Development of an optimized medium, strain and high-throughput culturing methods for Methylobacterium extorquens

PLoS One. 2013 Apr 30;8(4):e62957. doi: 10.1371/journal.pone.0062957. Print 2013.

Abstract

Methylobacterium extorquens strains are the best-studied methylotrophic model system, and their metabolism of single carbon compounds has been studied for over 50 years. Here we develop a new system for high-throughput batch culture of M. extorquens in microtiter plates by jointly optimizing the properties of the organism, the growth media and the culturing system. After removing cellulose synthase genes in M. extorquens strains AM1 and PA1 to prevent biofilm formation, we found that currently available lab automation equipment, integrated and managed by open source software, makes possible reliable estimates of the exponential growth rate. Using this system, we developed an optimized growth medium for M. extorquens using response surface methodologies. We found that media that used EDTA as a metal chelator inhibited growth and led to inconsistent culture conditions. In contrast, the new medium we developed with a PIPES buffer and metals chelated by citrate allowed for fast and more consistent growth rates. This new Methylobacterium PIPES ('MP') medium was also robust to large deviations in its component ingredients which avoided batch effects from experiments that used media prepared at different times. MP medium allows for faster and more consistent growth than other media used for M. extorquens.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Carbon / metabolism
  • Chelating Agents / pharmacology
  • Culture Media* / chemistry
  • Methylobacterium extorquens / drug effects
  • Methylobacterium extorquens / genetics
  • Methylobacterium extorquens / growth & development*
  • Methylobacterium extorquens / metabolism
  • Mutation

Substances

  • Bacterial Proteins
  • Chelating Agents
  • Culture Media
  • Carbon

Grants and funding

NFD was supported by a National Science Foundation (NSF) graduate student fellowship and this research was funded by an NSF CAREER grant awarded to CJM (DEB-0845893). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.