• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.204-210
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• 2006

Ethyl (S)-4-chloro-3-hydroxybutyrate is a useful intermediate for the synthesis of Atorvastatin, a chiral drug to hypercholesterolemia. In this research, two 4-chloro-3-hydroxybutyro-nitrile-degrading strains were isolated from soil sample. They were identified as Rhodococcus erythropolis strains by 16S rRNA analysis. The nitrile-degrading enzyme(s) were suggested to be nitrile hydratase and amidase rather than nitrilase from the result of thin layer chromatography analysis. The corresponding genes were obtained by PCR cloning method. The predicted protein sequences had identities more than 96% with nitrile hydratase ${\alpha}-subunit$, nitrile hydratase ${\beta}-subunit$, and amidase of R. erythropolis. The 4-chloro-3-hydroxybutyronitrile-hydrolyzing activities in both strains were increased dramatically by ${\varepsilon}-caprolactam$ which was known as good inducer for nitrile hydratase. Both intact cells and cell-free extract could hydrolyze the nitrile compound. So, the intact cell and the enzymes could be used as potential biocatalyst for the production of 4-chloro-3-hydroxybutyric acid.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.47-51
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• 2010

The objective of this study was to understand changes of plasma metabolites, hormones, and mRNA level of cytoplasmic phosphoenolpyruvate carboxykinase (PEPCK-C) in liver in spontaneous clinical ketosis; 10 clinically ketotic cows and 10 healthy cows were chosen from the same dairy farm. Eleven blood parameters and liver fat content were measured in all cows, and mRNA levels of PEPCK-C in liver were measured by semi-quantitative reverse transcription (RT) polymerase chain reaction (PCR). In ketotic cows, concentration of plasma glucose decreased (p<0.01), concentration of plasma nonesterified fatty acids (NEFA) and $\beta$-hydroxybutyric acid (BHBA) increased (p<0.01), liver fat content (18.8% wet weight) and activity of plasma aspartate aminotransferase (AST) increased (p<0.01), but concentration of plasma total bilirubin (TBIL), $\gamma$-glutamyl transpeptidase ($\gamma$-GT), and cholinesterase (CHE) increased (p>0.05). In addition, concentration of plasma insulin decreased (p<0.05), concentration of plasma glucagons decreased (p>0.05), and mRNA level of PEPCK-C in liver increased (p<0.05). It is concluded that the adaptative changes of metabolites, hormones, and mRNA level of PEPCK-C in ketotic cows were in favor of the enhancement of gluconeogenesis, the decrease of fat mobilization and the relief of ketosis, but these were still inadequate to relieve ketosis.

• Animal Bioscience
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• v.34 no.5
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• pp.855-866
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• 2021

Objective: Performance and physiological responses of dairy calves may change by using extruded soybean meal (ESBM) instead of common soybean meal (SBM) in starter feed. The aims of the current study were i) to determine the effect of extrusion processing of SBM on protein electrophoretic size, fourier transform infrared spectroscopy (FTIR) structures and Cornell Net Carbohydrate and Protein System (CNCPS) protein subfractions and ii) to determine the effect of substitution of SBM with ESBM in starter feed of Holstein heifer calves during pre and post-weaning on performance, nutrient digestibility, and blood metabolites. Methods: The SBM was substituted with ESBM at the level of 0%, 25%, 50%, 75%, and 100% (dry matter [DM] basis). Fifty heifer calves (initial body weight 40.3±0.63 kg) were used for the study. After birth, animals were fed colostrum for 3 days and then they were fed whole milk until weaning. Animals had free access to starter feed and water during the study. Results: Extrusion of SBM decreased electrophoretic protein size and increased rapidly degradable true protein fraction, changed FTIR protein and amide II region. With increasing level of ESBM in the diet, starter intake increased quadratically during the pre-weaning period (p<0.05) and body weight, DM intake and average daily gain increased linearly during the post-weaning and the whole study period (p<0.05). Tbe DM and crude protein digestibilities at week 14 and blood glucose and beta hydroxybutyric acid increased linearly in calves as the level of ESBM increased in the diet (p<0.05). Conclusion: Dairy calves performance and physiological responses were sensitive to SBM protein characteristics including electrophoretic size, FTIR structures and CNCPS protein fractions.

• Journal of Animal Science and Technology
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• v.66 no.3
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• pp.567-576
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• 2024

Subclinical ketosis (SCK) is a prevalent metabolic disorder that occurs during the transition to lactation period. It is defined as a high blood concentration of ketone bodies (beta-hydroxybutyric acid f ≥ 1.2 mmol/L) within the first few weeks of lactation, and often presents without clinical signs. SCK is mainly caused by negative energy balance (NEB). The objective of this study is to identify single nucleotide polymorphisms (SNPs) associated with SCK using genome-wide association studies (GWAS), and to predict the biological functions of proximal genes using gene-set enrichment analysis (GSEA). Blood samples were collected from 112 Holstein cows between 5 and 18 days postpartum to determine the incidence of SCK. Genomic DNA extracted from both SCK and healthy cows was examined using the Illumina Bovine SNP50K BeadChip for genotyping. GWAS revealed 194 putative SNPs and 163 genes associated with those SNPs. Additionally, GSEA showed that the genes retrieved by Database for Annotation, Visualization, and Integrated Discovery (DAVID) belonged to calcium signaling, starch and sucrose, immune network, and metabolic pathways. Furthermore, the proximal genes were found to be related to germ cell and early embryo development. In summary, this study proposes several feasible SNPs and genes associated with SCK through GWAS and GSEA. These candidates can be utilized in selective breeding programs to reduce the genetic risk for SCK and subfertility in high-performance dairy cows.

• Journal of Life Science
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• v.18 no.12
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• pp.1625-1630
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• 2008

A microorganism capable of producing high level of poly-3-hydoxybutyrate (PHB) from xylose was isolated from soil. The isolated strain J-65 was identified as Bacillus megaterium based on the morphological, biochemical and molecular biological characteristics. The optimum temperature and pH for the growth of B. megaterium J-65 were $37^{\circ}C$ and 8.0, respectively. The optimum medium composition for the cell growth was 2% xylose, 0.25% $(NH_4)_2SO_4$, 0.3% $Na_2HPO_4{\cdot}12H_2O$, and 0.1% $KH_2PO_4$. The optimum condition for PHB accumulation was same to the optimum condition for cell growth. Copolymer of ${\beta}$-hydroxybutyric and ${\beta}$-hydroxyvaleric acid was produced when propionic acid was added to shake flasks containing 20 g/l of xylose. Fermenter culture was carried out to produce the high concentration of PHB. In batch culture, cell mass was 9.82 g/l and PHB content was 35% of dry cell weight. PHB produced by B. megaterium J-65 was identified as homopolymer of 3-hydoxybutyric acid by GC and NMR.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1530-1540
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• 2016

This study was conducted to estimate the genetic parameters of ${\beta}$-hydroxybutyrate (BHBA) and acetone concentration in milk by Fourier transform infrared spectroscopy along with test-day milk production traits including fat %, protein % and milk yield based on monthly samples of milk obtained as part of a routine milk recording program in Korea. Additionally, the feasibility of using such data in the official dairy cattle breeding system for selection of cows with low susceptibility of ketosis was evaluated. A total of 57,190 monthly test-day records for parities 1, 2, and 3 of 7,895 cows with pedigree information were collected from April 2012 to August 2014 from herds enrolled in the Korea Animal Improvement Association. Multi-trait random regression models were separately applied to estimate genetic parameters of test-day records for each parity. The model included fixed herd test-day effects, calving age and season effects, and random regressions for additive genetic and permanent environmental effects. Abundance of variation of acetone may provide a more sensitive indication of ketosis than many zero observations in concentration of milk BHBA. Heritabilities of milk BHBA levels ranged from 0.04 to 0.17 with a mean of 0.09 for the interval between 4 and 305 days in milk during three lactations. The average heritabilities for milk acetone concentration were 0.29, 0.29, and 0.22 for parities 1, 2, and 3, respectively. There was no clear genetic association of the concentration of two ketone bodies with three test-day milk production traits, even if some correlations among breeding values of the test-day records in this study were observed. These results suggest that genetic selection for low susceptibility of ketosis in early lactation is possible. Further, it is desirable for the breeding scheme of dairy cattle to include the records of milk acetone rather than the records of milk BHBA.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.961-970
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• 2013

Eight multiparous Holstein cows ($569{\pm}47$ kg of BW; $84{\pm}17$ DIM) were used to evaluate the effects of different levels of coarsely ground wheat (CGW) as replacements for ground corn (GC) in diets on feed intake and digestion, ruminal fermentation, lactation performance, and plasma metabolites profiles in dairy cows. The cows were settled in a replicated $4{\times}4$ Latin square design with 3-wk treatment periods; four cows in one of the replicates were fitted with rumen cannulas. The four diets contained 0, 9.6, 19.2, and 28.8% CGW and 27.9, 19.2, 9.6, and 0% GC on dry matter (DM) basis, respectively. Increasing dietary levels of CGW, daily DM intake tended to increase quadratically (p = 0.07); however, apparent digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were significantly decreased (p<0.01) in cows fed the 28.8% CGW diets. Ruminal pH remained in the normal physiological range for all dietary treatments at all times, except for the 28.8% CGW diets at 6 h after feeding; moreover, increasing dietary levels of CGW, the daily mean ruminal pH decreased linearly (p = 0.01). Increasing the dietary levels of CGW resulted in a linear increase in ruminal propionate (p<0.01) and ammonia nitrogen ($NH_3$-N) (p = 0.06) concentration, while ruminal acetate: propionate decreased linearly (p = 0.03) in cows fed the 28.8% CGW diets. Milk production was not affected by diets; however, percentage and yield of milk fat decreased linearly (p = 0.02) when the level of CGW was increased. With increasing levels of dietary CGW, concentrations of plasma beta-hydroxybutyric acid (BHBA) (p = 0.07) and cholesterol (p<0.01) decreased linearly, whereas plasma glucose (p = 0.08), insulin (p = 0.02) and urea nitrogen (p = 0.02) increased linearly at 6 h after the morning feeding. Our results indicate that CGW is a suitable substitute for GC in the diets of dairy cows and that it may be included up to a level of 19.2% of DM without adverse effects on feed intake and digestion, ruminal fermentation, lactation performance, and plasma metabolites if the cows are fed fiber-sufficient diets.

• KSBB Journal
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• v.9 no.4
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• pp.365-371
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• 1994

The effects of ratios of initial concentration of carbon source to the initial concentration of nitrogen source in the fermentation media on both the yields of PHB fermentation variables and the accumulation of poly-${\beta}$-hydroxybutyric acid(PHB) were investigated. The fermentation media were composed of the combination of varing glucose concentrations, 10, 20, 25, 30, 40, $50g/\ell$ and the NH4Cl concentrations 0.33, 0.4, 0.5, 1.5, 3, $5g/\ell$. The yield of biomass on glucos, Yx/s, decreased very slowly according to the increase of the ratio of C to N. And the yield became constant at 0.35(g biomass/g glucose) with the ratio higher than 70. The yield of residual biomass, Yx/s, also decreased with the ratio of C to N and finally showed a constant value of 0.065(g residual biomass/g glucose) when the ratio was higher than 65. In accordance with the augmentation of the ratio, the yield of PHB, YPHB/S, however, increased and showed the maximum value of 0.35 (g PHB/g glucose) between 40 and 60 of the ratio. The maximum yield of PHB to the change of biomass, YPHB/S, was 0.87(g PHB/g biomass), and the yie1d YPHB/RX, was 4.2(g PHB/g residual biomass). The maximum accumulation percent of PHB to the final biomass was 81% when the ratio was higher than 67.

• Korean Journal of Microbiology
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• v.34 no.4
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• pp.212-218
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• 1998

An obligately methylotrophic bacterium which produces extracellular polysaccharide (EPS) was isolated through methanol-enrichment culture technique. The isolate was aerobic, nonmotile, and gram negative rod and exibited catalase, but no oxidase, activity. Plasmid, carotenoid, and poly-${\beta}$-hydroxybutyric acid were not found. The guanine plus cytosine content of DNA was 52-56%. The isolate was found to grow only on methanol and monomethylamine. Growth was optimal ($t_d=2.4h$) at $35^{\circ}C$ and pH 6.5 in a mineral medium containing 0.5% (v/v) methanol, 25 mM phosphate, and 0.212% ammonium sulfate. Methanol was assimilated through the ribulose monophosphate pathway. Maximun amount of EPS was produced in cells growing at the mid-stationary growth phase at $30^{\circ}C$ in a mineral medium (PH 6.5) containing 1.0% (v/v) methanol in the CIN ratio of 54.7. Thin-layer chromatographic and high performance liquid chromatographic analysis revealed that the EPS was composed of glucose and galactose. EPS which was not treated with ethanol (Pbe) exhibited stable viscosity under various concentrations of salts and temperatures hut showed high viscosity at low pH. EPS precipitated with ethanol (Pae) was found to be more stable in viscosity than the Pbe at various salt concentrations, temperatures, and pH. The Pae also exhibited higher viscosity than the Pbe and xanthan gum. Scanning electron microscopy revealed that the lyophilized Pbe and Pae have a multi-layered structure and a structure of thick fibers, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.217-223
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• 2019

Objective: An experiment was conducted to investigate the effects of feed intake restriction during late pregnancy on the function, anti-oxidation capability and acute phase protein synthesis of ovine liver. Methods: Eighteen time-mated ewes with singleton fetuses were allocated to three groups: restricted group 1 (RG1, 0.18 MJ ME/kg $W^{0.75}$ d, n = 6), restricted group 2 (RG2, 0.33 MJ ME/kg $W^{0.75}$ d), n = 6) and a control group (CG, ad libitum, 0.67 MJ ME/kg $W^{0.75}$ d, n = 6). The feed restriction period was from 90 days to 140 days of pregnancy. Results: The ewe's body weight, liver weights, water, and protein content of liver in the restricted groups were reduced compared with the CG group (p<0.05), but the liver fat contents in the RG1 group were higher than those of the CG group (p<0.05). The increased hepatic collagen fibers and reticular fibers were observed in the restricted groups with the reduction of energy intake. The concentrations of nonesterified free fatty acids in the RG1 and RG2 groups were higher than those of the CG group with the reduction of energy intake (p<0.05), but there were decreased concentrations of lipoprotein lipase and hepatic lipase in both restricted groups compared with the CG group (p<0.05). In addition, the increased concentrations of ${\beta}$-hydroxybutyric acid, triglycerides, malondialdehyde, total antioxidant capacity and activities of superoxide dismutase activity and catalase were found in the RG1 group, and the concentrations of cholinesterase in the RG1 group were reduced compared with the CG group (p<0.05). For the concentrations of acute phase proteins, the C-reactive protein (CRP) in the RG1 group were reduced compared with the CG group, but there were no differences in haptoglobin relative to the controls (p>0.05). Conclusion: The fat accumulation, increased hepatic fibrosis, antioxidant imbalance and modified synthesis of acute phase proteins were induced in ewe's liver by maternal malnutrition during late pregnancy, which were detrimental for liver function to accommodate pregnancy.