카로티노이드는 항산화 및 항암효과를 가지는 비타민 A의전구물질이다. 농촌진흥청 농업유전자원센터에서 보존하고 있는 호박자원 80자원의 과육에서 카로티노이드를 분석을 하였다. 유전자원은 한국, 멕시코, 인도의 원산지에 따라 호박 과육에서 카로티노이드를 분석하였다. 고성능 액체 크로마토그래피를 이용하여 총 9종의 카로티노이드 (크산토필류 3종과카로틴류 6종)를 분리하였다. 특히 카로티노이드 중 lutein과β-carotene 이 주로 분석이 되었다. 총 카로티노이드 함량 평균은 한국 육성종이 213.69 mg, 멕시코 재래종이 139.07mg, 인도 재래종이 69.13 mg, 그리고 한국 재래종 27.51 mg순으로 나타났다. 총 80 자원중 K188417(멕시코원산) 자원이카로티노이드 성분이 가장 많았다. 본 연구의 결과는 카로티노이드 고함유 호박 품종 개발 뿐 아니라 기능성 식품 개발의기초자료로 활용될 수 있을 것으로 사료된다.
The genus Pediococcus belongs to the lactic acid bacteria and includes 15 species which are used in the food industry as both starter and probiotic cultures. The importance of Pediococcus spp. is due to their use as starter cultures in fermented meat as well as to their presence as the natural microbiota in vegetables. The availability of P. pentosaceus in the food industry increases the need for reliable molecular techniques for strain identification. To date, the reliable molecular methods for definite identification at strain level of microorganisms used in food industry has not been developed. Molecular identification based on suitable marker genes could be a promising alternative to conventional molecular typing methods such as ribotyping. In this study, the applicability of seven housekeeping genes gyrB, pyc, pgm, leuS, glnA, and dalR in combination with the pgi gene in multilocus sequence typing of P. pentosaceus was assessed. Sequencing and comparative analysis of sequence data were performed on 6 strains isolated from various vegetables. In addition to 17 sequence types, two new sequence types were identified and these fortified sequence types and seven marker genes allowed for a clear differentiation of the strains analyzed, indicating their applicability in molecular typing.
γ-Aminobutyric acid (GABA)-containing salt was prepared by crystallization of a mixture of salt water from deep sea and fermentation broth by lactic acid bacteria that contained GABA converted from glutamic acid. Salt from deep sea water has a lower sodium content but higher calcium, potassium and magnesium contents than commercial salt. Instead of monosodium glutamate (MSG), glutamic acid was used for solving the residual MSG problem. Fermentation by a lactic acid bacterium converted 90% of added glutamic acid (5%, w/v) to GABA, and continuous production of colorless fermentation broth containing more than 3% (w/v) GABA was achieved by using an activated carbon. Mixtures of salt water and fermentation broths with various GABA concentrations were co-crystallized and the GABA content was analyzed. This analysis showed that more than 90% of GABA from broth was adsorbed to salt. The appearance and surface of this prepared GABA-containing salt were examined with an image analyzer and scanning electron microscope. No difference was found with commercial sun-dried salt and no separated particles were detected, which indicates that the co-crystallization process used is suitable for the production of GABAcontaining salt.
An alkalophilic microorganism, strain DK1122 producing an alkaline protease was identified. DK1122 was isolated from soil collected in central Korea. The strain DK1122 was Gram-positive, 0.7×2-4 μm in size, and its colony was yellowish white, The strain DK1122 was found to be spore-forming, catalase positive, oxidase positive, caseinolytic, and reduce nitrate to nitrite. The protease was produced aerobically on Horikoshi I agar medium (pH 9.0) with 1% (w/v) skim milk at 40°C for 24 h. Through 16S rRNA gene partial sequencing, the strain DK1122 had the 99.7% sequence similarity to 16S rRNA gene sequence of Bacillus pseudofirmus. Based on the biochemical and physiological properties as well as phylogenetic analysis, the isolated strain was named as Bacillus sp. DK1122. It is expected that Bacillus sp. DK1122 may be a promising candidate for a proudcer of an alkaline protease applicable to the food and detergent industries.