Received: 24-10-2022 / Accepted: 20-12-2022
The objective of this study was to immobilize Virgibacillus campisalisTT8.5 bacterial cells on a carrier in order to degrade histamine content in traditional fish sauce. Three immobilization techniques, adsorption, encapsulation and crosslinking with nine carriers were used. Factors affecting the immobilization process of bacteria on carrier such as cells/carrier (w/w) ratio, time and temperature of immobilization, salt concentration in buffer solution (%) and stirring speed (rpm) were investigated. The cell immobilization efficiency (%) and the ability to degrade histamine after 2 hours of reaction (%) of Virgibacillus campisalisTT8.5 were evaluated. Results indicate that, the adsorption technique with pig bone as carrier gave the highest immobilization efficiency and histamine degrading ability with 54.18% and 41.30% respectively. Suitable conditions for immobilization of Virgibacillus campisalisTT8.5 cells on pig bone were determined as follows: cell/carrier ratio 1/15 (w/w), stirring speed of 100 rpm, salt concentration of 15%, incubation time of 1 hour at 4C. The fixed bed bioreactor containing immobilized V. campisalisTT8.5 bacterial cells has potential application in histamine degradation in traditional fish sauce with efficiency of 37.1%.
