Proteus penneri encapsulation with maltodextrin and sodium alginate using a spray-drying method

Abstract

Proteus penneri has been isolated from the digestive tract and used for coffee fermentation. As its viability is compromised rapidly by unfavorable environmental conditions, encapsulation technique is used to protect it. The purpose of this study is to develop a bacterial encapsulation method that can preserve viability of Proteus penneri. The Proteus penneri were isolated from civet feces. Bacterial encapsulation was performed using a spray-drying method, and maltodextrin and sodium alginate were used as coating materials. We tested 15%, 20%, and 30% (w/v) concentrations of maltodextrin and 0.50%, 0.75%, and 1% (w/v) concentrations of sodium alginate. The encapsulated bacteria were stored for two weeks to study the stability of enzyme activity. We found that the spray-drying technology using maltodextrin as coating material resulted in a stable encapsulated bacterium. However, Proteus penneri did not survive well during the process. Loss of viability is caused by the membrane cell wall damage. After two weeks storage, bacterial viability decreased significantly. The enzymatic activity of the encapsulated cellulolytic bacteria was influenced by concentration of the bacteria, however the activity appeared to be stable after two weeks of storage.