沈菜類 熟成에 따르는 Microflora, 糖, pH 및 Vitamin B_12의 變化와 Pseudomonas sp.의 Vitamin B_12 生産性에 관하여 = Changes of Microflora, Sugar, pH, and Vitamin B_12 and the Productivity of Vitamin B_12 by Pseudomonas sp. during the Aging of Fermented Vegetables

다국어 초록 (Multilingual Abstract)

This study was to investigate the changes of microflora, sugar, pH, and vitamin B_(12) during the aging of fermented vegetables such as Tongkimchi and Dongchimi and the productivity of vitamin B_(12) by Pseudomonas denitrificans D-2-1 selected as vitamin B_(12) producing bacteria from Dongchimi. The main bacteria responsible for Tongkimchi fermertation were Lactobacillus plantarum, Leuconostoc mesenteroides and Streptococcus faecalis, but the main bacteria for Dongchimi fermentation were Leuconostoc mesenteroides and the genus Pseudomonas. In TongKimchi and Dongchimi sugar continuously decreased from ca. 3% and pH reduced from 5.8 to 4.0 and less, but increased as the over-ripening progresses. Vitamin B_(12) content of TonKimchi was higher than those of Dongchimi at the early stage, hut the opposite result at a later period. Vitamin B_(12) content of TongKimchi and Dongchimi reached its maximum at the middle period. Pseudomonas denitrificans D-2-1 cultured for 15 days on the media of radish juice produced vitamin B_(12) up to 274 ng/㎖, and the strain cultured on the media of radish juice containing 1.5% NaCl produced vitamin B_(12) of 261 ng/㎖. The strain cultured on the media of radish juice containing 3% NaCl and 0.1% L-glutamic acid as a nitrogen source produced vitamin B_(12) of 272 ng/㎖. In contrast to the amount of vitamin B_(12)(245 ng/㎖) obtained from the media in which L-glutamic acid was not added, the media containing L-glutamic acid increased the productivity of vitamin B_(12) up to 11%.