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336 PROCEEDINGS OF INTERNATIONAL SCIENTIFIC CONFERENCE ON APPLIED BIOTECHNOLOGYfrom A. hibisca P172-2 that can be applied to industrial production of pradimicin.The mutation point of rpsL gene of two mutant strains producing high pradimicin yield, A. hibisca M4 and A. hibisca M14, were analyzed. A. hibisca M4 contains a mutation at codon 43 (K43M) and A. hibisca M14 contains a mutation at codon 88 (K88R). Codons 43 and 88 are often changed when streptomycin is used to cause ribosome mutations in actinomycetes. In 1997, actinorhodin production was enhanced by a 15-fold in Streptomyces coelicolor using streptomycin. The mutation is also in the rpsL gene at codon 88 (K88E) [15]. In 2009, the production of actinomycin D of mutant strain from Streptomyces parvuluswas increased to 10-fold more than its of S. parvulus wild-type strain, and the mutation is K88R. Furthermore, the oligomycin production of the mutant strain from Streptomyces avermitilis was increased to 40-fold more than its of S. avermitilis wild-type strain, and the mutation is K43M [17]. From this, it can be observed that the two codons altered in this study are commonly modified when using streptomycin to induce mutation of actinomycetes. The increase in pradimicin yield in this study is lower than the yield increases for other compounds in Streptomyces strains with streptomycin-induced mutations. This difference may be attributed to variations in the host organism or the specific mutations involved. Moreover, this suggests that the ribosome engineering can still be used to generate mutant strains of A. hibisca P172-2 with a higher pradimicin yields.5. CONCLUSIONSRibosome engineering is a simple, time-saving and powerful strategy for enhancing natural product in actinomycete. In this study, 20 mutant strains were selected from A. hibisca P172-2 using streptomycin. Among them, 19 mutant strains produced