Lactic acid bacteria were isolated from seaweed and seagrass samples collected from various sea areas around Japan. Out of 208 isolates, 24 strains were catalase negative and showed clear holes on the agar media containing calcium carbonate due to the production of lactic acid, suggesting that these strains were considered to be lactic acid bacteria. Among these, 3 strains showed high production of lactic acid and were selected for further studies. These strains were found to be Lactobacillus delbrueckii subsp. lactis based on the 16S rDNA sequence analysis. The species is well-known as a plant-derived lactic acid bacterium of terrestrial origin. Physiological and biochemical characteristics of the three strains and their type strain (NBRC3202) were compared. Growth temperature and utilization of amygdalin, arbutin and salicin of the three strains were different from their type strain. The supernatant of fermented commercial soy milk of three isolated strains showed acceleration of synthesis of collagen and hyaluronic acid on normal human skin fibroblast. Among these strains, strain KM-2, which was isolated from Kumejima Town, in Okinawa Prefecture showed highest acceleration activities.
Chiaki Imada (Wed,) studied this question.