The role of nitric oxide in the mechanism of lactic acid bacteria substituting for nitrite GouMengxing LiuXuejun QuHongye 2019 <p>This study aims to reveal the role of nitric oxide (NO) in substituting nitrite with lactic acid bacteria. Three lactic acid bacterial strains (<i>L. fermentum</i> JCM1173, <i>L. fermentum</i> IFO3956, <i>Weissella cibaria</i> X31) with nitrite substitution ability were inoculated into fermented sausages, respectively. Results indicated that the ratio of nitrosomyoglobin (NO-Mb) to total pigments was positively correlated with the substitution ability of the strain. UV-visible and resonance Raman spectroscopy suggested the NO-Mb was five-coordinated. In addition, the intracellular NO detected by fluorescent DAF-FM probe showed that <i>W. cibaria</i> X31 had the strongest NO-producing ability. Inhibitory experiments showed that both nitrate reductase and nitric oxide synthase-like protein participated in the NO production. These results indicated the vital role NO played in the substitution through the formation of NO-Mb and demonstrated the sources of NO in lactic acid bacteria preliminarily.</p>