• Journal of Life Science
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• v.33 no.10
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• pp.842-850
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• 2023

Pyrrolnitrin, pyrrolomycin, and pyoluteorin are functional halogenated phenylpyrrole derivatives (HPDs) derived from microorganisms with diverse antimicrobial activities. Pyrrolnitrin is a secondary metabolite produced from L-tryptophan through four-step reactions in Pseudomonas fluorescens, Burkholderia cepacia, Serratia plymuthica, etc. It is currently used for the treatment of superficial dermatophytic fungal infections, has high antagonistic activities against soil-borne and foliar fungal infections, and has many industrial applications. Since pyrrolnitrin is easily decomposed by light, it is difficult to widely use it outdoors. As an alternative, fludioxonil, a synthetically produced non-systemic surface fungicide that is structurally similar and has excellent light stability, has been commercialized for seed and foliar treatment of plants. However, due to its high toxicity to aquatic organisms and adverse effects in human cell lines, many countries have established maximum residue levels and strictly control its levels. Pyrrolomycin and pyoluteorin, which have antibiotic/antibiofilm activity against Gram-positive bacteria and high anti-oomycete activity against the plant pathogen Pythium ultimum, respectively, were isolated and identified from microorganisms. This review summarizes the biosynthesis and production of natural pyrrolnitrin derived from bacteria and the characteristics of synthetic fludioxonil and other natural phenylpyrrole derivatives among the HPDs. We expect that a plethora of highly effective, novel HPDs that are safe for humans and environments will be developed through the generation of an HPD library by microbial biosynthesis and chemical synthesis.

• The Korean Journal of Food And Nutrition
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• v.30 no.1
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• pp.59-66
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• 2017

This study investigated the quality characteristics and biological activities of rice germ fermented by Bacillus spp. During the milling process, the contents of rice germ in the rice bran (Control) were adjusted to 30% (RG30) and 70% (RG70). The approximate composition, pH, total acidity, total soluble solid, total sugar, polyphenol and flavonoid contents were measured. DPPH radical scavenging activity, xanthine oxidase (XO) and angiotensin converting enzyme (ACE) activities were also determined. We observed that the moisture content decreased after fermentation, while the crude protein was significantly increased. Fermentation remarkably lowered the pH from 5.83~6.26 to 4.77~4.93, thereby elevating the total acidity. Fermentation also increased the total solid contents, from $0.40{\sim}0.87^{\circ}Bx$ to $1.63{\sim}2.20^{\circ}Bx$. The total sugar decreased to 136.81~151.53 mg/mL from 377.56~450.64 mg/mL. Polyphenol contents were the highest in control (0.59 and 0.73 mg/mL before and after fermentation, respectively). Fermentation significantly affected the increase of the polyphenols in both rice germ 30% and 70% samples, from 0.26 and 0.28 mg GAE/g before fermentation, to 0.52 and 0.70 mg GAE/g after fermentation, respectively. There was a slight increase in the flavonoid contents after fermentation. The $IC_{50}$ value of the electron donating ability, as evaluated by the DPPH method, was the lowest in control (3.77 and 3.36 mg/mL before and after fermentation, respectively). Fermentation increased the XO inhibition activity up to 63.69% in control, 49.81% in rice germ 30%, and 59.32% in rice germ 70%. The ACE inhibition activities were also increased in the fermented control, rice germ 30% and 70%, to 40.51%, 22.69% and 33.91%, respectively.

• Journal of Life Science
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• v.27 no.2
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• pp.131-138
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• 2017

In this study, for the efficient use of the byproduct of the omija (Schizandra chinensis Baillon: SC) processing industry, the ethanol extracts of the fruit (F), seed (S), and pomace (P) of SC were prepared, and their useful bioactivities were evaluated. For F-SC, S-SC, and P-SC, the extraction yields were 28.3%, 22.1%, and 7.2%, respectively, and the polyphenol contents were 8.81, 37.22, and 9.20 mg/g, respectively. The total flavonoid content in P-SC (4.31 mg/g) was 3.5-fold higher than that in F-SC (0.76 mg/g). In an antioxidation activity assay, P-SC showed stronger radical scavenging activities against DPPH anion, ABTS cation, and nitrite and stronger reducing power activities than the other extracts. The calculated concentration required for 50% radical scavenging activity, $RC_{50}s$, of P-SC for DPPH anion, ABTS cation, and nitrite was 226.2, 192.5, and $92.5{\mu}g/ml$, respectively. In an antimicrobial activity assay, F-SC, S-SC, and P-SC showed similarly strong growth inhibitions against Bacillus subtilis and P. vulgaris at a concentration of 0.5 mg/disc. F-SC and P-SC showed 15-fold extended time in thrombin, prothrombin, and activated partial thromboplastin time assays at a concentration of 5 mg/ml. The anticoagulation activity of P-SC (2.5 mg/ml) was comparable to that of aspirin (1.5 mg/ml). Furthermore, F-SC and S-SC showed very good platelet aggregation inhibitory activities. F-SC, S-SC, and P-SC did not show significant hemolysis against human red blood cell up to a concentration of 0.5 mg/ml. These results suggest that S-SC and P-SC, both of which are byproducts of the omija processing industry, show strong potential as novel antioxidant, antimicrobial, and antithrombosis agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.267-273
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• 2009

Antioxidative, antimicrobial activities and Raw 264.7 cell viability as cytotoxicity of various solvent extracts from leaf of Eriobotrya japonica Lindl. dried by different methods were investigated for processing as functional ingredient. In DPPH radical scavenging activity, RLE (80% EtOH extract of raw leaf) and FLE (80% EtOH extract of freeze-dried leaf) exhibited strong scavenging effect on $300{\mu}M$ DPPH radical solution (1.71 mg/mL and 2.11 mg/mL for RLE $SC_{50}$ and FLE $SC_{50}$). Also in nitric oxide scavenging activity, RLE and FLE showed strong activities (83.9% and 82.2% in 5 mg/mL sample concentration). Total phenolic compound contents of each extracts were found to be $73.7{\sim}215.4$ mg/g and RLE was showed the highest phenolic compound content. Also, total flavonoid contents were found to be $24.85{\sim}110.3$ mg/g and RLE was showed the highest flavonoid content. In antimicrobial activity, RLE was showed higher growth inhibition effect against all microbial strains. RLE, RLW (hot water extract of raw leaf), and FLW (hot water extract of freeze-dried leaf) exhibited strong antimicrobial activities against MRSA and S. aureus. In measurement of cytotoxicity by MTT assay, Raw 264.7 cell viabilities of 80% EtOH extracts showed better effect than water extracts. Especially viability of RLE was found be over 100% in every tested sample concentration.

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.116-135
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• 2004

This study was conducted to investigate effects of spent composts of Se-enriched mushrooms as the dietary Se source on muscular Se deposition and plasma glutathione peroxidase (GSH-Px) activity in the finishing Hanwoo steer. Twenty Hanwoo steers were used in the experiment and they were divided into four groups in a randomized complete block design with five replicates. Treatments were four levels (0.1, 0.3, 0.6 and 0.9ppm as fed basis) of dietary Se from the combination with spent composts of Se-enriched mushrooms and/or Se non-enriched mushrooms, in which each treatment was formulated with corn and corn gluten meal and so forth. Treatment diets were fed to Hanwoo steers for 90 days until the slaughter. Dry matter intakes had no significant differences among treatments and there were no significant differences for performances such as total BW gain and ADG among treatments. The Se concentration in blood was linearly increased with increasing dietary selenium levels and reached a plateau level after 8 weeks (p<0.001). Plasma GSH-Px activities had the similar trends to blood Se concentrations by showing that the increased dietary Se level significantly increased plasma GSH-Px activities of both total and Se-dependent (p<0.001). Muscle Se contents of Se-supplemented groups were linearly increased by 1.35 ~ 1.68 folds compared with the control group (0.1ppm; 0.273㎍/dry g) and especially those of the hind legs for 0.9ppm treatment showed the highest Se content as shown 0.457㎍ per dry gram (p<0.01) corresponding to approximately 70% increase of the control group. Se retention rate in the muscle of dietary Se originated from spent composts of Se-enriched mushrooms was estimated of maximum approximately 30% and dietary Se content showed the significant correlation with plasma GSH-Px activities and muscle Se contents (p<0.01). Accordingly, Se present in spent composts of Se-enriched mushroom as the dietary Se source not only had great bioavailabilities showing higher blood Se concentration and plasma GSH-Px activities, but also increased Se deposition in the muscle for Hanwoo beef cattle.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.1017-1025
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• 2016

This study was performed in order to investigate changes in platycosides, as well as antimicrobial activities of bronchus diseases-inducing bacteria (Corynebacterium diphtheriae, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pyogenes) of Platycodon grandiflorum root (PGR) fermented by lactic acid bacteria (Leuconostoc mesenteroides N12-4, Leuc. mesenteroides N58-5, Lactobacillus plantarum N76-10, L. plantarum N56-12, Lactobacillus brevis N70-9, and L. brevis E3-8). Growth of L. plantarum on PGR was most active during lactic acid fermentation using different strains. Total platycoside, platycoside E, platycodin A, polygalacin $D_2$, polygalacin D, and diapioplatyco-side E contents of PGR fermented for 96 h at $37^{\circ}C$ by Leuc. mesenteroides and L. plantarum increased, whereas contents of platycodin D and platycodin $D_3$ were reduced. The antimicrobial activity on PGR fermented by L. plantarum N56-12 exhibited strong microbial proliferation for all four kinds of bronchus disease-inducing bacteria and was higher than that of non-fermented PGR extract. MIC of fermented PGR extract by L. plantarum N56-12 on C. diphtheriae, K. pneumoniae, S. aureus, and S. pyogenes were 45, 10, 50, and 25 mg/mL, respectively. Thus, this result shows that the antimicrobial activities of bronchus disease-inducing bacteria and platycoside content of PGR by L. plantarum N56-12 were higher than that of non-fermented PGR extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1438-1446
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• 2016

The objectives of this study were to investigate the effects of superheated steam (SHS) treatment on the physicochemical and microbial properties of garlic. The garlic was treated by SHS at temperatures of 100, 150, 200, 250, 300, and $350^{\circ}C$ for 60 s. The moisture content of raw garlic was lower than that of SHS-treated garlic. The total thiosulfinate and pyruvate contents were dramatically reduced by SHS treatments. The antioxidant activities of garlic measured by ferric reducing/antioxidant power, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging assay, and total phenolics content decreased by SHS. The major volatile sulfur compounds of garlic such as diallyl disulfide, allicin, allyl sulfide, diallyl sulfide, and diallyl trisulfide were significantly reduced by SHS. The antimicrobial effects of raw garlic were stronger than those of SHS-treated garlic against three strains of bacteria, including Staphylococcus aureus, Escherichia coli, and Bacillus cereus. However, total aerobic bacteria in garlic were dramatically reduced by SHS from 8.6 to 2.9 log CFU/g. The results from the sensory evaluation show that SHS treatment of garlic above $200^{\circ}C$ provides better acceptably due to reduction of off-flavor and pungency of garlic. These results suggest that superheated steam treatment can used as an efficient process for reducing garlic off-flavor and pungency.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1158-1167
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• 2012

During the peeling, cutting, and shredding of wild root vegetables, the surface is exposed to air. This results in a rapid deterioration in quality and an increase in the potential of contamination by microorganisms, both of which reduce the shelf-life of wild root vegetables in retail markets. Thus, in this study, the effects of various washing treatments on the quality of wild root vegetables, including lotus root, burdock root, and bellflower root, were investigated at 10 and $24^{\circ}C$. Lotus root, burdock root and bellflower root were washed with 0.2% acetic acid (AA), 0.2% citric acid (CA), 500 ppm acidified sodium chlorite (ASC), and tap water (TW), which was used as a control, and stored at $10^{\circ}C$ and $24^{\circ}C$. The changes in total plate counts, coliform groups, polyphenol oxidase (PPO) activity, color, pH, and exterior appearance of the samples were then evaluated. The pH and initial microbial contamination levels were reduced when the root vegetables were washed with AA, CA, and ASC. In particular, initial population levels of total plate counts and coliform groups were not detected in lotus root and burdock root that had been washed with ASC and their growth was significantly (p<0.05) inhibited during storage at 10 and $24^{\circ}C$ when compared to the control (TW). In addition, the polyphenol oxidase (PPO) activities of the root vegetables washed with AA, CA and ASC were lower than that of root vegetables washed with TW. ASC was determined to be the most effective treatment for preventing microbial growth, tissue softening, and the development of browning and an unpleasant smell. At $10^{\circ}C$, the overall qualities of the wild root vegetables were maintained longer when compared to $24^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.5-10
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• 1998

The microbial degradation, photosensitizer-mediated photolysis, and bioceramic- accelerated degradation of the herbicide imazapyr were investigated using four types of soil. 1. Seven strains of microorganisms isolated from the soil A and the active sludge collected from the waste water disposal plant in CheongJu did not give any distinct degradation products in pure culture. When imazapyr (10ppm) was incubated for 14days with each of the 6strains of the known bacteria, they did not produce any noticeable products, either, suggesting that imazapyr was degraded very little by microorganisms in aqueous media. Meanwhile, when 50ppm of imazapyr was incubated in soil A and B for 6months, a degradation product of m/z 279 was detected. It turned out to be 2-[(1-carbamoyl-1,2-dimethylpropyl)carbamoyl]nicotinic acid, which was formed by the hydrolytic cleavage of the imidazolinone ring and by tautomerism. When imazapyr was exposed to sunlight, degradation rates were 14.6% under the control and 66.0, 76.5, 26.7, and 90.0% in the presence of PS-1 (100ppm), PS-1 (200ppm), PS-2(100ppm), and PS-3(100ppm), respectively, and a degradation product of m/z 149 was tentatively identified in the treatment of PS-1. 2. When soil C and D treated with bioceramic were incubated for 7weeks, the $^{14}C$-activities of $^{14}CO_2$ evolved were 2.03 and 1.12% of the originally applied ones, respectively, whereas those in control soils without bioceramic were 1.88 and 0.82% showing no significant defferences.After 5 weeks, however,the differences in the amounts of $^{14}CO_2$ between the two treatments increased gradually, suggesting the bioceramic effect.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1038-1047
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• 2018

This study confirmed possibility of cosmetic material for Espresso coffee grounds extracted at high temperature, high pressure, short time and Dutch coffee grounds extracted at low temperature, atmospheric pressure, long time. For this purpose, we evaluated the biological activities of antioxidant, anti-wrinkles and antimicrobial effects using ethanol extracts of Esproso and Dutch coffee grounds. The results of total polyphenolic compound contents was $90.39{\pm}0.04mg/g$ for Dutch coffee grounds extract, which was higher than $64.96{\pm}0.38mg/g$ for Espresso coffee grounds extract, based on $113.63{\pm}0.22mg/g$ for coffee beans extract as the reference one. DPPH radical scavenging activity and SOD-like activity of Dutch coffee grounds extract were found to be better than those of Espresso coffee grounds extracts, referenced on coffee bean extract. As a result of inhibition effect of Elastase activity, Dutch coffee grounds extract showed higher inhibition effect than Espresso coffee grounds extract, based on coffee bean extract. In addition, Dutch coffee grounds extract showed good anti-microbial effects at Escherichia coli, Bacillus, Propionibacterium acnes and there was little difference in the clear zone size between Dutch coffee grounds extract and coffee bean extract as a reference one. From the results of the experiments, it was confirmed that Dutch coffee grounds extract had excellent antioxidant, anti-wrinkle and antimicrobial effects and could be used as safe natural cosmetic material in the future.