Rotational vacuum concentrator rvc2 18

Cell-free culture supernatant was prepared as previously described [115 (link)], with modifications. Briefly, LF3872 was grown overnight in MRS broth under anaerobic conditions at 37 °C. The overnight culture was diluted to the concentration of 1 × 10⁸ CFU/mL in MRS broth and further grown anaerobically for 48 h. Cell-free culture supernatant was collected by centrifugation at 5000× g for 20 min at 4 °C; filter-sterilized using a 0.22 µm pore size filter (Millipore, Billerica, MA, USA); and concentrated by speed-vacuum drying (Rotational Vacuum Concentrator RVC2-18, Martin Christ, Osterode, Germany). The lyophilized sediment of CSLF3872 alone or together with the prebiotic was used to study the effectiveness of inhibiting the adhesion of proteobacteria pathogens (E. coli, Salmonella, and Campylobacter).

Native cell-free supernatant (CFS) was prepared from cultures of the LS7247 strain as previously described in [113 (link)] with modifications. Briefly, the LS7247 strain was grown for 18 h in MRS broth under anaerobic conditions at 37 °C. The culture was diluted to a concentration of 1 × 10⁸ CFU/mL in MRS broth and further grown anaerobically for 48 h. CFS was collected by centrifugation at 6000× g for 25 min at 4 °C, filter-sterilized using a 0.22 µm pore size filter (Millipore, Bedford, MA, USA), and concentrated by speed-vacuum drying (Rotational Vacuum Concentrator RVC2-18, Martin Christ, Osterode am Harz, Germany). To obtain the ∆CFS, proteinase K (1.0 mg/mL) was added to native CFS from LS7247 and incubated at 37 °C for 2 h.
Native CFS and ∆CFS from the LS7247 strain alone or together with the Actigen prebiotic (Alltech Inc., Nicholasville, KY, USA) were used to study the effectiveness of inhibiting the adhesion of SE and ST pathogens to human and animal enterocytes.

Aliquots of PLTX in 80% aqueous MeOH (125 ng/mL; 1.0 mL) were evaporated to dryness under N₂-stream using a Multiple Nitrogen Evaporator (Liebisch Labortechnik, Germany) at room temperature and under vacuum using a Rotational Vacuum Concentrator RVC 2-18 (Martin Christ, Osterode am Harz, Germany) at 30 °C for 5 h. Residues were re-dissolved in 50% aqueous MeOH (300 µL) and analyzed using both instruments. Experiments were performed in triplicate over 1 day and the relative data are expressed as mean ± STD.