• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2060-2065
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• 2016

Characteristics of E. coli O157:H7-specific infection bacteriophages (O157 coliphages) and broad-host-range bacteriophages for other E. coli serotypes (broad-host coliphages) were compared. The burst sizes of the two groups ranged from 40 to 176 PFU/infected cell. Distributions of the virulence factors stx1, stx2, ehxA, and saa between the two groups were not differentiated. Broad-host-range coliphages showed lower stability at $70^{\circ}C$, in relation to O157 coliphages. However, O157 coliphages showed high acid and ethanol tolerance by reduction of only 22% and 11% phages, respectively, under pH 3 and 70% ethanol for 1 h exposure. Therefore, these results revealed that the O157 coliphages might be more stable under harsh environments, which might explain their effective infection of the acid-tolerant E. coli O157:H7.

• Food Science and Industry
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• v.52 no.3
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• pp.241-260
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• 2019

Prebiotics are defined as substrates that are selectively utilized by host microorganisms conferring various health benefits. Current prebiotic researches not only focus on non-digestible oligosaccharides, but also extend to polyphenols and peptides. However, the extended scope of prebiotic research pertains its original purposes: promotion of beneficial bacteria in host guts and production of valuable metabolites. Maintenance of optimal gut microflora plays a key role in host health care benefits including anti-cancer activity, immune response modulation, blood lipid level reduction, increased mineral absorption, and weight loss. With increasing probiotics markets, prebiotics have also received much attention in functional food markets. Hence, many global food companies tempt to develop new prebiotics applicable for preventing human diseases as well as modulating immune system. In this review, we discuss current status of prebiotics research, market progress, and future perspectives of prebiotics.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.624-632
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• 2017

Penicillium expansum causes blue mold rot, a prevalent postharvest disease of pome fruit, and is also the main producer of the patulin. However, knowledge on the molecular mechanisms involved in this pathogen-host interaction remains largely unknown. In this work, a two-dimensional gel electrophoresis-based proteomic approach was applied to probe changes in P. expansum 3.3703 cultivated in apple juice medium, which was used to mimic the in planta condition. The results showed that the pH value and reducing sugar content in the apple juice medium decreased whereas the patulin content increased with the growing of P. expansum. A total of 28 protein spots that were up-regulated in P. expansum when grown in apple juice medium were identified. Functional categorization revealed that the identified proteins were mainly related to carbohydrate metabolism, secondary metabolism, protein biosynthesis or degradation, and redox homeostasis. Remarkably, several induced proteins, including glucose dehydrogenase, galactose oxidase, and FAD-binding monooxygenase, which might be responsible for the observed medium acidification and patulin production, were also detected. Overall, the experimental results provide a comprehensive interpretation of the physiological and proteomic responses of P. expansum to the host plant environment, and future functional characterization of the identified proteins will deepen our understanding of fungi-host interactions.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.1
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• pp.93-119
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• 2014

Tropical tasar silkworm, Antheraea mylitta (Lepidoptera: Saturniidae) is a polyphagous silk producing forest silkworm of commercial importance in India. Forest dependent people rear its larvae on different forestry host plants twice or thrice in a year for small household income. Larvae of A. mylitta feeds on many forest tree species, but always show a great degree of selectivity as a function of its behavioural responses to physical structure and chemical features of the host plants. Cocoon crop of A. mylitta is influenced by heterogeneity of tasar food plants and climatic conditions of the habitat. The role of host plants, temperature, humidity, rainfall, photoperiod and climatic variables on the growth and development of insects have clearly been demonstrated. This article entails an in-depth analysis on ecological and nutritional aspects of A. mylitta, which may provide selective information to researcher and forest managers, who are particularly associated with livelihood improvement of the poor people in forested area through location specific forest insect industry.

• Microbiology and Biotechnology Letters
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• v.29 no.1
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• pp.1-11
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• 2001

Lactic acid bacteria (LAB) are widely used for various food fermentation. With the recent advances in modern biotechnology, a variety of bio-products with the high economic values have been produced using microorganisms. For molecular cloning and expression studies on the gene of interest, E. coli has been widely used mainly because vector systems are fully developed. Most plasmid vectors currently used for E, coli carry antibiotic-resistant markers. As it is generally believed that the antibiotic resistance markers are potentially transferred to other bacteria, application of the plasmid vectors carrying antibiotic resistance genes as selection markers should be avoided, especially for human consump-tion. By contrast, as LAB have some desirable traits such that the they are GRAS(generally recognized as safe), able to secrete gene products out of cell, and their low protease activities, they are regarded as an ideal organism for the genetic manipulation, including cloning and expression of homologous and heterologous genes. However, the vec-tor systems established for LAB are stil insufficient to over-produce gene products, stably, limiting the use of these organisms for industrial applications. For a past decade, the two popular plasmid vectors, pAM$\beta$1 of Streptococcus faecalis and pGK12 theB. subtilis-E. coli shuttle vector derived from pWV01 of Lactococcus lactis ssp. cremoris wg 2, were most widely used to construct efficient chimeric vectors to be stably maintained in many industrial strains of LAB. Currently, non-antibiotic markers such as nisin resistance($Nis^{r}$ ) are explored for selecting recombi-nant clone. In addition, a gene encoding S-layer protein, slp/A, on bacterial cell wall was successfully recombined with the proper LAB vectors LAB vectors for excretion of the heterologous gene product from LAB Many food-grade host vec-tor systems were successfully developed, which allowed stable integration of multiple plasmid copies in the vec-mosome of LAB. More recently, an integration vector system based on the site-specific integration apparatus of temperate lactococcal bacteriophage, containing the integrase gene(int) and phage attachment site(attP), was pub-lished. In conclusion, when various vector system, which are maintain stably and expressed strongly in LAB, are developed, lost of such food products as enzymes, pharmaceuticals, bioactive food ingredients for human consump-tion would be produced at a full scale in LAB.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.323-327
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• 2014

To analyze the characteristics of bacteriophages in Enterococcus faecium, D-19 and F6 phages were induced from five E. faecium isolated from sprouts by the treatment with mitomycin C. The bacteriophages of D-19 and F-6 had long, non-contractile tails and icosahedral heads, and were members of Siphoviridae family. As the host spectrum, D-19 phage lysed five out of 55 strains of E. faecium, whereas F6 phage lysed only three strains. Both D-19 and F6 phages displayed similar and high stabilities against ethanol and pH capable of resisting the exposure to 100% ethanol and pH 4.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.329.2-330
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• 2002

This study was intended to establish test methods equivalent to those of "Interferon alfa-2 concentrated solution" monograph in European Pharmacophoeia(EP). Two recombinant interferon alfa concentrated solutions manufactured in Korea were tested according to the monograph of EP. Tests of identification(biological activity. isoelectric focusing. SDS-PAGE under reducing condition, peptide mapping). related proteins. impurities of moducular masses differing from that of interferon alfa-2(SDS-PAGE under reducing and non-reducing condition). bacterial endotoxin, protein, potency, host-cell-derrved proteins. and host-cell-derived DNA were performed in the laboratories of manufacrues and division of biotechnology. KFDA. The results of this study showed that specitications of interfenon alfa concentrated solutions manufactured in Korea were within the aceptance criteria of EP. Based on the study. specitications and test methods for interferon alfa concentrated solution can be established according to the monograph of EP suggesting the revision of Minimum requirements for biological products

• Proceedings of the Korean Nutrition Society Conference
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• 2002.05a
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• pp.175-175
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• 2002

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.5 no.2
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• pp.68-70
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• 2024

The genus Charops is one of the small genera of the subfamily Campopleginae with 30 species reporded worldwide. All of the known host insects of Charops striatus belong to the lepidopteran family Zygaenidae, perceived as harmful. C. striatus, one of the endoparasitoids from Elcysma westwoodi, is the most damaging lepidopteran pest of Prunus yedoensis. In South Korea, host plants of C. striatus were reported by Choi & Lee in 2008. In this paper, two new host plants, Crepidiastrum denticulatum and Zea mays, of Charops striatus are reporded for the first time from South Korea. Digital images and redescription of this species are provided.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.655-658
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• 2008

Although arabinose isomerase (E.C. 5.3.1.4), a commercial enzyme for edible tagatose bioconversion, can be expressed in an Escherichia coli system, this expression system might leave noxious by-products in food. To develop an eligible tagatose bioconversion with food-safe system, we compared the tagatose production activity of immobilized arabinose isomerase expressed in Bacillus subtilis (a host generally recognized as safe) with that of the enzyme expressed in E. coli. A 48% increase in tagatose production (4.3 g tagatose/L at $69.4\;mg/L{\cdot}hr$) was found using the B. subtilis-expressed immobilized enzyme system, compared to the E. coli-expressed enzyme system (2.9 g tagatose/L). The increased productivity with safety of the B. subtilis-expressed arabinose isomerase suggests that it is a more eligible candidate for commercial tagatose production.