Simple transformation of the filamentous thermophilic cyanobacterium Leptolyngbya sp. KC45

Abstract

Leptolyngbya sp. KC45 is a cyanobacterium isolated from a hot spring in the southern region of Thailand. This thermophilic and alkaliphilic strain can be cultured in an open pond without contamination under high pH growth condition. Additionally, its large trichome size makes it convenient for harvesting. Thus, Leptolyngbya sp. KC45 is a promising filamentous thermophilic cyanobacteria for the production of heterologous proteins. To establish the transformation protocol for this strain, we evaluated the antibiotic susceptibility and found that pGreen plasmid can transform this strain. 20 μg/mL ampicillin was used for screening of the transformant. Transformation of Leptolyngbya KC45 was achieved through simple electroporation. The significant expression of a gene introduced under the control of a heterologous promoter, Plac, indicated the functionality of this promoter even in cyanobacteria. This simple transformation protocol could be used for future genetic studies and application of synthetic biology in cyanobacteria.