Yangpumicins (YPMs), eg. YPM A, F, and G, are newly discovered enediynes
from Micromonospora yangpuensis DSM 45577, which could be exploited as
promising payloads of antibody-drug conjugates. However, the low yield
of YPMs in the wild-type strain (~1 mg/L) significantly
hampers their further drug development. In this study, a combined
ribosome engineering and fermentation optimization strategy has been
used for yield improvement of YPMs. One gentamycin-resistant M.
yangpuensis DSM 45577 strain (MY-G-1) showed higher YPMs production (7.4
± 1.0 mg/L), while it exhibits delayed sporulation and slender mycelium
under scanning electron microscopy. Whole genome re-sequencing of MY-G-1
reveals several deletion and single nucleotide polymorphism mutations,
which were confirmed by PCR and DNA sequencing. Further Box–Behnken
experiment and regression analysis determined that the optimal medium
concentrations of soluble starch, mannitol, and pharmamedia for YPMs
production in shaking flasks (10.0 ± 0.8 mg/L). Finally, the total titer
of YPM A/F/G in MY-G-1 reached to 15.0 ± 2.5 mg/L in 3-L fermenters,
which was about 11-fold higher than the original titer of 1.3 ± 0.3 mg/L
in wild-type strain. Our study may be instrumental to develop YPMs into
a clinical anticancer drug, and inspire the use of these multifaceted
strategies for yield improvement in Micromonospora species.
Yield improvement of enediyne yangpumicins in
Micromonospora yangpuensis
through ribosome engineering and fermentation optimization