Effect of treY gene inactivation on reducing of acarbose component C in Actinoplanes 8-22

Abstract:

[Objective] In acarbose producing strain Actinoplanes sp., treY, an important gene in trehalose synthesis, encodes an enzyme that catalyzes acarbose to produce component C during the fermentation. However, component C impacts the quality of acarbose products terribly. In current study, we construct a genetically engineered strain with reduced component C. [Methods] An in-frame knock-out plasmid pUAmT-YUD is constructed and transformed into acarbose-producing strain Actinoplanes 8-22 to inactivate treY by homologous recombination. [Results] Fermentation tests showed that component C produced by the recombinant strain Y810 was reduced by about 10-fold comparing with the parent strain, while the titer of acarbose was not affected. [Conclusion] Knockout of treY leads to compound C decrease in acarbose fermentation. The application of this trial will simplify the purification steps, improve the acarbose quality and reduce the cost to some extent. In addition, conjugation conditions of Actinoplanes are optimized and the conjugation efficiency is improved notably.

Key words:Acarbose component C, treY gene, conjugation, gene knock-out