Xu J, Xu X, Verstraete W
Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, 9000 Ghent, Belgium.
J Appl Microbiol. 2001 Apr;90(4):523-9. doi: 10.1046/j.1365-2672.2001.01278.x.
To examine the hypothesis of non-immune defence mechanisms based on nitrite.
The acidified media (nutrient broth or citrate-phosphate buffer) under aerobic conditions with additions of physiological levels of nitrite, L-ascorbic acid, iodide and thiocyanate were used to simulate gastric juice. The bactericidal effects of acidified nitrite on Escherichia coli and lactobacilli were investigated using bacterial plate counts. Conversion of acidified nitrite to nitric oxide, nitrogen dioxide and nitrate was also studied. Nitrite significantly increased the bactericidal effects on E. coli and lactobacilli. The bactericidal effects were enhanced by thiocyanate but not by L-ascorbic acid and iodide. L-Ascorbic acid and thiocyanate, but not iodide, enhanced the decomposition of acidified nitrite in nutrient broth. Acidified nitrite was converted to both nitric oxide and nitrate, but a portion of the acidified nitrite in nutrient broth may have been converted to other unidentified nitrogen compounds. Nitrogen dioxide was not detected in any of the samples.
The bactericidal effects of nitrite appeared to be primarily related to nitrous acid, and possibly to other unidentified nitrogenous metabolites, but not to nitric oxide and nitrogen dioxide.
The potential role of nitrite as an antimicrobial substance in the stomach may be of some importance in the ecology of the gastrointestinal tract and in host physiology.
检验基于亚硝酸盐的非免疫防御机制假说。
在有氧条件下，使用添加了生理水平亚硝酸盐、L-抗坏血酸、碘化物和硫氰酸盐的酸化培养基（营养肉汤或柠檬酸盐-磷酸盐缓冲液）来模拟胃液。采用细菌平板计数法研究酸化亚硝酸盐对大肠杆菌和乳酸菌的杀菌作用。还研究了酸化亚硝酸盐向一氧化氮、二氧化氮和硝酸盐的转化。亚硝酸盐显著增强了对大肠杆菌和乳酸菌的杀菌作用。硫氰酸盐增强了杀菌作用，而L-抗坏血酸和碘化物则没有。L-抗坏血酸和硫氰酸盐，而非碘化物，增强了营养肉汤中酸化亚硝酸盐的分解。酸化亚硝酸盐转化为一氧化氮和硝酸盐，但营养肉汤中的一部分酸化亚硝酸盐可能已转化为其他未鉴定的含氮化合物。在任何样品中均未检测到二氧化氮。
亚硝酸盐的杀菌作用似乎主要与亚硝酸有关，可能还与其他未鉴定的含氮代谢产物有关，但与一氧化氮和二氧化氮无关。
亚硝酸盐作为胃内抗菌物质的潜在作用在胃肠道生态和宿主生理学中可能具有一定重要性。
