Abstract
Six strains of spore-bearing lactic acid bacteria were isolated from rhizosphere of various wild plants by means of the following process: A small piece of specimen was immersed in a glucose broth, heated at 80° for 20min, incubated anaerobically, Clostridia allowed to develop, one loopful of the broth was plated if its pH was lowered below 4.0, and the pin-point colonies with transparent haloes were picked up.
The isolates are mesophilic, facultatively aerobic, and catalase-positive rods with peritrichous flagella and an oval endospore at the terminal. The characteristic features are as follows: pH value of the glucose, fructose, sucrose and generally inulin broth is brought to 3.8-3.2 with lactic acid produced in the homo-fermentative way.
These isolates were classified into the following two new species based on the isomeric types of lactic acid produced: Bacillus laevolacticus nov. sp. for five strains of the l-rotatory lactic acid producers, and Bacillus racemilacticus nov. sp. for the two strains of the dl-lactic acid producers.
