lactobacillus
A genus of lactic acid bacteria; used in scientific and medical contexts.
Lactobacillus is used in the fermentation of yogurt.
乳酸菌 is a broader term for lactic acid bacteria in general, while 乳酸桿菌 specifically refers to the rod-shaped genus Lactobacillus.
Compound of 乳酸 (lactic acid) + 桿菌 (rod-shaped bacterium).