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result(s) for
"Kim, Yo Han"
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Long-term high-grain diet altered the ruminal pH, fermentation, and composition and functions of the rumen bacterial community, leading to enhanced lactic acid production in Japanese Black beef cattle during fattening
by
Ishizuka, Naoki
,
Masaki, Tatsunori
,
Iwamoto, Eiji
in
Accumulation
,
Acid production
,
Adaptation
2019
To increase intramuscular fat accumulation, Japanese Black cattle are commonly fed a high-grain diet from 10 to 30 months of age although it can result in the abnormal accumulation of organic acids in the rumen. We explored the effect of long-term high-concentrate diet feeding on ruminal pH and fermentation, and its effect on the rumen bacterial community in Japanese Black beef cattle during a 20-month fattening period. Nine castrated and fistulated Japanese Black beef cattle were housed with free access to food and water throughout the study period (10-30 months of age). The fattening stages included Early, Middle, and Late stages (10-14, 15-22, and 23-30 months of age, respectively). Cattle were fed high-concentrate diets for the experimental cattle during fattening. The body weight of the cattle was 439 ± 7.6, 561 ± 11.6, and 712 ± 18.5 kg (mean ± SE) during the Early, Middle, and Late stages, respectively. Ruminal pH was measured continuously during the final 7 days of each stage, and rumen fluid and blood samples were collected on day 4 (fourth day during the final 7 days of the pH measurements). The 24-h mean ruminal pH during the Late stage was significantly lower than that during the Early stage. Total volatile fatty acid (VFA) during the Late stage was significantly lower than during the Early and Middle stages, but no changes were noted in individual VFA components. The lactic acid concentration during the Late stage was significantly higher than that during the Early and Middle stages. The bacterial richness indices decreased significantly during the Late stage in accordance with the 24-h mean ruminal pH. Among the 35 bacterial operational taxonomic units (OTUs) shared by all samples, the relative abundances of OTU8 (Family Ruminococcaceae) and OTU26 (Genus Butyrivibrio) were positively correlated with the 24-h mean ruminal pH. Total VFA concentration was negatively correlated with OTU167 (Genus Intestinimonas), and lactic acid concentration was correlated positively with OTU167 and OTU238 (Family Lachnospiraceae). These results suggested that long-term high-grain diet feeding gradually lowers ruminal pH and total VFA production during the Late fattening stage. However, the ruminal bacterial community adapted to feeding management and the lower pH during the Late stage by preserving their diversity or altering their richness, composition, and function, to enhance lactic acid production in Japanese Black beef cattle.
Journal Article
Changes in ruminal and reticular pH and bacterial communities in Holstein cattle fed a high-grain diet
2018
Background
Subacute ruminal acidosis (SARA) is characterized by a ruminal pH depression, and microbiota can also be affected by a higher acidity and/or dietary changes. Previous studies have revealed similar patterns in pH reduction in the rumen and reticulum, whereas changes in reticular pH and bacterial community following a high-grain diet are not fully understood. The aim of this study was to investigate the changes in reticular pH and bacterial community structure following a high-grain diet simultaneously with those in the rumen.
Results
SARA was diagnosed when ruminal and reticular pH remained under 5.6 for 350 ± 14 and 312 ± 24 min/d, respectively, on the last day of the CON period. During the CON period, lower proportion of acetic acid and higher proportion of butyric acid were observed compared with the HAY period. The proportions of acetic acid and propionic acid were lower and higher, respectively, in the rumen compared with the reticulum. From 454 pyrosequencing analysis, the relative abundance of several genera differed significantly between the two periods and the two locations. During the HAY period, higher relative abundances of
Prevotella
,
Eubacterium
,
Oscillibacter
, and
Succiniclasticum
and lower relative abundances of
Ruminococcus
,
Clostridium
, and
Olsenella
were identified compared with the CON period. Furthermore, the relative abundance of
Eubacterium
was lower in the rumen compared with the reticulum. Bacterial diversity indices were significantly different between the HAY and CON periods, being higher in the HAY period. The quantitative real-time PCR showed that the copy numbers of several cellulolytic bacteria (
Fibrobacter succinogenes
and
Ruminococcus albus
) were higher during the HAY period.
Conclusion
A high-grain diet showed similar impacts on the pH, fermentation, and bacterial community structure in the rumen and reticulum. During the CON period, ruminal and reticular pH decreased following the high-grain challenge, and lower bacterial diversity and changes in the bacterial composition, similarity, and bacterial copy numbers were observed due to a higher acidity and dietary changes compared with the HAY period. These changes may influence the fermentative ability of the rumen and reticulum.
Journal Article
Investigation of characteristics and classification for swine vertebral osteomyelitis in South Korea
2025
Background
Vertebral osteomyelitis (VO) is a major cause of condemnation in swine slaughterhouses, leading to economic losses for farmers. This study aimed to investigate the characteristics and classification of VO cases in South Korean slaughterhouses, focusing on their relationship with pyemia and their potential to reduce unnecessary total condemnation.
Results
Our findings confirmed that swine VOs are often associated with tail-biting injuries, particularly in the posterior vertebrae, underscoring tail biting as a prominent risk factor.
Trueperella pyogenes
were the most prevalent among the bacterial pathogens, while additional less common bacteria were also identified, warranting further research on their potential pathogenic roles. According to the VO classification scheme used in this study, 75% of the 20 VO cases examined were classified as acute VO, whereas the remaining cases were chronic.
It was revealed that only 10% (2/20) of the VO cases were in a state of pyemia at the time of slaughter (true pyemia) and these true pyemia cases were found only in the acute VOs.
Conclusions
The VO classification scheme tested in this study demonstrated high sensitivity (100%), indicating its robustness in avoiding false negatives and ensuring food safety. Of the carcasses that could have undergone unnecessary condemnation, 22.2% were excluded. The results indicate that the VO classification scheme is recommended as a measure to reduce unnecessary total condemnation induced by VO.
Journal Article
Methane Pyrolysis in Molten Potassium Chloride: An Experimental and Economic Analysis
2021
Although steam methane reforming (CH4 + 2H2O → 4H2 + CO2) is the most commercialized process for producing hydrogen from methane, more than 10 kg of carbon dioxide is emitted to produce 1 kg of hydrogen. Methane pyrolysis (CH4 → 2H2 + C) has attracted much attention as an alternative to steam methane reforming because the co-product of hydrogen is solid carbon. In this study, the simultaneous production of hydrogen and separable solid carbon from methane was experimentally achieved in a bubble column filled with molten potassium chloride. The melt acted as a carbon-separating agent and as a pyrolytic catalyst, and enabled 40 h of continuous running without catalytic deactivation with an apparent activation energy of 277 kJ/mole. The resultant solid was purified by water washing or acid washing, or heating at high temperature to remove salt residues from the carbon. Heating the solid product at 1200 °C produced the highest purity carbon (97.2 at%). The economic feasibility of methane pyrolysis was evaluated by varying key parameters, that is, melt loss, melt price, and carbon revenue. Given a potassium chloride loss of <0.1 kg of salt per kg of produced carbon, the carbon revenue was calculated to be USD > 0.45 per kg of produced carbon. In this case, methane pyrolysis using molten potassium chloride may be comparable to steam methane reforming with carbon capture storage.
Journal Article
JNK suppresses melanogenesis by interfering with CREB-regulated transcription coactivator 3-dependent MITF expression
by
Hong, A-reum
,
Kim, Ji-Hye
,
Yoo, Hanju
in
Animals
,
Antibodies
,
Enzyme Inhibitors - pharmacology
2020
Melanogenesis is a critical self-defense mechanism against ultraviolet radiation (UVR)-induced skin damage and carcinogenesis; however, dysregulation of melanin production and distribution causes skin-disfiguring pigmentary disorders. Melanogenesis is initiated by UVR-induced cAMP generation and ensuing activation of transcription factor CREB, which induces expression of the master melanogenic regulator MITF. Recent studies have demonstrated that recruitment of CRTCs to the CREB transcription complex is also required for UVR-stimulated melanogenesis. Therefore, modulation of cAMP-CRTC/CREB-MITF signaling may be a useful therapeutic strategy for UVR-associated skin pigmentary disorders.
: We identified the small-molecule Ro31-8220 from CREB/CRTC activity screening and examined its melanogenic activity in cultured mouse and human melanocytes as well as in human skin. Molecular mechanisms were deciphered by immunoblotting, RT-PCR, promoter assays, tyrosinase activity assays, immunofluorescent examination of CRTC3 subcellular localization, and shRNA-based knockdown.
: Ro31-8220 suppressed basal and cAMP-stimulated melanin production in melanocytes and human melanocyte co-culture as well as UVR-stimulated melanin accumulation in human skin through downregulation of MITF and tyrosinase expression. Mechanistically, down regulation of MITF expression by Ro31-8220 was due to inhibition of transcriptional activity of CREB, which was resulted from phosphorylation-dependent blockade of nuclear translocation of CRTC3 via JNK activation. The selective JNK activator anisomycin also inhibited melanin production through phosphoinhibition of CRTC3, while JNK inhibition enhanced melanogenesis by stimulating CRTC3 dephosphorylation and nuclear migration.
: Melanogenesis can be enhanced or suppressed via pharmacological modulation of a previously unidentified JNK-CRTC/CREB-MITF signaling axis. As Ro31-8220 potently inhibits UVR-stimulated melanin accumulation in human skin, suggesting that small-molecule JNK-CRTC signaling modulators may provide therapeutic benefit for pigmentation disorders.
Journal Article
Impact of Long-Term Supplementation with Probiotics on Gut Microbiota and Growth Performance in Post-Weaned Piglets
2024
This study aimed to investigate effects of long-term probiotic supplementation on gut microbiota and growth performance in health weaned piglets. The non-probiotic group (N-PrB) was fed only a basal diet, while the probiotic group (PrB) was fed a basal diet + probiotic combination (E. faecium 1.6 × 108 CFU/g, B. subtilis 2.0 × 108 CFU/g, S. cerevisiae 3.0 × 108 CFU/g). The probiotics combination was provided to the PrB, mixing with the basal diet in 5 kg/ton. As a result, the PrB exhibited significantly improved weight gain compared to the N-PrB (p = 0.00991). In the gut microbiome analysis, the PrB exhibited a significant increasing tendency of α-diversity compared to those of the N-PrB (p < 0.01). In the bacterial relative abundance changes in bacteria comprising the gut microbiota, Ruminococcaceae (p = 0.00281) and Prevotella (p = 0.00687) tended to significantly increase in the PrB, but decreased in the N-PrB. The Eubaterium coprostanoligenes group exhibited an increasing tendency in both groups, but tended to increase more significantly in the PrB compared to the N-PrB (p = 0.00681). Muribaculaceae tended to significantly increase in the N-PrB, but decreased in the PrB (p = 0.002779). In this study, significant differences on the gut microbiome were found according to the probiotics supplementation in the weaned piglets and these gut microbiome changes appeared to improve the growth performance.
Journal Article
L-765,314 Suppresses Melanin Synthesis by Regulating Tyrosinase Activity
2019
Although melanin production is a key self-defense mechanism against ultraviolet radiation (UVR)-induced skin damage, uneven or excessive deposition of melanin causes hyperpigmentary disorders. Currently available whitening agents are unsatisfactory because of issues with efficacy and safety. To develop more effective depigmenting agents, we performed high-throughput melanin content assay screening using the B16F10 melanoma cell line and identified L-765,314 as a drug that suppressed melanin production in cultured melanocytes in a dose-dependent manner as well as cAMP- or 12-O-tetradecanoylphorbol 13-acetate (TPA)-stimulated melanin production without cytotoxicity. Interestingly, melanogenic gene expression was not altered by L-765,314. Rather, diminished melanin production by L-765,314 appeared to be caused by downregulation of tyrosinase activity via inhibition of protein kinase C (PKC). Because L-765,314 did not show any adverse effect in melanocytes, altogether our data suggest that L-765,314 could be a potential therapeutic candidate for skin hyperpigmentary disorders and further discovery of selective inhibitors targeting PKC might be a promising strategy for the development of depigmenting agents to treat hyperpigmentary disorders.
Journal Article
Surface Modification of Matrimid® 5218 Polyimide Membrane with Fluorine-Containing Diamines for Efficient Gas Separation
by
Park, Jin Sung
,
Park, Ho Bum
,
Park, Jinmo
in
Carbon dioxide
,
Cellulose acetate
,
Climate change
2022
Polyimide membranes have been widely investigated in gas separation applications due to their high separation abilities, excellent processability, relatively low cost, and stabilities. Unfortunately, it is extremely challenging to simultaneously achieve both improved gas permeability and selectivity due to the trade-off relationship in common polymer membranes. Diamine modification is a simple strategy to tune the separation performance of polyimide membranes, but an excessive loss in permeability is also generally observed. In the present work, we reported the effects of diamine type (i.e., non-fluorinated and fluorinated) on the physicochemical properties and the corresponding separation performance of a modified membrane using a commercial Matrimid® 5218 polyimide. Detailed spectroscopic, thermal, and surface analyses reveal that the bulky fluorine groups are responsible for the balanced chain packing modes in the resulting Matrimid membranes compared to the non-fluorinated diamines. Consequently, the modified Matrimid membranes using fluorinated diamines exhibit both higher gas permeability and selectivity than those of pristine Matrimid, making them especially effective for improving the separation performance towards H2/CH4 and CO2/CH4 pairs. The results indicate that the use of fluorinated modifiers may offer new opportunities to tune the gas transport properties of polyimide membranes.
Journal Article
Fecal microbiota profiling in organic and conventional dairy farms differing in farm-level somatic cell counts and raw milk bacterial infections
by
Lee, Geun-Shik
,
Kizaki, Keiichiro
,
Ro, Younghye
in
Bacteria
,
Bacterial diseases
,
Bacterial infections
2026
This study investigated the fecal bacterial communities in commercial dairy farms with varying milk quality, defined by differences in somatic cell counts, to elucidate their association with productive performance and the presence of intramammary bacterial infections. Four dairy farms, selected to represent diverse management environments, included one organic farm (OF) and three conventional farms (CF1, CF2, and CF3), with comparable parity ranges and days in milk, while somatic cell counts across farms ranged from 52.9 to 390.3 × 10 3 cells/mL. Fecal bacterial community analysis identified 13 phyla and 190 genera, among which Order Lachnospirales (o_ Lachnospirales ), genus UCG-01 0 (g_ UCG-010 ), and genus Rikenellaceae RC9 gut group (g_ Rikenellaceae_RC9_gut_group ) showed the highest linear discriminant analysis (LDA) scores in OF, CF2, and CF3, respectively. Predicted functional pathway analysis of the fecal bacterial community identified 19 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways with significant differences. The pathway ‘various types of N-glycan biosynthesis’ ( ko00513 ), which may be associated with immune activity in cows, was most upregulated in CF2, whereas ‘steroid biosynthesis’ ( ko00100 ), related to fat metabolism in the rumen, was most downregulated in CF3 compared to OF. Correlation analyses of shared core taxa and milk parameters revealed that g_ Rikenellaceae_RC9_gut_group , g_ UCG-010 , and g_ UCG-005 , which are closely linked to cellulose digestion and energy metabolism, showed significant correlations with milk urea nitrogen and milk protein content. Among the KEGG pathways, indole alkaloid biosynthesis ( ko00901 ) and betalain biosynthesis ( ko00965 ), both associated with gut health, were positively correlated with milk yield. Subclinical mastitis infection rates ranged from 27.8 to 58.1% per farm and 9.72 to 25.6% per quarter, with Staphylococcus chromogenes being the most prevalent bacterial isolate, followed by S. aureus , S. simulans , and S. epidermidis . Farm-level similarity and dissimilarity analyses revealed statistically significant differences in fecal bacterial community structures, predicted functions, and distributions of raw milk bacterial infections. These findings indicate that the distribution and functional potential of fecal bacterial communities are closely associated with milk quality parameters, whereas their composition and the distribution of intramammary pathogens are highly farm-specific, highlighting the need for further research to clarify their relationship.
Journal Article
Long-term high-grain diet alters ruminal pH, fermentation, and epithelial transcriptomes, leading to restored mitochondrial oxidative phosphorylation in Japanese Black cattle
2020
To increase intramuscular fat accumulation, Japanese Black beef cattle are commonly fed a high-grain diet from 10 to 30 months of age. Castrated and fistulated cattle (
n
= 9) were fed a high-concentrate diets during the early, middle, and late stages consecutively (10–14, 15–22, 23–30 months of age, respectively). Ruminal pH was measured continuously, and rumen epithelium and fluid samples were collected on each stage. The 24-h mean ruminal pH during the late stage was significantly lower than that during the early stage. Total volatile fatty acid (VFA) and lactic acid levels during the late stage were significantly lower and higher, respectively, than those during the early and middle stages.
In silico
analysis of differentially expressed genes showed that “Oxidative Phosphorylation” was the pathway inhibited most between the middle and early stages in tandem with an inhibited upstream regulator (PPARGC1A, also called PGC-1α) but the most activated pathway between the late and middle stages. These results suggest that mitochondrial dysfunction and thereby impaired cell viability due to acidic irritation under the higher VFA concentration restored stable mitochondrial oxidative phosphorylation and cell viability by higher lactic acid levels used as cellular oxidative fuel under a different underlying mechanism in subacute ruminal acidosis.
Journal Article