Appl Microbiol Biotechnol (1989) 32:249-255 Mini-review Applied Microbiology Biotechnology © Springer-Vedag 1989 Engineering aspects of insect cell suspension culture: a review J. Wu ~, G. King 2, A. J. Daugulis 2, P. Faulkner 3, D. H. Bone 2, and M. F. A. Goosen 2 1 Department of Environmental Engineering, Hebei Institute of Chemical Engineering, Hebei, Shijiazhuang, Peoples Republic of China 2 Department of Chemical Engineering, Dupuis Hall, Queen's University, Kingston, Ontario, Canada K7L 3N6 3 Department of Microbiology & Immunology, Queen's University, Kingston, Ontario, Canada K7L 3N6 Summary. The development of insect cell suspen- sion culture techniques for the production of in- sect pathogenic viruses and recombinant proteins has been reviewed, with an emphasis on process scale-up and reactor design considerations. The problems of culture media cost and insect cell shear sensitivity have also been addressed. Introduction Insect cell culture may be employed for produc- ing a variety of bioproducts ranging in applica- tion from agricultural to human health care. The more promising areas of application are, for ex- ample, in the production of insect pathogenic vi- ruses and the production of recombinant proteins by the baculovirus expression system. As insecti- cides for agricultural pest control, viruses are only pathogenic to the target insects and are not haz- ardous to the environment. Due to the ever-in- creasing resistance of insect pests to chemical pes- ticides and concern about environmental pollu- tion, recombinant baculoviruses may provide a suitable alternative to chemical pesticides (Podg- waite 1985). The viral pesticide Baculovirus helio- this, which has been registered as a commercial product for general use in the United States has, for example, been used effectively on cotton to kill pest larvae (Ignoffo and Couch 1981) (Table l). The baculovirus Autographa californiea nu- clear polyhedrosis virus (AcNPV), on the other hand, has been shown to be suitable as a vector for the efficient expression of genes from many sources, such as bacteria, viruses, and mammals Offprint requests to: M. F. A. Goosen (Table 1). A good review article on the types of recombinant proteins produced in insect cells in- fected with the AcNPV expression vector is given by Luckow and Summers (1988). In addition, the study of the virus is making significant contribu- tions to insight into the molecular biology of gene function and regulation, as well as to the under- standing of protein function at the molecular level in both vertebrate and invertebrate systems (Luckow and Summers 1988; Summers and Smith 1987). Effective and economical cultivation of insect cells on a large-scale is an important step towards the commerical production of biochemicals in in- sect cell culture. When growing insect cells in monolayers or on the inside surface of culture vessels, large-scale production is not suitable be- cause the surface/volume ratio falls as the scale increases. This may cause prohibitive capital costs for large systems (Pollard and Khosrovi 1978). Growing cells in suspension culture is more likely to be used for continuous and large-scale produc- tion. A key difference between insect cell and mammalian cell culture appears to be the sensitiv- ity of the cells to culture conditions (i.e. hydrody- namics, immobilization). Insect cells, for example, are more sensitive to shear effects and immobili- zation conditions than hybridoma cells (Murham- mer and Goochee 1988a; King et al. 1989; Tramper et al. 1986; Maiorella et al. 1988). The objective of this review is to briefly survey the process development of insect cell cultivation in suspension culture with particular emphasis on problem areas. Insect cell lines and growth medium The development of insect cell lines started al- most three decades ago, when the first insect cell