• Journal of Microbiology and Biotechnology
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• v.19 no.6
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• pp.573-581
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• 2009

The complex enzyme pool secreted by the phytopathogenic fungus Fusarium graminearum in response to glucose or hop cell wall material as sole carbon sources was analyzed. The biochemical characterization of the enzymes present in the supernatant of fungal cultures in the glucose medium revealed only 5 different glycosyl hydrolase activities; by contrast, when analyzing cultures in the cell wall medium, 17 different activities were detected. This dramatic increase reflects the adaptation of the fungus by the synthesis of enzymes targeting all layers of the cell wall. When the enzymes secreted in the presence of plant cell wall were used to hydrolyze pretreated crude plant material, high levels of monosaccharides were measured with yields approaching 50% of total sugars released by an acid hydrolysis process. This report is the first biochemical characterization of numerous cellulases, hemicellulases, and pectinases secreted by F. graminearum and demonstrates the usefulness of the described protein cocktail for efficient enzymatic degradation of plant cell wall.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.219-227
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• 2023

This study was conducted to analyze the distribution and characteristics of fungal species in meju using the traditional method. Fungal distribution in meju was investigated using metagenomic and morphological analyses, based on which Aspergillus flavus/oryzae strains were identified as the dominant fungi in all meju samples, followed by Pichia, Rhizopus and Lichtheimia spp. As A. flavus/oryzae was dominant, we further evaluated the aflatoxin production ability and enzymatic activity of the isolates. Thin-layer chromatography and polymerase chain reaction revealed that the A. flavus/oryzae strains isolated from meju are non-aflatoxigenic fungi. Based on the analyses of amylase and protease activities, strains with high activities of amylase or protease were identified, which are proposed to be used as starters for meju fermentation.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.37-45
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• 2015

This study was conducted to determine the toxic effect of TNT and RDX on indigenous soil microbes by measuring enzymatic activity. Denitrification activity, dehydrogenase activity, phosphatase activity, and fluorescein diacetate hydrolytic activity were determined for military firing range, field, and paddy soils exposed to TNT, and RDX from 0 to 1,000 mg/kg and 0 to 4,000 mg/kg, respectively, for 2, 4, and 8 weeks. Soil microbial enzymatic activities decreased with higher TNT and RDX concentration and longer exposure time. Microbial enzymatic activities of firing range soil were higher than field and paddy soils, indicating that indigenous microbes in firing range might have been adapted to TNT and RDX due to pre-exposure of the explosives. In addition, the toxicity of TNT and RDX decreased with higher organic matter because TNT and RDX tend to absorb to soil organic matter. No Observable Effect Concentration (NOEC) values of each microbial enzymatic activity were derived by the geometric mean of NOECs from exposure times (2, 4, and 8 weeks) and soil types (firing range, field, paddy soil). The derived NOECs ranged from 45.3 to 55.2 mg/kg for TNT and 286 to 309 mg/kg for RDX.

• Korean Journal of Medicinal Crop Science
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• v.19 no.2
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• pp.77-82
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• 2011

The antioxidative activity of various enzymatic extracts from Sarcodon aspratus (S. aspratus) was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. For this study, the S. aspratus were enzymatically hydrolyzed by seven carbohydrases (Viscozyme, Celluclast, Dextrozyme, AMG, Promozyme, Maltogenase, and Termamyl) and eight proteases (${\alpha}$-chymotrypsin, Alcalase, Flavourzyme, Neutrase, papain, pepsin, Protamax, and trypsin). The DPPH radical scavenging activities of Viscozyme and pepsin extracts were the highest, and the half maximal inhibitory concentration ($IC_{50}$) values were 0.896 and 0.734mg/mL, respectively. The Celluclast and trypsin extracts showed the highest scavenging activities on alkyl radical, and their $IC_{50}$ values were 0.278 and 0.575mg/mL, respectively. The Celluclast extracts was decreased cell apoptosis in PC-12 cells against $H_2O_2$-induced oxidative damage. The findings of the present study suggest that enzymatic extracts of S. aspratus exhibit antioxidative activity against oxidative stress on PC-12 cells.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.860-873
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• 2018

Although ginseng marc is a by-product obtained during manufacturing of various commercial ginseng products and has been routinely discarded as a waste, it still contains considerable amounts of potential bioactive compounds, including saponins and polysaccharides. Previously, we reported that ginseng oligosaccharides derived from ginseng marc polysaccharides by enzymatic hydrolysis exert immunostimulatory activities in macrophages and these activated macrophages are in turn able to inhibit the growth of skin melanoma cells by inducing apoptosis. In the present study, a more detailed investigation of the immunostimulatory activity and underlying action mechanisms of an enzymatic hydrolysate (GEH) containing these oligosaccharides derived from ginseng marc polysaccharides was performed. The levels of proinflammatory cytokines and anti-inflammatory cytokines were measured in GEH-stimulated RAW264.7 macrophages using RT-PCR analysis and ELISA. The expression levels of Toll-like receptor 2 (TLR2) and TLR4, Dectin-1, and MerTK were measured by RT-PCR analysis or western blot analysis, and the phagocytic activities of GEH-challenged bone marrow-derived macrophages toward apoptotic Jurkat cells were assayed using fluorescence microscopy. GEH induced the production of both proinflammatory cytokines $TNF-{\alpha}$ and IL-6, and anti-inflammatory cytokine IL-10 in RAW 264.7 cells. The expression of the TLR2 and MerTK mRNAs was increased upon GEH treatment. Phagocytosis of apoptotic Jurkat cells was enhanced in GEH-treated macrophages. Based on the results, this enzymatic hydrolysate (GEH) containing oligosaccharides exerts immunostimulatory effects by maintaining the balance between M1 and M2 cytokines, facilitating macrophage activation and contributing to the efficient phagocytosis of apoptotic cells. Therefore, the GEH could be developed as value-added, health-beneficial food materials with immunostimulatory effects.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.566-570
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• 2018

Because glycosylation of aesculetin and its 6-glucoside, aesculin, enhances their biological activities and physicochemical properties, whole-cell biotransformation and enzymatic synthesis methodologies using Neisseria polysaccharea amylosucrase were compared to determine the optimal production method for glycoside derivatives. High-performance liquid chromatography analysis of reaction products revealed two glycosylated products (AGG1 and AGG2) when aesculin was used as an acceptor, and three products (AG1, AG2, and AG3) when using aesculetin. The whole-cell biotransformation production yields of the major transfer products for each acceptor (AGG1 and AG1) were 85% and 25%, respectively, compared with 68% and 14% for enzymatic synthesis. These results indicate that whole-cell biotransformation is more efficient than enzymatic synthesis for the production of glycoside derivatives.

• Nutrition Research and Practice
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• v.4 no.3
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• pp.183-190
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• 2010

Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against $H_2O_2$-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against $H_2O_2$-induced cell damage in vitro.

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.781-785
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• 1994

Uridine diphosphate(UDP)-galactose-4-epimerase-less mutants of Salmonella pullorum were isolated after mutagenic treatment with ethidium bromide. When isolated gal E mutants of S. pullorum A2 and D1 were grown in the presence of galactose(0.1 W/V), they exhibited marked bacteriolysis in heart infusion broth. The mutant strains were further investigated the characteristics of enzymatic activities in the Leoloir galactose pathway. Isolated A2 and D1 strains were completely deficient in UDP-galactose-4-epimerase activity. And the activity of other enzymes involved in galactose metabolism were reduced significantly.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.426-433
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• 2009

Fish scales have potential in functional food preparation due to their antioxidant and antihypertensive properties. We investigated the angiotensin I converting enzyme (ACE) inhibitory activity of Tilapia mossambica scale extracts. Hydrolysates of tilapia scales were prepared by enzymatic extraction using five proteases (${\alpha}$-chymotrypsin, Alcalase, Kojizyme, Protamex and trypsin) after scales were treated with hot water for 3 hr. Scale enzymatic hydrolysates prepared using both hot water and enzyme treatments exhibited elevated hydrolysis (about 25%-55%) compared to only enzyme treatment (about 15%-45%). Enzymatic hydrolysates (1 mg/mL) prepared by both hot water and enzyme treatments also showed significantly increased ACE inhibitory activities from about 20%-75%. The pattern of ACE inhibitory activities was similar to the degree of hydrolysis. Alcalase and ${\alpha}$-chymotrypsin hydrolysates displayed the highest ACE inhibitory activities ($IC_{50}$ = 0.83 mg/mL and 0.68 mg/mL, respectively). In addition, the ACE inhibitory effects of $IC_{50}$-chymotrypsin hydrolysates increased with decreasing molecular weight (5 kDa>, 10 kDa> and 30 kDa>), with the 5 kDa> fraction displaying the highest ACE inhibitory activity (about 89.9% and $IC_{50}$ = 0.1 mg/mL). We suggest that the peptide compounds of enzymatic hydrolysates prepared from tilapia scale enhances ACE inhibitory activity and might be useful as an antihypertensive material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1139-1145
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• 2006

In this study, antioxidant activities of enzymatic and methanolic extracts from E. cava stem and leave were evaluated by measuring the scavenging activities on 1,1 diphenyl 2 picrylhydrazyl (DPPH), hydroxyl radical, hydrogen peroxide and the inhibitory effects on DNA damage induced by oxidative stress of cells. Enzymatic extracts were prepared by enzymatic hydrolysis of both stem and leave using food grade five different carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme, Alcalase). The enzymatic extracts were lower than methanolic extracts in polyphenol contents, but higher in extraction yield by approximately 30%. The enzymatic extracts were superior to methanolic extracts in DPPH and H2O2 scavenging activities and DNA damage protective effect. There were no significant antioxidant activity difference between stem and leave, but the extracts of leave were relatively better than those of stem. In this study it is suggested that E. cava stem as well as its leave would be a good raw materials for antioxidants compound extraction and enzymatic hydrolysis would be a good strategy to prepare antioxidant extracts from seaweeds.