- 期刊
乳酸鹽和硝酸鹽對Veillonella dispar厭氧生長的影響
Effects of Lactate and Nitrate on the Anaerobic Growth of Veillonella dispar
摘要
Veillonella spp.是絕對厭氧革蘭氏陰性球菌，常從人類口腔與腸道分離出來。它們利用乳酸為主要碳源，生成短鏈脂肪酸如乙酸鹽和丙酸鹽，並使用硝酸鹽進行厭氧呼吸，產生亞硝酸鹽。近期研究顯示將Veillonella與短鏈脂肪酸、亞硝酸鹽的生成和促進人體健康聯繫起來。宿主口腔和胃腸道環境含有多樣且動態變化的的乳酸鹽與硝酸鹽的濃度，然而，Veillonella在不同乳酸鹽和硝酸鹽濃度下的生長尚未被仔細研究。本研究使用胰蛋白腖和酵母萃取物為基底的培養液（tryptone and yeast-extract based medium，TY培養液），在TY培養液添加不同濃度組合的DL-乳酸鹽（0～100mM）與硝酸鹽（0～15 mM），對人體共生厭氧菌V. dispar生長的影響，結果顯示，DL-乳酸鹽可促進V. dispar的厭氧生長，呈現劑量依賴效應。進一步比較V. dispar在添加107 mM DL-乳酸鹽或53.5 mM L-乳酸鹽培養液中的生長，兩組細菌生長無顯著差異，初步顯示D-乳酸鹽對此菌生長無顯著影響。此外，硝酸鹽能以劑量依賴效應促進V. dispar生長，且硝酸鹽生長促進的效應在乳酸鹽含量較低的培養液中較為明顯。總之，本研究的發現將可為Veillonella生理學基礎研究與應用提供知識基礎。
並列摘要
Veillonella spp. are obligate anaerobic, Gram-negative cocci commonly found in the human oral cavity and gut. They primarily catabolize lactate as the main carbon source, converting it into short-chain fatty acids such as acetate and propionate. In addition, they utilize nitrate for anaerobic respiration and produce nitrite. Recent studies have linked Veillonella, production of short-chain fatty acids and nitrite to the promotion of human health. The human oral and gastrointestinal compartments contain diverse and dynamic levels of lactate and nitrate. However, the growth of Veillonella under varying levels of lactate and/or nitrate have not been investigated in detail. In this study, we used a tryptone and yeast-extract based medium to investigate the growth of Veillonella dispar under varying concentrations of DL-lactate (0~100 mM) and nitrate (0~15 mM). Our results showed that DL-lactate resulted in a dose-dependent promotion in V. dispar growth. In addition, we found no signific ant difference in the growth of V. dispar when grown in the medium containing either 107 mM DL-lactate or 53.5 mM L-lactate. This suggested that there was no significant effect of D-lactate on the V. dispar growth. Moreover, our investigation de-monstrated that the examined nitrate concentration promoted V. dispar growth in a dose-dependent manner, with a more pronounced effect observed in the media with lower lactate concentration. Our findings elucidated the effects of lactate and nitrate on the anaerobic growth of human commensal bacteria. This study provides the knowledge basis for future investigation of bacterial physiology and the potential applications of Veillonella as next-generation probiotics.