• Korean Journal of Microbiology
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• v.51 no.3
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• pp.209-220
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• 2015

In this study, gut bacterial communities in xylophagous insects were analyzed using the pyrosequencing of 16S rRNA genes for their potential biotechnological applications in lignocelluloses degradation. The result showed that operational taxonomic units (OTUs), species richness and diversity index were higher in the hindgut than in the midgut of all insect samples analyzed. The dominant phyla or classes were Firmicutes (54.0%), Bacteroidetes (14.5%), ${\gamma}-Proteobacteria$ (12.3%) in all xylophagous insects except for Rhinotermitidae. The principal coordinates analysis (PCoA) showed that the bacterial community structure mostly clustered according to phylogeny of hosts rather than their habitats. In our study, the two carboxymethyl cellulose (CMC)-degrading isolates which showed the highest enzyme activity were most closely related to Bacillus toyonensis $BCT-7112^T$ and Lactococcus lactis subsp. hordniae $NCDO\;2181^T$, respectively. Cellulolytic enzyme activity analysis showed that ${\beta}-1,4-glucosidase$, ${\beta}-1,4-endoglucanase$ and ${\beta}-1,4-xylanase$ were higher in the hindgut of Cerambycidae. The results demonstrate that xylophagous insect guts harbor diverse gut bacteria, including valuable cellulolytic bacteria, which could be used for various biotechnological applications.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.15-21
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• 1997

The influence of delayed(1, 2, 3, 4 days) feeding and starvation on morphological change and survival rate of the spotted sea bass larvae was examined at the KORDI laboratories which located at Poryong Power Plant, Poryong-gun, Chungchongnam-do in November, 1996. 1. The larvae of spotted sea bass began to feed on rotifers at 5 days after hatching. In case of non-feeding, all of the larvae died at 9 days after hatching. The larvae which fed 1 day after the normal first feeding schedule(1 day delayed) grew normally and 2 days delayed groups showed 5.3% in survival rate at 9 days after hatching. In case of non-feeding and 3 or 4 days delayed groups, all of the larvae died between 9 and 10 days after hatching. 2. In case of non-feeding, total length of the larvae decreased gradually. 3. The percente ratio of gut height and mytome height to standard length in starved larvae has declined most rapidly compare to other demensions during the non-feeding period. The percente ratio of gut height to mytome height had also difference between unfed and fed larvae. At 9 days after hatching, the ratio of that between fed and unfed larvae were 84.5 % and 52.4 %, respectively. 4. The morphology of starving larvae were characterized as sharpened jaw, projected edge of lower part of clavicle and bending trunk with slenger gut.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.484-490
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• 1985

Gut contents of larval gunnels collected in Kyonggi Bay, Yellow Sea were examined in order to understand the feeding habit of the fish. There were some differences in the gut contents depending upon the body length of the fish. Most important food organisms were Copepoda followed by Appendicularia, fish eggs and Decapoda larvae. Although major food organisms were closely related to the size of zooplankton population, the fish showed a positive food selectivity for Copepoda with increasing body lengh, while there was a negative selectivity for Chaetognatha regardless of body length. However, there appeared to be no size preference on the food organisms by the larval gunnel.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.878-888
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• 2018

In the current study, the probiotic potential of approximately 250 strains of lactic acid bacteria (LAB) isolated from piglet fecal samples were investigated; among them Lactobacillus plantarum strain JDFM LP11, which possesses significant probiotic potential, with enhanced acid/bile tolerance, attachment to porcine intestinal epithelial cells (IPEC-J2), and antimicrobial activity. The genetic characteristics of strain JDFM LP11 were explored by performing whole genome sequencing (WGS) using a PacBio system. The circular draft genome have a total length of 3,206,883 bp and a total of 3,021 coding sequences were identified. Phylogenetically, three genes, possibly related to survival and metabolic activity in the porcine host, were identified. These genes encode p60, lichenan permease IIC component, and protein TsgA, which are a putative endopeptidase, a component of the phosphotransferase system (PTS), and a major facilitator in the gut environment, respectively. Our findings suggest that understanding the functional and genetic characteristics of L. plantarum strain JDFM LP11, with its candidate genes for gut health, could provide new opportunities and insights into applications in the animal food and feed additive industries.

• Journal of Microbiology and Biotechnology
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• v.24 no.2
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• pp.133-143
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• 2014

The development of the gut is controlled and modulated by different interacting mechanisms, such as genetic endowment, intrinsic biological regulatory functions, environment influences and last but no least, the diet influence. In this work, we compared the fecal microbiota of breast-fed (BF), formula-fed (FF), and mixed-fed (MF) infants from Hebei Province, China. By using high-throughput 16S rDNA sequencing analyses, we found some differences in gut microbiota in the three groups. Firmicutes and Proteobacteria were the dominant bacteria at the phylum level in the three groups, where FF infants showed a significant depletion in Bacteroidetes (p < 0.001) and Actinobacteria (p < 0.05). Enterobacteriaceae was the dominant bacteria at the family level in the three groups, but FF infants showed higher Enterobacteriaceae enrichment than BF and MF infants (p < 0.05); the abundance of the Bifidobacteriaceae was only 8.16% in the feces of BF infants, but higher than in MF and FF infants (p < 0.05). The number of genera detected (abundance >0.01%) in BF, MF, and FF infants was only 15, 16, and 13, respectively. This study could provide more accurate and scientific data for the future study of infant intestinal flora.

• Korean Journal of Veterinary Research
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• v.44 no.2
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• pp.171-177
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• 2004

The regional distributions and frequencies of argentaffin endocrine cells in gastrointestinal (GI) tract of osteoporotic Sprague-Dawley rat induced by ovariectomy were studied by Masson-Hamperl silver stain. The experimental animals were divided into two groups, one is non-ovariectomized group (Sham) and the other is ovariectomized group (OVX). Samples were collected from each part of GI tract (fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum) at 10th week after ovariectomy or sham operation. Argentaffin cells were detected throughout the entire GI tract with various frequencies regardless of ovariectomy except for the rectum of OVX in which no cells were detected. Most of these argentaffin cells in the mucosa of GI tract were generally spherical or spindle in shape (open type cell) while cells showing round in shape (close type cell) were rarely found in gland regions. Significant decrease of argentaffin cells was detected in OVX compared to that of Sham except for the fundus and jejunum. However, in the fundus and jejunum, argentaffin cells in OVX showed similar frequency compared to that of Sham. In conclusion, the endocrine cells are the anatomical units responsible for the production of gut hormones that regulate gut motility and digestion including absorption, and a change in their density would reflect the change in the capacity of producing these hormones and regulating gut motility and digestion. Ovariectomy induced severe quantitative changes of GI argentaffin endocrine cell density, and the abnormality in density of GI endocrine cells may contribute to the development of gastrointestinal symptoms in osteoporosis such as impairments of calcium and some lipids, frequently encountered in patients with postmenopausal osteoporosis.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1247-1259
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• 2018

Raspberries are polyphenol-rich fruits with the potential to reduce the severity of the clinical signs associated with obesity, a phenomenon that may be related to changes in the gut microbiota. The aim of this study was to investigate the effect of raspberry supplementation on the fecal microbiota using an in vivo model of obesity. Obese diabetic db/db mice were used in this study and assigned to two experimental groups (with and without raspberry supplementation). Fecal samples were collected at the end of the supplementation period (8 weeks) and used for bacterial 16S rRNA gene profiling using a MiSeq instrument (Illumina). QIIME 1.8 was used to analyze the 16S data. Raspberry supplementation was associated with an increased abundance of Lachnospiraceae (p = 0.009), a very important group for gut health, and decreased abundances of Lactobacillus, Odoribacter, and the fiber degrader S24-7 family as well as unknown groups of Bacteroidales and Enterobacteriaceae (p < 0.05). These changes were enough to clearly differentiate bacterial communities accordingly to treatment, based on the analysis of UniFrac distance metrics. However, a predictive approach of functional profiles showed no difference between the treatment groups. Fecal metabolomic analysis provided critical information regarding the raspberry-supplemented group, whose relatively higher phytosterol concentrations may be relevant for the host health, considering the proven health benefits of these phytochemicals. Further studies are needed to investigate whether the observed differences in microbial communities (e.g., Lachnospiraceae) or metabolites relate to clinically significant differences that can prompt the use of raspberry extracts to help patients with obesity.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.699-708
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• 2022

Antibiotic exposure during pregnancy have an adversely effects on offspring behavior and development. However, its mechanism is still poorly understood. To uncover this, we added ceftriaxone sodium to the drinking water of rats during pregnancy and conducted three-chamber sociability test, open-field test, and Morris water maze test in 3- and 6-week-old offspring. The antibiotic group offspring showed lower sociability and spatial learning and memory than control. To determine the role of the gut microbiota and their metabolites in the changes in offspring behavior, fecal samples of 6-week-old offspring rats were sequenced. The composition of dominant gut microbial taxa differed between the control and antibiotic groups. KEGG pathway analysis showed that S24-7 exerted its effects through the metabolic pathways including mineral absorption, protein digestion and absorption, Valine, leucine, and isoleucine biosynthesis. Correlation analysis showed that S24-7 abundance was negatively correlated with the level of VEGF, and metabolites associated with S24-7-including 3-aminobutanoic acid, dacarbazine, L-leucine, 3-ketosphinganine, 1-methylnicotinamide, and N-acetyl-L-glutamate-were also significantly correlated with VEGF levels. The findings suggest that antibiotic exposure during pregnancy, specifically ceftriaxone sodium, will adversely affects the behavior of offspring rats due to the imbalance of gut microbiota, especially S24-7, via VEGF and various metabolic pathways.

• Molecules and Cells
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• v.42 no.4
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• pp.313-320
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• 2019

Intraepithelial lymphocytes (IELs) develop through the continuous interaction with intestinal antigens such as commensal microbiome and diet. However, their respective roles and mutual interactions in the development of IELs are largely unknown. Here, we showed that dietary antigens regulate the development of the majority of $CD8{\alpha}{\beta}$ IELs in the small intestine and the absence of commensal microbiota particularly during the weaning period, delay the development of IELs. When we tested specific dietary components, such as wheat or combined corn, soybean and yeast, they were dependent on commensal bacteria for the timely development of diet-induced $CD8{\alpha}{\beta}$ IELs. In addition, supplementation of intestinal antigens later in life was inefficient for the full induction of $CD8{\alpha}{\beta}$ IELs. Overall, our findings suggest that early exposure to commensal bacteria is important for the proper development of dietary antigen-dependent immune repertoire in the gut.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.383-389
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• 2021

Obesity is associated with impaired intestinal epithelial barrier function, which contribute to host systemic inflammation and metabolic dysfunction. Korean traditional foods, fiber-rich bean products, have been various biological activities in anti-inflammatory responses, but has not reported the large intestinal health. In this study, we investigated the intestinal health promoting effect of cooked soybeans (CSB) on high fat diet (HFD)-induced obesity model. SD rat were fed either a HFD or HFD supplemented with 10.6% CSB (HFD+CSB) for animal experimental period. CSB treatment significantly decreased the HFD-induced weights of body and fat. Also, CSB treatment improved HFD-reduced tight junction components (ZO-1, Claudin-1, and Occludin-1) mRNA expression in large intestine tissue. Additionally, histopathological evaluation showed that CSB treatment attenuated the HFD-increased inflammatory cells infiltration and epithelial damages in large intestine tissue. At the genus level, effects of CSB supplement not yet clear, while dietary effects showed differential abundance of several genera including Lactobacillus, Duncaniella, and Alloprevotella. NMDS analysis showed significant microbial shifts by HFD, while CSB did not shift gut microbiota. CSB increased the abundance of the genera Anaerotignum, Enterococcus, Clostridium sensu stricto, and Escherichia/Shigella by linear discriminant analysis effect size analysis, while reduced the abundance of Longicatena and Ligilactobacillus. These findings indicate that CSB supplement improves HFD-deteriorated large intestinal health by the amelioration of tight junction component, while CSB did not shift gut microbiotas.