• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.984-992
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• 2009

The objective of this study was to determine the effects of milk supplemented with Sel-Plex on thyroid hormones, rectal temperature, plasma glucose and cholesterol concentrations, and body weight in suckling calves. Ten Holstein suckling male calves of approximately 1 month of age were selected and randomly allocated to one of two groups and fed either unsupplemented milk (control) or milk supplemented with 0.3 mg/kg DM Se from Sel-Plex (treated). The animals received treated milk and free choice starter for two months. Dry matter intake for each individual animal was recorded daily throughout the study. The calves were weighed and blood samples were taken weekly. Plasma concentrations of triiodothyronine ($T_{3}$), thyroxin ($T_{4}$) and $T_{3}$-Uptake were determined using radioimmunoassay kits. Plasma cholesterol and glucose concentrations were determined by enzymatic-colorimetric methods. Rectal temperature was recorded at blood sampling time. During the experiment, ambient temperature and relative humidity were recorded at the time of blood sampling and every four hours. Treatment significantly (p<0.01) affected the concentration of $T_{3}$, free $T_{3}$ index ($FT_{3}I$) and ratio of $T_{3}$:$T_{4}$ in plasma. The plasma concentrations of $T_{3}$ in treated calves were 33% higher than in the control. The plasma concentrations of $T_{4}$ (p<0.05), glucose (p<0.01) and cholesterol (p<0.01) were decreased in the treated group. Calves fed Sel-Plex had higher rectal temperature (p<0.01). Plasma free $T_{4}$ index (FT4I) did not differ significantly between the two groups. An increase in body weight was observed (p<0.09) in the treated group. The results indicated that milk fortified with Sel-Plex could increase tissue conversion of $T_{4}$ to $T_{3}$ and therefore improve thermometabolism in suckling calves.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.4
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• pp.556-563
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• 2018

Objective: Spirulina has been recognized formerly as a filamentous spiral-shaped blue- green algae but more recently as a genus of photosynthetic bacteria (Arthrospira). This microorganism is considered as a rich source of essential nutrients for human and animals. The present study was conducted to determine potential application of Spirulina for heat- exposed broilers. Methods: Two hundred and fifty Cobb 500 chicks with male to female in equal ratio with average initial weight of 615.6 g at 17 days of age were divided into 5 treatments with 5 replicates of 10 chicks. Treatment groups were as follows: positive and negative controls with 0% Spirulina supplement and three Spirulina receiving groups with 5 g/kg (0.5%), 10 g/kg (1%), and 20 g/kg (2%) supplementation. Spirulina receiving groups as well as positive control were exposed to high ambient temperature at $36^{\circ}C$ for 6 h/d from 38 to 44 days of age. Biochemical variables were measured in serum samples at 35, 38, 42, and 45 days of broiler chickens age. Results: The results showed that supplementation of the diet with Spirulina decreased concentration of stress hormone and some serum lipid parameters while enhanced humoral immunity response and elevated antioxidant status whereas it didn't meaningfully affect performance characteristics. Nevertheless, feed conversion ratio was improved numerically but not statistically in broilers fed with 1% Spirulina under high ambient temperature. Conclusion: Overall, the present study suggests that alleviation of adverse impacts due to high ambient temperature at biochemical level including impaired enzymatic antioxidant system, elevated stress hormone and lipid profile can be approached in broiler chickens through supplementation of the diet with Spirulina platensis.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.759-765
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• 2013

The gene encoding squalene synthase (SQS) of the lipid-producing heterotrophic microalga Aurantiochytrium sp. KRS101 was cloned and characterized. The krsSQS gene is 1,551 bp in length and has two exons and one intron. The open reading frame of the gene is 1,164 bp in length, yielding a polypeptide of 387 predicted amino acid residues with a molecular mass of 42.7 kDa. The deduced krsSQS sequence shares at least four conserved regions known to be required for SQS enzymatic activity in other species. The protein, tagged with $His_6$, was expressed into soluble form in Escherichia coli. The purified protein catalyzed the conversion of farnesyl diphosphate to squalene in the presence of NADPH and $Mg^{2+}$. This is the first report on the characterization of an SQS from a Thraustochytrid microalga.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.114.1-114.1
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• 2011

Bioenergy production from lignocellulosic biomass and agriculture wastes have been attracted because of its sustainable and non-edible source. Especially, canola is considered as one of the best feedstock for renewable fuel production. Oil extracted canola and its agriculture residues are reuseable for bioethanol production. However, a pretreatment step is required before enzymatic hydrolysis to disrupt recalcitrant lignocellulosic matrix. To increase the sugar conversion, more efficient pretreatment process was necessary for removal of saccharification barriers such as lignin. Alkaline pretreatment makes the lignocellulose swollen through solvation and induces more porous structure for enzyme access. In our previous work, aqueous ammonia (1~20%) was utilized for alkaline reagent to increase the crystallinity of canola residues pretreatment. In this study, significant factors for efficient soaking in aqueous ammonia pretreatment on canola residues was optimized by using the response surface method (RSM). Based on the fundamental experiments, the real values of factors at the center (0) were determined as follows; $70^{\circ}C$ of temperature, 17.5% of ammonia concentration and 18 h of reaction time in the experiment design using central composition design (CCD). A statistical model predicted that the highest removal yield of lignin was 54% at the following optimized reaction conditions: $72.68^{\circ}C$ of temperature, 18.30% of ammonia concentration and 18.30 h of reaction time. Finally, maximum theoretical yields of soaking in aqueous ammonia pretreatment were 42.23% of glucose and 22.68% of xylose.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1750-1759
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• 2020

The characterization of cytochrome P450 CYP125A13 from Streptomyces peucetius was conducted using cholesterol as the sole substrate. The in vitro enzymatic assay utilizing putidaredoxin and putidaredoxin reductase from Pseudomonas putida revealed that CYP125A13 bound cholesterol and hydroxylated it. The calculated K_D value, catalytic conversion rates, and Km value were 56.92 ± 11.28 μM, 1.95 nmol min^-1 nmol^-1, and 11.3 ± 2.8 μM, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis showed that carbon 27 of the cholesterol side-chain was hydroxylated, characterizing CYP125A13 as steroid C27-hydroxylase. The homology modeling and docking results also revealed the binding of cholesterol to the active site, facilitated by the hydrophobic amino acids and position of the C27-methyl group near heme. This orientation was favorable for the hydroxylation of the C27-methyl group, supporting the in vitro analysis. This was the first reported case of the hydroxylation of cholesterol at the C-27 position by Streptomyces P450. This study also established the catalytic function of CYP125A13 and provides a solid basis for further studies related to the catabolic potential of Streptomyces species.

• KSBB Journal
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• v.16 no.4
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• pp.398-402
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• 2001

Enzymatic hydrolysis of agar was carried out continuously to produce agarooligosaccharides by immobilized agarase in Packed-Bed Reactor. The reactor was constructed using a acryl tube with an internal diameter of 10 mm and a useful height of 140 mm. The Packed-Bed Reactor was 11 mL reactor volume as its length : diameter ratio was 14 : 1. The operation condition of reaction was performed with an 1 g/L agar concentration at 40$^{\circ}C$, 10 mM MOPS buffer(pH 7.0) and with the flow rate 3 mL∼48 mL/h at a dilution rate of 1.09∼5.45 h$\^$-1/. The hydrolysis products was identified DP6, DP4 and DP2 by HPLC. The conversion rate of agar was about 80% and amount of total agarooligosaccharide was 0.88 mg/mL at Packed-Bed Reactor.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1547-1552
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• 2009

Sphingomonas chungbukensis DJ77 has the ability to produce large quantities of an extracellular polysaccharide that can be used as a gelling agent in the food and pharmaceutical industries. We identified, cloned and expressed the UDP-glucose dehydrogenase gene of S. chungbukensis DJ77, and characterized the resulting protein. The purified UDP-glucose dehydrogenase (UGDH), which catalyzes the reversible conversion of UDP-glucose to UDPglucuronic acid, formed a homodimer and the mass of the monomer was estimated to be 46 kDa. Kinetic analysis at the optimal pH of 8.5 indicated that the $K_m\;and\;V_{max}$ for UDP-glucose were 0.18 mM and 1.59 mM/min/mg, respectively. Inhibition assays showed that UDP-glucuronic acid strongly inhibits UGDH. Site-directed mutagenesis was performed on Gly9, Gly12 Thr127, Cys264, and Lys267. Substitutions of Cys264 with Ala and of Lys267 with Asp resulted in complete loss of enzymatic activity, suggesting that Cys264 and Lys267 are essential for the catalytic activity of UGDH.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2156-2162
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• 2012

Many literatures focus on the biological relevance and the identification of biomarkers for disease activity assessment while less attention has been paid to the development of standard procedures for sample preparation and storage based on liquid chromatography technique. The influencing factors including protein precipitation, storage temperature, storage time, and reconstitution by ultra pure water were analyzed employing HPLC-DAD. The effects were investigated from five participants over three months by principal components analysis (PCA) and the values of percent changes (PC). The samples with protein precipitation might slow the rate of bacterial enzymatic conversion. After protein precipitation, the average PC of urine samples ($0.136{\pm}0.013$, n = 5) is relatively less than that of the serum samples ($0.173{\pm}0.026$, n = 5) for three months. Minimal effects on metabolic profiles of serum and urine (PC < 0.15) are reasonable for metabolomic studies after protein precipitation and storage at $-20^{\circ}C$ for two months.

• KSBB Journal
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• v.26 no.5
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• pp.400-406
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• 2011

This study was investigated to improve the saccharification yield of Ulva pertusa Kjellman by the high pressure homogenization process. It was found that the high pressure homogenization pretreatment effectively destructed the cell wall structures only by using water. The high pressure homogenization process was operated under various conditions such as 10000, 20000 or 30000 psi with different recycling numbers. The optimal condition was determined as 30000 psi and 2 pass of recycling numbers and the sugar conversion yields were 16.02 (%, w/w) of glucose and 14.70 (%,w/w) of xylose, respectively. In the case of enzymatic treating the hydrolyzates with 5 FPU/glucan of celullase and 100 units/mL of amyloglucosidase, 65.8% of carbohydrates was converted into glucose. Using the hydrolysates of Ulva pertusa Kjellman, 48.7% of ethanol was obtained in the culture S.cerevisiae. These results showed that the high pressure homogenization process could efficiently hydrolyze the marine resource by using only water for bioethanol production.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.502-506
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• 1995

A Bacillus strain which produces ${\beta}-galactosidase$ with high transgalactosylation activity, was isolated from soil and tentatively designated as Bacillus sp. A1. When ${\beta}-galactosidase$ from Bacillus sp. A1 reacted with 40% (w/w) lactose, transgalactosylation ratio reached up to 90% at the 70% conversion of the initial lactose. The biosynthesis of the enzyme in Bacillus sp. A1 required lactose as an inducer and was repressed by glucose. Observing that the addition of amino acids to culture medium resulted in enhancing, to a significant extent, both the growth and the enzyme production of the strain, yeast extract and commercially available hydrolysates of protein were examined for the suitability as amino acid source. As it turned out, SMP, an enzymatic hydrolysis product of soybean protein from Fuji Oil Co.(Japan), was the most suitable for optimization of the culture medium. When Bacillus sp. A1 was cultured in the presence of 0.5% SMP and 2% lactose, the enzyme activity increased up to $1.8\;U/m{\ell}-broth$.