Degradation of Histamine in Salted Fish Product by Halotolerant Bacillus Polymyxa

Abstract

Bacillus polymyxa D05-1 isolated from salted fish product which possess histamine degrading activity was added to the salted fish products and held at 30C for 6 weeks in this study. Aerobic plate counts (APCs) in low spiked samples (4.0 log CFU/g) were remained constant during storage time, whereas, those of control samples gradually increased during first 3 weeks of storage and thereafter remained constant. However, the aerobic plate counts (APCs) of high spiked samples (6.0 log CFU/g) rapidly decreased to 4.0 log CFU/g at first week of storage, and thereafter increased slightly. The both spiked samples had considerably lower levels of total volatile basic nitrogen (P < 0.05) than control samples at each sampling time except for second week storage. In general, histamine contents in the both spiked samples markedly decreased during 6 weeks storage, whereas those of control samples increased with increased storage time. After 6 weeks storage, the histamine contents in high and low spiked samples were reduced for 45.8% and 36.0%, respectively, as compared with control samples. These results indicated that B. polymyxa D05-1 could be utilized in salted fish fermentation to reduce histamine levels in fermented products. Practical Applications This study shows that Bacillus polymyxa D05-1 can be used as an additive to degrade histamine for salted fish product. In addition, B. polymyxa D05-1 could retard the increase of total volatile basic nitrogen in salted fish product. Therefore, this is an alternative method for the control of histamine in salted and fermented seafood.