Fast Preparation of Fish Sauce Treated With Marine Protease-Producing Bacillus zhangzhouensis sp.

Background: Traditional fish sauce is made from fish that have been coated in 30%–40% sea salt and fermented for up to 2 years. The preparation requires a long time, and the fish source contains considerable biogenic amines. In this report, by measuring the growth curve and identifying the intracellular enzyme and the activity of protease, B. zhangzhouensis with the highest activity of protease production was selected from eight strains, which were applied to the fermentation process of fish sauce. Results: Optimized by response surface methodology, the content of amino nitrogen was taken as the response value, and the best fermentation conditions were 4.15% inocula, pH 9.13, and 36.3°C. Under the optimized conditions, fish sauce samples were obtained by fermentation with B. zhangzhouensis for 15 h, 3 days, 7 days, 15 days, and 30 days, respectively. The contents of amino nitrogen, total nitrogen, biogenic amine, and various flavor substances were determined and compared with the traditional 2-year-fermented fish sauce. As a result, the 7-day-fermented fish sauce using B. zhangzhouensis had a similar composition of flavor substances to traditional fish sauce, but a much lower level of biogenic amines. Conclusion: The new method of preparing fish sauce with a fermentation condition of 4.15% B. zhangzhouensis , pH 9.13, and 36.3°C can improve the production efficiency of fish sauce, and the flavor is similar to that of traditional fish sauce.