Alternative methods of microorganism disruption for agricultural applications

This paper reviews various non-conventional techniques for microorganism disruption. Microorganism disruption plays a pivotal role in various agricultural applications such as disinfection of irrigation water, processing of crops and livestock products and the newly emerging area of bioenergy production for agricultural uses. Methods of treatment to destroy microorganisms for the purposes of disinfection or extraction of bio-products can be generally categorized as either thermal treatment methods or non-thermal treatment methods. The thermal methods for microbial disruption are not favorable in many applications such as food processing and water treatment due to its negative impact on product quality and process performance. The discussion of thermal methods for microorganism disruption will not be included in this review. Non-thermal treatments are divided into two groups; chemical and physical treatments. Owing to the concerns of the health organisations with regards to the use of chemical methods for microorganism disruption, the recent research efforts have been directed towards exploring alternative physical methods for rupturing microorganisms. The common alternative physical methods for microorganism disruption include mechanical and non-mechanical treatments. This paper discusses in details the use of the common mechanical treatments for cell disintegration. Such methods include ultrasound, shock wave, High Pressure Homogenization (HPH), Hydrodynamic Cavitation (HC), shear stress, bead milling and micro-fluidizer. The application of the non-mechanical methods for microbial disruption such as electrical treatment, non-thermal plasma, Ultra-Violet (UV), non-conventional chemical methods and some other treatments are also briefly addressed in this paper. Due to the importance of the mechanical methods in the current cell disruption research, more attention is directed to these methods in this work.