Continuous cultivation of a thermophilic bacterium Aeribacillus pallidus 418 for production of an exopolysaccharide applicable in cosmetic creams

Aims: The aim of this study was to evaluate the effectiveness of continuous cultivation approach for exopolysaccharide (EPS) production by a thermophilic micro-organism and the potential of the synthesized EPS for application in cosmetic industry. Methods and Results: Study on the ability of Aeribacillus pallidus 418, isolated as a good EPS producer, to synthesize the polymer in continuous cultures showed higher production in comparison with batch cultures. The degree of the EPS in the precipitate after continuous cultivation significantly increased. Non-Newtonian pseudoplastic and thixotropic behaviour of EPS determines the ability of the received cream to become more fluid after increasing time of application on the skin. Conclusions: This study demonstrates a highly efficient way for production of EPS from a continuous growth culture of A.pallidus 418 that have many advantages and can outperform batch culture by eliminating time for cleaning and sterilization of the vessel and the comparatively long lag phases before the organisms enter a brief period of high productivity. The valuable physico-chemical properties of the synthesized EPS influenced positively the properties of a commercial cream. Significance and Impact of the Study: EPSs from thermophilic micro-organisms are of special interest due to the advantages of the thermophilic processes and nonpathogenic nature of the polymer molecules. However, their industrial application is hindered by the comparatively low biomass and correspondingly EPS yield. Suggested continuous approach for EPS could have an enormous economic potential for an industrial scale production of thermophilic EPSs.