Effect of AHL-lactonase and nisin on microbiological, chemical and sensory quality of vacuum packaged sturgeon storage at 4ºC: AHL-lactonase and nisin inhibit sturgeon spoilage

Quorum sensing (QS) has been reported to be involved in bacterial food spoilage. Acetylated homoserine lactones (AHLs) are QS signals of Gram-negative bacteria. AHL lactonases AiiA AI96 is a QS inhibitor, and thus can theoretically be applied to control the Gram-negative bacteria caused sturgeon spoilage by inhibiting their AHL-based QS system. As Gram-negative bacteria and Gram-positive bacteria were both found in spoilage sturgeon, the combination of AiiA AI96 and nisin, which is an effective bactericide to control the Gram-positive bacteria, was used to control the bacteria spoilage of sturgeon. The results showed that AiiA AI96 at 6.6 × 10 −2 , 6.6 × 10 −1 and 6.6 U/mL could suppress the growth of microflora and delayed the increase of TVB-N, sensory score and biogenic amine levels of sturgeon. In addition, 6.6 U/mL AiiA AI96 coupled with 2000 AU/mL nisin exhibited the strongest inhibition effect on spoilage and extended their shelf life by about 5 days. In conclusion, AiiA AI96 combined with nisin could be used as a suitable biological preservative for chilled sturgeon fillets.