Exploring a High-Efficiency Genetic Transformation System for Engineering Saccharopolyspora pogona ASAGF58 To Improve Butenyl-Spinosyn Production

Butenyl-spinosyn is a potent insecticide potentially useful as a broad-spectrum pesticide. Because it is relatively nontoxic to mammals and does not damage the environment, there has been considerable interest in the use of butenyl-spinosyn for increasing agricultural production. However, genetically engineering Saccharopolyspora pogona ASAGF58 to increase its relatively low butenyl-spinosyn content remains challenging because it cannot be transformed efficiently. In this study, genes encoding novel methyltransferases (04455 and 28970) were identified in the Sa. pogona ASAGF58 genome through a bioinformatic-based analysis. Additionally, the transformation efficiency increased by 5.8- and 16.4-fold when foreign DNA was pre-methylated in ET-28970 and ET-04455, respectively, through bypassing of the restriction-modification system. A comparative proteomic analysis of Sa. pogona and Saccharopolyspora spinosa revealed that acetyl-CoA synthetase may be useful for improving butenyl-spinosyn production. The fermentation results indicated that compared with the wild-type butenyl-spinosyn content, overexpressing the acetyl-CoA synthetase gene increased butenyl-spinosyn production by 2-fold. The findings presented herein suggest that the strategy employed in this study may be applicable for the genetic engineering of other nonmodel Saccharopolyspora strains and increase target product yields.