• Journal of Environmental Health Sciences
• /
• v.5 no.1
• /
• pp.46-50
• /
• 1978

Aflatoxin, a mixture of the at least four toxic and carcinogenic metabolites, is known to be produced by only a few fungi. The toxins were designated aflatoxins because they were produced by the mold Aspergillus flavus(A. flavus). However, at least four other toxins and other species of the genus A. niger, A. parasiticus A. ruber and wentii have been reported to produce aflatoxins. And also the identical compounds may also be produced by molds, the Pencillium. At least four different species of Penicilliurn have been reported to produce aflatoxins (P. citrinurn, P. frequentans, P. puberulurn. and P. variable). So it is now known that the problem of Aflatoxin is not restricted to the single species A. flavus, even though that is a very common mold. Also additional aflatoxins have been discorvered. For sereral years, only four aflatoxins were known: $B_1, B_2, G_1$ and $G_2$, so designated by reason of their fluorescence and chromatographic charateristics. It is now known that there are really two new toxic materials in the milk. During the past year(1966) they were christened aflatoxin $M_1$ and $M_2$, since they were first found in milk. The two other and most recently discorvered aflatoxins were isolated late in 1966 from cultures of A. flavus, and were designated aflatoxin $B_2a$ and aflatoxin $G_2a$. In order to obtain a breaf information about extent of contamination of foodstuffs by aflatoxin which is known to produce eight different mold, aflatoxin detection of cereals and fermented foods on sale, such as polished rice, barley, wheat, wheat flour, lentil, red bean, soy bean, noodle, kochuj ang and Dwenjang (fermented soy bean paste) and chong Kuk, were carried out. The results of this investigation were summarized as follows: The hexane:$CHCl_3$ extracts of polished rice, barley wheat, wheat flour, lentil, red bean, noodle and kochujang yielded fluorescent spots on thin layer plates. However their Rfvalues were different from those of authentic aflatoxins. The fluorescent substances of the extract from soy bean, Dwenjang and chong kuk showed very similar Rf values to those of the standard aflatoxins. By two dimensional thin layer chromatography and comparison of ultra violet absorption spectra, it was found that these fluorescent substances were not aflatoxins. To conclude, aflatoxins themselves were not detected directly in those samples tested.

• Nutrition Research and Practice
• /
• v.8 no.4
• /
• pp.360-367
• /
• 2014

BACKGROUND/OBJECTIVES: The aim of this research was to study the different long term effects of consumption of dietary oil sources with varying omega-6/omega-3 (${\omega}-6/{\omega}-3$) polyunsaturated fatty acids (PUFAs) ratios on bone marrow fatty acid level, ex vivo prostaglandin $E_2$ ($PGE_2$) release, and mineral content of bone in rabbits. MATERIALS/METHODS: For this purpose, weaning and female New Zealand white rabbits were purchased and randomly divided into five groups and offered ad libitum diets containing 70 g/kg of added oil for 100 days. The dietary lipid treatments were formulated to provide the following ratios of ${\omega}-6/{\omega}-3$ fatty acids: 8.68 soy bean oil (SBO control), 21.75 sesame oil (SO), 0.39 fish oil (FO), 0.63 algae oil (DHA), and 0.68 algae oils (DHA/ARA). DHA and ARA are two types of marine microalgae of the genus Crypthecodinium cohnii. RESULTS: The dietary treatments had significant effects on the bone marrow fatty acids of rabbits. Rabbits fed the FO diet, containing the highest ${\omega}-3$ PUFA concentration, and those fed the SBO diet showed the highest ${\omega}-6$ PUFA. On the other hand, a positive correlation was observed between Ex vivo $PGE_2$ level and the ${\omega}-6/{\omega}-3$ dietary ratio. Significant effects of dietary treatment on femur Ca, P, Mg, and Zn contents were observed in both genders. CONCLUSIONS: Findings of the current study clearly demonstrated that dietary PUFA, particularly ${\omega}-6/{\omega}-3$ and ARA/EPA ratios are important factors in determining bone marrow fatty acid profile, and this in turn determines the capacity of bone for synthesis of $PGE_2$, thereby reducing bone resorption and improving bone mass during growth.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.1
• /
• pp.42-50
• /
• 2009

Fifty-four Pectobacterium carotovorum subsp. carotovorum strains isolated in Korea were characterized by a spectrum of antibacterial activities against 7 indicator strains chosen to represent various regions and host plants. All P. carotovorum subsp. carotovorum isolates tested could be grouped into 4 classes depending on the pattern of antibacterial substance production. All tested strains had DNA fragment(s) homologous to the genes encoding carotovoricin and 21 of them had genes homologous to DNA invertase. Sixteen strains had genes homologous to the genes encoding carocin S1. Several isolates produced antibacterial substances active against strains in Brenneria, Pantoea, and Pectobacterium genera that belonged formerly to the genus Erwinia. Strains in Pseudomonas or Xanthomonas sp. were not sensitive to the antibacterial substances produced by P. carotovorum subsp. carotovorum, except for X. albilineans that was sensitive to antibacterial substances produced by most strains in P. carotovorum subsp. carotovorum and P. betavasculorum KACC10056. These results demonstrated the diverse patterns of antibacterial substance production and the possibility of the existence of new antibacterial substance(s) produced by P. carotovorum subsp. carotovorum isolated in Korea.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.7
• /
• pp.1168-1177
• /
• 2018

The aim of this study was to investigate the microbial community of three tannery wastewater treatment plants (WWTPs) involved in nitrification by Illumina MiSeq sequencing. The results showed that highly diverse communities were present in tannery wastewater. A total of six phyla, including Proteobacteria (37-41%), Bacteroidetes (6.04-16.80), Planctomycetes (3.65-16.55), Chloroflexi (2.51-11.48), Actinobacteria (1.91-9.21), and Acidobacteria (3.04-6.20), were identified as the main phyla, and Proteobacteria dominated in all the samples. Within Proteobacteria, Beta-proteobacteria was the most abundant class, with the sequence percentages ranging from 9.66% to 17.44%. Analysis of the community at the genus level suggested that Thauera, Gp4, Ignavibacterium, Phycisphaera, and Arenimonas were the core genera shared by at least two tannery WWTPs. A detailed analysis of the abundance of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) indicated that Nitrosospira, Nitrosomonas, and Nitrospira were the main AOB and NOB in tannery wastewater, respectively, which exhibited relatively high abundance in all samples. In addition, real-time quantitative PCR was conducted to validate the results by quantifying the abundance of the AOB and total bacteria, and similar results were obtained. Overall, the results presented in this study may provide new insights into our understanding of key microorganisms and the entire community of tannery wastewater and contribute to improving the nitrogen removal efficiency.

• Journal of Korean society of Dental Hygiene
• /
• v.18 no.5
• /
• pp.843-852
• /
• 2018

Objectives: The study aimed to isolate the abundant bacteria in dental caries in children and to investigate the bacterial species involved in addition to those that have been previously reported. Methods: The specimens were collected from the supragingival plaques of each dental caries area, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, and from healthy subjects in the control group. Bacteria were cultured from these specimens, DNA was extracted from the isolated bacteria, and the 16S rRNA gene sequences were analyzed and identified. Results: Based on the results of the 16S rRNA gene sequence analysis for the 90 strains of dominant bacteria from the 45 specimens, 5, 7, 8, 7, and 13 species were identified from the supragingival plaques from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, respectively. In healthy teeth, Actinomyces naeslundii dominated. Corynebacterium durum, Ralstonia pickettii, and Streptococcus intermedius showed equal distribution. The dominant bacterial species in dental caries, S. sanguinis, showed the greatest difference in prevalence in pit and fissure caries. In deep dentinal caries, S. mutans and Lactobacillus rhamnosus were dominant; in smooth surface caries, S. mutans and S. sanguinis were dominant; and in the supragingival plaques of dental caries, S. sanguinis and S. mutans were dominant. Conclusions: The bacterial species isolated from dental caries encompassed four phyla, eight genera, and 22 species. In addition, the SS1-2 strain, belonging to the genus Neisseria, was identified as a new species from among the isolated strains.

• Journal of Life Science
• /
• v.19 no.1
• /
• pp.138-146
• /
• 2009

Garlic (Allium sativum) are an agronomically important genus because of their sulfur flavour components. The majority of the volatiles flavour principles are generated through the enzymatic hydrolysis of the non-volatile organosulfur compounds. However, these compounds may be possible sources of new novel bioacuve and therapeutic principles. Garlic has strong antioxidant activity, and epidemiological studies support the fad that diets rich of garlic may prevent some of the chronic diseases. The health cares of garlic likely arise from a wide variety of components, which may work synergistically. The chemical changes of garlic composition makes it plausible that a variation in processing can lead to acquisition of differential chemical compositions of garlic products. Especially highly unstable allicin can easily disappear during processing and are quickly transformed into a various organosulfur compounds. Various supplements of garlic, particularly aged garlic extract (AGE), are known to possess a promising antioxidant potential and are effective in prevention of chronic diseases because of the bioactive constituents. Although all of active ingredients of AGE are not elucidated, water-soluble components of AGE, including S-allylcysteine, S-allylmercaptane, steroid saponins, tetrahydro-${\beta}$-carboline derivatives, and fructosyl-arginine, appears to be associated with the pharmacological effects of AGE. Consequently, the allicin free garlic components such as S-allylcysteine, S-allylmercaptane, steroid saponins, tetrahydro-${\beta}$-carboline derivatives, and fructosyl-arginine can be applicable to standardization of the quality of commercial garlic products. This review provides an insight into garlic's biomarkers and presents evidence that they may either prevent or delay chronic disease associated with aging.

• Korean Journal Plant Pathology
• /
• v.14 no.5
• /
• pp.402-407
• /
• 1998

Phytophthora rot on jujube fruit has occurred at several cultivation areas in Kyung-buk and Kyung-nam provinces. Symptoms consisted of brownish to reddish rot on fruits resulting in early drop or mummification. The causal fungus isolated from infected fruits and adjacent leaf stalks was identified as Phytophthora citricola, which has never been reported in Korea. Sporangia were semi-papillate, noncaducous and highly variable in shapes. Plerotic oospores with paragynous antheridia were abundant is single cultures. Sporangia of two isolates were measured as 38-76$\times$20-40 ${\mu}{\textrm}{m}$ and averaged 51.4$\times$27.0 and 55.6$\times$36.0 ${\mu}{\textrm}{m}$. Oogonia were ranged from 26 to 36 ${\mu}{\textrm}{m}$ and averaged 31.3 and 32.0 ${\mu}{\textrm}{m}$. Colony pattern was slightly radiated with sparse aerial mycelia on common media. Minium, optimum and maximum temperatures for mycelial growth were recorded at 7, 25, and 32$^{\circ}C$, respectively. Among tested media, 10% V8A was the best and $25^{\circ}C$ was better than 15$^{\circ}C$ for oospore formation of the fungus. The jujube isolates of P. citricola were readily differentiated from other closely related species in the genus, namely; P. nicotianae, P. citrophthora, P. cactorum, P. capsici, and P. plalmivora on the basis of PCR-RFLP of r-DNA. The fungus showed strong pathogenicty to jujube, apple, pear, orange, persimmon and eggplant, and relatively weak to citron, tomato, pepper and cucumber. In this study, P. citrocola is firstly identified and jujube fruit rot caused by the fungus is recorded as a new disease in Korea.

• Natural Product Sciences
• /
• v.22 no.3
• /
• pp.154-161
• /
• 2016

Phytochemical investigation on the leaves of Pileostegia viburnoides Hook.f.et Thoms led to the isolation of twenty-five compounds, and their structures were identified as n-dotriacontane (1), taraxeryl acetate (2), friedelin (3), epifriedelinol (4), canophyllal (5), stigmast-4-en-3-one (6), stigmasterol (7), (24R)-5A-stigmastane-3,6-dione (8), ursolic acid (9), pomolic acid (10), umbelliferone (11), 4-epifriedelin (12), n-octatriacontanol (13), ${\beta}$-amyrin (14), ${\alpha}$-amyrin (15), taraxerol (16), nonadecanol (17), friedelane (18), arachic acid (19), protocatechuic acid (20), n-pentatriacontanol (21), hexadecanoic acid (22), vincosamide (23), daucosterol (24), and skimming (25), respectively. To our best knowledge, compounds 1, 2, 12, 13, 17 - 19 and 21-23 were new within Saxifragaceae family. Compounds 15, 16, and 20 were produced from this genus for the first time. Compounds 4, 14 and 25 were first obtained from species P. viburnoides and compounds 3, 5 - 11, and 24 were achieved from the leaves of P. viburnoides for the first time. Furthermore, the anti-neuroinflammatory activity of these isolates was evaluated.

• The Plant Pathology Journal
• /
• v.28 no.2
• /
• pp.123-136
• /
• 2012

Diseases caused by begomoviruses (family Geminiviridae, genus Begomovirus) constitute a serious constraint to tropical and sub-tropical agro-ecosystems worldwide. In recent years, they have also introduced in temperate regions of the world where they have great impact and are posing a serious threat to a variety of greenhouse crops. Begomoviral diseases can in extreme cases reduce yields to zero leading to catastrophic losses in agriculture. They are still evolving and pose a serious threat to sustainable agriculture across the world, particularly in tropics and sub-tropics. Till recently, there have been no records on the occurrence of begomoviral disease in South Korea, however, the etiology of other plant viral diseases are known since last century. The first begomovirus infected sample was collected from sweet potato plant in 2003 and since then there has been gradual increase in the begomoviral epidemics specially in tomato and sweet potato crops. So far, 48 begomovirus sequences originating from various plant species have been submitted in public sequence data base from different parts of the country. The rapid emergence of begomoviral epidemics might be with some of the factors like evolution of new variants of the viruses, appearance of efficient vectors, changing cropping systems, introduction of susceptible plant varieties, increase in global trade in agricultural products, intercontinental transportation networks, and changes in global climatic conditions. Another concern might be the emergence of a begomovirus complex and satellite DNA molecules. Thorough understanding of the pathosystems is needed for the designing of effective managements. Efforts should also be made towards the integration of the resistant genes for the development of transgenic plants specially tomato and sweet potato as they have been found to be widely infected in South Korea. There should be efficient surveillance for emergence or incursions of other begomoviruses and biotypes of whitefly. This review discusses the general characteristics of begomoviruses, transmission by their vector B. tabaci with an especial emphasis on the occurrence and distribution of begomoviruses in South Korea, and control measures that must be addressed in order to develop more sustainable management strategies.

• Korean Journal of Microbiology
• /
• v.43 no.3
• /
• pp.222-226
• /
• 2007

Proteases are degradative enzymes which hydrolyze a peptide bond between amino acids and they are abundantly applied to commercial field. In order to screen new source of pretense, bacteria secreting extracellular pretense were isolated by enrichment culture from deep sea water samples of East Sea, Korea. A bacterium, named as HJ19, showed the best growth and the largest clear zone in plates supplemented skim milk at $30^{\circ}C$. The partial DNA sequence analysis of the 16S rRNA gene, phenotypic tests and morphology identified that this strain was In genus Micrococcus. The strain HJ19 could not grow at $10^{\circ}C$ but it started growth and showed pretense activity at $20^{\circ}C$. The optimal growth was at $37^{\circ}C$ and the maximal protease activity at $30^{\circ}C$ was about 480unit/ml.