Naocl

The polyether sulfone (PES) ultrafiltration membrane modules, comprising 10 Multibore^® fibers, each containing 7 capillaries with an inner diameter of 0.9 mm, were supplied by inge GmbH (DuPont, Greifenberg, Germany). Each membrane module has an overall membrane surface of 0.05 m² and molecular weight cut-off (MWCO) of 100 kDa. Polydiallyldimethylammonium chloride (PDADMAC) (20% solution with a molecular weight of 250–350 kDa) and poly-(4-styrenesulfonic acid) (PSS) (molecular weight of 1000 kDa) were purchased from Sigma Aldrich (Schnelldorf, Germany). NaCl, MgSO₄, CaCl₂ and NaOCl were purchased from Carl Roth GmbH (Karlsruhe, Germany). All salts were of analytical grade.

Rucola (Eruca sativa L.) seeds were washed in Tween 80 1% (Sigma, United States) for 2 min, surface sterilized with sodium hypochlorite 12% (NaOCl, Roth, Germany) for 8 min and washed three times in sterile deionized water for 2 min. Sterilized seeds were placed on Hoagland’s solution (Sigma, United States) with 0.8% agar to germinate 4 days. Rhodococcus strains were pre-grown in TSB. Overnight grown cultures were washed two times in 1x PBS (AppliChem, Germany) and diluted to a concentration of 10⁷ CFUs. Seedlings were inoculated in the prepared bacterial solution of RL1, BG43, and djl6 for 1 h under shaking at 160 rpm at 28°C. Seedlings inoculated in 1x PBS served as negative control. Inoculated seedlings were transferred to an axenic system with 80 ml sterile quartz sand and 20 ml Hoagland’s solution in a sterile Phytatray II (Sigma, United States). Seedlings inoculated with RL1 were additionally transferred on plates with 0.5x Murashige and Skoog Medium (0.5x MS) including vitamins (Duchefa Biochemie, Netherlands); pH was adjusted to 5.7 with 2N KOH. No additional sucrose was added to 0.5x MS. The axenic system was placed in a Phytochamber (Weiss Technik, Modell SGC120PG2, Germany) with 23°C, 55% humidity, day-night-cycle 12 h : 12 h. After seven and 14 days freshly harvested roots were washed in 1x PBS, fixed in 55% EtOH and 1x PBS mix and stored at –20°C until further use.