lengthy storing but also for an easy transport of the inoculant metals biosorption by a biofilm of strain of bacillus sp nrrl b 30881 in a fixed bed bioreactor to perform a metals biosorption by a biofilm of strain of bacillus sp nrrl b 30881 a fixed bed bioreactor with a 90 l total capacity using polyvinyl chloride pvc as material was employed the central structure was constituted by a type 6 piping 315 mm nominal diameter and 1 3 m longitude pvc the lids were pvc collector lids for 315 mm tubes which were provided of a 12 7 mm tank outlet to provide oxygen a bayer type injector was employed this injector was constituted by the injector made of polypropylene and an acrylic casing in order to keep the temperature constant at 28 u00b0 c inside the bioreactor a heat interchange system was employed this system consisted of a coil immersed in a water bath which was thermo regulated by a heater haake model dc3 and a solenoid valve that controlled the inlet of cooling water which was automatically guided by a control interface opto22 and the software optocontol suit factoryfloor 4 0 two kinds of support materials were.