Potential targets of gene modification
No information was found indicating that any of the micro-organisms contained in the above-mentioned cleaning products were genetically modified in any way. However, there are indications in the literature that some of the genes involved in producing enzymes or biosurfactants and bioemulsifiers whose mode of action involves the increased solubilisation and breakdown of organic substances could be modified to enhance some of their properties. Thus, it is at least possible that genetically modified micro-organisms could find their way into cleaning products in the future, although it is questionable whether such products would continue to be regarded as “green”.
Some of the main targets for gene modification have been those coding for the production of various amylases and proteases used in detergent products, mainly with the aim of improving their activity at lower water temperatures and more alkaline pH levels (Kirk et al., 2002). For example, B. subtilis strains have been engineered to express some of these modified genes (Ness et al., 1999). As well, a number of recombinant lipase enzymes have been produced using engineered Bacillus and Aspergillus species (Hasan et al., 2010).
Much research has been conducted recently towards engineering improved versions of various biosurfactant and bio-emulsifying substances (such as surfactin, rhamnolipids and emulsans) for use in detergent and other cleaning product applications. For the most part, the aim of the research has been to increase yields of these substances when expressed in various bacterial species (mostly Bacillus, but also in a number of Acinetobacter, Pseudomonas and Serratia species as well). A thorough review of this research is provided in Satpute et al. (2010).