Vectors expressing kanA-kanB-kanK and other kanamycin production-related genes, Streptomyces species recombinant bacteria transformed with the vectors, a method of producing kanamycin antibiotics by the bacteria, and a new kanamycin compound produced by the bacterium are provided. With the use of the recombinant bacteria of the present invention, the direct fermentative biosynthesis of amikacin and tobramycin as semi-synthetic kanamycins is possible, and the yield of kanamycin B as a precursor of the semi-synthetic kanamycin is improved.

The present disclosure discloses recombinant Escherichia coli for expressing a synthesis pathway of asiaticoside and application thereof, and belongs to the field of bioengineering. Rhamnosyltransferase with an amino acid sequence shown in any one of SEQ ID NO: 25 to SEQ ID NO: 29, glucosyltransferase with an amino acid sequence shown in any one of SEQ ID NO: 10 to SEQ ID NO: 17 and UGT73AH1 reported in a document are transferred into E. coli BL21 (DE3)?pgi to realize co-expression. Fermentation results show that all 5 rhamnosyltransferases screened in the present disclosure can achieve effects, and a unique new peak appears at 0.596 min, which is consistent with a characteristic ion flow of an asiaticoside standard product. According to the present disclosure, barriers of the prior art are broken through, a new biosynthesis method for asiaticoside is provided, and industrialization of biosynthesis of asiaticoside becomes possible.