• Environmental Engineering Research
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• v.20 no.4
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• pp.370-376
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• 2015

This study investigated the effects of various arsenite concentrations on bio-hydrogen production from molasses using a sequence batch reactor (SBR) operated in a series of three batch cycles. In the first batch cycle, hydrogen production was stimulated at arsenite concentrations lower than 2.0 mg/L, while inhibition occurred at arsenite concentration higher than 2.0 mg/L compared to the control. Hydrogen production decreased substantially during the second batch cycle, while no hydrogen was produced during the third batch cycle at all tested concentrations. The toxic density increased with respect to the increase in arsenite concentrations (6.0 > 1.6 > 1.0 > 0.5 mg/L) and operation cycles (third cycle > second cycle > first cycle). The presence of microorganisms such as Clostridium sp. MSTE9, Uncultured Dysgonomonas sp. clone MEC-4, Pseudomonas parafulva FS04, and Uncultured bacterium clone 584CL3e9 resulted in active stimulation of hydrogen production, however, it was unlikely that Enterobacter sp. sed221 was not related to hydrogen production. The tolerance of arsenite in hydrogen producing microorganisms decreased with the increase in induction time, which resulted in severing the inhibition of continuous hydrogen production.

• IMMUNE NETWORK
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• v.19 no.1
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• pp.1.1-1.13
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• 2019

Systemic lupus erythematosus (SLE) is the prototypic systemic autoimmune disease characterized by production of autoantibodies to various nuclear antigens and overexpression of genes regulated by IFN-I called IFN signature. Genetic studies on SLE patients and mutational analyses of mouse models demonstrate crucial roles of nucleic acid (NA) sensors in development of SLE. Although NA sensors are involved in induction of antimicrobial immune responses by recognizing microbial NAs, recognition of self NAs by NA sensors induces production of autoantibodies to NAs in B cells and production of IFN-I in plasmacytoid dendritic cells. Among various NA sensors, the endosomal RNA sensor TLR7 plays an essential role in development of SLE at least in mouse models. CD72 is an inhibitory B cell co-receptor containing an immunoreceptor tyrosine-based inhibition motif (ITIM) in the cytoplasmic region and a C-type lectin like-domain (CTLD) in the extracellular region. CD72 is known to regulate development of SLE because CD72 polymorphisms associate with SLE in both human and mice and CD72^-/- mice develop relatively severe lupus-like disease. CD72 specifically recognizes the RNA-containing endogenous TLR7 ligand Sm/RNP by its extracellular CTLD, and inhibits B cell responses to Sm/RNP by ITIM-mediated signal inhibition. These findings indicate that CD72 inhibits development of SLE by suppressing TLR7-dependent B cell response to self NAs. CD72 is thus involved in discrimination of self-NAs from microbial NAs by specifically suppressing autoimmune responses to self-NAs.

• Journal of Environmental Health Sciences
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• v.33 no.2 s.95
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• pp.137-144
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• 2007

Yam, Prunella was stepwise extracted with hexane, chloroform, ethyl acetate, butanol, and water. Anti-microbial activity of each extract was investigated. Hexane extract was tested for anti-microbial effect on Streptocaccus mutans, one of causative factor of dental caries. Methanol extracts of 7 plants were investigated to anti-microbial effects on S. mutans KCTC 5316, P. gingivalis KCTC 5352, S. aureus KCTC 1927 by means of agar diffusion method. Methanol extract of Yam and Prunella revealed anti-microbial activity against S. mutans, P. gingivalis, and S. aureus. Also, hexane fraction of Yam revealed anti-microbial activity against S. mutans. In sequence of hexane, chloroform, ethylacetate, butanol fraction by Prunelia acted as potent anti-microbial agent on P. gingivalis. The measured MIC of hexane fraction of Yam and Prunella on S. mutans KCTC 5316 strain was 0.25 mg/ml and 0.5 mg/ml and the MIC of hexane fraction of Prunella on S. aureus was 0.5 mg/ml. The hexane fraction of Yam and Prunella suppressed viable ceil counts(VCC) of S. mutans, especially after 24 hrs. The Prunella hexane fraction suppressed VCC of S. aureus, after 12 and 24 hrs. Tested concentrations were 0.1, 0.25 and 0.5 mg/ml. the results were compared with control (0 mg/ml). The pH of S. mutans media and GTase activity were determined to evaluate the anticariogenic activity of Yam, Prunella hexane fraction. The pH were increased from 5.6 to 7.0-7.2 in concentration of 2.0 mg/ml. Yam hexane extraction revealed 35% inhibition to GTase activity and Punella inhibited 25% of GTase. These results suggest that the hexane extracts of Yam and prunella have Antibacterial activities against S. mutans, P. gingivalis, S. aureus and have preventive effect on dental caries.

• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.278-283
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• 1992

Aldehyde production by cells of a methanol utilizing yeast, Hansenula nonfermentans KYP-1 was improved when they were grown in a methanol-limited continuous culture, in comparison with cells grown in a batch culture. A higher cell yield was also obtained in continuous culture than in batch culture. This could be due to the fact that a lower methanol concentration was maintained in the jar fermentor to minimize growth inhibition by methanol. A maximum cell productivity of 0.219 g.$liter^{-1}.hr^{-l}$ and a cell yield of 47% were obtained at dilution rates of 0.1 $hr{-1}$ and 0.06 hr{-1}, respectively. The greatest amount of aldehyde was measured at a dilution rate of 0.08 $hr{-1}$. Under optimum reaction conditions, 915.7 mM of acetaldehyde was produced from 1.5 M ethanol after 21 hours reaction, with a conversion rate of 61%. Propionaldehyde and acrolein were produced with conversion rates of 32.7% and 44%, respectively.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.428-437
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• 2007

The potential for humic substances to serve as terminal electron acceptors in microbial respiration and the effects of humic substances on microbial azoreduction were investigated. The dissimilatory azoreducing microorganism Shewanella decolorationis S12 was able to conserve energy to support growth from electron transport to humics coupled to the oxidation of various organic substances or $H_2$. Batch experiments suggested that when the concentration of anthraquinone-2-sulfonate (AQS), a humics analog, was lower than 3 mmol/l, azoreduction of strain S12 was accelerated under anaerobic condition. However, there was obvious inhibition to azoreduction when the concentration of the AQS was higher than 5 mmol/l. Another humics analog, anthraquinone-2-sulfonate (AQDS), could still prominently accelerate azoreduction, even when the concentration was up to 12 mmol/l, but the rate of acceleration gradually decreased with the increasing concentration of the AQDS. Toxic experiments revealed that AQS can inhibit growth of strain S12 if the concentration past a critical one, but AQDS had no effect on the metabolism and growth of strain S12 although the concentration was up to 20 mmol/l. These results demonstrated that a low concentration of humic substances not only could serve as the terminal electron acceptors for conserving energy for growth, but also act as redox mediator shuttling electrons for the anaerobic azoreduction by S. decolorationis S12. However, a high concentration of humic substances could inhibit the bacterial azoreduction, resulting on the one hand from the toxic effect on cell metabolism and growth, and on the other hand from competion with azo dyes for electrons as electron acceptor.

• The Korean Journal of Mycology
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• v.11 no.4
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• pp.151-157
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• 1983

To find antitumor components in Korean basidiomycetes, the carpophores of Armillariella mellea which were collected in Gyeong Gi Province were extracted with distilled water at $90{\sim}100^{\circ}C$ for eight hours. The hot water extract was concentrated under reduced pressure, mixed with three-fold volumes of ethanol and allowed to stand at $4^{\circ}C$ overnight. The precipitate was centrifugated and lyophilized to yield a protein-polysaccharide fraction. It was examined for antitumor activity against sarcoma 180 implanted in ICR mice. The fraction showed 75.7%, 83.9%, and 94.1% of tumor inhibition ratios at the doses of 10, 20 and 50 mg/kg/day, respectively. The chemical analysis of the fraction showed that it contained a polysaccharide(41.3%) and a protein (35.0%). The hydrolyzates of the polysaccharide moiety contained fucose (4.5%), xylose (1.1%), galactose (17.4%), glucose (55.4%), mannose(19.4%), and one unknown monosaccharide. The protein moiety contained seventeen amino acids. The protein-polysaccharide from A. mellea was administered, i.p., to mice and caused an influx of polymorphonuclear leukocytes (PMN) at $5{\sim}24$ hours which was followed by an accumulation of macrophages and disappearance of the PMN at $48{\sim}72$ hours.

• Journal of Life Science
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• v.25 no.7
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• pp.757-764
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• 2015

The immature fruit of Rubus coreanus Miquel (bokbunja in Korean) is mainly consumed as a fruit wine due to its sour taste and low sugar content. The lees (LBW) remaining after the production of bokbunja wine are discarded as they have no specific usage. The aim of this study was to develop high-value-added biomaterials for functional foods and beauty/health products by investigating the anti-microbial, anti-oxidant, and anti-thrombosis activities of LBW using ethanol and hot water extracts and their subsequent organic solvent fractions. The ethyl acetate (EA) fraction of LBW extracts has a high polyphenol content (413–459 mg/g), and showed strong anti-microbial activity against gram-positive bacteria. The EA fraction also showed excellent radical-scavenging activity against DPPH anion, ABTS cation, and nitrite, with strong reducing power. The polyphenol-enriched EA fraction strongly inhibited thrombin, prothrombin, and blood coagulation factors. The butanol fraction showed a specific inhibition of coagulation factors, as measured in activated partial thromboplastin time assay, which is linked to intrinsic blood coagulation. The butanol fraction also showed strong inhibition of platelet aggregation, at levels comparable to aspirin. The residue of the hot-water extract, which is produced by sequential solvent fractionation of the LBW extract, showed superior inhibition against platelet aggregation when compared to aspirin. Our results suggest that the LBW, which are currently discarded, are a promising source of novel functional foods and beauty/health products.

• Food Science and Preservation
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• v.30 no.4
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• pp.691-702
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• 2023

This study aimed to develop high value-added mulberry (Morus alba) vinegar by fermenting mulberry with yeast and acetic acid bacteria, for using it in various foods. To select the optimal strain for mulberry fermentation, different strains were tested and Saccharomyces cerevisiae SRCM101756 and Acetobacter pasteurianus SRCM102419, exhibiting excellent alcohol and acetic acid production ability during mulberry fermentation, were selected for fermentation. Mulberry vinegar was prepared using mulberry wine and the selected acetic acid bacteria, and the physicochemical properties and physiological effects were measured. The pH was 2.98 and total acidity was 4.70% by day 9 of fermentation, establishing the possibility of developing them into vinegars for industrial use. The angiotensin-glucosidase inhibition activity of mulberry vinegar increased from 13.22% to 19.19% in the 100-fold dilution, and from 42.35% to 46.11% in the 50-fold dilution, from before fermentation to after fermentation, respectively. The angiotensin-converting enzyme inhibition activity of mulberry vinegar was found to significantly increase from 44.82% before fermentation to 63.88% after fermentation in the 25-fold dilution. Moreover, a significant increase in pancreatic lipase inhibition activity after fermentation was observed. Thus, mulberry vinegar can be used as a functional material in vinegar and other foods.

• Preventive Nutrition and Food Science
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• v.17 no.3
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• pp.210-216
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• 2012

The use of suitable sanitizers can increase the quality of fresh-cut produce and reduce the risk of foodborne illnesses. The objective of this study was to compare the washing effects of 100 mg/L sodium hypochlorite (SH) and 500 mg/L acidified sodium chlorite (ASC) on the prevention of enzymatic browning and the growth of microbial populations, including aerobic plate counts, E. coli, and coliforms, throughout storage at $4^{\circ}C$ and $10^{\circ}C$. Fresh-cut zucchini, cucumbers, green bell peppers, and root vegetables such as potatoes, sweet potatoes, carrots, and radishes were used. Compared to SH washing, ASC washing significantly (p<0.05) reduced microbial contamination on the fresh-cut produce and prevented browning of fresh-cut potatoes and sweet potatoes during storage. More effective inhibition of aerobic plate counts and coliforms growth was observed on fresh-cut produce treated with ASC during storage at $10^{\circ}C$. Polyphenol oxidase (PPO) activity of fresh-cut potatoes and sweet potatoes was more effectively inhibited after washing with ASC. The use of 500 mg/L ASC can provide effective antimicrobial and anti-browning treatments of fresh-cut produce, including processed root vegetables.

• BMB Reports
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• v.28 no.1
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• pp.83-86
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• 1995

In the course of screening for new aminopeptidase M inhibitors which were expected to be analgesic, immunopotentiating, or anti-metastatic agents, the novel synthetic substance MR-387C[(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-valyl-L-prolyl-L-leucine] (M.W. 504 daltons) was obtained. It was competitive with the substrate and had an $IC_{50}$ value of $0.04\;{\mu}m/ml$ ($7.9{\times}10^{-8}\;M$) and an inhibition constant ($K_i$) of $3.8{\times}10^{-8}\;M$. This novel MR-387C was compared with various known inhibitors of aminopeptidase M. It inhibited the enzyme more strongly than any other microorganism-originated inhibitor, except probestin.