Although antioxidant activities of Korean traditional fermented foods were reported by many researchers, study on antioxidant activity of microorganism originated from Korean traditional fermented foods was little. Therefore, we improved condition for antioxidant production by a bacterium isolated from home-made Chungkookjang. We selected a bacterial strain, which showed the highest antioxidative activity, from Chungkookjang and then named GJ. The selected GJ strain was identified as Bacillus methylotrophicus by alignment data of 16S rRNA gene nucleotide sequences. Improved medium compositions for DPPH radical scavenging activity were 0.25% sucrose, 1% peptone, 0.01% MgSO4·7H2O and initial pH 6.5, respectively. Optimal culture conditions were 30℃, 200 rpm and 4% inoculum volume, respectively. In improved conditions, DPPH radical scavenging activity of GJ reached to 91% in a short time. The strain GJ also possessed ACE inhibition and other antioxidative activities; ACE inhibition activity (49.4%), ABTS radical scavenging activity (99.8%), metal chelating activity (67.9%), SOD-like activity (36.5%) and reducing power (A700 = 5.982) were observed, respectively. Therefore, our results suggest that B. methylotrophicus GJ strain may be potential candidate for functional foods, cosmetic products for anti-aging and medicine for diseases caused by oxidative stress.

젓갈은 전남 목포지역의 대형마트 및 가정에서 수집하였으며 오징어젓, 갈치속젓, 꼴뚜기젓, 멸치젓 등 10여종의 젓갈로부터 균을 분리하였다. 이들 분리 유산균 중 3균주가 인공위액과 인공담즙액에서 내성을 나타내었다. 이들 분리된 균주 중 생존력이 왕성한 3균주는 모두 인공위액에서 2시간, 인공담즙액에서 24시간 생존 가능하였다. 특히 유산균 ML 36, ML 128, ML 178 외 2종의 효모는 초기 생균수와 인공위액에서 2시간 배양 후 생균수의