Bacterial cell disruption: a key unit operation in the recovery of intracellular products

The need for microbial cell disruption has hindered the large scale production of commercial biotechnological products of intracellular derivation. The intracellular nature of many recombinant products and the potential use of the bacterial storage product, PHB as a commodity thermoplastic have renewed interest in the improvement of this unit operation. This paper provides a review of processes of a mechanical, physical, chemical or biological nature used for cell disruption on both the laboratory and large scale. Applicability of the techniques to large scale operation is discussed. Modification of existing processes is suggested for the reduction of energy requirements and improved process economics. The requirements for the liberation of granular intracellular products such as inclusion bodies and virus-like yeast particles are distinguished from those for the liberation of soluble products, mainly proteinaceous in nature. The integrated nature of the process with both upstream and downstream processes is addressed. Finally, the recent approach of selective liberation of soluble products of interest is reviewed.