• Journal of Microbiology and Biotechnology
• /
• v.20 no.3
• /
• pp.550-557
• /
• 2010

Escherichia coli (E. coli) heat-labile enterotoxin B subunit (LTB) was regarded as one of the most powerful mucosal immunoadjuvants eliciting strong immunoresponse to coadministered antigens. In the research, the high-level secretory expression of functional LTB was achieved in P. pastoris through high-density fermentation in a 5-1 fermentor. Meanwhile, the protein was expressed in E. coli by the way of inclusion body, although the gene was cloned from E. coli. Some positive yeast and E. coli transformants were obtained respectively by a series of screenings and identifications. Fusion proteins LTB-6$\times$His could be secreted into the supernatant of the medium after the recombinant P. pastoris was induced by 0.5% (v/v) methanol at $30^{\circ}C$, whereas E. coli transformants expressed target protein in inclusion body after being induced by 1 mM IPTG at $37^{\circ}C$. The expression level increased dramatically to 250-300 mg/l supernatant of fermentation in the former and 80-100 mg/l in the latter. The LTB-6$\times$His were purified to 95% purity by affinity chromatography and characterized by SDS-PAGE and Western blot. Adjuvant activity of target protein was analyzed by binding ability with GMI gangliosides. The MW of LTB-6$\times$His expressed in P. pastoris was greater than that in E. coli, which was equal to the expected 11 kDa, possibly resulted from glycosylation by P. pastoris that would enhance the immunogenicity of co-administered antigens. These data demonstrated that P. pastoris producing heterologous LTB has significant advantages in higher expression level and in adjuvant activity compared with the homologous E. coli system.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.4
• /
• pp.372-377
• /
• 2017

A feeding trial was conducted to evaluate the effects of partial replacement of fishmeal (FM) protein in a practical diet for rockfish Sebastes schlegeli juveniles with mealworm Tenebrio molitor meal (WM), in terms of growth performance, feed utilization, whole body composition and hematological parameters. Four isonitrogenous and isoenergetic diets were formulated to contain 8, 16, 24 and 32% WM (designated as WM8, WM16, WM24 and WM32). A FM-based diet without WM inclusion was used as a control. Triplicate groups of rockfish ($2.6{\pm}0.07g$) were hand fed one of the experimental diets to visual satiation twice a day for 8 weeks. Weight gain of fish fed the WM32 diet was lower than that of control. No significant differences were found in daily feed intake, feed efficiency and protein efficiency ratio. The whole-body protein content of fish fed WM0 and WM8 diets were significantly higher than that of fish fed WM32 diet. No statistical differences were observed in hematological parameters. These results indicate that WM has potential as alternative to FM in practical diets for juvenile rockfish and can be used at an inclusion level of up to 24% without having a significant negative effects on growth and feed efficiency.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.1
• /
• pp.1-5
• /
• 2002

A fusion protein, consisting of a human epidermal growth factor (hEGF) as the recognition domain and human angiogenin as the toxin domain, can be used as a targeted therapeutic against breast cancer cells among others. The fusion protein was expressed as inclusion body in recombinant E. coli, and when the conventional, solution-phase refolding process was used the refolding yield was very low due to severe aggregation. It was probably because of the opposite electric charge at a neutral pH resulting from the vastly different pI values of each domain. The solid-phase refolding process that exploited the ionic interactions between ionic exchanger surface and the fusion protein was tried, but the adsorption yield was also very low, below $ 30\%$, regardless of the resins and pH conditions used. Therefore, to provide a higher ionic affinity toward the solid matrix, six lysine residues were tagged to the N-terminus of the hEGF domain. When heparin-Sepharose was used as the matrix, the adsorption capacity increased 2.5-3 times to about $88\%$. Besides the intrinsic affinity of angiogenin to heparin, the poly-lysine tag provided additional ionic affinity. And the subsequent refolding yield increased nearly 13-fold, from ca. $4.8\%$ in the conventional refolding of the untagged fusion protein to $63.6\%$. The process was highly reproducible. The refolded protein in the column eluate retained RNase bioactivity of angiogenin.

• Korean Journal of Poultry Science
• /
• v.47 no.3
• /
• pp.153-158
• /
• 2020

The effects of palm oil and soy oil supplementation in broiler chickens on growth performance and nutrient digestibility of dry matter, nitrogen, and energy was evaluated. In this experiment, 702 one-day-old Ross 308 cross bred chicks with an initial body weight of 42.23±0.05 g (mean±SD) were utilized in a completely randomized treatment design (13 replicates/treatment, 18 chickens/cage) and fed for 35 days with CON (basal diet), T1 (Basal diet + 1.3 % palm oil), and T2 (Basal diet + 1.3% soy oil). From days 1 to 7, the body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were not significantly affected by the supplementation with palm oil or soy oil. However, from days 7 to 21, BWG showed a tendency to increase compared to that with the control treatment. Moreover, BWG was significantly improved (P<0.05) with palm and soy oil supplementation during the overall experiment in comparison to that with the control diet. In addition, the palm oil-supplemented group had higher BWG than the soy oil treatment group (P<0.05). During the overall experiment, FI tended to increase in the T1 group compared to that in the other groups. There was no significant effect on FCR and nutrient digestibility of dry matter, nitrogen, and energy during the overall trial with the supplementation of palm or soy oil. In summary, the inclusion of dietary palm and soy oil has a beneficial effect on the growth performance of broiler chickens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.8
• /
• pp.1141-1146
• /
• 2005

A trial was conducted to evaluate the level of wheat substituted for corn in a traditional corn-soy diet and the xylanase supplementation effect on the growth performance and nutrient digestion of broiler chickens. This experiment was a randomized design with a 4${\times}$2 factorial arrangement with four levels of wheat substitution and two levels of enzyme inclusion in the diet. Wheat replaced 0, 25, 50 or 100% corn with or without 1 g/kg xylanase supplementation in iso-nitrogenous and iso-calorific experimental diets. The results showed that in the growing period, broilers attained the highest (p<0.05) body weight gain, feed intake, and relative small intestine weight when wheat was substituted at 25% for corn. The relative caecum weight increased (p<0.05) linearly with increasing levels of wheat substitution for corn. However, during the finishing period and entire experimental period from 0 to 6 weeks, no significant difference was shown in the growth performance among all treatments. Xylanase inclusion significantly improved the body weight gain, fat availability (p<0.01) and diet metabolisable energy (p<0.1) but decreased (p<0.05) the relative GI tract weight during the growing period. The digesta viscosity of 6-week old broilers was also decreased (p<0.05). It appears that wheat substituted for corn did not affect the growth performance, nutrient digestion, and the digesta viscosity of chickens. It is acceptable to completely substitute wheat for corn. Xylanase supplementation improved performance.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.5
• /
• pp.983-989
• /
• 2008

Human insulin is a hormone well-known to regulate the blood glucose level. Recombinant preproinsulin, a precursor of authentic insulin, is typically produced in E. coli as an inactive inclusion body, the solubilization of which needs the addition of reducing agents such as $\beta$-mercaptoethanol. To make authentic insulin, recombinant preproinsulin is modified enzymatically by trypsin and carboxypeptidase B. The effects of $\beta$-mercaptoethanol on the formation of human insulin derivatives were investigated in the enzymatic modification by using commercially available human proinsulin as a substrate. Addition of 1 mM $\beta$-mercaptoethanol induced the formation of various insulin derivatives. Among them, the second major one, impurity 3, was found to be identical to the insulin B chain fragment from $Phe_1$ to $Glu_{21}$. Minimization of the formation of insulin derivatives and concomitant improvement of the production yield of human insulin were achieved by the addition of hydrogen peroxide. Hydrogen peroxide bound with $\beta$-mercaptoethanol and thereby reduced the negative effects of $\beta$-mercaptoethanol considerably. Elimination of the impurity 3 and other derivatives by the addition of over 10 mM hydrogen peroxide in the presence of $\beta$-mercaptoethanolled to a 1.3-fold increase in the recovery efficiency of insulin, compared with those for the case without hydrogen peroxide. The positive effects of hydrogen peroxide were also confirmed with recombinant human preproinsulin expressed in recombinant E. coli as an inclusion body.

• Korean Journal of Poultry Science
• /
• v.7 no.2
• /
• pp.18-27
• /
• 1980

Infectious bursal disease, so called Gumboro disease, is found world-wide in areas of intensive poultry farming. The clinical signs of the disease are very indicative, but most infections occur unnoticed due to the age of infection of chicken as well as the degree of virulence of virus affected. Edematous and hemorrhagic lesions in BF at early course of infection and the complete atrophies of BF in later are the most characteristic. The infection is considered highly contagious by direct contact, by fecal material and by contaminated feed and water. The virus is also highly resistant in environment and belongs to Diploma virus with size of 55 to 60nm of Ribovirus group. IBDV grows in embryos, embryonic cells and BF of susceptible chickens. Immune-diffusion using agar gel is the method of a choice to determine IBDV infection in chickens. Maternal immunity is very effective in protecting chickens of critical age when IBDV infection severely damages the function of BF. Immunosuppressive effect of IBDV causes more production losses than direct effects of clinical disease of IBD. Inclusion body hepatitis, infectious anemia and gangrenous dermatitis syndrome are the disease associated with the immunosuppressive condition of chickens.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.3
• /
• pp.153-158
• /
• 1998

The internal structures of Arabidopsis thaliana infected with beet curly top virus (BCTV) were studied by light microscopy. Hyperplasia was observed in the inflorescence stems of Arabidopsis thaliana ecotype Sei-O at 2 weeks after BCTV-Logan inoculation and callus was induced on symptomatic tissues at 4 weeks after virus inoculation. The infection processes were revealed as follows: hyperplasia of phloem tissue, necrosis of hyperplastic phloems, lacuna formation of necrotic tissues, elongation and enlargement of cortex and epidermal cells surrounding the lacuna formed phloem tissues, induction of cell division in the enlarged cortex and epidermal cells, and induction of callus tissue. Callus formation on Arabidopsis was caused by the virus infection, and virus inclusion body was observed in both phloem and callus tissue by azure-A staining.

• Journal of Veterinary Science
• /
• v.22 no.4
• /
• pp.42.1-42.16
• /
• 2021

Background: Inclusion body hepatitis (IBH) is an economically important viral disease primarily affecting broiler and breeder chickens. All 12 serotypes of fowl adenovirus (FAdV) can cause IBH. Objectives: To characterize FAdV isolates based on phylogenetic analysis, and to study the pathogenicity of FAdV-8b in specific-pathogen-free (SPF) chickens following virus inoculation via oral and intramuscular (IM) routes. Methods: Suspected organ samples were subjected to virus isolation and polymerase chain reaction (PCR) for FAdV detection. Hexon gene sequencing and phylogenetic analysis were performed on FAdV-positive samples for serotype identification. One FAdV-8b isolate, UPM/FAdV/420/2017, was selected for fiber gene characterization and pathogenicity study and was inoculated in SPF chickens via oral and IM routes. Results: The hexon gene phylogenetic analysis revealed that all isolates belonged to FAdV-8b. The fiber gene-based phylogenetic analysis of isolate UPM/FAdV/420/2017 supported the grouping of that isolate into FAdV species E. Pathogenicity study revealed that, chickens infected with UPM/FAdV/420/2017 via the IM route had higher clinical score values, higher percent mortality, higher degree of the liver lesions, higher antibody response (p < 0.05), and higher virus shedding amounts (p < 0.05) than those infected via the oral route. The highest virus copy numbers were detected in liver and gizzard. Conclusions: FAdV-8b is the dominant FAdV serotype in Malaysia, and pathogenicity study of the FAdV-8b isolate UPM/FAdV/420/2017 indicated its ability to induce IBH in young SPF chickens when infected via oral or IM routes.

• Korean Journal of Agricultural Science
• /
• v.48 no.1
• /
• pp.11-19
• /
• 2021

This study was conducted on sows to evaluate the effect of flaxseed oil on the sows and their offspring's performance. Forty-eight (48) sows (Landrace × Yorkshire) and their offspring were assigned randomly to each treatment (Control and Control + flaxseed oil 0.5% [FX]). Body weight (BW), average daily feed intake (ADFI) and nutrient digestibility of the sows were estimated. Sow backfat thickness, days-to-estrus, and chest circumference were measured by different methods. In piglets, survival rate, the initial weight, weaning weight, and average daily gain (ADG) were calculated. Fecal scores of both the sows and piglets were recorded. Inclusion of FX did not influence (p > 0.05) the litter size, days-to-estrus, sow BW, ADFI and digestibility of nutrient throughout the experiment. Reduction in (p < 0.05) BW loss was observed with the FX supplementation in sows. Only the backfat thickness during the weaning period showed an increase (p < 0.05) by FX supplementation. Chest circumference was decreased (p < 0.05) in the FX group compared to the control. Sows fed the FX diet had a reduced (p < 0.05) fecal score only at weaning. Piglets' fecal score showed no significant differences for FX supplementation. However, the inclusion of FX brought about a higher (p < 0.05) birth weight, weaning weight, and average daily gain (ADG). In conclusion, our study suggests that FX has positive supplementary effects on a sow's body condition and its offspring's performance as a source of n-3 fatty acid.