|
In this study, we cloned and characterized three bacterial laccases from strains of the species Pediococcus parvulus, Lacticaseibacillus paracasei and Lactococcus lactis isolated from wine and cheese, and evaluated their biogenic amine degradation abilities in the presence/absence of artificial 2,2’-azinobis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) or natural (epicatechin) mediator compounds. Although some recombinant bacterial laccases have been characterized and re-vealed as biological tools to degrade biogenic amines using or not mediators, no previous research had been undertaken on the role of natural mediators, such as phenolic substrates found in wine and some vegetable food, in the degradation of biogenic amines. The three recombinant bacterial laccases exhibited sigmoidal kinetics, similar molecular mass, and different k0.5 and specific activi-ties on ABTS. They are acidophilic with optima temperature of 28ºC, and have low thermal stabil-ity at temperatures higher than 37ºC. The three laccases were able to degrade dopamine in ab-sence of any mediator, whereas the rest of amines were not degraded. The presence of ABTS somehow improved dopamine and tyramine degradation, while the addition of epicatechin did not improve their degradation. This is the first study in which the biogenic amine-degrading effi-ciency of an artificial mediator used by laccases is compared with a natural mediator.
|