摘要
乳酸菌(Lactic acid bacteria,LAB)主要是通过发酵产能的,但是有研究发现,在添加氯化高铁血红素后乳酸乳球菌(Lactococcus lactis)能形成一条呼吸链,在乳酸乳球菌(L.lactis)IL1403中发现了能够编码呼吸链蛋白的基因,同样的现象在粪链球菌中(Strepto coccus feacalis)也有发现。当氧出现在电子传递链中,质子的排出和质子运动势(PMF)的产生都会加倍。相比较其他的兼性或者专性厌氧菌,乳酸乳球菌(L.lactis)的呼吸作用可以促进代谢能量的产生,由于这种呼吸作用,乳酸乳球菌(L.lactis)有更好的生长得率和显著的存活率,这表明在发酵条件下产生的代谢能量不足,从而会限制乳酸乳球菌(L.lactis)的生长。氧在呼吸链中扮演了重要的有益角色,而不是起毒害作用。
The fermentative nature of LAB has been brought into question by the observation that L. lactis can form a respiratory chain in the presence of hemin; these results are consistent with the presence of genes in the genome of L. lactis IL1403 encoding respiratory chain proteins. A similar effect of hemin was found for Streptococcus faecalis. When oxygen is present electron transfer in this respiratory chain is coupled to the extrusion of protons and results in the generation of a PMF. Respiration can therefore contribute to the generation of metabolic energy in L. lactis in a similar way as in obligate and faeultative aerobic bacteria. As a result of this respiratory activity, L. lactis has a greater growth yield and a remarkable improvement of survival, indicating that the metabolic energy supply limits growth under fermentative conditions. With a functional respiratory chain, oxygen is beneficial instead of toxic for L. lactis.
出处
《东北农业大学学报》
CAS
CSCD
北大核心
2009年第6期132-136,共5页
Journal of Northeast Agricultural University
基金
"十一五"国家科技支撑计划(2006BAD06A11)