不同温度及pH条件对乳酸菌生长影响的研究

Effects of Different Temperatures and pH on the Growth of Lactic Acid Bacteria

实验用改良MC培养基为载体，通过目测菌液浑浊度。测定菌液OD600值和培养终点时pH值，对从酸马奶中分离出的乳酸菌的生长温度及pH值进行了研究。结果表明。在不加缓冲液的培养基中．在pH6．5～8．5、40℃培养时。所有菌株生长良好，且发酵葡萄糖和乳糖产生乳酸．降低环境的酸度。当环境条件超出这一范围时．乳酸菌生长受到抑制。从OD600值看出．实验分离到的24株菌最适pH都在6．5左右．最适生长温度在40℃左右．但pH值与温度的范围在各菌株间略有差异。

This experiment is designed to analyze the effects of different temperatures and pH on lactic acid bacteria（LAB） isolated from koumiss by improved MC culture .The OD600, pH and vaccine opacity of the culture at terminal were measured. The results of this experiment are summarized as follows： the LAB can massively grow in 40 ℃ and pH 6.5-8.5 in non - buffer culture, produce the lactic acids and lower the acidity of the environment. The LAB growth is inhibited beyond the range. The pH 6.5 and 40 ℃ are the most suitable condition to these 24 strains, but every strain performs different scope.