Supplementary File I.xlsx and Supplementary File II.docx included: Figure S1: LC-MS results of PQQ and its adducts; Figure S2: The molecular masses of PQQ as determined by LC-MS; Figure S3: Colonies of R. palustris CGA009 pre-cultured under autotrophic conditions and subsequently cultured on different growth media; Figure S4: The non-inoculated control and the growth curves of R. palustris CGA009 under photoheterotrophic conditions with fish sauce and MSG as carbon sources; Figure S5: The colonies from pellet inoculated-Arabidopsis plant juices on LB plates; Figure S6: The colonies from supernatant inoculated-Arabidopsis plant juices on LB plates; Table S1: The PQQ-dependent glucose dehydrogenase activity of E. coli membrane protein (EcMP) after freeze-thaw cycles.