Growth of brown bullhead (BB) and other fish cell lines on microcarriers and the production of channel catfish virus (CCV).

The growth of brown bullhead (BB) fish cells and other poikilothermic cell lines on four commercially available brands of microcarrier beads was evaluated. Three of the microcarriers carry a positive surface charge, while the fourth carries a negative surface charge. The four microcarriers vary in their capacity to support the growth of the BB cells and other poikilothermic cell lines tested. The polyacrylamide beads by Bio-Rad and the polystyrene beads by Nunc were found to best support the growth of the anchorage-dependent BB cells. Although the DEAE-dextran beads by Flow Laboratories were also found to be satisfactory, similar Cytodex 1 beads by Pharmacia, were found to support the growth of BB cells poorly. Both the polyacrylamide and polystyrene beads were found to be satisfactory for reuse after resterilization. In contrast, the DEAE-dextran beads were unsatisfactory since they sustained obvious mechanical damage. The BB growth rate and final cell density in microcarrier culture were dependent on the concentration of beads in culture and of the size of the initial cell inoculum. In terms of cell yield per milliliter of culture medium the microcarrier culture was superior to conventional stationary cultures. Microcarrier spinner cultures of BB cells consistently produced higher yields of channel catfish virus than conventional monolayers of the same cells. Two important advantages of the microcarrier system are its suitability for large scale as well as small scale production of both cells and virus.