腐植酸钠对植物乳杆菌生长、代谢及形态的影响

本试验通过在MRS液态培养基中添加不同浓度的腐植酸钠,比较植物乳杆菌生长、代谢及形态变化,初步探讨了液态条件下腐植酸钠对植物乳杆菌的抑制作用。结果表明,1%~5%腐植酸钠降低了植物乳杆菌的活菌数,但可提前6h达到生长最高点;3%腐植酸钠作用后,植物乳杆菌的有机酸产量发生了改变,且菌落变小,菌体变粗;透射电镜结果表明腐植酸钠使得植物乳杆菌细胞壁和细胞膜结构部分变得模糊。因此,液态条件下腐植酸钠通过改变植物乳杆菌的代谢途径、形态结构达到抑制其生长的作用。

Effect of Sodium Humate on the Growth,Metabolism and Morphology of Lactobacillus plantarum

The effect of sodium humate with different concentration in the MRS liquid medium on the growth, metabolism and morphology of Lactobacillus plantarum were investigated, to probe the sterilization mechanism of sodium humate. The result showed that in the MRS liquid medium sodium humate (1% to 5%) made the viable count of Lactobacillus plantarum reach the highest point of growth 6 h earlier than control, while it could make the number of Lactobacillus plantarum sightly decreased. Adding 3% sodium humate changed the metabolism of organic acid and made the colony of Lactobacillus plantarum smaller and darker. The result of transmission electron micro-scope showed that the boundaries blur between cell wall and cell membrane. So it followed that in the liquid medium sodium humate inhibited the growth of Lactobacillus plantarum by changing their metabolism and morphology.