• Journal of Applied Biological Chemistry
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• v.55 no.1
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• pp.47-53
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• 2012

Increasing concerns over green farming technology, plant growth promoting rhizobacterium (PGRP) having growth promoting as well as plant disease suppressing properties was recently preferred to use for biological control of plant pathogens infecting plant. We measured the influence of the selected microbial consortium agents-a mixture of PGPR strains-, commercial bio-fungicide, and chemical pesticides on soil microbial community in red pepper field. The activities of soil enzyme such as dehydrogenase, urease, phosphatase, ${\beta}$-glucosidase, and cellulase were analyzed to investigate that of soil microbial community. We also measured plant length, main stem, stem diameter, number of branches and yields of red-pepper in order to observe the red pepper growth promotion. The results of measuring enzyme activities were dehydrogenase 3.5584 ${\mu}g$ TPF $g^{-1}h^{-1}$, urease 15.8689 ${\mu}g$ $NH_4{^-}N$ $g^{-1}h^{-1}$, phosphatase 0.5692 ${\mu}g$ PNP $g^{-1}h^{-1}$, ${\beta}$-glucosidase 2.4785 ${\mu}g$ PNP $g^{-1}h^{-1}$, and cellulase 86.1597 ${\mu}g$ glucose $g^{-1}h^{-1}$ in the soil treated with the microbial consortium agents, so it came out to be very active in the soil. Observing the growth of red-peppers, the main-stem length and the stem diameter were 6.1% and 8.1% higher in the soil treated with the selected microbial consortium agent than the chemical pesticides. After harvesting, yields were 7.3% higher in the soil treated with selected microbial consortium agents than the chemical pesticides. These results showed that microbial consortium agents contribute to increasing soil microbial diversity, growth promoting, and yield of red pepper.

• The Korean Journal of Mycology
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• v.24 no.1 s.76
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• pp.38-48
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• 1996

The survival or colonization of beneficial organsisms and suppression of root rot of ginseng (Panax ginseng) by two distinct bacteria, Pseudomonas cepacia, Bacillus cereus and three mycorrhiza in pot soil were investigated and compared with uninoculated root. In separate inoculation, colonization of roots by P. cepacia was maintained at 6.25 (log cfu/g root) during growth for 10 days under pot culture conditions comparing to $5.62{\sim}6.19$ by mixed treatment with other organisms. Colonizations of P. cepacia were gradually decreased from 6.25 (log cfu/g root) in 10 days growth to 3.01 (log cfu/g root) in 270 days incubation period. This reduction was also investgated in combination treatments by B. cereus or F. solani. The numbers of Fusarium spp. were colonized high number in rhizosphere soil from 3.33 to 3.67 (log cfu/g root) in control within $10{\sim}60$days after treatment of pathogen F. solani, but it's numbers were markedly decreased in 270 days cultivation of plant from 3.33 to 1.02 (log cfu/g root) after treatment. In treatment of beneficial strains of P. cepacia and B. cereus, P. cepacia significantly suppressed the development of root rot from 4.3 in control to 1.2 in treatment, whereas B. cereus alone had no effect on the rate of disease suppression. The disease index $(1.8{\sim}2.3)$ in combination of two bacteria was reduced in plants inoculated with both P. cepacia and B. cereus comparing to the index (4.3) of control. As an effect of inoculation with mycorrhiza on disease suppression, suppression of root rot by F. solani was reduced to $1.2{\sim}1.6$ in disease index in treatment of Glomus albidum and Acaulospora longular comparing to 4.3 of control. In the treatment of bacterial strain P. cepacia and mycorrhizal fungus Glomus albidum, the disease suppression was apparent to 1.2 and 1.2 comparing to 4.3 of control in disease index respectively.

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.217-227
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• 2023

The consumption of ready-to-eat side dishes is rapidly growing in South Korea. These foods are particularly vulnerable to microbiological contamination as they are often cooked without any treatment, such as heating or stored at room temperature after cooking. Hence, in 2022, we analyzed the ready-to-eat side dishes sold in Gyeongsangnam-do, South Korea for microbiological contamination. We collected 100 samples from supermarkets in 7 cities, and then examined them for presence of food-borne pathogens and sanitary indicator bacteria. In the analysis of the food-borne pathogens, Bacillus cereus and Clostridium perfringens were isolated from 51 samples (51.0%) and 3 samples (3.0%), respectively. However, both quantitatively met the Korean Food Standards Codex. Genes of five different enterotoxins and one emetic toxin were analyzed from the 51 isolated B. cereus strains. We detected enterotoxin entFM (100.0%), nheA (94.1%), hblC (58.8%), cytK (56.9%), and bceT (41.2%) in 51 isolates, and emetic toxin gene, CER, in only one (2.0%) isolate. We did not detect C. perfringens toxin gene (cpe) that causes food poisoning in any one of the three C. perfringens isolates. In the case of sanitary indicator bacteria, Kimchi had the highest levels of total aerobic bacteria and coliforms, followed by Saengchae, Jeotgal, Jeolim, Namul, and Jorim, respectively. We counted total aerobic bacteria at two different storage temperatures (4℃ and 20℃) to determine the effect of storage temperature. When stored at 20℃, total aerobic bacteria count increased in most of the ready-to-eat side dishes, except for Jeotgal. This result conclusively shows the need for refrigerating the ready-to-eat side dishes after purchase. Further research is needed to assess the risk and safety of the ready-to-eat side dishes available in the market and determine appropriate safety management practices.

• Journal of Life Science
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• v.34 no.7
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• pp.500-508
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• 2024

Recently, there has been increasing interest in enhancing the indoor air quality, particularly in response to the growing utilization of public facilities. The focus of this study was on assessing the efficacy and safety of an air sterilizer equipped with electrolytic salt catalysts. To that end, we evaluated the antimicrobial activity of the vapor spraying from the air sterilizer and its cytotoxicity in condensed form on human cell lines (HaCaT, BEAS-2B, and THP-1). Against the test organisms, which comprised five bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium) and one fungal strain (Candida albicans), the air sterilizer exhibited relatively high antimicrobial activities ranging from 10.89 to 73.98% following 1 and 3 hr of vapor spraying, which were notably time-dependent. Importantly, cytotoxicity assessments on human cells indicated no significant harmful effect even at a 1.0% concentration. Comprehensive safety evaluations included morphological observations, gene expression (Bcl-2, Bax) tests, and FACS analysis of intracellular ROS levels. Consistent with previous cytotoxicity findings, these estimates demonstrated no significant changes, highlighting the air sterilizer's safety and antimicrobial activities. In a simulated 20-hr operation within an indoor environment, the air sterilizer not only showed an 89.4% removal of total bacteria but also a 100.0% removal of Escherichia sp. and fungi. This research outlines the potential of the developed electrolytic salt catalyst air sterilizer to effectively remove indoor microbial pollutants without compromising human safety, underscoring the solution that it offers for improving indoor air quality.

• Journal of Life Science
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• v.34 no.7
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• pp.485-492
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• 2024

Sea cucumbers contain more than 50% protein in their solid content, and they also possess various bioactive substances such as saponins and mucopolysaccharides. This study analyzed the activities of various enzymes derived from Bacillus and lactic acid bacteria and determined to degrade the components of sea cucumbers. Among the analyzed strains, B. subtilis K26 showed the highest activities in protease and xylanase and relatively high activity in cellulase. Accordingly, samples of sea cucumber and water were mixed in equal proportions, sterilized, and then fermented by inoculating them with B. subtilis K26. Following this, a higher amino acid content was observed between 1.5 and 7.5 hr, a lower residual solid content in this time, and a lesser fermentation odor. The saponin content in fermented sea cucumber powder extracted with butanol was measured to be 1.12 mg/g. The chondroitin sulfate content was evaluated to be 5.11 mg/g in raw sea cucumber. The total polyphenol content, flavonoid content, and antioxidant activities were 6.95 mg gallic acid equivalent/g, 3.69 mg quercetin equivalent/g, and 3.69 mg quercetin equivalent/g in raw sea cucumber, respectively. Moreover, the DNA damage protective effect of fermented sea cucumber extract was found to be concentration-dependent, with a very strong effect at very low concentrations. Overall, we suggest that sea cucumber fermented with B. subtilis K26 has a high potential as a food for inhibiting oxidation, enhancing immunity, and improving muscle function in the human body thanks to its high free amino acid content.

• Food Science and Preservation
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• v.30 no.6
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• pp.1056-1071
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• 2023

This study aimed to investigate the quality and microbial population changes for 90 days under two fermentation conditions, outdoors and indoors (35℃), with starters (single or mixed) in soybean paste. Bacillus velezensis NY12-2 (S1), Debaryomyces hansenii D5-P5 (S2), Enterococcus faecium N78-11 (S3), and their mixtures (M) were used for the makjang fermentation. The content of amino-type nitrogen among the makjang samples was highly shown in the indoors, followed by M, S3, and S2. The glutamic and aspartic acid contents in the M sample fermented in the indoors showed the highest values of 867.42±77.27 and 243.20±15.79 mg/g, respectively. By the electronic tongue analysis, the M sample fermented in the indoors exhibited lower saltiness and higher umami than the others. Consequently, we expect that using mixed strains, such as Bacillus, Debaryomyces, and Enterococcus, under constant conditions showed potential to the quality improvement of soy products.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.53-59
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• 1990

The antagonistic fluorescent pseudomonas, which was isolated from continuous cropping rhizosphere of pepper and cucumber, was identified as Pseudomonas fluorescens (P.f.). For further study, transformant was derived from the isolated P.f. after spontaneous mutation to give antibiotic resistance to nalidixic acid and rifampicin as marked strain. Both P.f. and transformant strains were used for this study and the results obtained were summarized as follows. 1. One of the most effective antagonistic strain, KR164, was selected against F. solani, F. oxysporum, R. solani and this strain was identified and classified as Pseudomonas fluorescens biotype IV. 2. Transformant, KR1641, was derived from strain KR164 and both strains had the same biological and biochemical characteristics. 3, Mycelial lysis and abnormal mycelia of plant pathogenic fungi were microscopically observed after simultaneous culture of fungus and given bacterial strain. 4. The length of chinese cabbage to the autolyzed became longer with given bacterial strain in dark culture. 5. Percentage of germination, number of leaves, length of height, and length of root in chinese cabbage in pot experiment were improved by inoculation of given bacterial strain. 6. The number of given bacterial strain kept generally stable until 34 days after inoculation of itself in pot experiment. Inoculation of given bacterial strain did affect the number of plant disease fungi to be decreased but did not affect the number of other bacteria, Bacillus, in pot experiment.

• Journal of Food Hygiene and Safety
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• v.19 no.2
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• pp.60-65
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• 2004

120 samples of ready-to-eat salad product were purchased at department stores, marts and family restaurants in metro area. Coliform bacteria and food borne pathogenic bacteria were isolated from these samples. In 73 samples among the 120 salad product samples, coliform bacteria and food borne pathogenic bacteria were detected by 60.8％ of isolated rate. Salad were classified into organic and non-organic salad. According to a salad type, salad were classified into vegetable salad and mixed vegetable salad with fried chicken and extra food. According to a packing type, packed salad product and salad-bar product were classified. After the classification, the results of each cases were compared. There is no statistical relation between cultivation or packing methods and contaminated bacteria. But the incidence number of microbial strains was significantly different between vegetable salad and mixed vegetable salad(p＜0.005). In vegetable salad, more various strains were detected. E. coli was isolated in 10 cases among the 90 cases in non-organic vegetable and in 7 cases among the 30 cases in organic salad. Food borne pathogenic bacteria were isolated in non-organic vegetable salad product. Staphylococcus aureus was isolated in 4 cases of vegetable salad product and Salmonella spp. isolated in 1 case. After 5 times examination of each 4 market products, the total number of aerobic bacteria was average 4.8$\pm$0.19 log cfu/g. One sample from this product, saline and a detergent for vegetable were used for 3 minutes to notice the effect. As a result, when saline was used 5 times and detergent for vegetable was used 1 time, bacterial contamination was decreased up to 95.5％.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.320-326
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• 2012

This study was conducted to investigate the antibacterial and antioxidative activities of water and ethanol extracts from a mixture of roasted coffee and red ginseng. The antibacterial effects of each extract were determined by the classical paper disc method. A water extract of mixture samples inhibited growth of all strains, but antibacterial effects were mostly weakened. Ethanol extracts showed stronger antibacterial effects than water extracts in all strains except Gram negative Escherichia coli and the fungi strain Candida albicans. Also, the antibacterial effect of the Bacillus cereus strain appeared in all samples, and the ES2 sample formed a clear zone of 19 and 20 mm against Pseudomonas aeruginosa and S. Typhimurium respectively (MIC=0.25 and 0.125 mg/mL). Determinations of free radical elimination for the different mixture extracts using 1,1-diphenyl-2-picrylhydrazyl (DPPH) were compared with ascorbic acid and butylated hyderoxytoluene as positive controls. The water and ethanol extracts of mixture samples (100 ${\mu}g/mL$) showed 55.38~60.01% and 59.37~70.50% DPPH scavenging activities, respectively. DPPH scavenging activities of all mixture samples were slightly higher than roasted coffee and red ginseng samples. However, DPPH scavenging activity decreased when red ginseng extract composed more than 70% of the total extract. The total polyphenol in the mixture samples measured by the Folin-Denis method revealed the highest level of polyphenol content in ethanol extract of sample 3, whereas polyphenol content differed with different mixture ratios, ranging from 105.16~119.79 mg/g in ethanol extract. In the water extract, the polyphenol content was greatest with water extract of sample 1, whereas in other samples the content varied from 93.75~109.18 mg/g.

• Food Science and Preservation
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• v.19 no.6
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• pp.858-865
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• 2012

In this research, the soaking and steaming conditions of Korean wheat meju according to the degree of milling were investigated, and the quality characteristic was analyzed, for the manufacture of the standardized Korean wheat meju. As a result of the changes in weight, volume, moisture content, and moisture absorption amount, which indicate the physical properties of Korean wheat meju using 20% polished wheat, 50% polished wheat, whole wheat, and whole wheat flour, most of the wheat materials reached the equilibrium state after 4 hours of soaking. Also, the appropriate steaming time to complete the cooking of the wheat materials was found to be 10 min at $100^{\circ}C$, except for whole wheat. The 20 and 50% polished wheat materials were selected for Korean wheat meju based on the soaking and steaming results. The selected wheat materials were fermented using Aspergillus oryzae and Bacillus subtilis M1, respectively, and the quality properties and enzyme activities showed that A. oryzae would be effective for the manufacture of Korean wheat meju. Also, the 50% polished wheat showed higher total sugar content, reducing sugar content, and ${\alpha}$-amylase activity than the 20% polished wheat. Therefore, it is supposed that the fermentation of 50% polished wheat by A. oryzae would be appropriate for manufacturing superior Korean wheat meju.