• Korean journal of food and cookery science
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• v.29 no.6
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• pp.841-846
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• 2013

Developing a menu for foodservice operations utilizing a Yaksun meets with the desire of customers who have keen interest in health food. In addition, it is possible to expect the additional advantage of decreasing hygiene risk, which can be caused by large quantity cooking, by the efficacy of medicinal herbs used in Yaksun. Accordingly, this study provides with basic information for the development of a Yaksun menu for foodservice operations utilizing Gwackhyang by evaluating the sensory quality and microbiological quality of bean soup added of Gwackhyang. The standard plate counting significantly decreased as the addition quantity of Gwackhyang increased (p<0.001). All bean soups, which were kept at room temperature and refrigerator for 3 hours after cooking, met the safety standard 5.00 CFU/g. The number of coliforms also significantly decreased as the addition quantity of Gwackhyang increased. The bean soups in control group exceeded the safety standard of 2.00 CFU/g after 1 hour at room temperature and in refrigerator. On the other hand, all Gwackhyang bean soups met safety standard, only excluding G1 with 1% Gwackhyang kept at room temperature. Accordingly, it has been confirmed that the addition of Gwackhyang during bean soup production decreases the microorganism level of bean soup. Both standard plate counting and the number of coliforms significantly increased after 3 days in refrigerator; however, the increasing extent of Gwackhyang bean soups were less than the control group bean soups. The control group received scored highest in 3 sensory characteristics out of 5 sensory characteristics. However, G1 with 1% Gwackhyang also scored highest in 2 sensory characteristics, which were taste and overall preference. G2 also scored 4.45 in color and 4.15 in fragrance, which were lower than the control group but were above average.

• Environmental Engineering Research
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• v.15 no.4
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• pp.183-190
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• 2010

Biogenic Mn oxides are expected to have great potential in the control of water pollution due to their high catalytic activity, although information on biological Mn oxidation is not currently sufficient. In this study, the growth of a Mn oxidizing microorganism, Pseudomonas putida MnB1, was examined, with the Mn oxides formed by this strain characterized. The growth of P. putida MnB1 was not significantly influenced by Mn(II), but showed a slightly decreased growth rate in the presence of Pb(II) and EE2, indicating their insignificant adsorption onto the cell surface. Mn oxides were formed by P. putida MnB1, but the liquid growth medium and resulting biogenic solids were poorly crystalline, nano-sized particles. Biogenic Mn oxidation by P. putida MnB1 followed Michaelis-Menten kinetics, with stoichiometric amounts of Mn oxides formed, which corresponded with the initial Mn(II) concentration. However, the formation of Mn oxides was inhibited at high initial Mn(II) concentration, suggesting mass transfer obstruction of Mn(II) due to the accumulation of Mn oxides on the extracellular layer. Mn oxidation by P. putida MnB1 was very sensitive to pH and temperature, showing sharp decreases in the Mn oxidation rates outside of the optimum ranges, i.e. pH 7.43-8.22 and around 20-$26^{\circ}C$.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.327-343
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• 2012

In order to develop a high cellulolytic direct-fed microorganism (DFM) for ruminant productivity improvement, this study isolated cellulolytic bacteria from the rumen of Holstein dairy cows, and compared their cellulolytic abilities via DM degradability, gas production and cellulolytic enzyme activities. Twenty six bacteria were isolated from colonies grown in Dehority's artificial (DA) medium with 2% agar and cultured in DA medium containing filter paper at $39^{\circ}C$ for 24h. 16s rDNA gene sequencing of four strains from isolated bacteria showed that H8, H20 and H25 strains identified as Ruminococcus flavefaciens, and H23 strain identified as Fibrobacter succinogenes. H20 strain had higher degradability of filter paper compared with others during the incubation. H8 (R. flavefaciens), H20 (R. flavefaciens), H23 (F. succinogenes), H25 (R. flavefaciens) and RF (R. flavefaciens sijpesteijn, ATCC 19208) were cultured in DA medium with filter paper as a single carbon source for 0, 1, 2, 3, 4 and 6 days without shaking at $39^{\circ}C$, respectively. Dry matter degradability rates of H20, H23 and H25 were relatively higher than those of H8 and RF since 2 d incubation. The cumulative gas production of isolated cellulolytic bacteria increased with incubation time. At every incubation time, the gas production was highest in H20 strain. The activities of carboxymethylcellulase (CMCase) and Avicelase in the culture supernatant were significantly higher in H20 strain compared with others at every incubation time (p<0.05). Therefore, although further researches are required, the present results suggest that H20 strain could be a candidate of DFM in animal feed due to high cellulolytic ability.

• Journal of Animal Science and Technology
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• v.62 no.2
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• pp.239-246
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• 2020

Microorganism residing in the gut has been known to have important roles in the animal body. Microbes and host microenvironment are highly related with host's health including energy metabolism and immune system. Moreover, it reported that gut microbiome is correlated with diseases like obesity in human and dogs. There have been many studies to identify and characterize microbes and their genes in human body. However, there was little information of microbiome in companion animals. Here, we investigated microbiota communities in feaces from twenty - four Beagles (aged 2 years old) and analyzed the taxonomy profile using metagenomics to study the difference among gut microbiome based on body condition score (BCS). gDNA was isolated from feaces, sequenced and clustered. Taxonomy profiling was performed based on the NCBI database. BCS was evaluated once a week according to the description provided by World Small Animal Veterinary Association. Firmicutes phylum was the most abundant followed by Bacteroidetes, Fusobacteria, Proteobacteria and Actinobacteria. That main microbiota in gut were differently distributed based on the BCS. Fusobacteria has been known to be associated with colon cancer in human. Interestingly, Fusobacteria was in the third level from the top in healthy dog's gut microbiome. In addition, Fusobacteria was especially higher in overweight dogs which had 6 scales of BCS. Species Fusobacterium perfoetens was also more abundant when dogs were in BCS 6. It implied that F. perfoetens would be positively related with overweight in dogs. These finding would contribute to further studies of gut microbiome and their functions to improve dog's diets and health condition.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.470-474
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• 2003

DNA sequence information on small-subunit rRNA gene (16S rDNA) obtained from food-poisoning bacterial culture was used to investigate the presence of bacterial pathogens in food. By reverse dot blot detection method, presence of food-poisoning bacteria could be confirmed on hybridization of digoxigenin-labeled 16S rDNA Polymerase Chain Reaction (PCR) primer product and biotin-labeled specific oligonucleotide probe. Escherichia coli, Bacillus cereus. and Salmonella sp. were used as the representative food-poisoning bacterial microorganisms. An oligonucleotide probe, based on the variable region of 16S rRNA gene, was used as the specific probe. These tools may be more useful than classic biochemical method for rapid identification of contaminated food.

• Journal of Soil and Groundwater Environment
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• v.24 no.4
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• pp.1-10
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• 2019

Recently, groundwater contamination by mixed occurrence of arsenic (As) and nitrate ($NO_3{^-}$) has been a serious environmental issue all around world. In this study, we investigated the microbial As(III) oxidation characteristic under denitrification process to examine the feasibility of the microbial consortia in wetland sediment to simultaneously treat these two contaminants. The detail objectives of this study were to investigate the effects of $NO_3{^-}$ on the oxidation of As(III) in anaerobic environments and observe the microbial community change during the As oxidation under denitrification process. Results showed that the As(III) was completely and simultaneously oxidized to As(V) under denitrification process, however, it occurred to a much less extent in the absence of sediment or $NO_3{^-}$. In addition, the significant increase of As(III) oxidation rate in the presence of $NO_3{^-}$ suggested the potential of As oxidation under denitrification by indigenous microorganisms in wetland sediment. Genera Pseudogulbenkiania, and Flavisolibacter were identified as predominant microbial species driving the redox process. Conclusively, this study can provide useful information on As(III) oxidation under denitrifying environment and contribute to develop an effective technology for simultaneous removal of As(III) and $NO_3{^-}$ in groundwater.

• Journal of Life Science
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• v.29 no.1
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• pp.135-145
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• 2019

Zymomonas mobilis has been recognized as a potential industrial ethanologen for many decades due to its outstanding fermentation characteristics, including high ethanol tolerance, fast sugar uptake rate, and high theoretical ethanol yield. With the emergence of the postgenomic era and the recent announcement of DuPont's world largest cellulosic ethanol production process, research on this bacterium has become even more important to harness successful application not only for use in the bioethanol process but also in other biochemical processes, which can be included in bio-refinery. As an important industrial microorganism, Z. mobilis will likely be exposed to various stressful environments, such as toxic chemicals, including the end-product ethanol and fermentative inhibitory compounds (e.g., furan derivatives, organic acids, and lignin derivatives in pretreatment steps), as well as physical stresses, such as high temperature during large-scale ethanol fermentation. This review focuses on recent information related to the industrial robustness of this bacterium and strain development to improve the ethanol yield and productivity in the lignocellulosic ethanol process. Although several excellent review articles on the strain development of this bacterium have been published, this review aims to fill gaps in the literature by highlighting recent advances in physiological understanding of this bacterium that may aid strain developments and improve the ethanol productivity for lignocellulosic biomass.

• Mycobiology
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• v.48 no.6
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• pp.476-483
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• 2020

The genus Pholiota (Strophariaceae, Basidiomycota) is made up of wood-rotting saprotrophic mushrooms characterized by a yellow or brown pileus with scales and/or slimy, and by a brownish smooth spore with a germ pore. However, these features are not enough to distinguish its species, or separate the genus Pholiota from other brown-spored wood-rotting genera such as Hypholoma and Stropharia. Although internal transcribed spacer (ITS) sequencebased identification has improved identification accuracy for species of Pholiota, most Pholiota species in Korea are reported based on morphological features. To evaluate the taxonomy of Pholiota species, we investigated 62 specimens collected from 1999 to 2019 in Korea using ITS sequence analysis and morphological observation. Twelve of the 16 recorded Pholiota species in Korea were identified. While eight species were clearly separated, the ITS analysis did not distinguish three in the Pholiota adiposa complex. Therefore, further investigation is required to distinguish these three species. ITS sequences deposited in GenBank confirm that P. highlandensis exists in Korea. The presence of the other four Pholiota species could not be confirmed through specimens or sequence information in GenBank. A taxonomic key and the ITS sequence data for Korean Pholiota species are included and can be good baselines for further research on Pholiota taxonomy and diversity.

• KSBB Journal
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• v.21 no.2
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• pp.144-150
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• 2006

The exploitation of metagenome, the access to the natural extant of enormous potential resources, is the way for elucidating the functions of organism in environmental communities, for genomic analyses of uncultured microorganism, and also for the recovery of entirely novel natural products from microbial communities. The major breakthrough in metagenomics is opened by the construction of libraries with total DNAs directly isolated from environmental samples and screening of these libraries by activity and sequence-based approaches. Screening with activity-based approach is presumed as a plausible route for finding new catabolic genes under designed conditions without any prior sequence information. The main limitation of these approaches, however, is the very low positive hits in a single round of screening because transcription, translation and appropriate folding are not always possible in E. coli, a typical surrogate host. Thus, to obtain information about these obstacles, we studied the genetic organization of individual URF's(unidentified open reading frame from metagenome sequenced and deposited in GenBank), especially on the expression factors such as codon usage, promoter region and ribosome binding site(rbs), based on DNA sequence analyses using bioinformatics tools. And then we also investigated the above-mentioned properties for 4100 ORFs(Open Reading Frames) of E. coli K-12 generally used as a host cell for the screening of noble genes from metagenome. Finally, we analyzed the differences between the properties of URFs of metagenome and ORFs of E. coli. Information derived from these comparative metagenomic analyses can provide some specific features or environmental blueprint available to screen a novel biocatalyst efficiently.