“…The trickle bed reactor (TBR, Fig. 1 Comamonas testosteroni (G -rods), Pseudomonas putida (G -rods) and Bacillus cereus (G + rods) all being primary styrene and acetone degraders] was immobilized in both the reactors and then used in previous study conducted with the same substrates (Paca et al 2012b). Similar to this previous study, the reactors were operated in a concurrent airwater down-flow mode at the same empty bed retention time of 53 s. The same dilute mineral medium of the following composition was used in both reactors (per liter): 0.4 g (NH 4 ) 2 SO 4 , 0.3 g KNO 3 , 0.1 g NaCl, 0.125 g K 2 HPO 4 , 0.085 g KH 2 PO 4 , 0.34 g MgCl 2 .…”