Affiliation:
1. Guangxi Key Laboratory of Green Processing of Sugar Resources, Guangxi University of Science and Technology, Liuzhou 545006, China
Abstract
Ultrasound-mediated transformation has become a feasible means for plasmid transformation of microorganisms due to its simple operation, low influence from external factors, and low equipment requirements. This study investigated the effects of ultrasonic power, ultrasonic application time, microorganism growth phase, wash buffer, and Mg2+/Ca2+ presence on transformation efficiency. Using stationary-phase Escherichia coli in 0.1 M phosphate-buffered saline, the optimal ultrasonic power was 130 W, the optimal ultrasonic time was 12 s (working, 1 s; pause, 2 s), and the maximum transformation efficiency reached 3.24 × 105 CFU/µg in the presence of Mg2+. Based on scanning electron microscopy, the mechanism underlying ultrasound-mediated transformation of microorganisms with an ultrasonic homogenizer involved the cavitation phenomenon, with reversible pore formation accompanied by cell expansion. This method was less dependent on cell types in comparison to other transformation methods, and it also achieved good transformation effect in Saccharomyces cerevisiae. This is the first time that the phenomenon of ultrasound-mediated microbial (microbubble-free) transformation has been reported using scanning electron microscopy, which has important significance for the mechanism analysis of relevant subsequent studies.
Funder
central government’s special fund for local science and technology development
Guangxi Science and technology base and talents special project
National Natural Science Foundation of China
Guangdong Basic and Applied Basic Research Foundation
Guangxi university of science and technology
Subject
Process Chemistry and Technology,Chemical Engineering (miscellaneous),Bioengineering