• 한국환경성돌연변이발암원학회지
• /
• 제22권4호
• /
• pp.319-323
• /
• 2002

In order to investigate the safety of Aralia elata extract causing the reduction in the blood glucose level and oxidative stress in diabetes animals, these genotoxicity studies in bacterial and mammalian cell assay system such as Ames bacterial reverse mutation test and chromosomal aberration assay were performed. As results, in Ames bacterial reversion assay the extract in the range of 5,000-625 ug/plate did not induce mutagenicity in Salmonella typhimurium TA 98, TA 100, TA 1535 and TA 1537 strains with and without metabolic activation of S-9 mixture. For chromosomal aberration assay, $IC_{50}$ (50% inhibition concentration of cell growth) of the extract were determined; 792 $\mu\textrm{g}$/$m\ell$ without and 524 $\mu\textrm{g}$/$m\ell$ with S-9 mixture in Chinese hamster lung (CHL) fibroblast cell culture. Any significant chromosomal aberration was not observed in CHL cells treated with the extract at the concentrations of 792, 396 and 198 $\mu\textrm{g}$/$m\ell$ or 524, 262 and 131 $\mu\textrm{g}$/$m\ell$ in the absence or presence of S-9 metabolic activation, respectively. From these results, Aralia elata extract did not induce any harmful effects on the gene in bacteria and mammalian cell system used in these experiments.

• KSBB Journal
• /
• 제18권2호
• /
• pp.94-99
• /
• 2003

Gluconacetobacter hansenii PJK의 경우 배지 조성 중 탄소원보다는 질소원 및 acetic acid가 BC 생산에 더 많은 영향을 미쳤다. 또한 BC 생산능은 pH 4.1-6.0 범위에서 배지의 초기 pH 영향을 거의 받지 않았으며 BC에 둘러싸인 균주보다 배양 상등액에 존재하는 균주의 BC 생산능이 더 우수하였다. G. hansenii PJK의 BC 생산은 fructose metabolism이 아닌 glucose metabolism으로 이루어지며 배지 성분 중 fructose와 lactate는 Cel$^{-}$ mutant의 발생 및 성장을 촉진시켰으며 TCA cycle에 위치하는 succinate의 첨가는 BC 생산에 거의 영향을 미치지 않았다.

• Journal of Plant Biotechnology
• /
• 제30권3호
• /
• pp.215-219
• /
• 2003

This study was conducted to find optimum bacterial density for improving the efficiency of transformation mediated by Agrobacterium tumefaciens in apples. Regeneration(15％) and transformation frequency(10％) were increased in resuspension-culture density $A_{600}$ 1.3 from preculture density $A_{600}$ 0.7 of Agrobacterium tumefaciens in ′Fuji′. In ′Gala′, 20% regeneration and 16% transformation frequency were observed at optimum bacterial density $A_{600}$ 0.7 form preculture density $A_{600}$ 1.3. ′Mclntosh as well as "Gala" were 25％regeneration and 10％ transformation frequency. Hence a frequency optimum condition of bacterial density for the efficient transformation of apple could be depend on apple genotypes.

• Journal of Species Research
• /
• 제9권4호
• /
• pp.325-338
• /
• 2020

The animal gut is filled with highly diverse microbes associated with host metabolism, physiology, and pathology. However, numerous animal gut microbes have not been cultured or reported. We isolated various bacterial species using culture-dependent approaches during a comprehensive investigation of endangered endemic vertebrate species in the Republic of Korea. A total of 18 unrecorded bacterial species were isolated from the feces of an Oriental stork (Ciconia boyciana), and from the intestinal tracts of a cobitid fish (Kichulchoia multifasciata) and a Korean splendid dace (Coreoleuciscus splendidus). Based on a phylogenetic analysis of 16S rRNA gene sequences, we discovered species belonging to the phyla Actinobacteria (eight species), Firmicutes (seven species), Proteobacteria (two species), and Bacteroidetes (one species). Based on their high 16S rRNA gene sequence similarities (>98.7%) and formation of monophyletic clades with type species, each species was classified into an independent and predefined bacterial species. Gram-stain reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and NIBR IDs for each species are described in the species description section.

• Journal of Applied Biological Chemistry
• /
• 제59권2호
• /
• pp.149-154
• /
• 2016

An endophytic bacterial strain was isolated from kimchi, a Korean traditional fermented Brassica campestris and identified as Bacillus subtilis MJMP2 based on the 16S rRNA sequence. This strain showed strong antagonistic activity against Xanthomonas oryzae pv. oryzae (Xoo) KACC10331, the pathogen of bacterial rice blight disease, as well as activity against some other rice phytopathogenic fungi. The active compound was purified through size-exclusion chromatography and preparative High-performance liquid chromatography. The molecular weight was determined as m/z 1043 by mass spectroscopy, which is identical to that of iturin A. Furthermore, a crude extract from the culture supernatant of Bacillus subtilis MJMP2 showed inhibitory activity against rice blight disease in both a rice leaf explant assay and a pot assay. The crude extract also enhanced the length of roots of Arabidopsis thaliana. These results suggest that the strain Bacillus subtilis MJMP2 could be used as a biological agent to control rice blight disease.

• Environmental Engineering Research
• /
• 제24권3호
• /
• pp.495-500
• /
• 2019

Bioremediation of bacterial algae is one of wastewater treatment by utilizing symbiosis of bacterial algae, which is relatively inexpensive and safe for the environment. The aims of this research were: (1) to investigate initial characteristic of boezem water of Kalidami Surabaya, (2) to investigate the effect of potassium (K) element and carbon source addition toward the reduction of $NH_3-N$ content and organic matter in $KMnO_4$ of boezem water. The research conducted in a laboratory in batches without adding aeration. The initial stage of this research was conducting alga culture until it was obtained chlorophyll-a algae concentration of $3.5{\pm}0.5mg/L$. The best result of range finding test was a comparison of boezem water volume with algal which were about 25%:75%. The research conducted in duplo over 18 d. The result of the research can be concluded that boezem water of Kalidami Surabaya for the parameter of pH, temperature, $NH_3-N$, dissolved oxygen, chemical oxygen demand, biological oxygen demand, and number of $KMnO_4$ show that it enables to do bioremediation of bacterial algae. Decrease efficiency occurred in a reactor with the addition of element K 3% and source C. $NH_3-N$ and $KMnO_4$ final content 0.164 mg/L and 30 mg/L, respectively.

• Journal of Microbiology and Biotechnology
• /
• 제32권5호
• /
• pp.621-629
• /
• 2022

Bacterial outer membrane vesicles (OMVs) typically contain multiple immunogenic molecules that include antigenic proteins, making them good candidates for vaccine development. In animal models, vaccination with OMVs has been shown to confer protective immune responses against many bacterial diseases. It is possible to genetically introduce heterologous protein antigens to the bacterial host that can then be produced and relocated to reside within the OMVs by means of the host secretion mechanisms. Accordingly, in this study we sought to develop a novel platform for recombinant OMV (rOMV) production in the widely used bacterial expression host species, Escherichia coli. Three different lipoprotein signal peptides including their Lol signals and tether sequences-from Neisseria meningitidis fHbp, Leptospira interrogans LipL32, and Campylobactor jejuni JlpA-were combined upstream to the GFPmut2 model protein, resulting in three recombinant plasmids. Pilot expression studies showed that the fusion between fHbp and GFPmut2 was the only promising construct; therefore, we used this construct for large-scale expression. After inducing recombinant protein expression, the nanovesicles were harvested from cell-free culture media by ultrafiltration and ultracentrifugation. Transmission electron microscopy demonstrated that the obtained rOMVs were closed, circular single-membrane particles, 20-200 nm in size. Western blotting confirmed the presence of GFPmut2 in the isolated vesicles. Collectively, although this is a non-optimized, proof-of-concept study, it demonstrates the feasibility of this platform in directing target proteins into the vesicles for OMV-based vaccine development.

• 한국식생활문화학회지
• /
• 제23권5호
• /
• pp.629-638
• /
• 2008

The principal objective of this study was to determine the quality characteristics of seasoned sauce and seasoned pork rib to which pine needle powder was added during storage. The pH value, color value, active bacterial cell count, lipid oxidation, shear force, and sensory evaluation of seasoned sauce and seasoned pork rib to which 0, 1, 2, 3 and 4% pine needle powder was added were measured during storage at $5^{\circ}C$. The storage periods for the seasoned sauce were 0, 1, 3, 5, 7, 14, 21 and 30 days, and the storage periods for the seasoned pork ribs were 0, 1, 3, 5, 7 days. We determined that the pH values of both seasoned sauce and seasoned pork rib decreased with increasing quantities of pine needle powder and longer storage periods. The lightness (L) and yellowness (b) of the seasoned sauce were increased and the redness (a) of that decreased with increasing pine needle powder contents and longer storage periods. The L, a, and b values of the seasoned pork rib decreased with increasing pine needle powder contents, whereas the L and b values of that were decreased and the a value increased with longer storage periods. The active bacterial cell count of the seasoned sauce was detected at between $10^2$ to $10^4$ CFU/mL over a storage period of 30 days, regardless of the addition of pine needle powder; additionally, the addition of 4% pine needle powder resulted in the lowest active bacterial cell count among the samples. The active bacterial cell count in the seasoned pork rib decreased with increasing additions of pine needle powder, and was increased during storage. The influence of pine needle powder contents on the active bacterial cell count of seasoned pork rib were minimal, and the active bacterial cell count of that was suppressed by the addition of only 1% pine needle powder. Lipid oxidation in the seasoned pork rib was suppressed by the addition of more than 2% pine needle powder. We noted no difference in the shear force of the seasoned pork rib to which pine needle powder was added. In our sensory evaluation, the intensity of color (greenish brown), flavor (herbal flavor) and taste (bitter & herbal taste) of the seasoned pork rib increased with increasing pine needle powder contents, whereas the texture of the seasoned pork rib evidenced no differences. The overall acceptability of the seasoned pork rib with 0, 1 and 2% added pine needle powder was higher than that of the seasoned pork rib with 3 and 4% added pine needle powder. Thus, the addition of 2% pine needle powder to seasoned pork rib sauce yielded appropriate results with regard to antibacterial, antioxidative, and sensory properties.

• 미생물학회지
• /
• 제46권1호
• /
• pp.73-79
• /
• 2010

극지연구소(KOPRI)는 국내외적으로 유일하게 남북극 지역에서 분리한 저온적응성 박테리아 균주를 대상으로 culture collection(약 6,300균주)을 구축하여 운영하고 있다. 보유 중인 프로테아제(protease) 생산 균주들(총 874균주) 중에서 활성이 높은 프로테아제를 생산하는 78개의 균주들을 1차 선발한 후, 1% skim milk가 포함된 0.1${\times}$ ZoBell 고체배지에 접종하고 다양한 온도($5-30^{\circ}C$)에서 배양하면서 세포외분비성 프로테아제의 활성을 비교하였다. 위의 신속하고 직접적인 균주 스크리닝 방법을 통해서, 최종적으로 저온활성 프로테아제를 생산하는 15개의 저온적응성 균주들을 선발하였다. 최종 선발된 균주들은 16S rRNA 유전자의 분석결과 Pseudoalteromonas (13균주)와 Flavobacterium (2균주) 속(genus)으로 분류되었고, $5-15^{\circ}C$ 저온에서도 활성을 나타내는 저온성 프로테아제를 생산하였다. 15개 균주들이 생산하는 각각의 프로테아제는 특이적 화합물에 의한 효소활성 억제 정도에 따라 5개의 그룹(serine protease, aspartic protease, cysteine protease, metalloprotease, 그리고 미분류 프로테아제)으로 분류되었다. 본 실험을 통해서 선발한 남북극 유래 박테리아 균주들은 새로운 저온활성 프로테아제를 발굴하기 위한 유용한 생물자원으로서의 가치를 가지고 있다.

• 미생물학회지
• /
• 제15권1호
• /
• pp.20-30
• /
• 1977

Relationship of soil properties and seasonal variation on microbilogical population to-continuous culture and first-time culture of ginseng was investigated by bimonthly from May 1976 to January 1977. pH and P contents of 2 years continuous culture of soil were higher than other culture plot of soil, and contraty to the above, 2 years first-time culture of ginseng soil was conplot of soil, and contraty to the above, 2 years first-time culture of ginseng soil was contained more potassium contents than other culture plot of soil. In microbiological fluctuation with seasonr in various soil conditions, the population, trends of Fusarium spp., Erwiniaspp., and flourescent Psedudomonas spp. were increased in May and July in general, but decreased in the other month. It was observed that in all type of soil, Fusarium spp. was distributed in abundance in and on rihizosphere, and decreased the propagules numbers as soil depth increase. The numbers of Erwinia spp. and fluorescent Pseudo-monas spp. were distributed greater in numbers on the surface zone of soil depth decreasing the numbers along the soil layer increase, and also in 2years continuous culture of soil especially, a great numbers of Erwinia spp. and fluorescent Pseudomonas were evenly distributed in surface zone and rhizosphere. Ginseng disease with a high incidence of bacterial disease in continuous culture of 2 and 4 years was seemed to be associated with soil bacteria that was high in numbers of Erwinia spp. and fluorescent Pseudomonas spp. in May and July.