• Journal of Microbiology and Biotechnology
• /
• v.21 no.7
• /
• pp.703-710
• /
• 2011

Enzymatic saccharification of corn stover using Phanerochaete chrysosporium and Gloeophyllum trabeum and subsequent fermentation of the saccharification products to ethanol by Saccharomyces cerevisiae and Escherichia coli K011 were achieved. Prior to simultaneous saccharification and fermentation (SSF) for ethanol production, solid-state fermentation was performed for four days on ground corn stover using either P. chrysosporium or G. trabeum to induce in situ cellulase production. During SSF with S. cerevisiae or E. coli, ethanol production was the highest on day 4 for all samples. For corn stover treated with P. chrysosporium, the conversion to ethanol was 2.29 g/100 g corn stover with S. cerevisiae as the fermenting organism, whereas for the sample inoculated with E. coli K011, the ethanol production was 4.14 g/100 g corn stover. Corn stover treated with G. trabeum showed a conversion 1.90 and 4.79 g/100 g corn stover with S. cerevisiae and E. coli K011 as the fermenting organisms, respectively. Other fermentation co-products, such as acetic acid and lactic acid, were also monitored. Acetic acid production ranged between 0.45 and 0.78 g/100 g corn stover, while no lactic acid production was detected throughout the 5 days of SSF. The results of our experiment suggest that it is possible to perform SSF of corn stover using P. chrysosporium, G. trabeum, S. cerevisiae and E. coli K011 for the production of fuel ethanol.

• Journal of the Korean Magnetic Resonance Society
• /
• v.16 no.2
• /
• pp.91-102
• /
• 2012

Metabolomics is the systematic identification and quantification of all metabolites in an organism or biological sample. NMR has been used as a major application tool in plant metabolomics such as quality control, chemotaxonomy, and analysis of genetically modified plants. Herbal medicines are the important therapeutics and are used to manage common diseases such as cold, inflammation, pain, heart diseases, liver cirrhosis, diabetes and central nerve system diseases. Herb plants include various kinds of species such as geranium, mint, and thyme and so on and contain different kinds of metabolites. We performed NMR-based metabolomics study on the seven different species of herb plants using $^1H$ NMR experiments and OPLS-DA to understand the correlation between the classification of herb plants and their metabolite contents. This study showed clear metabolic discrimination among various herb plants. This metabolmics study found several diagnostic NMR signals which are able to be used as bio-markers for identification of the specific herb plants among various species. Clear metabolic discrimination of herb plants suggests three chemotaxonomic groups of herb species.

• The Korean Journal of Malacology
• /
• v.27 no.2
• /
• pp.143-148
• /
• 2011

Even though ark shell, Scapharca broughtonii is commercially important species, its artificial seed production is not yet fully developed. This study was carried out to understand the effect of three microalgal species on gonadal development and sex maturation of S. broughtonii in terms of broodstock management and food organism. Isochrysis galbana, Phaeodactylum tricornutum and Tetraselmis tetrathele were supplied to S. broughtonii broodstock in single or mixed. And condition index, gonadal development, sexual maturation and survival of the broodstock were analysed. After 45 rearing days, frequency of ripe stage of gonadal phases, rate of induced sexual maturation and survival of S. broughtonii broodstock fed mixed diet with 3 microalgal species or single diet of T. tetrathele were the highest.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.4
• /
• pp.388-396
• /
• 2021

Antimicrobial resistance patterns of Escherichia coli were investigated. Strains were isolated from 310 shellfish, 36 crustaceans, and 12 fish collected off the West Coast of Korea from April 2019 to October 2020. Two hundred and ninety-five E. coli strains were isolated from shellfish, 100 from crustaceans, and 54 from fish. Strains isolated from shellfish showed the highest resistance to ampicillin (27.5%), whereas those from crustaceans were resistant to sulfisoxazole (30.0%) and those from fish were resistant to ampicillin (59.3%) and sulfisoxazole (59.3%). Ceftazidime resistance was observed in strains isolated from short neck and hard clams, whereas gentamicin resistance was observed in strains from fish. Multi-drug resistance was observed in 56 strains (48.7%) isolated from shellfish, 11 (28.2%) from crustaceans and 27 (73.0%) from fish. Depending on the source of isolation, the strains showed specific antimicrobial resistance tendency. Strains isolated from shellfish showed 12 different multi-drug resistance patterns, whereas those from crustaceans showed high resistance (59%) to a single antimicrobial agent and those from fish showed a broad trend of multi-drug resistance to more than eight antimicrobials.

• Korean Journal of Agricultural Science
• /
• v.46 no.1
• /
• pp.85-92
• /
• 2019

This study was intended to provide basic data for a health functional food study by exploring antioxidant activity of reflux extract according to the concentration of ethanol and the extract of ultrasonic waves extracted and reflux extracted under the same solvent conditions. In the same solvent condition, the reflux extract ($75.10{\pm}1.99mg$) showed a higher total phenol content than the ultrasonic wave extract ($51.74{\pm}2.28mg$). Flavonoids also had a higher reflux extract ($25.05{\pm}1.53mg$) than did ultrasonic extracts ($16.23{\pm}1.95mg$). Reflux extract according to ethanol concentration was found to have a higher phenol content than the 70% ethanol extract ($40.60{\pm}1.49mg$) in 60% ethanol extract. Flavonoid content was also similar to phenol content in reflux extract as determined by ethanol concentration from 60% ethanol ($25.05{\pm}1.53mg$) to 70% ethanol extract ($6.60{\pm}0.46mg$). In addition, the antioxidant activity (DPPH, TEAC, FRAP, ORAC) of the reflux extract in the same solvent conditions tended to be higher than that of ultrasonic extracts. Also, 60% ethanol extract had better antioxidant activity than 70% ethanol extract. However, an analysis of phenolic acid content through HPLC showed that the ultrasonic extract had a higher content in the same solvent condition than did the reflux extract. Not only the presence of phenolic acid, but also those of other compounds are believed to be attributed to the activity of antioxidants. Therefore, further studies are needed to clarify this phenomenon.

• Journal of Distribution Science
• /
• v.22 no.3
• /
• pp.33-47
• /
• 2024

Purpose: Most emerging-market countries are concerned about the technology boom, which is accompanied by an increase in revenue from online sales and services. This finding has been demonstrated during the COVID-19 pandemic; however, is this tendency continuing in the new normal, and what factors are driving the increase in consumer decisions? The purpose of this research is to investigate how the decision to utilize online services will be affected in the new normal as well as propose a new research approach in this field. Research Design, Methodology and Approach: By following a deductive research method associated with positivist philosophy, a survey in South Vietnam with 426 respondents using a convenience sampling method was conducted. The reliability of the measurement scales was examined by using the SPSS program. The SmartPLS programme was utilised to assess the measurement and structural models as well as test hypotheses by using partial least squares structural equation modelling. Results: According to the research findings, decision-making has been impacted by social influences, perceived usefulness, perceived ease of use, perceived trust, perceived price, and perceived convenience. Conclusions: The research results also bring significant contributions not only in practice in providing management implications but also in theory. The research model has also demonstrated the feasibility of employing the stimuli-organism-response framework and combining the theory of perceived risk with the technology acceptance model via the explanation of decision-making.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.4
• /
• pp.550-555
• /
• 1997

Vibrio cholerae non-O1 (V. cholerae non-O1) was previously called nonagglutinable or noncholera vibrios, since it fails to react with polyvalent O1 antisera. This organism is biochemically and genetically indistinguishable from V. cholerae O1 except serological difference. V. cholerae non-O1 strains are often detected in the environment including bays, estuaries, and fresh water, and also found in food. Therefore it is designated food borne bacterium in Japan. However, research papers on V. cholerae non-O1 are very rare in Korea. In order to investigate bacteriological characteristics of V. cholerae non-O1, we isolated V. cholerae non-O1 from the environmental sea water. Among the isolated V. cholerae non-O1 strains, we selected the strain which had the most strong hemolytic activity, named as V. cholerae non-O1 FM-3. The optimum growth conditions of V. cholerae non-O1 FM-3 were $37^{\circ}C$ and pH 8.5 in BHI broth (containing $0.5\%$ sodium chloride), and it grew better than V. cholerae non-O1 ATCC 25872. But both were not able to grow in BHI broth added $5.0\%$ of sodium chloride or adjusted to pH 5.0. According to the experimental results on the susceptibility test against various antibiotics, there were no significant differences between the isolated strain and reference strain (V. cholerae non-O1 ATCC 25872). Most of the antibiotics examined had bacteriostatic action against V. cholerae non-O1 FM-3 while vancomycin, oxacillin, colistin, polymyxin B, and sulfadiazine had no bacteriostatic activity.

• Food Science and Preservation
• /
• v.19 no.2
• /
• pp.167-172
• /
• 2012

The antimicrobial activities of $Smilax$ $china$ L. against spoilage bacteria isolated from $Mang-gae$ rice cake were investigated and the storage stability of the $Mang-gae$ rice cake was enhanced. Spoilage bacteria, which cause $Mang-gae$ rice cake to rot, were isolated from commercial $Mang-gae$ rice cake, and most of the isolated strains were identified as $Bacillus$ sp. After the leaves, roots, shoots, and stalks of the $Smilax$ $china$ L. were extracted using 50% ethanol as the solvent, their antimicrobial activities were investigated using the paper disc method by treating them with 50 ${\mu}L$ of $Bacillus$ $cereus$, which is known as a major pathogenic micro-organism in foods that contain starch, as the test organism. The antimicrobial activities of the extracts were compared according to the size of the clear zones around the paper discs. The root extract showed significant antimicrobial activities. When red beans, which are used as stuffing for $Mang-gae$ rice cake, were treated with the root extract of the $Smilax$ $china$ L., the viable cell count of the $Mang-gae$ rice cake was 5.04 Log CFU/g after 48-hr storage, and the cake showed significantly slower growth of bacteria than with commercial products. These results show that treatment of red beans with $Smilax$ $china$ root extract could improve the storage stability of $Mang-gae$ rice cake.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.3
• /
• pp.316-322
• /
• 2011

BACKGROUND: Pesticides concentration was monitored in 50 agricultural lakes, and ecological risk for aquatic organism was assessed using risk quotient (RQ) and probabilistic methods. METHODS AND RESULTS: Pesticides concentrations detected in 50 agricultural lakes during peak season (June and September) were in the range of $0.17{\sim}0.99{\mu}g/L$. The RQ for algae and the other species was estimated to be 0.25 and below 0.01, indicating medium risk and no risk. Oxadiazon predominantly contributed to RQ value of 99% for algae, fishes, and amphibians. In terms of hazardous concentration at 5% of species ($HC_5$), ecological risk quotients (ERQ) for oxadiazon ranged from 0.18~0.33, showing a medium risk level. Overall, the concentrations of pesticides were much lower than $HC_5$), value. Probability of combined ecological risk for pesticides ranged from 1.82% to 2.41%. CONCLUSION(s): Combined ecological risk probability did not exceed the acceptable level of 5%, indicating no ecological risk for selected aquatic species. This study suggests that regular ecological risk assessment (ERA) will be required to protect and manage an agricultural lake. Not only ERA at screening level by comparing exposure with toxic effects for aquatic species also advanced ERA technique considering species in indigenous to Korea, chronic toxicity, pulse dose, fate, and environmental factors should be required.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.3
• /
• pp.227-231
• /
• 2004

A total of 219 polymerase chain reaction tests of genetically modified (GM) DNA sequences in soybean seeds and soybean sprouts were conducted during 2000-2001. No CM gene was found in 96 tests of soybean seeds. However, either a functional CP4EPSPS gene or the 355 promoter gene was found three times in 2000 and eight times in 2001, in between 0.01 and 0.17％ of soybean spout products, in 123 tests. Since the amount of GM genes was much less than the threshold limit of 3％, none of the 11 positive soybean-sprout samples needed to be libeled GM crops. Of these, seven sprout samples were from domestic seeds and four were from seeds imported from China. To find the contamination route, the raw materials, seed surface, floor of the storage room, area around the selection machine, surface of the packaging film and corn powder used in the package were tested. The 35S promoter gene was detected in only two samples of the corn powder (0.1％). Although we could not find the cause of the GM contamination, the sprout package film is one possibility. In total,8.9％ of the soybean sprout tests were GM positive, but the amounts were much less than the threshold of 3％. This means that there are frequent false-positives and these would threaten the sprout industry if GMO were decided qualitatively. Food companies should make their safety data available to the public and make an effort to address people's concerns about GM food more openly. In addition, there is a need to establish a quantitative test for GM genes in sampled water and a sampling method for raw materials.