when cultured in Gram's composite medium , which is half of E. coli’s. This high growth efficiency can significantly shorten the experimental period and allow researchers to obtain results more quickly. In addition, ribosomes of V. natriegens can reach 115,000 in a single cell during the exponential growth phase, compared to 70,000-90,000 ribosomes in E. coli , which allows V. natriegens> to have a higher capacity for protein production. Also, its high growth rate can shorten the culture time and significantly save the cost of cultivation and maintenance of microbial growth for protein production. Researchers have introduced 7 types of more than 100 target genes into V. natriegens and E. coli. Surprisingly, most recombinant proteins could be expressed in V. natriegens without optimizing the optimal growth conditions, and more than 20 genes were even more effectively expressed in V. natriegens. The expression of N-acetyl amino acid racemase, isopentene synthase and ribonucleoside diphosphate kinase in V. natriegens was respectively 2.6, 5.2 and 12 times higher than that in E. coli , confirming the potential of V. natriegens as a novel cell factory. Moreover, if we consider the future use of chassis microorganisms in extreme conditions such as arid soils and high salinity oceans, V. natriegens, which has evolved over millions of years to adapt to these environments, would be a suitable choice.
The sequencing of the V. natriegens was completed in 2013 with a size of 5.16M bp. 4,578 coding sequences, 11 rRNA manipulators and 129 tRNA-coding genes have been annotated [5-6]. Many genetic parts have also been characterized in V. natriegens, such as some basic constitutive promoters, ribosom binding sites, and terminators . Meanwhile, it has been shown that some common induced promoters can function in V. natriegens, such as the IPTG-induced LacUV5 and trc promoters, the arabinose-regulated araBAD promoter, the temperature-regulated phage pR promoter, and the tetracycline-induced Tet promoter, which allows protein expression in V. natriegens to proceed in a controlled form [7,8]. Plasmids from different origins (e.g. p15A and pMB1) carrying resistance genes for chloramphenicol, tetracycline, ampicillin or kanamycin can be well replicated and maintained in V. natriegens [2,7,8]. In addition, V. natriegens can also take up exogenous DNA fragments by natural transformation, chemical transformation, and electrotransformation . Furthermore, only 10 ng of fragments are required to enter V. natriegens successfully by electrotransformation . These results demonstrate that V. natriegens can be used for routine molecular cloning experiments. Moreover, with its fast growth rate and high protein yield, it is expected to be developed as a new chassis organism.