• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.976-986
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• 2018

Knowledge about the gut bacterial communities associated with insects is essential to understand their roles in the physiology of the host. In the present study, the gut bacterial communities of a laboratory-reared insecticide-susceptible (IS), and a field-collected insecticide-resistant (IR) population of a major rice pest, the brown planthopper Nilaparvata lugens, were evaluated. The deep-sequencing analysis of the V3 hypervariable region of the 16S rRNA gene was performed using Illumina and the sequence data were processed using QIIME. The toxicological bioassays showed that compared with the IS population, IR population exhibited 7.9-, 6.7-, 14.8-, and 18.7-fold resistance to acephate, imidacloprid, thiamethoxam, and buprofezin, respectively. The analysis of the alpha diversity indicated a higher bacterial diversity and richness associated with the IR population. The dominant phylum in the IS population was Proteobacteria (99.86%), whereas the IR population consisted of Firmicutes (46.06%), followed by Bacteroidetes (30.8%) and Proteobacteria (15.49%). Morganella, Weissella, and Enterococcus were among the genera shared between the two populations and might form the core bacteria associated with N. lugens. The taxonomic-to-phenotypic mapping revealed the presence of ammonia oxidizers, nitrogen fixers, sulfur oxidizers and reducers, xylan degraders, and aromatic hydrocarbon degraders in the metagenome of N. lugens. Interestingly, the IR population was found to be enriched with bacteria involved in detoxification functions. The results obtained in this study provide a basis for future studies elucidating the roles of the gut bacteria in the insecticide resistance-associated symbiotic relationship and on the design of novel strategies for the management of N. lugens.

• Journal of Ecology and Environment
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• v.48 no.2
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• pp.120-127
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• 2024

Bats serve as vectors and natural reservoir hosts for various infectious viruses, bacteria, and fungi. These pathogens have also been detected in bat feces and can cause severe illnesses in hosts, other animals, and humans. Because pathogens can easily spread into the environment through bat feces, determining the bacterial communities in bat guano is crucial to mitigate potential disease transmission and outbreaks. This study primarily aimed to examine bacterial communities in the feces of insectivorous bats living in South Korea. Fecal samples were collected after capturing 84 individuals of four different bat species in two regions of South Korea, and the bacterial microbiota was assessed through next generation sequencing of the 16S rRNA gene. The results revealed that, with respect to the relative abundance at the phylum level, Myotis bombinus was dominated by Firmicutes (47.24%) and Proteobacteria (42.66%) whereas Miniopterus fuliginosus (82.78%), Rhinolophus ferrumequinum (63.46%), and Myotis macrodactylus (78.04%) were dominated by Proteobacteria. Alpha diversity analysis showed no difference in abundance between species and a significant difference (p < 0.05) between M. bombinus and M. fuliginosus. Beta-diversity analysis revealed that Clostridium, Asaia, and Enterobacteriaceae_g were clustered as major factors at the genus level using principal component analysis. Additionally, linear discriminant analysis effect size was conducted based on relative expression information to select bacterial markers for each bat species. Clostridium was relatively abundant in M. bombinus, whereas Mycoplasma_g10 was relatively abundant in R. ferrumequinum. Our results provide an overview of bat guano microbiota diversity and the significance of pathogenic taxa for humans and the environment, highlighting a better understanding of preventing emerging diseases. We anticipate that this research will yield bioinformatic data to advance our knowledge of overall microbial genetic diversity and clustering characteristics in insectivorous bat feces in South Korea.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.417-426
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• 2020

Bacillus amyloliquefaciens is an important plant disease-preventing and growth-promoting microorganism. B. amyloliquefaciens WS-8 can stimulate plant growth and has strong antifungal properties. In this study, we sequenced the complete genome of B. amyloliquefaciens WS-8 by Pacific Biosciences RSII (PacBio) Single Molecule Real-Time (SMRT) sequencing. The genome consists of one chromosome (3,929,787 bp) and no additional plasmids. The main bacteriostatic substances were determined by genome, transcriptome, and mass spectrometry data. We thereby laid a theoretical foundation for the utilization of the strain. By genomic analysis, we identified 19 putative biosynthetic gene clusters for secondary metabolites, most of which are potentially involved in the biosynthesis of numerous bioactive metabolites, including difficidin, fengycin, and surfactin. Furthermore, a potential class II lanthipeptide biosynthetic gene cluster and genes that are involved in auxin biosynthesis were found. Through the analysis of transcriptome data, we found that the key bacteriostatic genes, as predicted in the genome, exhibited different levels of mRNA expression. Through metabolite isolation, purification, and exposure experiments, we found that a variety of metabolites of WS-8 exert an inhibitory effect on the necrotrophic fungus Botrytis cinerea, which causes gray mold; by mass spectrometry, we found that the main substances are mainly iturins and fengycins. Therefore, this strain has the potential to be utilized as an antifungal agent in agriculture.

• Environmental Analysis Health and Toxicology
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• v.15 no.4
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• pp.131-137
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• 2000

The release of hazardous waste materials into the environment poses serious risks in humans and ecosystems. The risk assessment of environmental pollutants including hazardous chemicals requires a comprehensive measurement of hazard and exposure of the chemicals that can be achieved by toxicity evaluation using a biological system such as biomarkers. In this report we have tried to develop a biomarker used to elucidate a molecular basis of, and to monitor abnormal behaviors caused by diazinon in Japanese medaka (Oryzias latipes) as a model organism. First, an attempt was made to clone tyrosine hydroxylase gene from Japanese medaka that would be a candidate for a biomarker for neuronal modulations and behaviors. For monitoring experiments at behavioral and molecular biological levels, the fish were treated under different sublethal conditions of diazinon and their behavioral responses were observed . In this study we have successfully cloned a partial TH gene from the medaka fish through PCR screening of an ovary cDNA library. DNA sequencing analysis revealed that the amplified fragment was 327 bp encoding 109 amino acids. Comparing the DNA sequence of medaka TH with other species, TH gene revealed the DNA sequence was completely identical to that of rat TH. In the RT-PCR, 330 Up of mRNA was consistently amplified in all the treated samples including control There were no significant differences in the TH expression level regardless of treating concentrations (1∼5,000 ppb) and time (0∼48 hr) The reason appeared to be that RT-PCR was not performed using through a quantitative analysis normalized against an actin gene expression. Organ or tissue - specific detection of TH activity and mRNA as biomarkers will be a useful monitoring tool for neurobehavioral changes in fish influenced by toxic chemicals. Furthermore, quantitative analysis of locomotive patterns and its correlation with the neurochemical and molecular data would be highly useful in measuring toxicity and hazard ofvarious environmental pollutants.

• Journal of Animal Reproduction and Biotechnology
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• v.39 no.2
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• pp.67-80
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• 2024

Background: Post-ovulatory aging (POA) of oocytes is related to a decrease in the quality and quantity of oocytes caused by aging. Previous studies on the characteristics of POA have investigated injury to early embryonic developmental ability, but no information is available on its effects on mitochondrial fission and mitophagy-related responses. In this study, we aimed to elucidate the molecular mechanisms underlying mitochondrial fission and mitophagy in in vitro maturation (IVM) oocytes and a POA model based on RNA sequencing analysis. Methods: The POA model was obtained through an additional 24 h culture following the IVM of matured oocytes. NMN treatment was administered at a concentration of 25 μM during the oocyte culture process. We conducted MitoTracker staining and Western blot experiments to confirm changes in mitochondrial function between the IVM and POA groups. Additionally, comparative transcriptome analysis was performed to identify differentially expressed genes and associated changes in mitochondrial dynamics between porcine IVM and POA model oocytes. Results: In total, 32 common genes of apoptosis and 42 mitochondrial fission and function uniquely expressed genes were detected (≥ 1.5-fold change) in POA and porcine metaphase II oocytes, respectively. Functional analyses of mitochondrial fission, oxidative stress, mitophagy, autophagy, and cellular apoptosis were observed as the major changes in regulated biological processes for oocyte quality and maturation ability compared with the POA model. Additionally, we revealed that the activation of NAD⁺ by nicotinamide mononucleotide not only partly improved oocyte quality but also mitochondrial fission and mitophagy activation in the POA porcine model. Conclusions: In summary, our data indicate that mitochondrial fission and function play roles in controlling oxidative stress, mitophagy, and apoptosis during maturation in POA porcine oocytes. Additionally, we found that NAD⁺ biosynthesis is an important pathway that mediates the effects of DRP1-derived mitochondrial morphology, dynamic balance, and mitophagy in the POA model.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.436-446
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• 2006

The purpose of this study was to isolate and identify the bacteria in chronic maxillary sinusitis (CMS) lesions from 3 patients and to determine the antimicrobial susceptibility of them against 10 antibiotics. One of them was odontogenic origin and the others were non-odontogenic origin. Pus samples were collected by needle aspiration from the lesions and examined by culture method. Bacterial culture was performed in three culture systems (anaerobic, CO2, and aerobic incubator). Identification of the bacteria was performed by 16S rRNA gene (16S rDNA) nucleotide sequencing method. To test the sensitivity of the bacteria isolated from the maxillary sinusitis lesions against seven antibiotics, penicillin G, amoxicillin, tetracycline, ciprofloxacin, cefuroxime, erythromycin, clindamycin, and vancomycin, minimum inhibitory concentration (MIC) was performed using broth dilution assay. Our data showed that enterobacteria such as Enterobacter aerogenes (30%), Klebsiella pneumoniae (25%), and Serratia marcescens (15%) were predominately isolated from the lesion of non-odontogenic CMS of senile patient (70 year old). Streptococcus spp. (40.3%), Actinomyces spp. (27.4%), P. nigrescens, M. micros, and P. anaerobius strains were isolated in the lesion of odontogenic CMS. In the lesion of non-odontogenic CMS, Streptococcus spp. (68.4%), Rothia spp. (13.2%), and Actinomyces sp. (10.5%) were isolated. The susceptibility pattern of 10 antibiotics was determined according to the host of the bacteria strains ratter than the kinds of bacterial species. Even though the number of CMS was limited as three, these results indicate that antibiotic susceptibility test must be accompanied with treatment of CMS. The combined treatment of two or more antibiotics is better than single antibiotic treatment in the presence of multidrug-resistant bacteria in the CMS lesions.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.355-362
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• 2008

This study was carried out to assess the fermentation properties of lactic acid bacteria (LAB) isolated from bovine colostrum and effects of feeding fermented colostrum feed on the growth to piglet. A total of 427 colonies were isolated from bovine colostrum on the BCP plate count agar. These LAB isolated were subcultured in 10% reconstituted skim milk, and seven strain thereof were selected for their highest acid productions, and two strain thereof were finally selected for their excellent sugar utilization. These strains were identified as Streptococcus thermophilus and Streptococcus macedonicus based on l6S rDNA sequencing data, named S. thermophilus CNB-11 and S. macedonicus CNB-11 respectively. For fermentation profiles, sugar utilization, acid production and viable cell counts were excellent in S. thermophilus CNB-11 as compared with S. macedoniclts CNB-11 after 48 hour. The effect of feeding fermented colostrum feed 0.5% using S. thermophilus CNB-11 was investigated for growth rate, analysis of blood and incidence of diarrhea. 24 heads of piglets were divided into two groups: the experimental and the control of 12 animals each. The average growth rate in the pigs fed fermented colostrum feed was higher 16.73% compared with control diet (p<0.05). There were no differences in the concentrations of blood glucose, cholesterol, albumin and globulin in pigs fed fermented colostrum feed as compared with control piglets. Incidence of diarrhea was no in pigs fed fermented colostrum feed as compared with control piglets.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.719-728
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• 2007

The cysteine and glycine rich protein 3 (CSRP3), apolipoprotein B mRNA editing enzyme catalytic polypeptide‐like 2(APOBEC2) and caveolin (CAV) gene family(CAV1, CAV2, CAV3) have been reported to play important roles for carcass and meat quality traits in pig, mouse, human and cattle. As an initial step, we investigated SNPs in these 5 genes among eight different cattle breeds. Eighteen primer pairs were designed from bovine sequence data of NCBI database to amplify the partial gene fragments. Sequencing results revealed 9 SNPs in the coding regions of three caveolin genes, 1 SNP in CSRP3 and 3 SNPs in APOBEC2 gene. All the identified SNPs were confirmed by PCR-RFLP. Also, 9 more intronic SNPs were detected in these genes. However, all identified mutations in the coding region do not change amino acid sequence. Allelic distributions were significantly different for 5 SNPs in CAV2, CAV3, CSRP3 and APOBEC2 genes among the eight different breeds. These results gave some clues about the polymorphisms of these genes among the cattle breeds and will be useful for further searches for identifying association between these SNPs and meat quality traits in cattle.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.5
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• pp.275-282
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• 2005

By using differential display, we identified one of the genes encoding the multi-subunit complex protein V-ATPase, c subunit gene (ATP6L), and showed alterations of the gene expression by oxidative stresses. Expression of the ATP6L gene in Neuro-2A cells was increased by the treatment with $H_2O_2$ and incubation in hypoxic chamber, implying that the expression of the ATP6L gene is regulated by oxidative stresses. To examine mechanisms involved in the regulation of the gene expression by oxidative stresses, the transcriptional activity of the rat ATP6L promoter was studied. Transcription initiation site was determined by primer extension analysis and DNA sequencing, and promoter of the rat ATP6L and its deletion clones were constructed in reporter assay vector. Significant changes of the promoter activities in Neuro-2A cells were observed in two regions within the proximal 1 kbp promoter, and one containing a suppressor was in -195 to -220, which contains GC box that is activated by binding of Sp1 protein. The suppression of promoter activity was lost in mutants of the GC box. We confirmed by electrophoretic mobility shift and supershift assays that Sp1 protein specifically binds to the GC box. The promoter activity was not changed by the $H_2O_2$ treatment and incubation in hypoxic chamber, however, $H_2O_2$ increased the stability of ATP6L mRNA. These data suggest that the expression of the ATP6L gene by oxidative stresses is regulated at posttranscriptional level, whereas the GC box is important in basal activities of the promoter.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1082-1089
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• 2007

Serological anlysis of recombinant cDNA expression libraries (SEREX) has led to identification of several categories of new antigens recognized by the immune system of cancer patients, which are referred to as the cancer immunome. We analyzed normal testis cDNA expression libraries with serumobtained from non-small lung cancer patient and isolated 40 distinct antigen designated KP-LuT-1 through KP-LuT-40. Among these antigens 20 antigens were previously identified by SEREX analysis of other tumor types, and 20 out of 40 antigens (50%) did not match entries in Cancer Immunome Database and were considered newly identified antigens. Sequencing analysis showed that the anti-gens comprised 26 functional known proteins and 14 noble/uncharacterized gene products. Of these, the hypothetical protein KP-LuT-6 was shown tissue-restricted. RT-PCR showed it to be expressed strongly only in normal testis. In addition to normal tissues-restricted expression, KP-LuT-6 mRNA was detected in lung tumor samples(3/l0), stomach tumor samples(3/l0), and breast tumor samples(l/5), whereas not detected in colon tumor samples(O/I2). These data suggest that KP-LuT-6 is a cancer/testis (CT)-like antigen as a potential target for cancer immunotherapies.