@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} } @misc{RiedelCommichauBenndorfetal., author = {Riedel, Ramona and Commichau, Fabian M. and Benndorf, Dirk and Hertel, Robert and Holzer, Katharina and Mardoukhi, Mohammad Saba Yousef and Noack, Laura and Martienssen, Marion}, title = {Biodegradation of selected aminophosphonates by the bacterial isolate Ochrobactrum sp. BTU1}, series = {Microbial Research}, volume = {280}, journal = {Microbial Research}, issn = {0944-5013}, doi = {10.1016/j.micres.2024.127600}, pages = {1 -- 12}, abstract = {Aminophosphonates, like glyphosate (GS) or metal chelators such as ethylenediaminetetra(methylenephosphonic acid) (EDTMP), are released on a large scale worldwide. Here, we have characterized a bacterial strain capable of degrading synthetic aminophosphonates. The strain was isolated from LC/MS standard solution. Genome sequencing indicated that the strain belongs to the genus Ochrobactrum. Whole-genome classification using pyANI software to compute a pairwise ANI and other metrics between Brucella assemblies and Ochrobactrum contigs revealed that the bacterial strain is designated as Ochrobactrum sp. BTU1. Degradation batch tests with Ochrobactrum sp. BTU1 and the selected aminophosphonates GS, EDTMP, aminomethylphosphonic acid (AMPA), iminodi(methylene-phosphonic) (IDMP) and ethylaminobis(methylenephosphonic) acid (EABMP) showed that the strain can use all phosphonates as sole phosphorus source during phosphorus starvation. The highest growth rate was achieved with AMPA, while EDTMP and GS were least supportive for growth. Proteome analysis revealed that GS degradation is promoted by C-P lyase via the sarcosine pathway, i.e., initial cleavage at the C-P bond. We also identified C-P lyase to be responsible for degradation of EDTMP, EABMP, IDMP and AMPA. However, the identification of the metabolite ethylenediaminetri(methylenephosphonic acid) via LC/MS analysis in the test medium during EDTMP degradation indicates a different initial cleavage step as compared to GS. For EDTMP, it is evident that the initial cleavage occurs at the C-N bond. The detection of different key enzymes at regulated levels, form the bacterial proteoms during EDTMP exposure, further supports this finding.}, language = {en} }