• 한국환경농학회지
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• 제35권1호
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• pp.32-38
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• 2016

본 연구는 상승온도가 벼재배나 볏짚 및 요소 투입과의 복합작용을 통해 토양미생물에 미치는 영향에 대한 평가를 하였다. 상승온도에 의해 토양이화학성이 부분적으로 영향을 받았으며, 이러한 환경변화는 토양미생물에 간접적인 영향을 줄것으로 판단된다. 온도가 전체 토양미생물 밀도에 미치는 효과는 크지 않았으며, 방선균만 온도의 증가로 감소하였기 때문에 미생물 군집구성이 온도변화에 의해 부분적으로만 영향을 받았다는 것을 보여준다. 또한, 벼 재배에 의해 전체 PLFA 수치가 1.3배 증가하였다는 것은 식물이 토양미생물에 크게 영향을 미칠 수 있는 인자라는 것을 의미한다. 따라서 이러한 미생물 밀도 및 군집 변화가 물질순환이나 토양의 기능성에 미치는 영향에 대한 추가적인 검토가 필요할 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1373-1380
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• 2018

Objective: This study was designed to investigate the effects of temperature and storage time on the evolution of bacterial communities in swine manure. Methods: Manure was stored at $-20^{\circ}C$, $4^{\circ}C$, $20^{\circ}C$, or $37^{\circ}C$ and sampled at 7-day intervals over 28 days of storage, for a total of 5 time points. To assess the bacterial species present, 16S ribosomal RNA gene sequences were analyzed using pyrosequencing. Results: After normalization, 113,934 sequence reads were obtained, with an average length of $466.6{\pm}4.4bp$. The diversity indices of the communities reduced as temperature and storage time increased, and the slopes of rarefaction curves decreased from the second week in samples stored at $-20^{\circ}C$ and $4^{\circ}C$. These results indicate that the richness of the bacterial community in the manure reduced as temperature and storage time increased. Firmicutes were the dominant phylum in all samples examined, ranging from 89.3% to 98.8% of total reads, followed by Actinobacteria, which accounted for 0.6% to 7.9%. A change in community composition was observed in samples stored at $37^{\circ}C$ during the first 7 days, indicating that temperature plays an important role in determining the microbiota of swine manure. Clostridium, Turicibacter, Streptococcus, and Lactobacillus within Firmicutes, and Corynebacterium within Actinobacteria were the most dominant genera in fresh manure and all stored samples. Conclusion: Based on our findings, we propose Clostridium as an indicator genus of swine manure decomposition in an anaerobic environment. The proportions of dominant genera changed in samples stored at $20^{\circ}C$ and $37^{\circ}C$ during the fourth week. Based on these results, it was concluded that the microbial communities of swine manure change rapidly as storage time and temperature increase.

• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1715-1724
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• 2019

Objective: As laying hens become aged, laying performance and egg quality are generally impaired. One of the practical methods to rejuvenate production and egg quality of aged laying hens with decreasing productivity is a forced molting. However, the changes in intestinal microbiota after forced molting of aged hens are not clearly known. The aim of the present study was to analyze the changes in excreta bacterial communities after forced molting of aged laying hens. Methods: A total of one hundred 66-wk-old Hy-Line Brown laying hens were induced to molt by a 2-d water removal and an 11-d fasting until egg production completely ceased. The excreta samples of 16 hens with similar body weight were collected before and immediately after molting. Excreta bacterial communities were analyzed by high-throughput sequencing of bacterial 16S rRNA genes. Results: Bacteroidetes, Firmicutes, and Proteobacteria were the three major bacterial phyla in pre-molting and immediate post-molting hens, accounting for more than 98.0%. Lactobacillus genus had relatively high abundance in both group, but decreased by molting (62.3% in premolting and 24.9% in post-molting hens). Moreover, pathogenic bacteria such as Enterococcus cecorum and Escherichia coli were more abundant in immediate post-molting hens than in pre-molting hens. Forced molting influenced the alpha diversity, with higher Chao1 (p = 0.012), phylogenetic diversity whole tree (p = 0.014), observed operational taxonomic unit indices (p = 0.006), and Simpson indices (p<0.001), which indicated that forced molting increased excreta bacterial richness of aged laying hens. Conclusion: This study improves the current knowledge of bacterial community alterations in the excreta by forced molting in aged laying hens, which can provide increasing opportunity to develop novel dietary and management skills for improving the gastrointestinal health of aged laying hens after molting.

• Journal of Veterinary Science
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• 제22권3호
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• pp.37.1-37.14
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• 2021

Background: Ticks are one of the most common external parasites in dogs, and are associated with the transmission of a number of major zoonoses, which result in serious harm to human health and even death. Also, the increasing number of pet dogs and pet owners in China has caused concern regarding human tick-borne illnesses. Accordingly, studies are needed to gain a complete understanding of the bacterial composition and diversity of the ticks that parasitize dogs. Objectives: To date, there have been relatively few reports on the analysis of the bacterial community structure and diversity in ticks that parasitize dogs. The objective of this study was to investigate the microbial composition and diversity of parasitic ticks of dogs, and assessed the effect of tick sex and geographical region on the bacterial composition in two tick genera collected from dogs in China. Methods: A total of 178 whole ticks were subjected to a 16S ribosomal RNA (rRNA) next generation sequencing analysis. The Illumina MiSeq platform targeting the V3-V4 region of the 16S rRNA gene was used to characterize the bacterial communities of the collected ticks. Sequence analysis and taxonomic assignment were performed using QIIME 2 and the GreenGene database, respectively. After clustering the sequences into taxonomic units, the sequences were quality-filtered and rarefied. Results: After pooling 24 tick samples, we identified a total of 2,081 operational taxonomic units, which were assigned to 23 phyla and 328 genera, revealing a diverse bacterial community profile. The high, moderate and low prevalent taxa include 46, 101, and 182 genera, respectively. Among them, dominant taxa include environmental bacterial genera, such as Psychrobacter and Burkholderia. Additionally, some known tick-associated endosymbionts were also detected, including Coxiella, Rickettsia, and Ricketssiella. Also, the potentially pathogenic genera Staphylococcus and Pseudomonas were detected in the tick pools. Moreover, our preliminary study found that the differences in microbial communities are more dependent on the sampling location than tick sex in the tick specimens collected from dogs. Conclusions: The findings of this study support the need for future research on the microbial population present in ticks collected from dogs in China.

• 대한수의학회지
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• 제64권2호
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• pp.17.1-17.10
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• 2024

This study examined the colostrum nutritive composition, immunoglobulin (Ig), and microbial community in Holstein and Jersey dairy cows according to the time after calving. The experiment used seven Holstein and three Jersey dairy cows. Colostrum was collected immediately after calf calving, 12, and 24 hours, and stored at -80℃ until analysis. An analysis of the nutritive composition in colostrum was performed using LactoScop. The immune indicators were analyzed using an ELISA Kit, and the microbial community was assessed using a Macrogen Inc. The protein level was high in all colostrum samples from Holstein dairy cows compared with Jersey dairy cows, but there was no significant difference according to the time after calving. Immune index analysis revealed high IgG and IgA concentrations in the colostrum of Holstein cows immediately after calving and 12 and 24 hours after calving, but the differences were not significant. The microbial community at the genus level revealed Staphylococcus to be predominant at a high rate in the colostrum of Holstein dairy cows and Enterococcus in Jersey dairy cows 12 hours after calving. Pseudomonas was predominant at a high rate in the colostrum of Jersey lactating cows immediately and 12 hours after calving. Chryseobacterium was predominant at a high rate in Holstein dairy cows 12 and 24 hours after calving. In conclusion, these results are expected to be used as research data on the correlation between quality, immunity, and microbial community in the colostrum.

• Journal of Periodontal and Implant Science
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• 제46권3호
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• pp.136-151
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• 2016

Peri-implant disease is a serious problem that plagues today's dentistry, both in terms of therapy and epidemiology. With the expansion of the practice of implantology and an increasing number of implants placed annually, the frequency of peri-implant disease has greatly expanded. Its clinical manifestations, in the absence of a globally established classification, are peri-implant mucositis and peri-implantitis, the counterparts of gingivitis and periodontitis, respectively. However, many doubts remain about its features. Official diagnostic criteria, globally recognized by the dental community, have not yet been introduced. The latest studies using metagenomic methods are casting doubt on the assumption of microbial equivalence between periodontal and peri-implant crevices. Research on most of the features of peri-implant disease remains at an early stage; moreover, there is not a commonly accepted treatment for it. In any case, although the evidence so far collected is limited, we need to be aware of the current state of the science regarding this topic to better understand and ultimately prevent this disease.

• 대한수의학회지
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• 제61권1호
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• pp.2.1-2.6
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• 2021

The reproductive tracts have an intimate relationship with reproduction because there are bacterial communities that can affect reproductive health. The differences in the bacterial community of periparturient dairy cows were investigated. Vaginal and fecal samples were collected seven days before and after calving, and DNA was extracted to sequence the V3-V4 regions of the 16S rRNA genes. In the postpartum vaginas, operational taxonomic units, Chao1, Shannon, and Simpson were decreased, and phyla Fusobacteria and Bacteroidetes were increased. In summary, bacterial abundance can affect the periparturient biological differences in dairy cows, suggesting a susceptibility to infection within one week after calving.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1205-1212
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• 2018

Objective: The aim of this experiment was to evaluate the effects of different dietary ratio of metabolizable glucose (MG) to metabolizable protein (MP) on growth performance, blood metabolites, rumen fermentation parameters and the ruminal microbial community of 8 to 10-month-old heifers. Methods: A total of 24 Holstein heifers weighing an average of 282.90 kg (8 month of age) were randomly assigned to four groups of six. The heifers were fed one of four diets of different dietary MG/MP (0.97, 1.07, 1.13, and 1.26). Results: The results showed that the ratio of MG/MP affected the growth performance, blood metabolites, rumen fermentation parameters and the ruminal microbial community of heifers. The average daily gain of heifers was enhanced by increasing the ratio of MG/MP (p<0.05). The concentration of blood urea nitrogen, cholesterol, and low density lipoprotein cholesterol as well as the concentration of total volatile fatty acid in the rumen fluid of heifers decreased with the improvement in the ratio of dietary MG/MP (p<0.05). However, the relative amount of Ruminococcus albus and Butyrivibrio fibrisolvens in the rumen of heifers was increased significantly (p<0.05) when the dietary MG/MP increased. At the same time, with the improvement in dietary MG/MP, the amount of Fibrobacter succinogenes increased (p = 0.08). Conclusion: A diet with an optimal ratio (1.13) of MG/MP was beneficial for the improvement of growth, rumen fermentation, dietary protein and energy utilization of 8 to 10-month-old dairy heifers in this experiment.

• 식물병연구
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• 제26권4호
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• pp.202-209
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• 2020

유기농업은 지속가능한 농업을 위해서 필요하며, 생물 다양성 유지를 위해 필수적인 경작 방법으로 전 세계적으로 성장하고 있는 농업 분야 중 하나이다. 유기농업은 인류의 건강과 환경에 유해한 영향을 끼질 수 있는 화학적 제재의 사용을 줄이고, 친환경적 동·식물성 비료, 식물 추출물, 미생물 제재 등이 사용되기 때문에 소비자에게 안전한 농산물을 제공할 수 있다. 노지 고추를 대상으로 3년간 유기농업 환경과 관행농업 환경에서 주요 병해 발생과 토양 미생물상의 조사하였다. 토양 미생물상의 차이는 차세대 염기서열 분석 기법을 활용하여 조사하였으며, 유기농업에 사용되는 제제의 종류에 따라 토양 미생물상이 다르게 형성되었다. 바이러스, 탄저병에 대해서는 관행농업에서의 병 발생률이 낮았으나, 청고병은 미생물 제재 사용에 의해 병 발생률이 낮게 나타났다. 미생물 제재를 사용한 토양에서 투입된 미생물이 토양 미생물에서 검출되었으며, 이는 미생물이 실제 토양에 정착했음을 시사한다.

• 대한지역사회영양학회지
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• 제28권3호
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• pp.181-191
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• 2023

Objectives: The incidence of inflammatory bowel disease (IBD) is increasing globally, and excessive added sugar consumption has been identified as one of the contributing factors. In the context of IBD, it is essential to explore functional sweeteners that can improve metabolic health and minimize the risk of IBD-related symptoms. This review article aims to shed light on the effects of natural mono- and di-saccharides as alternative sweeteners, specifically focusing on potential benefits for IBD. Methods: A comprehensive literature review was performed using PubMed and Google Scholar databases with articles published after the year 2000. The search terms 'IBD', 'added sugar', 'sweeteners', 'mono-saccharide', and 'di-saccharide' were combined to retrieve relevant articles. A total of 21 manuscripts, aligning with the objectives of the study, were selected. Papers focusing on artificial or high-intensity sweeteners were excluded to ensure relevant literature selection. Results: Multiple studies have emphasized the association between the high consumption of added sugars such as simple sugars and the increased risk of developing IBD. This is suggested to be attributed to the induction of pro-inflammatory cytokine productions and dysbiosis of the gut microbiota. Consequently, there is a growing demand for safe and functional sweeteners, in particular mono- and di-saccharides, that can serve as alternatives for IBD patients. Those functional sweeteners regulate inflammation, oxidative stress, and Intestinal barrier protection, and restore microbiome profiles in various IBD models including cells, animals, and humans. Conclusions: Understanding these mechanisms resolves the link between how sugar consumption and IBD, and highlights the beneficial effects of natural alternative sweeteners on IBD when they were administered by itself or as a replacement for simple sugar. Further, exploration of this relationship leads us to recognize the necessity of natural alternative sweeteners in dietary planning. This knowledge could potentially lead to more effective dietary strategies for individuals with IBD.