Department of Biosciences, Saurashtra University, Rajkot, India.
Anaerobe. 2011 Oct;17(5):217-22. doi: 10.1016/j.anaerobe.2011.07.001. Epub 2011 Jul 12.
In vitro mutagen binding ability of human Lactobacillus rhamnosus 231 (Lr 231) was evaluated against acridine orange (AO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 2-amino-3, 8-dimethylimidazo-[4,5-f]-quinoxaline (MeIQx) and 4-nitro-o-phenylenediamine (NPD). Binding of AO by Lr 231 is due to adsorption, thereby leading to removal of mutagen in solution and is instantaneous, pH- and concentration-dependent. Whereas, binding of MNNG and MeIQx by Lr 231 results into biotransformation leading to detoxification with subsequent loss of mutagenicity as determined by spectral analysis, thin layer chromatography and Ames test. Binding of mutagen by Lr 231 was dependent on culture age and optimum binding of AO, MNNG and MeIQx was observed to occur with 24 h old culture. Cells of Lr 231 were subjected to different chemical treatments prior to binding studies. Results indicated cell wall component such as cell wall polysaccharide, peptidoglycan, carbohydrates and proteins plays an important role in adsorption of AO, also involving hydrophilic and ionic interactions. Binding, biotransformation and detoxification of MNNG and MeIQx by Lr 231 was dependent on cell surface characteristics mainly involving carbohydrates, proteins, teichoic acid/lipoteichoic acid, hydrophobic interaction and presence of thiol group. L. rhamnosus 231 bound MNNG instantaneously. More than 96 (p < 0.01) and 70% (p < 0.05) cells remained viable after mutagen binding and various pretreatments respectively. This study shows Lr 231 exhibits ability to bind and detoxify potent mutagens, and this property can be useful in formulating fermented foods for removal of potent mutagens.
我们评估了人源鼠李糖乳杆菌 231（Lr 231）对吖啶橙（AO）、N-甲基-N'-硝基-N-亚硝胍（MNNG）、2-氨基-3,8-二甲基咪唑[4,5-f]-喹喔啉（MeIQx）和 4-硝基邻苯二胺（NPD）的体外致突变结合能力。Lr 231 对 AO 的结合是由于吸附作用，从而导致溶液中的致突变剂被去除，且该过程是瞬时的，依赖于 pH 值和浓度。然而，Lr 231 对 MNNG 和 MeIQx 的结合导致生物转化，从而解毒，随后通过光谱分析、薄层层析和艾姆斯试验确定致突变性丧失。Lr 231 对致突变剂的结合依赖于培养年龄，对 AO、MNNG 和 MeIQx 的最佳结合观察到发生在 24 小时龄的培养物中。在结合研究之前，将 Lr 231 的细胞进行了不同的化学处理。结果表明，细胞壁成分，如细胞壁多糖、肽聚糖、碳水化合物和蛋白质，在 AO 的吸附中发挥重要作用，同时涉及亲水和离子相互作用。Lr 231 对 MNNG 和 MeIQx 的结合、生物转化和解毒依赖于细胞表面特性，主要涉及碳水化合物、蛋白质、磷壁酸/脂磷壁酸、疏水相互作用和巯基的存在。L. rhamnosus 231 能瞬时结合 MNNG。在致突变结合和各种预处理后，分别有超过 96%（p < 0.01）和 70%（p < 0.05）的细胞保持存活。这项研究表明，Lr 231 具有结合和解毒潜在致突变剂的能力，这种特性可用于配制发酵食品以去除潜在致突变剂。
