• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1322-1332
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• 2019

In this paper, we systematically investigated the influence of some selected ligands on the U-phosphate precipitation induced by soil bacteria. These organics are widely ranging from acetate, lactate, salicylate and citrate to oxalate. The results revealed that uranium could be biomineralized on bacteria as $UO_2HPO_4{\cdot}4H_2O$ or $(UO_2)_3(PO_4)_2{\cdot}4H_2O$. The influence of organic ligands on the biomineralization had clear-cut correlations with its complexation abilities to uranyl. It was clearly found that the U-phosphate biomineralization was affected noticeably by the strong ligands (oxalate and citrate). Further study discovered that when the organic ligands were uncompetitive with biotic $PO_4^{3-}$ for uranyl, the transformation of uranyl species from ${\beta}-UO_2(OH)_2$ colloidal particles to free $UO_2^{2+}$-ligands ions could facilitate the U-phosphate biomineralization. However, when the organic ligands competed with biotic $PO_4^{3-}$ for uranyl, the U-phosphate biomineralization were inhibited. Our results highlight the importance of complex interactions of strong organic ligands with uranyl during the bacterial precipitation of U-P compounds and thus for the mobilization and immobilization of radio-nuclides in the nature.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.391-402
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• 2021

Earthworms play an important role in soil fertilization, interacting continually with microorganisms. This study aims to demonstrate the existence of beneficial microorganisms living in the earthworm's immune system, the coelomic fluid. To achieve this goal, a molecular identification technique was performed, using cytochrome c oxidase I (COI) barcoding to identify abundant endogenic earthworms inhabiting the temperate zone of Rabat, Morocco. Then, 16S rDNA and ITS sequencing techniques were adopted for bacteria and fungi, respectively. Biochemical analysis, showed the ability of bacteria to produce characteristic enzymes and utilize substrates. Qualitative screening of plant growth-promoting traits, including nitrogen fixation, phosphate and potassium solubilization, and indole acetic acid (IAA) production, was also performed. The result of mitochondrial COI barcoding allowed the identification of the earthworm species Aporrectodea molleri. Phenotypic and genotypic studies of the sixteen isolated bacteria and the two isolated fungi showed that they belong to the Pseudomonas, Aeromonas, Bacillus, Buttiauxella, Enterobacter, Pantoea, and Raoultella, and the Penicillium genera, respectively. Most of the isolated bacteria in the coelomic fluid showed the ability to produce β-glucosidase, β-glucosaminidase, Glutamyl-β-naphthylamidase, and aminopeptidase enzymes, utilizing substrates like aliphatic thiol, sorbitol, and fatty acid ester. Furthermore, three bacteria were able to fix nitrogen, solubilize phosphate and potassium, and produce IAA. This initial study demonstrated that despite the immune property of earthworms' coelomic fluid, it harbors beneficial microorganisms. Thus, the presence of resistant microorganisms in the earthworm's immune system highlights a possible selection process at the coelomic fluid level.

• 식물병연구
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• 제26권4호
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• pp.210-221
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• 2020

곤충은 장내에 서식하고 있는 미생물과 상호작용을 통해 공생하는 것으로 알려져 있으며, 이러한 공생자는 공진화를 통하여 극한 환경에서도 서식을 가능하게 한다. 이러한 관점에서 토양 속에서 부엽토와 식물 잔재를 먹고 사는 장수풍뎅이 유충의 장내에 존재하는 공생자는 식물병원균을 방제하는 데 유용한 미생물이 존재할 것으로 생각된다. 따라서, 식물병원균에 대해 활성을 갖는 유용 미생물 10종을 장수풍뎅이 유충의 소화기관 전장, 중장, 후장으로부터 분리하였다. 분리된 10종의 유용 미생물은 유묘 검정을 통하여 토마토 잿빛곰팡이병, 배추 뿌리혹병, 고추 탄저병, 고추 역병에 대하여 강력한 항균 활성을 확인하였다. 10종의 항균활성 미생물은 형태적 특성과 16s rRNA gene 분석으로 Bacillus속 4종, Paenibacillus속 3종 및 Streptomyces속 3종으로 동정되었다. 유용 미생물은 인산 가용화, indole-3-acetic acid, siderophore 생성 활성이 우수하며 진균외막가수분해 효소인 β-1,3-glucanase, pretease 활성을 보였다. 10종의 유용 미생물 중, DM152 균주는 토마토와 고추 식물체의 모든 기관에서 생장을 촉진시켰다. 따라서, 장수풍뎅이 유충의 소화기관으로부터 분리된 10종의 장내 미생물은 생물학적 방제제 및 생물비료의 활용 가능성을 나타내었다.

• Animal Bioscience
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• 제34권3_spc호
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• pp.393-404
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• 2021

Objective: This study compared the catechin composition of different tea byproducts and investigated the effects of dietary supplementation with green tea byproducts on the accumulation of abdominal fat, the modulation of lipid metabolism, and the inflammatory response in red feather native chickens. Methods: Bioactive compounds were detected, and in vitro anti-obesity capacity analyzed via 3T3-L1 preadipocytes. In animal experiments, 320 one-day-old red feather native chickens were divided into 4 treatment groups: control, basal diet supplemented with 0.5% Jinxuan byproduct (JBP), basal diet supplemented with 1% JBP, or basal diet supplemented with 5×106 colony-forming unit (CFU)/kg Bacillus amyloliquefaciens+5×106 CFU/kg Saccharomyces cerevisiae (BA+SC). Growth performance, serum characteristics, carcass characteristics, and the mRNA expression of selected genes were measured. Results: This study compared several cultivars of tea, but Jinxuan showed the highest levels of the anti-obesity compound epigallocatechin gallate. 3T3-L1 preadipocytes treated with Jinxuan extract significantly reduced lipid accumulation. There were no significant differences in growth performance, serum characteristics, or carcass characteristics among the groups. However, in the 0.5% JBP group, mRNA expression of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) were significantly decreased. In the 1% JBP group, FAS, ACC and peroxisome proliferator-activated receptor γ levels were significantly decreased. Moreover, inflammation-related mRNA expression levels were decreased by the addition of JBP. Conclusion: JBP contained abundant catechins and related bioactive compounds, which reduced lipid accumulation in 3T3-L1 preadipocytes, however there was no significant reduction in abdominal fat. This may be due to a lack of active anti-obesity compounds or because the major changes in fat metabolism were not in the abdomen. Nonetheless, lipogenesis-related and inflammation-related mRNA expression were reduced in the 1% JBP group. In addition, dietary supplementation with tea byproducts could reduce the massive amount of byproducts created during tea production and modulate lipid metabolism and the inflammatory response in chickens.

• Animal Bioscience
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• 제35권2호
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• pp.204-216
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• 2022

Objective: The aim of this study was to investigate the effects of dietary supplementation with a multi-strain probiotic (MSP) product containing of Bifidobacterium animalis, Lactobacillus casei, Streptococcus faecalis, and Bacillus cerevisiae on growth, health, and fecal bacterial composition of dairy calves during the first month of life. Methods: Forty Holstein calves (24 female and 16 male) at 2 d of age were grouped by sex and date of birth then randomly assigned to 1 of 4 treatments: milk replacer supplementation with 0 g (0MSP), 2 g (2MSP), 4 g (4MSP), and 6 g (6MSP) MSP per calf per day. Results: Supplementation of MSP did not result in any significant differences in parameters of body measurements of calves during the 30 d period. As the dosage of MSP increased, the average daily gain (p = 0.025) and total dry matter intake (p = 0.020) of calves showed a linear increase. The fecal consistency index of the 2MSP, 4MSP, and 6MSP group calves were lower than that of the 0MSP group calves (p = 0.003). As the dosage of MSP increased, the concentrations of lactate dehydrogenase (p = 0.068) and aspartate aminotransferase (p = 0.081) in serum tended to decrease, whereas the concentration of total cholesterol increased quadratically (p = 0.021). The relative abundance of Dorea in feces was lower (p = 0.011) in the 2MSP, 4MSP, and 6MSP group calves than that in the 0MSP group calves. The relative abundance of Dorea (p = 0.001), Faecalibacterium (p = 0.050), and Mitsuokella (p = 0.030) decreased linearly, whereas the relative abundance of Prevotella tended to increase linearly as the dosage of MSP increased (p = 0.058). Conclusion: The MSP product can be used to reduce the diarrhea, improve the performance, and alter the composition of the fecal bacteria in neonatal dairy calves under the commercial conditions.

• 한국수산과학회지
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• 제54권6호
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• pp.896-903
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• 2021

For the safety assessment of microbiological and chemical hazards in raw short-neck clam Ruditapes philippinarum distributed in the Yeongnam and Honam areas during the spring season, the contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine pathogenic bacteria (Staphylococcus aureus, Salmonella spp., Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, enterohemorrhagic Escherichia coli, Yersinia enterocolitica, Bacillus cereus, Campylobacter jejuni) as microbiological hazards, and heavy metals (lead, cadmium, total mercury), benzopyrene, shellfish poison (paralytic, diarrhetic, amnesic), and radioactivity (¹³¹I, ¹³⁴Cs+¹³⁷Cs) were also analyzed in 15 samples based on the methods of the Korean Food Code. The average contamination levels of total viable bacteria were 3.11 (1.40-4.49) log CFU/g, and coliforms were detected in 5 out of 15 samples (1.18-1.85 log CFU/g). E. coli and S. aureus were not detected in all samples. Furthermore, the presence of 8 pathogens were not detected in all samples. The average contamination levels of lead, cadmium, and total mercury were 0.155 (0.079-0.264), 0.160 (0.040-0.287), and 0.017 (0.008-0.026) mg/kg, respectively. Benzo(a)pyrene, shellfish poison, and radioactivity were not detected in all samples. The results of this study suggest that the safety against all microbiological and chemical hazard factors in raw short-neck clams distributed in markets has been assured.

• 한국수산과학회지
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• 제54권6호
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• pp.904-911
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• 2021

For the safety assessment of microbiological and chemical hazards in dried sea mustard, fifteen samples of dried sea mustards Undaria pinnatifida were purchased from the supermarkets distributed throughout Korea. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine pathogenic bacteria [Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Bacillus cereus, Vibrio spp., Clostridium perfringens, Enterohemorrhagic Escherichia coli (EHEC), Yersinia enterocolitica and Campylobacter jejuni/coli] were quantitatively or qualitatively assessed. Also, the heavy metals (lead, cadmium, total mercury, and inorganic arsenic), and radioactivity (¹³¹I, ¹³⁴CS+¹³⁷CS) were quantitatively assessed. This microbial and chemical analysis was performed using standard methods in Korean food code. The total viable bacteria ranged from 4.3×10² (5.0×10-1.5×10³) CFU/g. Coliforms and E. coli were not detected in all samples (ND, <1 log₁₀ CFU/g). All nine pathogenic bacteria were qualitatively detected as negative. The contamination levels of lead, cadmium, total mercury, and inorganic arsenic were 0.036 (0.015-0.051), 0.117 (0.088-0.156), 0.030 (0.017-0.048), and 0.058 (0.056-0.064) mg/kg, respectively. Radioactivity was also not detected in any sample. The microbial contamination levels determined in the current study may be potentially used as basis for performing microbial risk assessments of dried sea mustards.

• 한국가금학회지
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• 제49권4호
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• pp.247-253
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• 2022

본 연구는 우리나라 여름철에 육용 종계에게 γ-Amino-butyric(GABA)와 생균제를 급여하였을 때, 계란품질, 혈액 생화학 조성 및 corticosteron에 미치는 영향에 대하여 조사하였다. 본 연구는 49주령의 육용 종계 총 72수를 무작위로 선발하여 3 처리(대조구, GABA, 생균제)를 두었고, 시험구당 8반복으로 반복당 3수씩 완전임의배치하여 실험을 실시하였다. GABA와 생균제는 배합사료 내 각각 50 mg/kg과 0.1%의 농도로 급여하여 6주간 실험을 진행하였다. 6주 후 육용 종계의 난중, 난백고 높이, Haugh units, 난황색, 난각 두께 및 난각 강도에서 처리구간의 유의적인 차이를 보이지 않았다. 또한 모든 혈액 내 생화학 조성에서 GABA와 생균제 급여로 인한 유의적인 차이를 보이지 않았다. 혈중 corticosterone 농도는 CON의 14.18 ng/mL에비하여 GABA는 8.02 ng/mL 그리고 생균제는 8.30 ng/mL으로 크게 감소하였다(P<0.05). 이와 같은 corticosterone 수준의 감소는 스트레스 완화와 상호작용적 반응을 일으킨 것이라 사료된다. 결과적으로 본 연구에서 여름철 고온으로 인한 육용 종계 스트레스는 GABA 및 생균제 급여로 인하여 감소하였으며, 향후 이에 대한 보다 더 다양한 세부적 연구가 필요할 것으로 판단된다.

• 한국가금학회지
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• 제49권4호
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• pp.239-246
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• 2022

본 연구는 여름철 γ-aminobutyric(GABA)와 생균제 급여가 산란 종계의 생산성, 계란품질, 혈액 생화학 조성, corticosteron에 미치는 효과를 조사하였다. 24주령의 산란 종계 총 105수를 3개 처리(대조구, GABA, probiotics), 처리당 7반복, 반복당 5수로 설정하여 사양실험을 실시하였다. GABA와 생균제는 배합사료 내 각각 50ppm과 0.1%로 첨가하여, 총 6주간 실험을 실시하였다. 전기간 산란종계의 평균 계란 생산량, 산란량은 대조구보다 생균제 급여 처리구에서 유의적으로 높았으며(P<0.05), FCR은 생균제 급여 처리구에서 낮은 값을 나타내었다(P<0.05). 산란 종계 계란의 난중, 난백고 높이, Haugh units, 난황색, 난각두께, 난각강도에서 처리구간의 유의적인 차이를 보이지 않았다. 또한 모든 혈청 생화학 조성에서 유의적인 차이를 보이지 않았다. 혈청 내 corticosterone 농도는 GABA와 생균제 급여로 인하여 대조구보다 유의적으로 감소하였다(P<0.05). 따라서 GABA와 생균제 급여 시 고온기 산란 종계의 스트레스를 완화시킬 수 있는 것으로 사료되며, 특히 생균제 급여는 계란 생산성 및 산란량 성적을 개선할 수 있는 것으로 나타났다.

• 한국유기농업학회지
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• 제29권4호
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• pp.561-574
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• 2021

본 연구는 Fusarium spp.에 의해 발생하는 천마 괴경썩음병에 대하여 유기농업자재의 방제효과를 검정하기 위해 수행되었다. 유기농업자재 15품목을 대상으로 실내에서 항균활성 검정과 실내시설에서 천마 자마에 포자현탁액 접종을 통한 자마검정을 실시하였다. 이중 미생물제인 7품목의 유기농업자재가 Fusarium spp.의 균사생장을 억제하였다. 천마 자마를 이용한 검정에서 3품목의 유기농업자재가 70% 이상의 우수한 방제효과를 나타냈다. 그 중에서 sulfur가 유효성분인 광물질 제제의 억제효과가 가장 뛰어났다. 그 다음으로 3품목의 유기농업자재를 선발하여 예방적 효과와 치료적 효과를 검정하기 위해 적용하였는데, 예방적 처리를 했을 때 3품목 모두 병 발생에 대한 억제 효과가 상당히 높았다. 특히 sulfur와 B. subtilis의 예방적 효과는 각각 93.2%, 86.9%로 탁월하였으며, 치료적 효과는 73.3%, 60.2%로 상대적으로 낮게 나타났다. 반면, citronella + paraffin oil + ethyl alcohol은 예방적 효과와 치료적 효과가 각각 73.3%, 67.0%로 비슷한 효과를 나타냈다. 이 연구를 통해 시설하우스 내 연작 재배지에서 잘 발생하는 천마 괴경썩음병은 유기농업자재로 충분히 방제될 수 있으며, 예방적 처리가 더욱 중요하며 효과적임이 확인되었다.