Profiling Microbial Interactions under Cadmium Stress

Samples were collected to determine the concentrations of DPrP, its metabolites, and Cd(II) during incubation. Extraction and detection of DPrP were carried out according to the method described previously [23 (link)]. The metabolites produced during the degradation process were identified by HPLC-MS [24 (link)]. The amino acids and fatty acids in the supernatant were detected by LC-MS [25 (link)] and GC-MS [26 (link)], respectively. The adsorption of Cd(II) on the surface and inside of bacteria was determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS) [27 (link)]. The Cd(II) concentration in the supernatant was investigated by ICP-MS (Agilent Technologies 7800 ICP-MS) analysis [28 (link)]. Quantitative PCR (qPCR) was used to quantify the ratio of DNA levels of the specific estG/xcpR genes to determine the ratios of ZM05 to ZM03 in the coculture system under Cd(II) stress [29 (link),30 (link)]. The primers used in qPCR are listed in Supplementary Table S1. For the transcriptional analysis, CK (control), CD (monoculture under 0.8 mM Cd²⁺), and CO (coculture under 0.8 mM Cd²⁺) samples were harvested for RNA extraction, and sample information is provided in Table S2.