• Microbiology and Biotechnology Letters
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• v.45 no.1
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• pp.63-70
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• 2017

A functional screen of 60,672 fosmid metagenomic clones amplified from marine sediment obtained from the Dokdo islets in Korea identified the gene EstES1, whose product, EstES1, displayed lipolytic properties on tributyrin-supplemented media. EstES1 is a 576 amino acid protein with a predicted molecular weight of 59.4 kDa including 37 N-terminal leader amino acids. EstES1 exhibited the highest sequence similarity (44%) to a carboxylesterase found in Haliangium ochraceum DSM14365. Phylogenetic analysis indicated that EstES1 belongs to a currently uncharacterized family of lipases. Within the conserved domain, EstES1 retains the catalytic triad that consists of the consensus penta-peptide motif, GESAG. EstES1 demonstrated a broad substrate specificity toward the long acyl group of ethyl esters (C2-C12), and its optimal activity was recorded toward p-Nitrophenyl butyrate (C4) at pH 9.0 and $40^{\circ}C$ (specific activity of 255.4 U/mg). The enzyme remained stable in the ranges of $60-65^{\circ}C$ and pH 9.0-10.5 and in the presence of methanol, ethanol, isopropanol, and dimethyl sulfoxide. Therefore, EstES1 has potential for use in industrial applications involving high temperature, organic solvents, and/or alkaline conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.98-105
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• 2018

The sale of brown rice batches composed of rice produced in different years is prohibited in Korea. Thus, new methods for the identification of the year of production are critical for maintaining the distribution of high quality brown rice. Here, we describe the exploitation of an enzyme that can be used to discriminate between freshly harvested and one-year-old brown rice. The degree of enzyme activity was visualized through freshness test with Guaiacol, Oxydol, and p-phenylenediamine reagents. With electronic eye equipment, we selected 29 color codes for identifying new brown rice and old brown rice. The discrimination power of selected color codes showed a minimum of 0.263 to a maximum of 0.922 and an average value of 0.62. The accuracy with which new brown rice and old brown rice could be identified was 100% in principal component analysis (PCA) and discriminant function analysis (DFA). The DFA analysis had greater discriminatory power than did the PCA analysis. A verification test using new brown rice, old brown rice, or a mixture of the two was then performed to validate our method. The accuracy of identification of new and old brown rice was 100% in both cases, whereas mixed brown rice samples were correctly classified at a rate of 96.9%. Additionally, in order to test whether the discriminant constructed in winter can be applied to samples collected in summer, new and old brown rice stored for 8 months were collected and tested. Both new and old brown rice collected in summer were classified as old brown rice and showed 50% identification accuracy. We were able to attribute these observations to changes in enzyme content over time, and therefore we conclude, it will be necessary to develop discriminants that are specific to distinct storage periods in the near future.

• Korean Journal of Poultry Science
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• v.41 no.2
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• pp.105-113
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• 2014

The current study was performed to investigate the effects of dietary supplementation of dried coffee meal (CM) on growth performance, intestinal and blood biochemical index, intestinal enzymes, and cecal microbial populations. A total of 162, 3-day-old male broiler chicks were randomly allocated into three dietary groups: control group (CON), basal diet added with 0.5% CM (CM I), and basal diet added with 1.0% CM (CM II). Dietary supplementation of CM did not change bird performance and the relative weight of intestinal mucosal tissues. The birds fed the diet supplemented with CM (0.5 and 1.0%) significantly decreased mucosal glucose concentration (P<0.05) without affecting blood glucose level compared with those fed control diet. The level of blood aspartate aminotransferase (AST) significantly increased in CM II group (P<0.05) without affecting ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GTP) compared with that in the CON group. The specific activity of intestinal maltase, leucine aminopeptidase (LAP) and alkaline phosphatase (ALP) were not affected by dietary supplementation of CM, whereas sucrase activity in birds fed the diet supplemented with CM was decreased (P<0.05) compared to that in the control birds. The colony forming units (CFU) of E. coli in the cecum of CM-fed birds was significantly decreased (P<0.05) compared with that of control birds without changing the CFU of Lactobacillus. In conclusion, dietary supplementation of lower level of CM (0.5%) can be used as a beneficial feed resource without liver toxicity in broiler chicks.

• KSBB Journal
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• v.23 no.3
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• pp.257-262
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• 2008

In this study, the reaction conditions for lipase-catalyzed resolution of racemic naproxen 2,2,2-trilfluoroethyl thioester were optimized, and the effect of surfactants was investigated. Among the organic solvents tested, the isooctane showed the highest conversion (92.19%) in a hydrolytic reaction of (S)-naproxen 2,2,2-trifluoroethyl thioester. In addition, the isooctane induced the highest initial reaction rate of (S)-naproxen 2,2,2-trifluoroethyl thioester ($V_s=2.34{\times}10^{-2}mM/h$), the highest enantioselectivity (E = 36.12) and the highest specific activity ($V_s/(E_t)=7.80{\times}10^{-4}mmol/h{\cdot}g$) of lipase. Furthermore, reaction conditions such as temperature, concentration of the substrate and enzyme, and agitation speed were optimized using response surface methodology (RSM), and the statistical analysis indicated that the optimal conditions were $48.2^{\circ}C$, 3.51 mM, 30.11 mg/mL and 180 rpm, respectively. When the optimal reaction conditions were used, the conversion of (S)-naproxen 2,2,2-trifluoroethyl thioester was 96.5%, which is similar to the conversion (94.6%) that was predicted by the model. After optimization of reaction conditions, the initial reaction rate, lipase specific activity and conversion of (S)-naproxen 2,2,2-trifluoroethyl thioester increased by approximately 19.54%, 19.12% and 4.05%, respectively. The effect of surfactants such as Triton X-100 and NP-10 was also studied and NP-10 showed the highest conversion (89.43%), final reaction rate of (S)-naproxen 2,2,2-trifluoroethyl thioester ($V_s=1.175{\times}10^{-2}mM/h$) and enantioselectivity (E = 59.24) of lipase.

• Journal of Environmental Science International
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• v.19 no.12
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• pp.1323-1334
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• 2010

The effect of nitric oxide (NO) on antioxidant system and protective mechanism against oxidative stress under UV-B radiation was investigated in leaves of maize (Zea mays L.) seedlings during 3 days growth period. UV-B irradiation caused a decrease of leaf biomass including leaf length, width and weight during growth. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated UV-B stress induced growth suppression. NO donor permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under UV-B stress, suggesting that NO has protective effect on chloroplast membrane in maize leaves. Flavonoids and anthocyanin, UV-B absorbing compounds, were significantly accumulated in the maize leaves upon UV-B exposure. Moreover, the increase of these compounds was intensified in the NO treated seedlings. UV-B treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in maize leaves, while NO donor prevented UV-B induced increase in the contents of malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that NO serves as antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, catalase (CAT) and ascorbate peroxidase (APX) in maize leaves in the presence of NO donor under UV-B stress were higher than those under UV-B stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3- oxide (PTIO), a specific NO scavenger, to the maize leaves arrested NO donor mediated protective effect on leaf growth, photosynthetic pigment and free radical scavenging activity. However, PTIO had little effect on maize leaves under UV-B stress compared with that of UV-B stress alone. $N^{\omega}$-nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), significantly increased $H_2O_2$ and MDA accumulation and decreased antioxidant enzyme activities in maize leaves under UV-B stress. This demonstrates that NOS inhibitor LNNA has opposite effects on oxidative resistance. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative stress induced by UV-B radiation and thus confer UV-B tolerance.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.73-79
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• 2010

The Korea Polar Research Institute (KOPRI) has assembled a culture collection of cold-adapted bacterial strains from both the Arctic and Antarctic. To identify excellent protease-producers among the proteolytic bacterial collection (874 strains), 78 strains were selected in advance according to their relative activities and were subsequently re-examined for their extracellular protease activity on $0.1{\times}$ ZoBell plates supplemented with 1% skim milk at various temperatures. This rapid and direct screening method permitted the selection of a small group of 15 cold-adapted bacterial strains, belonging to either the genus Pseudoalteromonas (13 strains) or Flavobacterium (2 strains), that showed proteolytic activities at temperatures ranging between $5-15^{\circ}C$. The cold-active proteases from these strains were classified into four categories (serine protease, aspartic protease, cysteine protease, and metalloprotease) according to the extent of enzymatic inhibition by a class-specific protease inhibitor. Since highly active and/or cold-adapted proteases have the potential for industrial or commercial enzyme development, the protease-producing bacteria selected in this work will be studied as a valuable natural source of new proteases. Our results also highlight the relevance of the Antarctic for the isolation of protease-producing bacteria active at low temperatures.

• Journal of Life Science
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• v.21 no.6
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• pp.893-900
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• 2011

Prostatic acid phosphatase (PAP) is one of the widely used biomarkers in the diagnosis of prostate cancer. It was initially identified in 1935 and is the most abundant phosphatase in the human prostate. PAP is a prostate-specific enzyme that is synthesized in prostate epithelial cells. It belongs to the acid phosphatase group that shows enzymatic activity in acidic conditions. PAP is abundant in prostatic fluid and is thought to have a role in fertilization and oligospermia. It also has a potential role in reducing chronic pain. But one of the most apparent functions of PAP is the dephosphorylation of macromolecules such as HER-2 and PI3P that are involved in the ERK1/2 and MAPK pathways, which in turn leads to inhibition of cell growth and tumorigenesis. Currently, clinical trials using PAP DNA vaccine are underway and FDA-approved immunotherapy using PAP is commercially available. Despite these clinically important aspects, molecular mechanisms underlying PAP regulation are not fully understood. The promoter region of PAP was reported to be regulated by NF-${\kappa}B$, TNF-${\alpha}$, IL-1, androgen and androgen receptors. Here, the features of PAP gene and protein structures together with the function, regulation and roles of PAP in prostate cancer are discussed.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.166-174
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• 2007

To know the effect of enzymatic pre-treatment on softwood Kraft pulp, two xylanse-encoding genes, named xynl and xynll were isolated from Thrichoderma ressei. Structural genes of xylanase (XYNI, XYNII) and cellulase (EGIV-CBDII) were isolated from T. ressei and Rumicoccus albus respectively, and expressed in E. coli. bacterial culture. The specific activity of purified recombinant XYNI is higher than XYNII. The brightness of XYNI treated softwood Kraft pulp increased to 29.9%. On further sequential treatment with EGIV-CBDII and XYNI the brightness of softwood Kraft pulp were improved to 9.1 and 73% respectively. As expected the Kappa number of softwood Kraft pulp also decreased 8.1, 4.6 and 3.2% respectively. Results further indicate that this sequential combination of enzyme treatment has synergic effect for improving bleaching of softwood Kraft pulp.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.2
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• pp.123-134
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• 2014

Recent advances in the diagnosis and treatment of inborn errors of metabolism (IEM) have improved substantially the prognosis of many of these diseases, if diagnosed early enough before irreversible damage occurs. Diseases of inborn errors of metabolism are so diverse over several hundred disease up to now and may be several thousand in near future, and these diversities of IEMs make clinicians embarassed. The signs of neurological dysfunctions of many IEMs manifesting in the neonatal period is very nonspecific, such as poor feeding, poor sucking, apnea or tachypnea, vomiting, hypertonia, hypotonia, seizure, letharginess, consciousness change and coma. But after neonatal period, the signs of neurological deficits become specific and localized. The results of routine basal laboratory tests such as metabolic acidosis, hyperammonemia, lactic acidemia, ketonemia or hyperuricemia can give very important clinical clues for the diagnosis of IEMs. Even no abnormal findings on routine laboratory test could be very important clue for NKH, sulfite oxidase deficiency and peroxisomal disorders. These various clinical manifestations of these diverse diseases can be categorized and summarized. This makes it essential that the practicing clinicians be familiar with the clinical presentations and symptomatic and systematic approaches of these disorders. Characteristic clinical presentations, methods of symptomatic and systematic approach and typing of various disorders is discussed in this review.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.87-92
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• 2005

Pronase, a protease produced for commercial purpose by Streptomyces griseus, was composed of serine protease, alkaline protease, aminopeptidase and carboxypeptidase complex, and it has been widely used as anti-inflammatory drugs for human therapy. In this study, we developed a new integration vector, pHJ101 derived from pSET152, containing strong promoter, ermE, to overexpress a certain protease gene. Specific PCR primers for cloning of sprA (a gene for S. griseus protease A) and sprB (a gene for S. griseus protease B) genes were designed from the basis of nucleotide sequence in databases and amplified by PCR. Plasmid pHJ201 and pHJ202 were constructed by inserting of amplified each gene in a vector pHJ101. S. griseus HA and S. griseus HB were respectively obtained by conjugal process of a parent strain, S. griseus IFO 13350 with the recombinant Escherichia coli harboring plasmid pHJ201 or pHJ202. When protease activity was measured in flask cultivation, produced protease levels of S. griseus HA and S. griseus HB increased about 5.3 times and 5 times, respectively, more than that of parent strain. And, the constructed integrating plasmid pHJ101 was applicable for overexpression of a certain gene in Streptomyces sp.