• Natural Product Sciences
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• v.16 no.3
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• pp.148-152
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• 2010

Microbial metabolism studies of yangonin (1), a major styryl lactone from Piper methysticum, have resulted in the production of three hydroxylated metabolites (2-4). The chemical structures of these compounds were elucidated to be 4-methoxy-6-(12-hydroxystyryl)-2-pyrone (2),4-methoxy-6-(11,12-dihydroxystyryl)-2-pyrone (3),and 4,12-dimethoxy-6-(7,8-dihydroxy-7,8-dihydrostyryl)-2-pyrone (4) on the basis of the chemical and spectroscopic analyses. The compounds 3 and 4 are reported herein as microbial metabolites of yangonin for the first time.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.279-293
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• 2009

Quantitative risk assessments are related to implementing hazard analysis and critical control points (HACCP) by its potential involvement in identifying critical control points (CCPs), validating critical limits at a CCP, enabling rational designs of new processes, and products to meet required level of safety, and evaluating processing operations for verification procedures. The quantitative risk assessment is becoming a standard research tool which provides useful predictions and analyses on microbial risks and, thus, a valuable aid in implementing a HACCP system. This paper provides a review of microbial modeling in quantitative risk assessments, which can be applied to HACCP systems.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1073-1085
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• 2012

Soil microbial communities are immensely diverse and complex with respect to species richness and community size. These communities play essential roles in agricultural soil because they are responsible for most of the nutrient cycles in the soil and influence the plant diversity and productivity. However, the majority of these microbes remain uncharacterized because of poor culturability. Next-generation sequencing techniques have revolutionized many areas of biology by providing cheaper and faster alternatives to Sanger sequencing. Among them, amplicon pyrosequencing is a powerful tool developed by 454 Life Sciences for assessing the diversity of complex microbial communities by sequencing PCR products or amplicons. This review summarizes the current opinions in amplicon sequencing of soil microbial communities, and provides practical guidance and advice on sequence quality control, aligning, clustering, OTU- and taxon-based analysis. The last section of this article includes a few representative studies conducted using amplicon pyrosequencing.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.303-316
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• 1994

Microbial digestion of feed in the rumen involves a sequential attack culminating in the formation of fermentation products and microbial cells that can be utilized by the host animal. Most feeds are protected by a cuticular layer which is in effect a microbial barrier that must be penetrated or circumvented for digestion to proceed. Microorganisms gain access to digestible inner plant tissues through damage to the cuticle, or via natural cell openings (e.g., stomata) and commence digestion from within the feed particles. Primary colonizing bacteria adhere to specific substrates, divide to form sister cells and the resultant microcolonies release soluble substrates which attract additional microorganisms to the digestion site. These newly attracted microorganisms associate with primary colonizers to form complex multi-species consortia. Within the consortia, microorganisms combine their metabolic activities to produce the diversity of enzymes required to digest complex substrates (e.g., cellulose, starch, protein) which comprise plant tissues. Feed characteristics that inhibit the microbial processes of penetration, colonization and consortia formation can have a profound effect on the rate and extent of feed digestion in the rumen. Strategies such as feed processing or plant breeding which are aimed at manipulating feed digestion must be based on an understanding of these basic microbial processes and their concerted roles in feed digestion in the rumen.

• Journal of Microbiology and Biotechnology
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• v.28 no.12
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• pp.1955-1970
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• 2018

Several genetic strategies have been proposed for the successful transformation and expression of microbial transgenes in model and crop plants. Here, we bring into focus the prominent applications of microbial transgenes in plants for the development of disease resistance; mitigation of stress conditions; augmentation of food quality; and use of plants as "bioreactors" for the production of recombinant proteins, industrially important enzymes, vaccines, antimicrobial compounds, and other valuable secondary metabolites. We discuss the applicable and cost-effective approaches of transgenesis in different plants, as well as the limitations thereof. We subsequently present the contemporary developments in targeted genome editing systems that have facilitated the process of genetic modification and manifested stable and consumer-friendly, genetically modified plants and their products. Finally, this article presents the different approaches and demonstrates the introduction and expression of microbial transgenes for the improvement of plant resistance to pathogens and abiotic stress conditions and the production of valuable compounds, together with the promising research progress in targeted genome editing technology. We include a special discussion on the highly efficient CRISPR-Cas system helpful in microbial transgene editing in plants.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.121-128
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• 2022

L-asparaginase (ASNase) is a therapeutic enzyme used to treat acute lymphoblastic leukemia. Currently, the most widely used ASNases are originated from bacteria. However, owing to the adverse effects of bacterial ASNases, new resources for ASNase production should be explored. Fungal enzymes are considered efficient and compatible resources of natural products for diverse applications. In particular, fungal species belonging to the genus Trichoderma are well-known producers of several commercial enzymes including cellulase, chitinase, and xylanase. However, enzyme production by marine-derived Trichoderma spp. remains to be elucidated. While screening for extracellular ASNase-producing fungi from marine environments, we found four strains showing extracellular ASNase activity. Based on the morphological and phylogenetic analyses using sequences of translation elongation factor 1-alpha (tef1α), the Trichoderma isolates were identified as T. afroharzianum, T. asperellem, T. citrinoviride, and Trichoderma sp. 1. All four strains showed different ASNase activities depending on the carbon sources. T. asperellem MABIK FU00000795 showed the highest ASNase value with lactose as a carbon source. Based on our findings, we propose that marine-derived Trichoderma spp. are potential candidates for novel ASNase production.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.98-105
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• 2006

This study was performed to investigate the product characteristics of meat products sold in Korean markets and determine if these products meet the comsumer demands. The total nineteen meat produce were evaluated the physico-chemical, textural properties, and microbial counts of total bacteria and Enterobacteriaceae. pH values were ranged from 5.46 to 6.69, moisture $47.6{\sim}65.3%,\;fat\;14.2{\sim}34.7%,\;and\;9{\sim}20%$ and the pH values of ham products were higher than those of sausages. Purge loss(%) and expressible moisture(%) were ranged $2.40{\sim}7.44\;and\;6.10{\sim}21.2%$ respectively. Varied hunter color values (Lightness $59.6{\sim}75.7$, Redness $11.6{\sim}21.1$, Yellowness $2.30{\sim}l1.4$) were observed. Texture profile analysis values were observed and Frank A sausages made with chicken had highest fracturability, hardness and springiness, whereas loin ham and beershinken had highest cohesiveness, gumminess and chewiness. Most meat products had the total microbial counts of less than 3 log CFU/g and Enterbacteriaceae were not detected (< 2 log CFU/g) in this study. These data suggested that the meat products sold in Korean market were various and relatively safe. In addition, well-being meat products, such as low-fat, salt and containing functional ingredient, should be developed to meet the consumer needs these days.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.593-605
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• 2018

The present study was undertaken to assess the efficacy of sapota powder (SP) as natural preservatives and its better utilization in food processing with the incorporation of various levels of SP (2, 4, and 6%) by replacing lean meat. Based on the sensory attributes, pork patties with 4% incorporation of SP was found optimum and selected for further storage studies with control under aerobic and modified atmosphere packaging at refrigeration temperature ($4{\pm}1^{\circ}C$) for 42 days for assessing its antioxidant and antimicrobial efficiency. During entire storage period, indicators of lipid oxidative parameters such as thiobarbituric acid reactive substances (TBARS), free fatty acids (FFA) and peroxide value (PV) followed an increasing trend for control as well as treated products; however, treated product showed a significantly (p<0.05) lower value than control. A significantly lower (p<0.05) microbial count in treated patties than control was noted during entire storage. The sensory attributes are better retained in treated product as compared to control and even on $42^{nd}$ day, overall acceptability of treated patties was found to fall in moderately acceptable category (5.95 in aerobic packets and 5.91 in modified atmosphere packets). Therefore SP has potential to enhance antioxidant and antimicrobial properties of pork patties during storage.

• The Korea Journal of Herbology
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• v.22 no.4
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• pp.75-80
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• 2007

Objectives : This study was conducted to control microorganisms of deer antler products with ethanol and heat process. Methods : The deer antler of Cervus elaphus was used for this study. The sliced deer antler of market condition were processed with 70% ethanol only (酒洗) and 70% ethanol with heat (酒炙). The microorganisms were isolated and incubated on Luria broth (LB) plates at $37^{\circ}C$ for 24 h. Results : The number of isolated microorganism colony were 201.1, 33.5 and 2.0 ea from each sliced deer antler of market condition, 70% ethanol only and 70% ethanol with heat process, respectively. Conclusions : These results suggested that 70% ethanol with heat processing is effective for reducing microbial contamination of deer antler products.

• Archives of Pharmacal Research
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• v.5 no.1
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• pp.21-23
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• 1982

To develop new potent antitumor substancces with low toxicity from natural products, especially from higher fungi of Korea, the carpophores of some wild basidiomycetes were collected and the antitimor test for their polysaccharides was done. The dried carpophores were extracted with hot water, and from the extracts, crude polysaccharides were obtained by alcohol precipitation. The alcohol precipitated crude polysaccharides were partially purified by dialysis and then used as the samples for antitumor tests. Among tested, the polysaccharide of Laccaria laccata, Trametes sanguineus, Armlliariella mellea, Clitocybe in fundibuliformis, and Xeromphalina campanella respectively showed the inhibition ratio of 75%, 72%, 94% 55%, and 47% when administered i. p. once dailly for ten days at the dose level of 20mg/kg/day into the mice implanted with $10^{6}$ cells of sarcoma 180/mouse. However, those of Craterellus cornucopiodes, Daedaleopsis confrogosa, and Coriolus sp. showed almost no activities.