Streptomyces tsukubensis sp. nov., a producer of the immunosuppressant tacrolimus

摘要

Streptomyces is well-known as a good producer of pharmaceutically important chemical compounds, not only antibiotics but also physiologically active compounds. Tacrolimus was found as a strong immunosuppressant from a culture broth of an actinomycete strain, 'Streptomyces tsukubaensif 9993, which was isolated from a soil sample collected from Mount Tsukuba, Ibaraki, Japan, in 1984. The first report of this comgound was published in 1987, and the drug was launched in 1993 in Japan as an immunosuppressive agent for the prevention of graft rejection after liver transplantation. To date, it has been sold in about 90 countries in several therapeutic areas, including organ transplantation, myasthenia gravis, articular rheumatism, lupus nephritis, ulcerative colitis and atopic dermatitis, among others. After initial discovery of the compound, several taxonomically diverse streptomycete strains were reported as tacrolimus producers, including S. tacrolimicus ATCC 55098, S. davuligerus CKD 1119 and S. kanamyceticus KCC S-0433T.4 Further, biosynthetic gene clusters of tacrolimus in some strains have been reported.