• 한국미생물·생명공학회지
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• 제48권3호
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• pp.328-336
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• 2020

본 연구에서는 국내 낙동강 수계에서 신규하게 분리된 미세조류인 Parachlorella sp. 종의 바이오매스 및 지방산 생산성에 대한 배지의 영향을 연구하였다. 미세조류 배양에 통상적으로 사용되는 BG-11, TAP, BBM 배지를 사용하여 바이오매스 생산성은 TAP 배지에서, 지방산 축적은 BBM 배지에서 가장 잘 일어나는 것으로 확인되었고, 지방산 생산성을 향상시키기 위해 암모니아와 아세트산을 사용하는 TAP 배지의 조성을 변화하여 BBM 배지처럼 지방산 축적을 유도하며 바이오매스 생산성을 증가시킨 MTAP 배지를 개발하였다. 전체적인 바이오매스와 지방산 생산성을 높이기 위해서는 MTAP-1 배지가 적합하여 바이오매스 생산성과 지방산 생산성은 기존의 TAP 배지 대비 각각 14%, 45% 증가하였다. 생리 활성 효과로 인해 관심도가 높은 오메가-3 지방산의 생산에는 MTAP-4 배지가 가장 적합하여 바이오매스 생산성과 오메가-3 지방산 생산성이 기존 BBM 배지 대비 각각 18%, 39% 증가하여 목표 중점 생산물질(바이오매스, 총 지방산, 또는 오메가-3 지방산)의 생산성을 향상시킬 수 있는 신규 배지 2종의 조성을 개발하였다.

• 한국식품영양과학회지
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• 제37권5호
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• pp.671-675
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• 2008

대다수 숙성 김치의 미생물 조성이 L. mesenteroides와 L. sakei로 구성되며, 이러한 혼합조성을 가진 김치가 맛이 있다는 점을 바탕으로 김치 맛을 가장 좋게 하며 김치 미생물을 조절하는 능력을 가진 두 균주 L. mesenteroides K2M5와 L. sakei K5M3을 각각 김치스타터로 선정하였다. 선정된 두 가지 균주들은 베타 용혈현상을 보이지 않았고, 암모니아나 인돌을 생성하지 않았으며, 젤라틴을 용해하지 않았고, phenylalanine deaminase, ${\beta}$-glucuronidase, ${\beta}$-glucosidase, 7${\alpha}$-dehydroxylase, nitroreductase 등의 효소 활성에서 음성을 보여 산업적으로 사용하여도 안전한 것으로 나타났다. 선정된 두 가지 균주를 첨가하여 제조한 김치는 비첨가 김치에 비해 실험실 평가와 다수의 일반인을 상대로 한 비교평가에서 맛이 더 우수하였고, 미생물 조성은 오직 첨가한 균주로만 구성되어 선정한 균주들은 김치 맛을 좋게 하고 미생물 조성을 일정하게 조절하는 능력이 있는 스타터로 사용될 수 있음을 보여주었다. 스타터를 첨가한 김치는 대조김치에 비해 젖산 등의 유기산 함량이 특이하게 높았으나 산도, 염도, 당 함량 등에서는 큰 차이를 나타내지 않았다.

• Journal of Microbiology and Biotechnology
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• 제6권3호
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• pp.213-218
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• 1996

Hot-water extract, Fr. 1, of Phellinus linteus mycelium was fractionated into Fr. 2, 3, 4, and 5 by the difference of solubility in ethanol. The polysaccharide fractions were studied for their immunostimulating activity on in vitro T-independent polyc1onal antibody response to trinitrophenyl-haptened SRBC (sheep red blood cell). The Fr. 4 with the highest immunostimulating activity was subjected to DEAE-cellulose ion exchange chromatography and gave five fractions, 4-I, II, III, IV, and V. The in vitro immunostimulating assay of the five fractions showed that 4-I and 4-III had a similar activity to that of LPS but the other fractions had low activity. By analyses of chemical composition and HPLC, all fractions obtained were found to be heteropolysaccharide-protein complex. The molecular weights ranged from 9, 000 to 15, 000. Sugar analyses showed that glucose, galactose, mannose, arabinose, and xylose were main component. Uronic acid and amino sugar were also detected in the fractions. It should be noted that the molecular weight (15, 000) of 4-III was very small and the structure of 4-III may be different from the known immunostimulating branched $\beta$-(1longrightarrow3)-glucan.

• Asian-Australasian Journal of Animal Sciences
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• 제30권9호
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• pp.1261-1269
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• 2017

Objective: The effect of flavonoids from alfalfa on the microbial flora was determined using molecular techniques of 16S ribosome deoxyribonucleic acid (rDNA) analysis. Methods: Four primiparous Holstein heifers fitted with ruminal cannulas were used in a $4{\times}4$ Latin square design and fed a total mixed ration to which alfalfa flavonoids extract (AFE) was added at the rates of 0 (A, control), 20 (B), 60 (C), or 100 (D) mg per kg of heifer BW. Results: The number of operational taxonomic units in heifers given higher levels of flavonoid extract (C and D) was higher than for the two other treatments. The Shannon, Ace, and Chao indices for treatment C were significantly higher than for the other treatments (p<0.05). The number of phyla and genera increased linearly with increasing dietary supplementation of AFE (p<0.05). The principal co-ordinates analysis plot showed substantial differences in the microbial flora for the four treatments. The microbial flora in treatment A was similar to that in B, C, and D were similar by the weighted analysis. The richness of Tenericutes at the phylum level tended to increase with increasing AFE (p = 0.10). The proportion of Euryarchaeota at the phylum level increased linearly, whereas the proportion of Fusobacteria decreased linearly with increasing AFE supplementation (p = 0.04). The percentage of Mogibacterium, Pyramidobacter, and Asteroleplasma at the genus level decreased linearly with increasing AFE (p<0.05). The abundance of Spirochaeta, Succinivibrio, and Suttonella at the genus level tended to decrease linearly with increasing AFE (0.05

• 한국토양비료학회지
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• 제49권2호
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• pp.144-156
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• 2016

Soil is a dynamic biological system, in which it is difficult to determine the composition of microbial communities. Knowledge of microbial diversity and function in soils are limited because of the taxonomic and methodological limitations associated with studying the organisms. In this review, approaches to measure microbial diversity in soil were discussed. Research on soil microbes can be categorized as structural diversity, functional diversity and genetic diversity studies, and these include cultivation based and cultivation independent methods. Cultivation independent technique to evaluate soil structural diversity include different techniques such as Phospholipid Fatty Acids (PLFA) and Fatty Acid Methyl Ester (FAME) analysis. Carbon source utilization pattern of soil microorganisms by Community Level Physiological Profiling (CLPP), catabolic responses by Substrate Induced Respiration technique (SIR) and soil microbial enzyme activities are discussed. Genetic diversity of soil microorganisms using molecular techniques such as 16S rDNA analysis Denaturing Gradient Gel Electrophoresis (DGGE) / Temperature Gradient Gel Electrophoresis (TGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP), Single Strand Conformation Polymorphism (SSCP), Restriction Fragment Length Polymorphism (RFLP) / Amplified Ribosomal DNA Restriction Analysis (ARDRA) and Ribosomal Intergenic Spacer Analysis (RISA) are also discussed. The chapter ends with a final conclusion on the advantages and disadvantages of different techniques and advances in molecular techniques to study the soil microbial diversity.

• 한국구조물진단유지관리공학회 논문집
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• 제28권4호
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• pp.62-67
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• 2024

이 논문에서는 콘크리트 내 미생물을 보호하는 최적의 미생물 담체로서 세포 친화적이며 높은 수분 흡수율과 미생물의 생체광물형성 조건을 효과적으로 부여하면서 균일한 제작 및 보관이 가능한 키토산 기반 고분자 미생물 비드 담체를 개발·최적화하고 이를 적용한 모르타르의 자기치유성능을 분석하였다. 원형 모양의 미생물 내생포자를 혼입하기 위하여 키토산과 알지네이트 고분자를 조합한 원형 형태의 미생물 비드 담체를 개발하였으며, 담체 내 조성물질의 조절로 탄산칼슘 생성량을 능동적으로 조절할 수 있었다. 키토산을 포함한 하이드로젤 비드담체에서 생체광물 형성량과 결정의 크기가 최대로 나타났으며, 이를 적용한 모르타르 균열의 경우, 균열 발생 후 96시간 이내에 최대균열폭 0.3mm의 균열이 자기치유가 완료됨을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.15-21
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• 2003

Two microbial communities of activated sludge in the same municipal wastewater, but treated with different systems, were studied and compared using molecular microbiological approaches. The bacterial 16S rDNA sequences from 124 clones were analyzed, however, the majority of them were not closely related to any known species, and found to belong to 8 different phylogenetic groups and 3 different unidentified groups. The relative frequencies of each group were similar between the two microbial communities. Fingerprinting using terminal restriction fragment length polymorphism (T-RFLP) showed that the putative Nitrospira-related populations were more diverse and quantitatively higher in the KNR process system than in the other system using a conventional activated sludge process. The relationship between the bacterial community composition and the higher removal efficiency of nitrogen and phosphorus in the KNR process is discussed.

• Membrane and Water Treatment
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• 제8권4호
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• pp.337-353
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• 2017

Membrane fouling at different solids retention times (SRT) (7, 12 and 20 days) was studied under well-controlled conditions in a laboratory-scale aerobic submerged membrane bioreactor under constant biomass concentration using a synthetic high strength wastewater. An increase in SRT was found to improve membrane performance and this correlated to changes in the total production of bound extracellular polymeric substances (EPS), and the composition and properties of bound EPS using X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FTIR) and floc sizes. A larger amount of total bound EPS was found at the lowest SRT (7 days) tested but the ratio of proteins (PN) to carbohydrates (CH) in bound EPS increased with an increase in SRT. Similarly, the quantity of soluble microbial products (SMP) decreased with an increase in SRT and the SMP PN/CH ratio increased with an increase in SRT. SMP concentrations positively correlated to the percentage of membrane pore blocking resistance. The quantity of total bound EPS and total SMP positively corresponded to the membrane fouling rate, while the PN/CH ratio in the bound EPS and SMP negatively correlated to the membrane fouling rate. The results show that both the quantity and composition of bound EPS and SMP and floc sizes are important in controlling membrane fouling.

• 보존과학회지
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• 제37권4호
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• pp.357-361
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• 2021

In order to determine the changes in microbial community due to termites, soil microorganisms surrounding the termites were investigated. First, bacterial communities from soil with termites collected at Seonamsa temple, Suncheon city, Korea were compared by next-generation sequencing (NGS, Illumina Miseq). The bacterial composition of soil from Daeungjeon without termites and the soil from Josadang, Palsangjeon, and Samjeon with termites were compared. Next, the bacterial composition of these soils was also compared with that of humus soil cultured with termites. A total high-quality sequences of 71,942 and 72,429 reads were identified in Seonamsa temple's soil and humus soil, respectively. The dominant phyla in the collected Seonamsa temple's soil were Proteobacteria (27%), Firmicutes (24%) and Actinobacteria (21%), whereas those in the humus soil were Bacteriodetes (56%) and Proteobacteria (37%). Using a two-dimensional plot to explain the principal coordinate analysis of operational taxonomic unit compositions of the soil samples, it was confirmed that the samples were divided into soil with and without termites, and it was especially confirmed that the Proteobacteria phylum was increased in humus soil with termites than in humus soil without termites.

• Mycobiology
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• 제49권3호
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• pp.249-257
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• 2021

Plants pollination are conducted through various pollinators such as wind, animals, and insects. Recently, the necessity for artificial pollination is drawing attention as the proportion of natural pollinators involved is decreasing over the years. Likewise, the trade in pollen for artificial pollination is also increasing worldwide. Through these imported pollens, many unknown microorganisms can flow from foreign countries. Among them, spores of various fungi present in the particles of pollen can be dispersed throughout the orchard. Therefore, in this study, the composition of fungal communities in imported pollen was revealed, and potential ecological characteristics of the fungi were investigated in four types of imported pollen. Top 10 operational taxonomic unit (OTU) of fungi were ranked among the following groups: Alternaria sp., Cladosporium sp., and Didymella glomerata which belong to many pathogenic species. Through FUNGuild analysis, the proportion of OTUs, which is assumed to be potentially plant pathogens, was higher than 50%, except for apple pollen in 2018. Based on this study of fungal structure, this information can suggest the direction of the pollen quarantine process and contribute to fungal biology in pollen