• Applied Biological Chemistry
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• v.50 no.2
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• pp.107-110
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• 2007

The putative laccase gene, yacK of Escherichia coli, K-12 is not expressed in lab culture conditions. The laccase gene was amplified by PCR and subcloned into pET28a vector. The laccase overproduced in E. coli harboring pET28a was purified by His-affinity column chromatography. The purified laccase, which has the apparent molecular weight of 55,000 on the SDS-polyacrylamide gel showed enzyme activity on the guaiacol solution and agar plate. Optimum temperature and pH were around 65$^{\circ}C$ and 5.0, respectively.

• Restorative Dentistry and Endodontics
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• v.39 no.1
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• pp.32-38
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• 2014

Objectives: In this study, we evaluated the antibacterial activity of self-etching adhesive systems against Streptococcus mutans using the agar diffusion method. Materials and Methods: Three 2-step systems, Clearfil SE Bond (SE, Kuraray), Contax (CT, DMG), and Unifil Bond (UnB, GC), and three 1-step systems, Easy Bond (EB, 3M ESPE), U-Bond (UB, Vericom), and All Bond SE (AB, BISCO) were used. 0.12% chlorhexidine (CHX, Bukwang) and 37% phosphoric acid gel (PA, Vericom) were used as positive controls. Results: The antibacterial activity of CHX and PA was stronger than that of the other groups, except SE. After light activation, the inhibition zone was reduced in the case of all 2-step systems except CT. However, all 1-step systems did not exhibit any inhibition zone upon the light activation. Conclusions: SE may be better than CT or UnB among the 2-step systems with respect to antibacterial activity, however, 1-step systems do not exhibit any antibacterial activity after light curing.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1197-1200
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• 2009

The whitening effect, tyrosinase inhibition, and cytotoxicity of neoagarotetraose were measured after its purification from hydrolyzed agar by gel filtration chromatography. In melanoma B16F10 cells, the melanin content of neoagarotetraose-treated cells was the same as that treated by kojic acid or arbutin. In addition, tyrosinase of melanoma cells was strongly inhibited by neoagarotetraose at a concentration of $1{\mu}g/ml$ and similarly inhibited at 10 and $100{\mu}g/ml$ compared with those by arbutin or kojic acid. The activity of mushroom tyrosinase showed a 38% inhibition by neoagarotetraose at $1{\mu}g/ml$, and this inhibitory effect was more efficient than that by kojic acid. Neoagarotetraose revealed a similar $IC_{50}$ (50% inhibition concentration) value for mushroom tyrosinase as that by kojic acid. These data suggest that the neoagarotetraose generated from agar by recombinant $\beta$-agarase might be a good candidate as a cosmetic additive for the whitening effect.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1116-1122
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• 2011

In this study, site-directed mutagenesis was performed on the ${\beta}$-agarase AgaA gene from Zobellia galactanivorans to improve its catalytic activity and thermostability. The activities of three mutant enzymes, S63K, C253I, and S63K-C253I, were 126% (1,757.78 U/mg), 2.4% (33.47 U/mg), and 0.57% (8.01 U/mg), respectively, relative to the wild-type ${\beta}$-agarase AgaA (1,392.61 U/mg) at $40^{\circ}C$. The stability of the mutant S63K enzyme was 125% of the wild-type up to $45^{\circ}C$, where agar is in a sol state. The mutant S63K enzyme produced 166%, 257%, and 220% more neoagarohexaose, and 230%, 427%, and 350% more neoagarotetraose than the wild-type in sol, gel, and nonmelted powder agar, respectively, at $45^{\circ}C$ over 24 h. The mutant S63K enzyme produced 50% more neoagarooligosaccharides from agar than the wild-type ${\beta}$-agarase AgaA from agarose under the same conditions. Thus, mutant S63K ${\beta}$-agarase AgaA may be useful for the production of functional neoagarooligosaccharides.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.345-348
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• 1985

Recombinant chimeric plasmid constructed with Xba I digested pUBl10 and -pE194 was transformed by polyethylene glycol induced protoplast transformation system into Bacillus subtilis BR 151 on the mannitol regeneration media, and two genes of antibiotics resistance were expressed simultaneously in the transfromant. Transformation frequency of the recombinant plasmid was 6.5 $\times$ 10$^{-5}$ on the mannitol regeneration agar plate containing neomycin and erythromycin. The replication of recombinant plasmid in the recipient cells was confirmed by the alkaline extraction method and agarose gel electrophoresis.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.459-469
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• 1992

The immobilization characteristics of Zymomonas mobilis for ethanol production were examined. Four different strains of Zymomonas mobilis have been used for ethanol production. Among those, Zymomonas mobilis KCTC 1534 has been selected as the best strain for the highest ethanol productivity from glucose and sucrose. The optimum temperature and pH of the selected strain for ethanol production were $37^{\circ}C$ and 5.0 respectively for both free and immobilized cells. When the cells were immobilized by the gel entrapment method, the immobilized cells could produce ethanol at a little higher temperature than free cells. Calcium alginate was selected as the best gel for immobilizing cells. The immobilized cells could maintain the viability of 80% in 10 weeks storage at $4^{\circ}C$ in the medium with 2% calcium chloride. 20-25 hours of preincubation in 10% glucose solution was required for the activation of immobilized cells entrapped within calcium alginate gel.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.575-580
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• 2014

Model gel food samples of yanggaeng (Y) were prepared for the elderly with various gelling agents, including agar (AG), low acyl gellan (GL), ${\kappa}$-carrageenan (CA), locust bean gum (LB), glucomannan (GM), and xanthan gum (XA) in different combinations as follows (in 1:1 ratio): LB+CA, GM+XA, and GM+CA. The quality characteristics of the different combinations were compared. The results revealed that water loss was highest for Y-GL, whereas there was no significant difference among the other samples. Y-GL showed the highest values for lightness in color, whereas Y-AG showed the lowest. Regarding textural properties, Y-LB+CA had the highest hardness value, whereas Y-GL had the lowest; the hardness of Y was related to the cross-section of the added gel. Finally, Y-GM+XA exhibited the highest score in overall acceptability in the sensory test by elderly, indicating that the preferable texture by elderly is slightly chewy, but not adhesive.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.465-469
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• 1996

Pathological and virological investigations were conducted on suspected outbreaks of infectious bursal disease (IBD) in a broiler farm and five pullet-raising poultry farms of Mymensingh and Tangail districts of Bangladesh. About 80 to 100 percent chicks were affected at the age of 26 to 45 days and mortality varied from 20 to 30 percent in broilers and 40 to 80 percent in layer chicks. Signs, symptoms, gross and microscopic lesions were typical of acute IBD. Several isolates of virus could be obtained by embryo inoculation and the virus was diagnosed as infectious bursal disease virus (IBDV) by agar gel immunodiffusion test (AGID). The virus isolate belonged to the very virulent pathotype of IBDV causing 100 percent mortality in three weeks old chicks on experimental infection.

• Korean Journal of Veterinary Research
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• v.8 no.1
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• pp.6-10
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• 1968

순화(純化)된 뉴켓슬병(病) 바이러스를 얻기 위(爲)한 기초적(基礎的)인 실험(實驗)으로 바이러스 재료(材料)를 완형액(緩衡液)의 종류(種類) 및 수소(水素)이온 농도(濃度), 한천농도(寒天濃度)를 달리한 한천(寒天)겔칼럼에 통과(通過)시켰다. 그러고 바이러스 재료(材料)의 혈구응집력가(血球凝集力價)와 총질소량(總窒素量)을 비교(比較) 측정(測定)하여 다음과 같은 결과(結果)를 얻었다. 1. 한천(寒天)겔 응과법(凝過法)을 뉴켓슬병(病) 바이러스의 순화(純化)에 간단(簡單)히 이용(利用) 할수 있다. 2. pH 7.0 이상(以上)의 인산식염(燐酸食鹽) 완형액(緩衡液)과 5~8%의 한천농도(寒天濃度) 입자(粒子)를 이용(使用)할때 가장 좋은 결과(結果)를 얻을 수 있었다. 3. 매시(每時) 5~10ml의 유출속도(流出速度)일때 55ml 부터 80ml의 유출액중(流出液中)에서 고농도(高濃度)의 바이러스를 얻을 수 있었다.

• Korean Journal of Veterinary Service
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• v.30 no.4
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• pp.551-555
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• 2007

A slaughtered 3 years old cow was diagnosed as bovine leukosis by postmortem inspection, agar gel immunodifusion (AGID) test, and polymerase chain reaction (PCR). It showed no special clinical signs except emaciation. Grossly, we observed enlargement of mediastinal and pelvic lymph nodes, and tubercle -like mass on pleura and lung surface, and masses on right atrium and ventricle.