• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.569-573
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• 2001

A pectic substance from citron peel was extracted with different methods to establish the optimum extraction conditions. The extraction yields of pectin with HCl, citrate and tartrate (concentration : 0.1 N, extraction ratio : 1 : 20) were 17.9%, 15.6% and 11.4%, respectively. Six times of 65% ethanol washing step was followed after first ethanol precipitation of acid extract for pure pectin. The degree of esterification (DE) of pectins was in the range of 43.0~47.6% and intrinsic viscosity was in the range of 0.94~2.63 (η$_{sp}$ /C (dL/g)). The sugar compositions such as rhamnose, xylose, glucuronic acid, galacturonic acid, galactose and glucose were little different in three kinds of pectins except for the content of arabinose.

• Journal of Ginseng Research
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• v.23 no.4
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• pp.217-221
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• 1999

We have isolated an antithrombin active polysaccharide in red ginseng by procedures comprising three major steps involving alkaline extraction, anion exchange and gel permeation chromatography. Active polysaccharide behaved as a single band on cellulose acetate membrane electrophoresis. The average molecular mass was estimated to be about 177 kDa by gel filtration. This polysaccharide was found to be an acidic heteropolysaccharide that contains uronic acid moiety $(40.2\%)$, sulfate group $(9.2\%)$ and protein $(1.5\%)$ in addition to neutral sugar consisted of rhamnose, mannose, galactose, arabinose, glucose, fucose and xylose in a molar ratio of 1.00 : 0.88 : 0.86 : 0.78: 0.70 : 0.33 : 0.22. This polysaccharide inhibited blood coagulation via the intrinsic pathway like heparin in a dose-dependent manner. The clotting of fibrinogen by thrombin was also mitigated by the presence of this polysaccharide.

• Food Science and Preservation
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• v.5 no.4
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• pp.350-354
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• 1998

This paper was investigated to changes of cell components during drying for studies on the softening of jujube fruits. The contents of alcohol-insoluble material, cell wall and water-soluble material were not changed at 6 days of drying, but alcohol-insoluble materials and cell wall were decreased at 9 days of drying, however water-soluble materials were increased. Pectin and hemicellulose were not changed at 6 days of drying. Pectin and alkali-soluble hemicellulose were remarkable decreased at 9 days of drying, but acid-soluble hemicellulose was increased. Water-soluble pectin was not changed at 6 days of drying, but increased at 9 days of drying. EDTA-soluble and insoluble pectin were decreased after 6 days of drying. The non-cellulosic neutral sugars were not changed at 6 days of drying. The contents of arabinose, galactose and total neutral suger were decreased at 9 days of drying.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.161-167
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• 2020

The goal of this study was to isolate and characterize the wild yeast strains from the gut of earthworm(Eisenia andrei). The 19 yeast strains isolated from 5 gut of earthworm samples from Nanji water regeneration center in Goyang-si, Gyeonggi-do, Korea. Among them, 16 strains were recorded and 3 strains, Yarrowia deformans YP242 (=KACC48778), Sporidiobolus pararoseus YP66 (=KCTC27963) and Naganishia liquefaciens YI9 (=KACC48948) were recorded for the first time in Korea. The microbiological characteristics of these previously unrecorded yeasts were investigated. All three strains were oval-shaped, convex and smooth. However, they showed some differences in colony color and result of carbon assimilation assays. YP242 was white-colored and assimilated glycerol, L-arabinose and N-acetyl-D-glucosamine as carbon sources. YP66 was red-colored and assimilated D-Saccharose. YI9 was whitecolored and positive for 2-keto-D-gluconate assimilation.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.229-235
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• 2020

The goal of this study was to isolate and identify the wild yeast strains in intestine of Othius punctulatus collected in Cheongju-si, Chungcheongbuk-do, Korea and characterize their unrecored yeast strains. We isolated 16 wild yeast strains from 5 intestine samples from Othius punctulatus. The 16 wild yeast strains were included three strains in the genus Aureobasidium, four strains in the genus Cystofilobasidium, one strain in the genus Mrakia, three strains in the genus Naganishia, two strains in the genus Saitozyma, two strains in the genus Sampaiozyma and one strain in the genus Scheffersomyces. Among them Cystofilobasidium capitatum YP53, Cystofilobasidium capitatum YP71, Cystofilobasidium macerans YS620, Cystofilobasidium macerans YS622, Mrakia aquatica YP158 and Scheffersomyces stipitis YI5 were recorded for the first time in Korea. The microbiological characteristics and carbon assimilation of these previously unrecorded yeasts were investigated. Almost all of them were oval-shaped. And, glycerol, L-arabinose, xylitol, and inositol are not utilized.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.39-46
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• 1998

This study was carried out to obtain the basic data for artificial culture of Sparassis crispa. The optimal conditions for the mycelial growth were $25^{\circ}C$ and pH 4, respectively. The mycelial density of S. crispa was most compact in the Hamada media, whereas colony diameter was prominent in the Hoppkins media. Carbon sources such as maltose, arabinose and mannitol were favorable for stimulating a mycelial growth of S. crispa. Glycine, one of nitrogen sources also appeared to be favorable to the mycelial growth. The optimum C/N ratio was about 20 : 1 in case that 1% glucose as carbon source was mixed with the basal medium. Fumaric acid or lactic acid as organic acid was most favorable to the mycelial growth.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2522-2527
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• 2010

The aim of this study was to investigate the tyrosinase inhibitory activity and antimicrobial activity by mixtures of ultrasonicated chitosan and Maillard reaction products. Analysis of tyrosinase was purified from potato and confirmed by active staining after SDS-PAGE. Maillard reaction products (MRPs) were formed from various sugars (glucose, fructose, galactose, xylose, arabinose or ribose) and cystein. MRPs inhibited the tyrosinase purified from potato. The highest tyrosinase inhibitory activity was shown by MRP from glucose and cystein. Ultrasonicated chitosan (over 1 hr) showed antimicrobial activity at the concentration of 1% against E. coli and S. aureus. For the development of antibrowning agent with antimicrobial activity, tyrosinase inhibitory and antimicrobial activity by the mixtures of ultrasonicated chitosan and MRP were tested. 1:1 mixture of ultrasonicated chitosan and MRP from glucose and cystein was the best antibrowning agent having antimicrobial activity.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.511-518
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• 2018

Initiation of spore germination in filamentous fungi such as Aspergillus nidulans and Botrytis cinerea requires the presence of nutrients. In this study, involvement of sugar sensing machinery was suggested in the germination of A. nidulans spores. Germination did not occur when the spores of A. nidulans were incubated in distilled water, whereas they were successfully germinated in the presence of 5% glucose with a germination rate of over 98% after 6hr incubation. Similar results were obtained when the spores were incubated in the presence of various sugars such as fructose, sucrose, and starch. Interestingly, spore germination was not observed in the presence of D-arabinose, whereas L-arabinose could induce germination as determined by the formation of germ tubes, indicating the presence of sugar sensing machinery that distinguish between the enantiomers of sugars. This inference was further supported by a decrease in germination rate (less than 25%) upon treatment of spores with trypsin. Subsequent MALDI-TOF mass spectrometry analysis of the surface proteins of spores identified ten proteins among which eight were involved in sugar metabolism. Taken together, our results suggest that spore germination in A. nidulans is initiated by the interaction of sugars with sugar binding proteins on the surface of spores.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.37-43
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• 2019

The gene encoding an ${\alpha}-{\text\tiny{L}}-arabinofuranosidase$ (BvAF) GH51 from Bacillus velezensis FZB42 was cloned and expressed in Escherichia coli. The corresponding open reading frame consists of 1,491 nucleotides which encode 496 amino acids with the molecular mass of 56.9 kDa. BvAF showed the highest activity against sugar beet (branched) arabinan in 50 mM sodium acetate buffer (pH 6.0) at $45^{\circ}C$. However, it could hardly hydrolyze debranched arabinan and arabinoxylans. The time-course hydrolyses of branched arabinan and arabinooligosaccharides (AOS) revealed that BvAF is a unique exo-hydrolase producing exclusively ${\text\tiny{L}}-arabinose$. BvAF could cleave ${\alpha}-(1,2)-$ and/or ${\alpha}-(1,3)-{\text\tiny{L}}-arabinofuranosidic$ linkages of the branched substrates to produce the debranched forms of arabinan and AOS. Although the excessive amount of BvAF could liberate ${\text\tiny{L}}-arabinose$ from linear AOS, it was extremely lower than that on branched AOS. In conclusion, BvAF is the arabinan-specific exo-acting ${\alpha}-{\text\tiny{L}}-arabinofuranosidase$ possessing high debranching activity towards ${\alpha}-(1,2)-$ and/or ${\alpha}-(1,3)-linked$ branches of arabinan, which can facilitate the successive degradation of arabinan by $endo-{\alpha}-(1,5)-{\text\tiny{L}}-arabinanase$.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.272-279
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• 2021

Two genes encoding probable α-ʟ-arabinofuranosidase (E.C. 3.2.1.55) isozymes (ABFs) with 92.3% amino acid sequence identity, ABF51A and ABF51B, were found from chromosomes 3 and 5 of Saccharomycopsis fibuligera KJJ81, an amylolytic yeast isolated from Korean wheat-based nuruk, respectively. Each open reading frame consists of 1,551 nucleotides and encodes a protein of 517 amino acids with the molecular mass of approximately 59 kDa. These isozymes share approximately 49% amino acid sequence identity with eukaryotic ABFs from filamentous fungi. The corresponding genes were cloned, functionally expressed, and purified from Escherichia coli. SfABF51A and SfABF51B showed the highest activities on p-nitrophenyl arabinofuranoside at 40~45℃ and pH 7.0 in sodium phosphate buffer and at 50℃ and pH 6.0 in sodium acetate buffer, respectively. These exoacting enzymes belonging to the glycoside hydrolase (GH) family 51 could hydrolyze arabinoxylo-oligosaccharides (AXOS) and arabino-oligosaccharides (AOS) to produce only ʟ-arabinose, whereas they could hardly degrade any polymeric substrates including arabinans and arabinoxylans. The detailed product analyses revealed that both SfABF51 isozymes can catalyze the versatile hydrolysis of α-(1,2)- and α-(1,3)-ʟ-arabinofuranosidic linkages of AXOS, and α-(1,2)-, α-(1,3)-, and α-(1,5)-linkages of linear and branched AOS. On the contrary, they have much lower activity against the α-(1,2)- and α-(1,3)-double-substituted substrates than the single-substituted ones. These hydrolases could potentially play important roles in the degradation and utilization of hemicellulosic biomass by S. fibuligera.