• 한국습지학회지
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• 제24권2호
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• pp.69-82
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• 2022

본 연구는 상시 담수 상태의 복합생태 논습지에서 유기농 벼-큰징거미새우 복합생산 조건 시 1) 논습지 토양 화학성 및 세균 군집 특성을 파악하여 토양 화학성과 세균 간의 상관관계를 분석하고, 2) 유기농 벼 단작 토양과 관행 벼 단작 토양의 세균 군집과 비교하여 유기농 복합생태 토양의 미생물 다양성을 비교 분석하는 것이다. 토양 화학성의 경우 유기농 복합생산 운영 기간이 길수록 유효인산과 유기물 함량이 증가한다. 모든 토양 시료에서 문(Phylum) 수준의 세균 분석 결과 9개의 주요 문이 분포되어 있으며, 모든 토양 시료에서 Proteobacteria가 우점하고 있다. 속(Genus) 수준 분셕 결과 37개의 주요 속이 분류되었으며, 벤다이어그램 분석 결과 모든 토양 시료에 존재하는 250개의 OTU가 분류되었고, 유기농 벼재배 토양에 특화된 561개의 OTU가 관찰되었다. 주좌표분석 결과 관행 벼 단작 토양의 세균 군집과 비교하여 유기농 벼 단작 토양과 유기농 복합생태 논습지 토양의 세균 군집 간 유사도가 높은 것으로 나타났다.

• 한국식품과학회지
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• 제50권4호
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• pp.400-406
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• 2018

본 연구는 국내 수도권, 충청, 강원 등지의 중소기업형 소규모 양조장에서 생산되는 탁주와 약주의 미생물 군집 분포를 차세대 염기서열 분석기법을 이용하여 조사하였다. 각 시료별로 미생물 분포에 따른 품질의 차이를 나타냈으며 특히 백미 또는 소맥분을 주로 사용한 탁주와 달리 약주는 찹쌀과 백미를 주원료로 사용하여 각각 독특한 주질과 미생물 분포에 영향을 주었다. 주요검출 미생물로 진균류는 S. cerevisiae가 대부분을 차지하였으며 세균의 경우 Firmicutes문에는 유산균인 Lactobacillus, Leuconostoc, Lactococcus, Weisella 속 등이 우점종으로 확인되었다. 곡물인 원재료에 의해 Cyanobacteria 문의 Chloroplast 속과 제조 환경에 의한 유입으로 추정되는 Cronobacter 속, Enterobacter 속 또한 검출되었다. 이러한 다양한 미생물의 분포는 제조 지역, 주원료, 그리고 제조 방법에 기인할 것으로 판단되며 명확한 상관관계는 확인할 수 없었으나 본 연구 결과 유통과정의 제품 안전성 확보를 위해 양조장별 미생물 관리가 필요할 것으로 판단된다.

• 한국축산식품학회지
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• 제38권5호
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• pp.936-949
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• 2018

Changes in microbial community and physicochemical traits of chicken summer sausage made from spent layer thigh added with different level (0%, 0.1%, 0.3%, and 0.5% w/w) of ground chopi (Zanthoxylum piperitum) during manufacture were analyzed. The microbial community was profiled and analyzed by sequencing 16S rRNA gene using Illumina MiSeq. Samples were taken from raw sausage batter, after 15 h of fermentation, 8 h of cooking including cooling down, and 7 d of drying. The final pH of the sausage was reduced by the addition of ground chopi. However, no clear effect on water activity was observed. Ground chopi inhibited the development of red curing color after fermentation as it exhibited antimicrobial effect. However, the effect on species richness and microbial composition after cooking was unclear. Ground chopi delayed lipid oxidation during manufacture and the effect was dependent on the addition level. Fermentation reduced the species richness with a dominancy of lactic acid bacteria. The profile of microbiota in the raw batter was different from other stages, while the closest relationship was observed after cooking and drying. Proteobacteria was predominant, followed by Firmicutes and Bacteroidetes in raw samples. Firmicutes became dominating after fermentation and so forth, whereas other predominant phylum decreased. At genus level, unclassified Lactobacillales was the most abundant group found after fermentation and so forth. Therefore, the overall microbial composition aspects were mainly controlled during fermentation by the abundance of lactic acid bacteria, while bacterial counts and lipid oxidation were controlled by cooking and the addition of ground chopi.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제30권1호
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• pp.100-110
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• 2017

Objective: The gastrointestinal tract of sheep contain complex microbial communities that influence numerous aspects of the sheep's health and development. The objective of this study was to analyze the composition and diversity of the microbiota in the gastrointestinal tract sections (rumen, reticulum, omasum, abomasum, duodenum, jejunum, ileum, cecum, colon, and rectum) of sheep. Methods: This analysis was performed by 454 pyrosequencing using the V3-V6 region of the 16S rRNA genes. Samples were collected from five healthy, small tailed Han sheep aged 10 months, obtained at market. The bacterial composition of sheep gastrointestinal microbiota was investigated at the phylum, class, order, family, genus, and species levels. Results: The dominant bacterial phyla in the entire gastrointestinal sections were Firmicutes, Bacteroidetes, and Proteobacteria. In the stomach, the three most dominant genera in the sheep were Prevotella, unclassified Lachnospiraceae, and Butyrivibrio. In the small intestine, the three most dominant genera in the sheep were Escherichia, unclassified Lachnospiraceae, and Ruminococcus. In the large intestine, the three most dominant genera in the sheep were Ruminococcus, unclassified Ruminococcaceae, and Prevotella. R. flavefaciens, B. fibrisolvens, and S. ruminantium were three most dominant species in the sheep gastrointestinal tract. Principal Coordinates Analysis showed that the microbial communities from each gastrointestinal section could be separated into three groups according to similarity of community composition: stomach (rumen, reticulum, omasum, and abomasum), small intestine (duodenum, jejunum, and ileum), and large intestine (cecum, colon, and rectum). Conclusion: This is the first study to characterize the entire gastrointestinal microbiota in sheep by use of 16S rRNA gene amplicon pyrosequencing, expanding our knowledge of the gastrointestinal bacterial community of sheep.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.227-235
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• 2018

Foodborne illness represents a major threat to public health and is frequently attributed to pathogenic microorganisms on fresh produce. Recurrent outbreaks often come from vegetables that are grown close to or within the ground. Therefore, the first step to understanding the public health risk of microorganisms on fresh vegetables is to identify and describe microbial communities. We investigated the phyllospheres on Chinese cabbage (Brassica rapa subsp. pekinensis, N = 54). 16S rRNA gene amplicon sequencing targeting the V5-V6 region of 16S rRNA genes was conducted by employing the Illumina MiSeq system. Sequence quality was assessed, and phylogenetic assessments were performed using the RDP classifier implemented in QIIME with a bootstrap cutoff of 80%. Principal coordinate analysis was performed using a weighted Fast UniFrac matrix. The average number of sequence reads generated per sample was 34,584. At the phylum level, bacterial communities were composed primarily of Proteobacteria and Bacteroidetes. The most abundant genera on Chinese cabbages were Chryseobacterium, Aurantimonadaceae_g, Sphingomonas, and Pseudomonas. Diverse potential pathogens, such as Pantoea, Erwinia, Klebsiella, Yersinia, Bacillus, Staphylococcus, Salmonella, and Clostridium were also detected from the samples. Although further epidemiological studies will be required to determine whether the detected potential pathogens are associated with foodborne illness, our results imply that a metagenomic approach can be used to detect pathogenic bacteria on fresh vegetables.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1517-1526
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• 2018

Investigating bacterial diversity and its metabolic capabilities is crucial for interpreting the ecological patterns in a desert environment and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physicochemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrats of a desert (Thar Desert, India) with a hot, arid climate, very little rainfall and extreme temperatures. Analysis of physico-chemical parameters and subsequent variance analysis (p-values < 0.05) revealed that sulfate, potassium and magnesium ions were the most variable between the quadrats. Microbial diversity of the two quadrats was studied using Illumina bar-coded sequencing by targeting V3-V4 regions of 16S rDNA. As for the results, 702504 high-quality sequence reads, assigned to 173 operational taxonomic units (OTUs) at species level, were examined. The most abundant phyla in both quadrats were Actinobacteria (38.72%), Proteobacteria (32.94%), and Acidobacteria (9.24%). At genus level, Gaiella represented highest prevalence, followed by Streptomyces, Solirubrobacter, Aciditerrimonas, Geminicoccus, Geodermatophilus, Microvirga, and Rubrobacter. Between the quadrats, significant difference (p-values < 0.05) was found in the abundance of Aciditerrimonas, Geodermatophilus, Geminicoccus, Ilumatobacter, Marmoricola, Nakamurella, and Solirubrobacter. Metabolic functional mapping revealed diverse biological activities, and was significantly correlated with physicochemical parameters. The results revealed spatial variation of ions, microbial abundance and functional attributes in the studied quadrats, and patchy nature in local scale. Interestingly, abundance of the biotechnologically important phylum Actinobacteria, with large proposition of unclassified species in the desert, suggested that this arid environment is a promising site for bioprospection.

• 한국미생물·생명공학회지
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• 제46권3호
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• pp.277-287
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• 2018

Current reports suggest that obesity is a serious global health issue. Emerging evidence has predicted strong links between obesity and the human gut microbiota. However, only a few such studies have been conducted in Asia, and the gut microbiota of lean and obese adult Asians remains largely unexplored. Here, we investigated the potential relationship between gut microbiota, body massindex (BMI), and metabolic parameters in adults from Thailand, where obesity is increasing rapidly. Fecal and blood samples were collected from 42 volunteers who were allocated into lean, overweight, and obese groups. The fecal microbiota was examined by quantitative PCR analysis. Bacteroidetes, Firmicutes, and Staphylococcus spp. and methanogens were most abundant in lean volunteers. Overweight volunteers majorly harbored Christensenella minuta and Akkermansia muciniphila, ${\gamma}-Proteobacteria$, and bacteria belonging to the genus Ruminococcus. Methanogens and bacteria belonging to the phylum Bacteroidetes were negatively correlated with adiposity markers (BMI and waist circumference), but positive correlated with high-density lipoprotein, suggesting that they can be used as leanness markers. While some of our results agree with those of previous reports, results regarding the contributions of specific taxa to obesity were inconsistent. This is the first study to report the adult gut microbiota in Southeast Asian populations using molecular techniques and biochemical markers and provides a foundation for future studies in this field.

• 대한수의학회지
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• 제57권3호
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• pp.159-167
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• 2017

The microbial community is known to have a key role during the rearing period of broilers. In this study, gut microbial composition and diversity were examined to evaluate the relationships between these factors and broiler growth performance. By applying 454-pyrosequencing of the V1-V3 regions of bacterial 16S rRNA genes, six fecal samples from four- and 28-day-old chickens from three broiler farms and 24 intestinal samples of broilers with heavy and light body weights were analyzed. Microbial composition assessment revealed Firmicutes to be the most prevalent phylum at farm A, while Proteobacteria were predominant at farms B and C. Fecal microbial richness and diversity indices gradually increased from four to 28 days at all three farms. Microbial diversity assessment revealed that small intestine microbial diversity was lower in heavy birds than in light birds. In light birds, the Firmicutes proportion was lower than that in heavy birds. In conclusion, each broiler farm revealed a specific microbial profile which varied with the age of the birds. The microbial communities appeared to affect growth performance; therefore, gut microbial profiles can be utilized to monitor growth performance at broiler farms.

• 한국환경보건학회지
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• 제43권6호
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• pp.491-498
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• 2017

Objective: Bacterial abundance and community compositions have been examined in Asian dust events, clarifying their impacts on public health. This study aims to determine the bacterial community compositions and viable bacteria in Asian dust particles in the Asian dust or non-Asian dust event of March 2016. Methods: The dust samples were collected using the high volume air sampler or high volume cascade impactor, and bacterial 16S rRNA genes were amplified using PCR, followed by pyrosequencing. Bacterial diversity index, richness estimate and community composition in the particles were analyzed from the sequencing data using Mothur software. Results: The results showed that the diversity and richness during Asian dust events were higher than them in non-Asian dust events. The total bacterial community analysis showed that at the phylum Proteobacteria, Actinobacteria and Firmicutes were the most dominant of Asian dust events and non-Asian dust events. In addition, the bacterial colony counts were higher during Asian dust event, comparing with non-Asian dust event. Conclusions: This study showed that bacterial community and richness of Asian dust samples was more complex and higher than non-Asian dust samples in Gyeonggi-do, Korea, which could affect public health and environment. Thus, the continuous monitoring of Asian dust could be an alternative for managing airborne bacteria.