• 한국초지조사료학회지
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• 제42권4호
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• pp.276-285
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• 2022

This study evaluated the effect of lactic acid bacteria (LAB, a mixture of Enterococcus faecium and Lactobacillus plantarum) supplementation, the storage temperature, and storage period on the fermentation characteristics and in vitro ruminal digestibility of a total mixed ration (TMR). The TMR was prepared into two groups, namely, CON (control TMR without the LAB) and ML (supplementing a mixture of E. faecium and L. plantarum in the ratio of 1% and 2% (v/w), respectively). Both groups were divided and stored at 4℃ or 25℃ for 3, 7, and 14 d fermentation periods. Supplementing LAB to the TMR did not affect the chemical composition of TMR except for the lactate and acetate concentration. Storage temperatures affected (p<0.05) the chemical composition of the TMR, including pH, lactate, and acetate contents. The chemical composition of TMR was also affected (p<0.05) by the storage period. During in vitro rumen fermentation study, the ML treatment showed lower (p<0.05) dry matter digestibility at 24 h incubation with a higher pH compared to the CON. There was no difference in the in vitro dry matter digestibility (IVDMD) of TMR between the CON and ML treatment however, at 24 h, ML treatment showed lower (p<0.05) IVDMD with a higher pH compared to the CON. The effects of storage temperature and period on IVDMD were not apparent at 24 h incubation. In an in vivo study using Holstein steers, supplementing LAB to the basal TMR for 60 d did not differ in the final body weight and average daily gain. Likewise, the fecal microbiota did not differ between CON and ML. However, the TMR used for the present study did include a commercial yeast in CON, whereas ML did not; therefore, results were, to some extent, compromised in examining the effect of LAB. In conclusion, storage temperature and period significantly affected the TMR quality, increasing acetate and lactate concentration. However, the actual effects of LAB supplementation were equivocal.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.132-148
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• 2023

Ruminants are the main contributors to methane (CH₄), a greenhouse gas emitted by livestock, which leads to global warming. In addition, animals experience heat stress (HS) when exposed to high ambient temperatures. Organic trace minerals are commonly used to prevent the adverse effects of HS in ruminants; however, little is known about the role of these minerals in reducing enteric methane emissions. Hence, this study aimed to investigate the influence of dietary organic trace minerals on rumen fermentation characteristics, enteric methane emissions, and the composition of rumen bacteria and methanogens in heat-stressed dairy steers. Holstein (n=3) and Jersey (n=3) steers were kept separately within a 3×3 Latin square design, and the animals were exposed to HS conditions (Temperature-Humidity Index [THI], 82.79 ± 1.10). For each experiment, the treatments included a Control (Con) consisting of only basal total mixed rations (TMR), National Research Council (NRC) recommended mineral supplementation group (NM; TMR + [Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm]/kg dry matter), and higher concentration of mineral supplementation group (HM; basal TMR + [Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm]/kg dry matter). Higher concentrations of trace mineral supplementation had no influence on methane emissions and rumen bacterial and methanogen communities regardless of breed (p > 0.05). Holstein steers had higher ruminal pH and lower total volatile fatty acid (VFA) concentrations than Jersey steers (p < 0.05). Methane production (g/d) and yield (g/kg dry matter intake) were higher in Jersey steers than in Holstein steers (p < 0.05). The relative abundances of Methanosarcina and Methanobrevibacter olleyae were significantly higher in Holstein steers than in Jersey steers (p < 0.05). Overall, dietary organic trace minerals have no influence on enteric methane emissions in heat-stressed dairy steers; however, breed can influence it through selective alteration of the rumen methanogen community.

• Journal of Microbiology and Biotechnology
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• 제33권2호
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• pp.219-227
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• 2023

Lettuce is one of the most consumed vegetables worldwide. However, it has potential risks associated with pathogenic bacterial contamination because it is usually consumed raw. In this study, we investigated the changes in the bacterial community on lettuce (Lactuca sativa L.) in Chungcheong-do, South Korea, and the prevalence of foodborne pathogens on lettuce in different seasons using 16S rRNA gene-based sequencing. Our data revealed that the Shannon diversity index showed the same tendency in term of the number of OTUs, with the index being greatest for summer samples in comparison to other seasons. Moreover, the microbial communities were significantly different between the four seasons. The relative abundance of Actinobacteriota varied according to the season. Family Micrococcaceae was most dominant in all samples except summer, and Rhizobiaceae was predominant in the microbiome of the summer sample. At the genus level, the relative abundance of Bacillus was greatest in spring samples, whereas Pseudomonas was greatest in winter samples. Potential pathogens, such as Staphylococcus and Clostridium, were detected with low relative abundance in all lettuce samples. We also performed metagenome shotgun sequencing analysis on the selected summer and winter samples, which were expected to be contaminated with foodborne pathogens, to support 16S rRNA gene-based sequencing dataset. Moreover, we could detect seasonal biomarkers and microbial association networks of microbiota on lettuce samples. Our results suggest that seasonal characteristics of lettuce microbial communities, which include diverse potential pathogens, can be used as basic data for food safety management to predict and prevent future outbreaks.

• Journal of Periodontal and Implant Science
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• 제53권3호
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• pp.233-244
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• 2023

Purpose: An implant-supported prosthesis consists of an implant fixture, an abutment, an internal screw that connects the abutment to the implant fixture, and the upper prosthesis. Numerous studies have investigated the microorganisms present on the implant surface, surrounding tissues, and the subgingival microflora associated with peri-implantitis. However, there is limited information regarding the microbiome within the internal screw space. In this study, microbial samples were collected from the supragingival surfaces of natural teeth, the peri-implant sulcus, and the implant-abutment screw hole, in order to characterize the microbiome of the internal screw space in healthy subjects. Methods: Samples were obtained from the supragingival region of natural teeth, the peri-implant sulcus, and the implant screw hole in 20 healthy subjects. DNA was extracted, and the V3-V4 region of the 16S ribosomal RNA was sequenced for microbiome analysis. Alpha diversity, beta diversity, linear discriminant analysis effect size (LEfSe), and network analysis were employed to compare the characteristics of the microbiomes. Results: We observed significant differences in beta diversity among the samples. Upon analyzing the significant taxa using LEfSe, the microbial composition of the implant-abutment screw hole's microbiome was found to be similar to that of the other sampling sites' microbiomes. Moreover, the microbiome network analysis revealed a unique network complexity in samples obtained from the implant screw hole compared to those from the other sampling sites. Conclusions: The bacterial composition of the biofilm collected from the implant-abutment screw hole exhibited significant differences compared to the supra-structure of the implant. Therefore, long-term monitoring and management of not only the peri-implant tissue but also the implant screw are necessary.

• Animal Bioscience
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• 제35권10호
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• pp.1575-1584
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• 2022

Objective: An experiment was conducted to evaluate the effects of partially replacing soybean meal (SBM) with sunflower meal (SFM) with added exogenous multienzymes (MEs) on various biological parameters in broilers. Methods: One week-old, 400 broiler chicks were randomly divided into four treatments (control, 3SFM, 6SFM, and 9SFM) with 5 replicates/treatment (20 chicks/replicate). Control diet was without SFM and MEs, while diets of 3SFM, 6SFM, and 9SFM treatments were prepared by replacing SBM with SFM at levels of 3%, 6%, and 9%, respectively, and were supplemented with MEs (100 mg/kg). Feeding trial was divided into grower (8 to 21 day) and finisher phases (22 to 35 day). External marker method was used to measure the nutrient digestibility. At the end of trial, twenty birds (one birds per replicate) with similar body weight were slaughtered for samples collection. Results: No significant effect of dietary treatments was found on all parameters of growth performance and carcass characteristics, except relative weight of bursa. Weight (25.0 g) and length (15.80 cm) of duodenum were significantly (p<0.05) higher in 3SFM than control. Lowest (p<0.05) villus height/crypt depth ratio was found in 3SFM and 9SFM than control. Most of meat quality parameters remained unaffected, however, highest pH of breast meat (6.16) and thigh meat (6.44) were observed in 9SFM and 3SFM, respectively. Lowest (p<0.05) cook loss of thigh meat was found in 6SFM (31.76%). Ileal digestibility of crude protein was significantly (p<0.05) higher in 3SFM (72.35%) than control (69.46%). In addition, amylase (16.87 U/mg) and protease (85.18 U/mg) activities were significantly (p<0.05) higher in 3SFM than control. However, cecal microbial count remained unaffected. Conclusion: Partial replacement (up to 9%) of SBM with SFM, with added MEs can help to improve the nutrient digestibility, intestinal morphology, and digestive enzyme activities without affecting cecal microbial count and growth performance in broilers.

• Journal of Animal Science and Technology
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• 제65권6호
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• pp.1290-1307
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• 2023

This study investigated the effect of processed forms (defatted or hydrolyzed) of black soldier fly larvae (Hermetia illucens L., BSFL) as a protein substitute on broilers. Experiment 1 was a feeding experiment, and Experiment 2 was a metabolism experiment. In Experiment 1, a total of 120 day-old Arbor Acres broilers (initial body weight 39.52 ± 0.24 g) were used for 28 days. There were 8 replicate pens, and 5 broilers were assigned to each pen. In Experiment 2, a total of 36 day-old broilers (initial body weight 39.49 ± 0.21 g) were used for the metabolism trial. There were 2 broilers in a metabolism cage and six replicate cages per treatment. The dietary treatments were as follows: a basal diet (CON), a basal diet without fishmeal and substitute with defatted BSFL (T1), a basal diet without fishmeal and a substitute with hydrolyzed BSFL (T2). In Experiment 1, during the entire experimental period, the T2 group significantly increased (p < 0.05) body weight gain and feed intake compared to the CON and T1 groups. The feed conversion ratio showed a lower tendency (p = 0.057) in the T2 group than in the CON and T1 groups. At 2 weeks, the CON and T2 groups were significantly higher (p < 0.05) crude protein (CP) digestibility than the T1 group. At 4 weeks, the total protein level significantly increased (p < 0.05) in the CON and T2 groups compared to the T1 group. In Experiment 2, the CP digestibility significantly increased (p < 0.05) in the T2 group compared to the CON and T1 group at weeks 2 and 4. At week 4 amino acid digestibility, the T2 group significantly increased (p < 0.05) lysine, methionine, tryptophan, and glycine digestibility compared to the T1 group. There was no difference in fecal microbiota among the treatment groups. In conclusion, feeding hydrolyzed BSFL as a fishmeal substitute in broiler diets improved growth performance, CP digestibility, and specific amino acid digestibility. Therefore, it is considered that hydrolyzed BSFL in broiler diets can be sufficiently used as a new protein source.

• Fisheries and Aquatic Sciences
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• 제27권3호
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• pp.180-194
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• 2024

Mass mortalities of mud crab Scylla spp. larvae due to pathogenic Vibrio spp. outbreaks have frequently occurred in hatcheries. To overcome this problem, probiotics containing Bacillus subtilis bacteria are applied to inhibit pathogenic ones. We tested different doses of probiotic-containing B. subtilis (10⁸ CFU/g) on the Scylla tranquebarica larvae and investigated the microbiota population, including Vibrio. Water quality, larvae development, and crablet production were also monitored. The recently hatched larvae were grown in twelve conical fiber tanks filled with 200 L sterile seawater, with a salinity of 30 ppt at a stocking density of 80 ind/L. Four different doses of probiotics were applied in the larvae rearing, namely, A = 2.5 mg/L, B = 5 mg/L, C = 7.5 mg/L, and D = 0 mg/L, with three replicates. Next-generation sequencing analysis was used to obtain the abundance of microbes in the whole body of megalopa and the water media for larvae rearing after applying probiotics. Sixteen Raw Deoxyribonucleic Acid samples (eight from a whole body of megalopa extraction from four treatments of probiotics defined as A, B, C, D, and eight from water media extraction from four treatments of probiotic defined as E, F, G, H) were prepared. Then, they were sent to the Genetics Science Laboratory for NGS analysis. Ammonia, nitrite, total organic matter (TOM), larvae, and crablet production were monitored. Based on the Next-generation sequencing analysis data, the Vibrio spp. decreased significantly (p < 0.05) than control test (D) in megalopa-applied probiotics at the doses of 2.5 mg/L (A) and 7.5 mg/L (C) and in the water media for megalopa rearing treated with probiotics at the dosage of 5.0 mg/L (F). Ammonia in the zoea stage in B treatment and TOM in the zoea and megalopa stage in B and C treatments were decreased significantly (p < 0.05). It impacts the higher number of zoea survival in treatments B and C. Finally, it results in a significantly high crablet production in treatments B and C. Therefore, the dosage of 5 mg/L to 7.5 mg/L improves crablet S. tranquebarica production significantly.

• IMMUNE NETWORK
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• 제21권4호
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• pp.25.1-25.16
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• 2021

Asthma is a heterogeneous disease whose development is shaped by a variety of environmental and genetic factors. While several recent studies suggest that microbial dysbiosis in the gut may promote asthma, little is known about the relationship between the recently discovered lung microbiome and asthma. Innate lymphoid cells (ILCs) have also been shown recently to participate in asthma. To investigate the relationship between the lung microbiome, ILCs, and asthma, we recruited 23 healthy controls (HC), 42 patients with non-severe asthma, and 32 patients with severe asthma. Flow cytometry analysis showed severe asthma associated with fewer natural cytotoxicity receptor (NCR)⁺ILC3s in the lung. Similar changes in other ILC subsets, macrophages, and monocytes were not observed. The asthma patients did not differ from the HC in terms of the alpha and beta-diversity of the lung and gut microbiomes. However, lung function correlated positively with both NCR⁺ILC3 frequencies and microbial diversity in the lung. Sputum NCR⁺ILC3 frequencies correlated positively with lung microbiome diversity in the HC, but this relationship was inversed in severe asthma. Together, these data suggest that airway NCR⁺ILC3s may contribute to a healthy commensal diversity and normal lung function.

• 한국식품영양과학회지
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• 제34권10호
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• pp.1536-1544
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• 2005

본 연구에서는 당뇨환자를 위한 아이스크림을 개발할 목적으로 아이스크림의 주원료인 우유단백질, 유지방과 설탕의 일부를 노란콩과 검정콩, 대두유 및 프럭토올리고당으로 대체한 아이스크림을 제조하여 동물실험을 통하여 산화스트레스 완화와 장 미생물생태 개선에 미치는 효과를 규명하였다. 동결건조한 아이스크림을 AIN-93 식이의 $30{\%}$수준으로 첨가하여 실험식이를 제조하였다. 5주령 된 Sprague Dawley 종 수컷 쥐를 당뇨를 유발하지 않은 정상군과 당뇨군 5군으로 나누고, streptozotocin으로 당뇨를 유발하고, 실험식이를 자유롭게 4주 동안 섭취시켰다. 희생된 쥐의 장기와 혈액을 취하고, 항산화능 및 장내미생물생태에 미치는 효과를 측정하여 다음과 같은 결과를 얻었다. 혈장의 지질과 산화물 농도는 당뇨군이 정상군보다 유의하게 높았다. 당뇨군 중에서 콩아이스크림군과 올리고당첨가 검정콩아이스크림군이 우유아이스크럼군에 비해 혈장 지질과산화물의 농도가 유의하게 낮았으며, 올리고당 첨가 우유아이스크림과 올리고당 첨가 노란콩아이스크림을 섭취한 군도 낮은 경향을 보였다. 간에서의 지질과산화물 농도는 우유아이스크림군만이 정상군에 비해 유의하게 높았으며, 올리고당 또는 콩 첨가 아이스크림군 모두 정상군과 유의한 차이를 보이지 않았다. 적혈구의 SOD 활성은 콩아이스크림군이 우유아이스크림군에 비하여 유의하게 높았다. 적혈구에서의 GSH-Px 활성과 catalase 활성은 올리고당첨가 검정콩아이스크림군이 다른 군에 비해 유의하게 높았다. 유익한 혐기성균인 Latobacilli 균수와 Bifidobacteria 균수가 올리고당첨가 콩아이스크림군에서 분변 중에 유의하게 증가하였으며, 콩아이스크림과 올리고당첨가 아이스크림도 우유아이스크림에 비해 유익한 세균의 증식을 촉진시켰다. 결론적으로 올리고당 첨가 콩아이스크림은 당뇨쥐에서 산화스트레스를 억제하고 장생태를 개선하는 효과를 보였다.

• 한국유기농업학회지
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• 제27권4호
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• pp.479-499
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• 2019

본 연구는 제주지역 무 주산지에서 재배 방법(유기 vs. 관행)과 토양 종류(화산회토 vs. 비화산회토)에 따른 토양의 화학적 특성, 미생물 활성 그리고 미생물 군집 조성을 분석하고 요인간 연관성을 구명하기 위하여 수행하였다. 전반적으로 유기와 관행의 재배 방식에 따른 토양 화학성은 처리간 뚜렷한 경향을 보이지는 않았으나 토양 미생물체량, 효소 활성, 종 풍부도와 다양성 그리고 미생물 군집 분포 등은 유의한 차이를 보였다. 반면에 토양 종류에 따른 화학성과 미생물 군집 분포 등 미생물학적 특성은 뚜렷한 차이를 보였다. 특히 유기재배 토양에서 관행 대비 토양의 세균, 방선균 및 사상균 그리고 미생물체량이 증가하였으며, Org-NA 토양에서 탈수소효소 활성, 종 풍부도(Chao 1) 그리고 종 다양성(Phyrogenetic diversity) 지수가 가장 높았다. 무 재배 토양에 분포하고 있는 주요 세균 문은 Proteobacteria, Acidobacteria, Chloroflexi, Firmicutes 그리고 Actinobacteria 등 5종이었으며 재배 방법 및 토양 종류에 관계없이 Proteobacteria 문이 화산회토에서 25.9%, 비화산회토에서 21.9~24.9%로 가장 높은 분포를 보였다. 그리고 대체로 화산회토와 비화산회토 토양 종류별로 유사한 군집 조성을 보였으며, 화산회토에서는 재배 방법별 주요 문의 군집 조성은 큰 차이가 없었으나 비화산회토에서는 차이를 보였다. 특히, Firmicutes는 Org-NA 토양에서 21.0%, Acidobacteria는 Con-A에서 21.6%로 가장 높은 분포를 보였는데 대체로 화산회토와 관행재배 토양에서 높은 경향을 보였다. 또한 재배 방법 및 토양 종류별 미생물 군집을 대표하는 바이오마커를 찾기 위하여 LEfSe 분석을 실시한 결과, Firmicutes 문의 분포가 비화산회토와 유기재배 토양에서 유의하게 증가하였다. 그리고 토양 화학성 중에서 총유기탄소 함량, 유효인산 그리고 치환성칼륨 함량은 Firmicutes 등 주요 세균 문과 유의한 상관관계를 보였다.