@misc{HertelSchoeneMittelstaedtetal., author = {Hertel, Robert and Sch{\"o}ne, Kerstin and Mittelst{\"a}dt, Carolin and Meißner, Janek and Zschoche, Nick and Collignon, Madeline and Kohler, Christian and Friedrich, Ines and Schneider, Dominik and Hoppert, Michael and Kuhn, Ramona and Schwedt, Inge and Scholz, Patricia and Poehlein, Anja and Martienssen, Marion and Ischebeck, Till and Daniel, Rolf and Commichau, Fabian M.}, title = {Characterization of glyphosate-resistant Burkholderia anthina and Burkholderia cenocepacia isolates from a commercial Roundup® solution}, series = {Environmental Microbiology Reports}, volume = {14}, journal = {Environmental Microbiology Reports}, number = {1}, issn = {1758-2229}, doi = {10.1111/1758-2229.13022}, pages = {70 -- 84}, abstract = {Roundup® is the brand name for herbicide solutions containing glyphosate, which specifically inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase of the shikimate pathway. The inhibition of the EPSP synthase causes plant death because EPSP is required for biosynthesis of aromatic amino acids. Glyphosate also inhibits the growth of archaea, bacteria, Apicomplexa, algae and fungi possessing an EPSP synthase. Here, we have characterized two glyphosate-resistant bacteria from a Roundup solution. Taxonomic classification revealed that the isolates 1CH1 and 2CH1 are Burkholderia anthina and Burkholderia cenocepacia strains respectively. Both isolates cannot utilize glyphosate as a source of phosphorus and synthesize glyphosate-sensitive EPSP synthase variants. Burkholderia. anthina 1CH1 and B. cenocepacia 2CH1 tolerate high levels of glyphosate because the herbicide is not taken up by the bacteria. Previously, it has been observed that the exposure of soil bacteria to herbicides like glyphosate promotes the development of antibiotic resistances. Antibiotic sensitivity testing revealed that the only the B. cenocepacia 2CH1 isolate showed increased resistance to a variety of antibiotics. Thus, the adaptation of B. anthina 1CH1 and B. cenocepacia 2CH1 to glyphosate did not generally increase the antibiotic resistance of both bacteria. However, our study confirms the genomic adaptability of bacteria belonging to the genus Burkholderia.}, language = {en} } @misc{SchwedtSchoeneEckertetal., author = {Schwedt, Inge and Sch{\"o}ne, Kerstin and Eckert, Maike and Pizzinato, Manon and Winkler, Laura and Knotkova, Barbora and Richts, Bj{\"o}rn and Hau, Jann-Louis and Steuber, Julia and Mireles, Raul and Noda-Garcia, Lianet and Fritz, G{\"u}nter and Mittelst{\"a}dt, Carolin and Hertel, Robert and Commichau, Fabian M.}, title = {The low mutational flexibility of the EPSP synthase in Bacillus subtilis is due to a higher demand for shikimate pathway intermediates}, series = {Environmental Microbiology}, volume = {25}, journal = {Environmental Microbiology}, number = {12}, issn = {1462-2912}, doi = {10.1111/1462-2920.16518}, pages = {3604 -- 3622}, abstract = {Glyphosate (GS) inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase that is required for aromatic amino acid, folate and quinone biosynthesis in Bacillus subtilis and Escherichia coli. The inhibition of the EPSP synthase by GS depletes the cell of these metabolites, resulting in cell death. Here, we show that like the laboratory B. subtilis strains also environmental and undomesticated isolates adapt to GS by reducing herbicide uptake. Although B. subtilis possesses a GS-insensitive EPSP synthase, the enzyme is strongly inhibited by GS in the native environment. Moreover, the B. subtilis EPSP synthase mutant was only viable in rich medium containing menaquinone, indicating that the bacteria require a catalytically efficient EPSP synthase under nutrient-poor conditions. The dependency of B. subtilis on the EPSP synthase probably limits its evolvability. In contrast, E. coli rapidly acquires GS resistance by target modification. However, the evolution of a GS-resistant EPSP synthase under non-selective growth conditions indicates that GS resistance causes fitness costs. Therefore, in both model organisms, the proper function of the EPSP synthase is critical for the cellular viability. This study also revealed that the uptake systems for folate precursors, phenylalanine and tyrosine need to be identified and characterized in B. subtilis.}, language = {en} }