Obligately anaerobic mutant lactic acid bacterium and preparation method therefor, and expression vector functioning in obligately anaerobic lactic acid bacterium

摘要

The present invention provides an obligately anaerobic lactic acid bacterium having no risk of causing side effects in normal tissue and promising as a safe therapeutic agent and a gene transporter for a disease that is in an anaerobic environment such as a solid tumor, a preparation method therefor, and an expression vector useful in the preparation method. The obligately anaerobic lactic acid bacterium of the present invention has been artificially mutated from being facultatively anaerobic to being obligately anaerobic and, furthermore, is capable of being transformed by an expression vector having introduced thereinto a gene for expressing an active protein useful for the treatment of a disease that is in an anaerobic environment. Furthermore, the expression vector of the present invention functions in an obligately anaerobic lactic acid bacterium and contains a Lactobacillus-derived plasmid replication protein gene (Rep), a secretion signal sequence (PslpA-SSartP) comprising a Lactobacillus-derived s-layer gene promoter and a Lactobacillus-derived PrtP protein secretion signal, and one or more selection marker genes. The expression vector of the present invention enables producing an extremely safe and excellent therapeutic agent and gene transporting microorganism for a disease that is in an anaerobic environment.