Screening of Lactic Acid Bacteria Strains with Respiration Ability in the Present of Heme

25 strains of Lactic Acid Bacteria were selected to carry on aerobic cultivating test. It was found that LD33 and 1031 could undergo respiration in the present of heme. compared with the original strain cultivated under fermentative conditions , both its biomass and pH increased. After 45 days storaged at 4°C, the strain LD33 cultivated under fermentative condition was less than 10CFU/mL, while the viable cell count of strain cultivated under respiratory condition was remain 108CFU/mL. Aerobic respiratory metabolism shift occurred in the early exponential growth was indicated by the growth curve and pH curve.

The Production of Lactic Acids grom Lactobacillus acidophilus

ABSTRACT.The ratio of D-and L-lactic acid produced in media by 39 strains of the L. acidophilus group lactic acid bacteria (A1-A4,B1, and B2 subgroups) was analyzed by high performance liquid chromatography (HPLC). L. acidophilus (A1) and L. jhonsonii (B2) produced the lowest ( 5 strains average : 41.9%) contents of D-lactic acid in MRS broth, respectively. Generally, the most dominant lactic acid (more than 50%) produced by each strain in MRS broth was a D-type isomer, except for the A1 subgroup. In L. gasseri DSM 20243T (B1), increases in the sugar content in MRS broth induced both a high production of total lactic acids and a high ratio of D-lactic acid. In skim milk, D-lactic acid decreased by 20 – 30 % in 5 strain types of the L. acidophilus group except L. amylovorus JCM 1126 T (A3). By sequentially changing the medium, the content of D-lactic acid in the final MRS broth reverted to almost the same level of that in the initial MRS broth. These results indicated that the ratio of D-lactic acid produced by L. acidophilus group bacteria may be controlled by improving fermentative condition