DSpace collection: 期刊論文

Production, purification and characterisation of a chitosanase from Bacillus cereus

Tue, 18 Mar 2014 08:19:30 GMT

title: Production, purification and characterisation of a chitosanase from Bacillus cereus abstract: In the present work, a chitosanase was induced from a squid pen powder-containing Bacillus cereus TKU031 medium, and the addition of 0.05 % (w/v) boric acid or sodium tetraborate resulted in 195 and 177 % enhancement, respectively, in TKU031 chitosanase production. The purified TKU031 chitosanase exhibited optimum activity at pH 5 and 50 °C and was stable at pH 5–9 and <50 °C. The TKU031 chitosanase that was used for chitooligomers preparation was studied. The enzyme products revealed various chitooligomers with different degrees of polymerisation from 3 to 8, as determined by a MALDI-TOF–mass spectrometer, confirming the endo-type nature of the TKU031 chitosanase.

Toxicity assessments of chalcone and some synthetic chalcone analogues in a zebrafish model

Thu, 13 Mar 2014 04:02:37 GMT

title: Toxicity assessments of chalcone and some synthetic chalcone analogues in a zebrafish model abstract: The aim of this study was to investigate the in vivo toxicities of some novel synthetic chalcones. Chalcone and four chalcone analogues 1a–d were evaluated using zebrafish embryos following antibody staining to visualize their morphological changes and muscle fiber alignment. Results showed that embryos treated with 3'-hydroxychalcone (compound 1b) displayed a high percentage of muscle defects (96.6%), especially myofibril misalignment. Ultrastructural analysis revealed that compound 1b-treated embryos displayed many muscle defect phenotypes, including breakage and collapse of myofibrils, reduced cell numbers, and disorganized thick (myosin) and thin (actin) filaments. Taken together, our results provide in vivo evidence of the myotoxic effects of the synthesized chalcone analogues on developing zebrafish embryos.

纖維素分解酶生產菌Streptomyces actuosusA-151之培養基探討

Thu, 11 Jul 2013 03:29:16 GMT

title: 纖維素分解酶生產菌Streptomyces actuosusA-151之培養基探討

Expression, purification and DNA-binding activity of tilapia muscle-specific transcription factor, MyoD, produced in Escherichia coli

Thu, 13 Jun 2013 03:24:03 GMT

title: Expression, purification and DNA-binding activity of tilapia muscle-specific transcription factor, MyoD, produced in Escherichia coli abstract: MyoD is one of several helix-loop-helix proteins regulating muscle-specific gene expression. Using a reverse transcription-polymerase chain reaction, 5′-rapid cDNA end amplification, and plaque hybridization, MyoD cDNA was cloned from the mRNA of tilapia dorsal skeletal muscle. The 1015 bp MyoD cDNA product contained an 846 bp open reading frame with flanking regions of 115 and 64 bp at the 5′- and 3′-ends, respectively. Results showed that the tilapia MyoD sequence, which includes one polypeptide of 281 amino acids, shared sequence identities of 64.3, 64.1, 62.6 and 62.4% with those of zebrafish, carp, and two rainbow trout, respectively. Results from a molecular phylogenic tree assay showed that the tilapia MyoD was more closely related to those of other fishes than of higher vertebrates. Using Escherichia coli, a pET expression system, and an Ni2+-NTA column, we purified ∼35 kDa recombinant tilapia MyoD. Results from an electrophoretic mobility shift assay demonstrated that the purified E. coli-produced tilapia MyoD was capable of binding to the DNA fragment sequence CA(C/T)(C/A)TG. © 2002 Elsevier Science Inc. All rights reserved.

Erratum to ''Expression, purification and DNA-binding activity oftilapia muscle-specific transcription factor, MyoD, produced inEscherichia coli''

Thu, 13 Jun 2013 03:23:56 GMT

title: Erratum to ''Expression, purification and DNA-binding activity oftilapia muscle-specific transcription factor, MyoD, produced inEscherichia coli'' abstract: For a better understanding of the hyperlipidemic function of saturated fat, we have studied the comparative effects of diet supplementation with 10 and 20% coconut oil on the main lipid classes of chick plasma. Changes in fatty acid composition of free fatty acid and triglyceride fractions were parallel to that of the experimental diet. Thus, the increase in the percentages of 12:0 and 14:0 acids may contribute to the hypercholesterolemic effects of coconut oil feeding. Plasma phospholipids incorporated low levels of 12:0 and 14:0 acids whereas 18:0, the main saturated fatty acid of this fraction, also increased after coconut oil feeding. The percentage of 20:4 n-6 was higher in plasma phospholipids than in the other fractions and was significantly decreased by our dietary manipulations. Likewise, minor increases were found in the percentages of 12:0 and 14:0 acids in plasma cholesterol esters. However, the percentage of 18:2 acid significantly increased after coconut oil feeding. Our results show a relationship between fatty acid composition of diets and those of plasma free fatty acid and triglyceride fractions, whereas phospholipids and cholesterol esters are less sensitive to dietary changes.

Treatment with sodium benzoate leads to malformation of zebrafish larvae

Fri, 07 Jun 2013 02:32:04 GMT

title: Treatment with sodium benzoate leads to malformation of zebrafish larvae abstract: Sodium benzoate (SB) is a commonly used food preservative and anti-microbial agent in many foods from soup to cereals. However, little is known about the SB-induced toxicity and teratogenicity during early embryonic development. Here, we used zebrafish as a model to test the toxicity and teratogenicity because of their transparent eggs; therefore, the organogenesis of zebrafish embryos is easy to observe. After low dosages of SB (1-1000 ppm) treatment, the zebrafish embryos exhibited a 100% survival rate. As the exposure dosages increased, the survival rates decreased. No embryos survived after treatment with 2000 ppm SB. The 50% lethal dose (LD(50)) of zebrafish is found to be in the range of 1400-1500 ppm. Gut abnormalities, malformation of pronephros, defective hatching gland and edema in pericardial sac were observed after treatment with SB. Compared to untreated littermates (vehicle-treated control), SB-treated embryos exhibited significantly reduced tactile sensitivity frequencies of touch-induced movement (vehicle-treated control: 27.60+/-1.98 v.s. 1000 ppm SB: 7.89+/-5.28; N=30). Subtle changes are easily observed by staining with specific monoclonal antibodies F59, Znp1 and alpha6F to detect morphology changes in muscle fibers, motor axons and pronephros, respectively. Our data showed that the treatment of SB led to misalignment of muscle fibers, motor neuron innervations, excess acetyl-choline receptor cluster and defective pronephric tubes. On the basis of these observations, we suggest that sodium benzoate is able to induce neurotoxicity and nephrotoxicity of zebrafish larvae.

Purification and some properties of three xylanases from Aspergillus aculeatus F-50

Fri, 31 May 2013 03:34:00 GMT

title: Purification and some properties of three xylanases from Aspergillus aculeatus F-50 abstract: Three distinct extracellular xylanases (FIa-, FIb-, and FIII-xylanases) from a culture filtrate of Aspergillus aculeatus No. F-50 were purified to homogeneity by SDS polyacrylamide gel electrophoresis. The molecular weights of FIa-, FIb-, and FIII-xylanases were estimated to be 18,000, 26,000, and 52,000, and their pI values were pH 5.6, 9.0, and 3.8, respectively. The pH optima of xylanase activities were from 4.5 to 5.0. The optimum temperatures for enzyme activities were from 50℃ to 70℃. All three xylanases were highly specific for xylan hydrolysis, and they did not cleave xylobiose.

Purification and characterization of two bifunctional chitinases/lysozymes extracellularly produced by Pseudomonas aeruginosa K-187 in a shrimp and crab shell powder medium

Fri, 31 May 2013 03:33:54 GMT

title: Purification and characterization of two bifunctional chitinases/lysozymes extracellularly produced by Pseudomonas aeruginosa K-187 in a shrimp and crab shell powder medium abstract: Two extracellular chitinases (FI and FII) were purified from the culture supernatant of Pseudomonas aeruginosa K-187. The molecular weights of FI and FII were 30,000 and 32,000, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 60,000 and 30,000, respectively, by gel filtration. The pIs for FI and FII were 5.2 and 4.8, respectively. The optimum pH, optimum temperature, pH stability, and thermal stability of FI were pH 8, 50 degrees C, pH 6 to 9, and 50 degrees C; those of FII were pH 7, 40 degrees C, pH 5 to 10, and 60 degrees C. The activities of both enzymes were activated by Cu2+; strongly inhibited by Mn2+, Mg2+, and Zn2+; and completely inhibited by glutathione, dithiothreitol, and 2-mercaptoethanol. Both chitinases showed lysozyme activity. The purified enzymes had antibacterial and cell lysis activities with many kinds of bacteria. This is the first report of a bifunctional chitinase/lysozyme from a prokaryote.

Human aldehyde dehydrogenase E3 isozyme: The N-terminal primary structure

Fri, 31 May 2013 03:33:50 GMT

title: Human aldehyde dehydrogenase E3 isozyme: The N-terminal primary structure

Inhibition of Lysozyme Activity by Acidic Polymers

Fri, 31 May 2013 03:33:44 GMT

title: Inhibition of Lysozyme Activity by Acidic Polymers

Ethanol fermentation in a tower fermenter using self-aggregatingSaccharomyces uvarum

Fri, 31 May 2013 03:33:34 GMT

title: Ethanol fermentation in a tower fermenter using self-aggregatingSaccharomyces uvarum abstract: A self-aggregating strain ofSaccharomyces uvarum (U4) was used as a biocatalyst to carry out continuous ethanol fermentation in a tower fermentor equipped with a cell separator. Cell aggregates (2–3 mm) formed a stable packed bed in the fermentor, and the cell separator retained yeast cells effectively. Corn steep liquor was used as a nitrogen source for the fermentation of corn syrup and black strap molasses. An ethanol productivity of 54 g/L/h was reached using corn syrup at a dilution rate of 0.7/h, and sugar concentration in the feed was 15% (w/v). For molasses fermentation, an ethanol productivity of 22 g/L/h was obtained at a dilution rate of 0.7/h, and sugar concentration in the feed was 12.5% (w/v). Ethanol yields obtained from tower fermentation are higher than those obtained from flask fermentation (96% for corn syrup fermentation and 92% for molasses fermentation). No significant loss in fermentation activity was observed after 3 mo of operation.

Evidence for mitochondrial localization of betaine aldehyde dehydrogenase in rat liver - purification, characterization and comparison with human cytoplasmic E3 isozyme

Fri, 31 May 2013 03:33:29 GMT

title: Evidence for mitochondrial localization of betaine aldehyde dehydrogenase in rat liver - purification, characterization and comparison with human cytoplasmic E3 isozyme abstract: Betaine aldehyde dehydrogenase has been purified to homogeneity from rat liver mitochondria. The properties of betaine aldehyde dehydrogenase were similar to those of human cytoplasmic E3 isozyme in substrate specificity and kinetic constants for substrates. The primary structure of four tryptic peptides was also similar; only two substitutions, at most, per peptide were observed. Thus, betaine aldehyde dehydrogenase is not a specific enzyme, as formerly believed; activity with betaine aldehyde is a property of aldehyde dehydrogenase (EC 1.2.1.3), which has broad substrate specificity. Up to the present time the enzyme was thought to be cytoplasmic in mammals. This report establishes, for the first time, mitochondrial subcellular localization for aldehyde dehydrogenase, which dehydrogenates betaine aldehyde, and its colocalization with choline dehydrogenase. Betaine aldehyde dehydrogenation is an important function in the metabolism of choline to betaine, a major osmolyte. Betaine is also important in mammalian organisms as a major methyl group donor and nitrogen source. This is the first purification and characterization of mitochondrial betaine aldehyde dehydrogenase from any mammalian species.

Human aldehyde dehydrogenase E3 isozyme is a betaine aldehyde dehydrogenase

Fri, 31 May 2013 03:33:25 GMT

title: Human aldehyde dehydrogenase E3 isozyme is a betaine aldehyde dehydrogenase abstract: The E3 isozyme of human aldehyde dehydrogenase (EC 1.2.1.3), with broad substrate specificity, which also catalyzes dehydrogenation of 4-aminobutyraldehyde, was purified and sequenced recently (1,3). It has been shown during this investigation to have betaine aldehyde dehydrogenase activity. Betaine aldehyde and 4-aminobutyraldehyde activities copurified on six chromatographic columns. Molecular properties of the homogeneous product were identical with those of E3 isozyme. Activity with betaine aldehyde was considerably higher than that with 4-aminobutyraldehyde, the best known substrate. Thus, human E3 isozyme and betaine aldehyde dehydrogenase (EC 1.2.1.8) are the same enzyme.

Betaine aldehyde dehydrogenase from rat liver mitochondrial matrix

Fri, 31 May 2013 03:33:20 GMT

title: Betaine aldehyde dehydrogenase from rat liver mitochondrial matrix abstract: An NAD-linked aldehyde dehydrogenase which in addition to aliphatic and aromatic aldehydes, metabolizes aminoaldehydes and betaine aldehyde, has been purified to homogeneity from male Sprague–Dawley rat liver mitochondria. The properties of the rat mitochondrial enzyme are similar to those of a rat liver cytoplasmic betaine aldehyde dehydrognase and the human cytoplasmic E3 isozyme. The primary structure. of four tryptic peptides were also similar; only one difference in primary structure was observed. The close similarity of properties of the cytoplasmic with the mitochondrial form suggest that the cytoplasmic and mitochondrial betaine aldehyde dehydrogenase may be coded for by the same nuclear gene. Investigation of the mitochondrial form by isoelectric focusing resulted in visualization of multiple forms, different from those seen in the cytoplasm suggesting that the enzyme may be processed in the mitochondria.

Betaine aldehyde, betaine, and choline levels in rat liver during ethanol metabolism

Fri, 31 May 2013 03:33:12 GMT

title: Betaine aldehyde, betaine, and choline levels in rat liver during ethanol metabolism abstract: Betaine aldehyde levels were determined in rat livers following 4 weeks of ethanol feeding, employing the Lieber-De Carli liquid diet. The results showed that the levels of betaine aldehyde are unaffected by alcohol feeding to rats. These levels in both experimental and control animals were found to be quite low, 5.5 nmol/g liver. Betaine aldehyde levels have not been determined previously in mammalian liver because of methodological difficulties. This investigation employed fast atom bombardment-mass spectroscopy to determine the levels of betaine aldehyde, betaine, and choline. The decrease in betaine levels following ethanol administration confirmed the results of other investigators. Choline levels determined during this investigation were lower than previously reported. The reason for starting this investigation was the fact that the enzyme that catalyzes betaine aldehyde dehydrogenation to betaine, which is distributed in both mitochondria and the cytoplasm, was found to also metabolize acetaldehyde with K(m) and V(max) values lower than those for betaine aldehyde. Thus, it appeared likely that the metabolism of acetaldehyde during ethanol metabolism might inhibit betaine aldehyde conversion to betaine and thereby result in decreased betaine levels (Barak et al., Alcohol 13: 395-398, 1996). The fact that betaine aldehyde levels in alcohol-fed animals were similar to those in controls demonstrates that competition between acetaldehyde and betaine aldehyde for the same enzyme does not occur. This complete lack of competition suggests that betaine aldehyde dehydrogenase in the mitochondrial matrix may totally metabolize betaine aldehyde to betaine without any involvement of cytoplasmic betaine aldehyde dehydrogenase.

Cellulase and xylanase production byAspergillus sp. G-393

Fri, 31 May 2013 03:33:05 GMT

title: Cellulase and xylanase production byAspergillus sp. G-393

Prevalence and antibiotic resistance of Listeria species in food products in Taipei, Taiwan

Wed, 20 Mar 2013 03:10:02 GMT

title: Prevalence and antibiotic resistance of Listeria species in food products in Taipei, Taiwan abstract: A total of 400 samples including meat products, dairy and dairy products, fresh vegetables, fresh seafood, and ready-to-eat food products from supermarkets in Taipei area were collected and analyzed for the prevalence of Listeria species. The overall occurrence of Listeria spp. was 16.5%, and most of them were isolated from meat products and vegetables. Listeria monocytogenes was isolated from 22 out of the 400 (5.5%) samples studied. Other species found were Listeria innocua (7.5%), Listeria ivanovii (1%), Listeria seeligeri (0.5%), Listeria grayi (0.5%) and Listeria welshimeri (1.5%). The possibility of antibiotic resistance of the 66 isolated Listeria spp. was also examined by the standard disk diffusion method. L. monocytogenes strains isolated from food sample were treated with 8 antibiotics currently used in human or domestic animal therapy. Considering the fact that L. monocytogenes is slowly becoming antibiotic resistant, a continuous examination of emerging antimicrobial resistance of this pathogen is important to ensure effective treatment of human listeriosis. Overall, Listeria spp. was resistant to penicillin (7.58%), chloramphenicol (3.7%) and tetracycline (1.96%), but sensitive to amoxicillin, vancomycin, ampicillin, rifampicin and sulfamethoxazole. The results in this study are helpful in enriching the data on antibiotic resistance of strains isolated from food and in developing effective risk management strategies.

Conversion of shrimp shell by using Serratia sp. TKU017 fermentation for the production of enzymes and antioxidants

Wed, 27 Feb 2013 01:39:59 GMT

title: Conversion of shrimp shell by using Serratia sp. TKU017 fermentation for the production of enzymes and antioxidants abstract: A chitinase (CHT), and a protease (PRO) were purified from the culture supernatant of Serratia sp. TKU017 with shrimp shell as the sole carbon/nitrogen source. The molecular masses of CHT and PRO determined by SDS-PAGE were approximately 65 kDa and 53 kDa, respectively. CHT was inhibited by Mn2+, Cu2+ and PRO was inhibited by most tested divalent metals, EDTA. The optimum pH, optimum temperature, pH stability, and thermal stability of CHT and PRO were (pH 5, 50°C, pH 5–7, ＜50°C) and (pH 9, 40°C, pH 5–11, ＜40°C), respectively. PRO retained 95% of its protease activity in the presence of 0.5 mM SDS. The result demonstrates that PRO is SDS-resistant protease and probably has a rigid structure. The 4th day supernatant showed the strongest antioxidant activity (70%, DPPH scavenging ability) and the highest total phenolic content (196±6.2 μg of gallic acid equival/mL). Significant associations between the antioxidant potency and the total phenolic content, as well as between the antioxidant potency and free amino groups, were found for the supernatant. With this method, we have shown that shrimp shell wastes can be utilized and it’s effective in the production of enzymes and antioxidants, facilitating its potential use in industrial applications and functional foods.

Purification and characterization of chitinases and chitosanases from a new species strain Pseudomonas sp. TKU015 using shrimp shells as a substrate

Wed, 27 Feb 2013 01:39:55 GMT

title: Purification and characterization of chitinases and chitosanases from a new species strain Pseudomonas sp. TKU015 using shrimp shells as a substrate abstract: A chitinase (CHT1) and a chitosanase (CHS1) were purified from the culture supernatant of Pseudomonas sp. TKU015 with shrimp shell wastes as the sole carbon and nitrogen source. The optimized conditions of this new species strain (Gen Bank Accession Number EU103629) for the production of chitinases were found to be when the culture was shaken at 30 °C for 3 days in 100 mL of medium (pH 8) containing 0.5% shrimp shell powder (SSP) (w/v), 0.1% K2HPO4, and 0.05% MgSO4·7H2O. The molecular weights of CHT1 and CHS1 determined by SDS–PAGE were approximately 68 kDa and 30 kDa, respectively. The optimum pH, optimum temperature, pH stability, and the thermal stability of CHT1 and CHS1 were pH 6, 50 °C, pH 5–7, <50 °C and pH 4, 50 °C, pH 3–9, <50 °C, respectively. CHT1 was inhibited completely by Mn2+ and Fe2+, and CHS1 was inhibited by Mn2+, Cu2+, and PMSF. CHT1 was only specific to chitin substrates, whereas the relative activity of CHS1 increased when the degree of deacetylation of soluble chitosan increased.

Purification and characterization of a protease extracellularly produced by Monascus purpureus CCRC31499 in a shrimp and crab shell powder medium

Wed, 27 Feb 2013 01:39:51 GMT

title: Purification and characterization of a protease extracellularly produced by Monascus purpureus CCRC31499 in a shrimp and crab shell powder medium abstract: Monascus purpureus CCRC31499 produced a protease when it was grown in a medium containing shrimp and crab shell powder (SCSP) of marine wastes. An extracellular protease was purified from the culture supernatant to homology. The protease had a molecular weight of 40,000 and a pI of 7.9. The optimal pH, optimum temperature, pH stability, and thermal stability of the protease were pH 7–9, 40 °C, pH 5–9, and 40 °C, respectively. In addition to protease activity, CCRC31499 also exhibited activity of enhancing vegetable growth in culture supernatant. This is also the first report of isolation of a protease from Monascus species.

Purification and characterization of three novel keratinolytic metalloproteases produced by Chryseobacterium indologenes TKU014 in a shrimp shell powder medium

Wed, 27 Feb 2013 01:39:47 GMT

title: Purification and characterization of three novel keratinolytic metalloproteases produced by Chryseobacterium indologenes TKU014 in a shrimp shell powder medium

The antitumor activity of the hydrolysates of chitinous materials hydrolyzed by crude enzyme from Bacillus amyloliquefaciens V656

Wed, 27 Feb 2013 01:39:43 GMT

title: The antitumor activity of the hydrolysates of chitinous materials hydrolyzed by crude enzyme from Bacillus amyloliquefaciens V656 abstract: Chitin, colloidal chitin and water-soluble chitosan were hydrolyzed by crude enzyme solution produce by Bacillus amyloliquefaciens V656. The hydrolysates with 12 h hydrolysis contained optimal (GlcNAc)6 and showed higher antitumor activity. Among those chitinous materials, the most effective one was the hydrolysates of water-soluble chitosan, which inhibited the growth of CT26 cells and reduced the survival rate to 34% in 1 day. Since the hydrolysate of water-soluble chitosan contained the optimal hexamer/(GlcNAc)6 at 12 h, it is conjectured that the antitumor activity should be related to (GlcNAc)6. This conjecture was further affirmed by experiment with pure (GlcNAc)6. However, This phenomenon might be due to the synergistic effect of the oligomers (GlcNAc)n, n = 1–6 in the hydrolysates. The antitumor effect of the chitinous hydrolysates is worth further investigation. The aim of this study was to investigate the induced apoptosis in CT26 cells by the hydrolysates of chitinous materials. It was found that the hydrolysates (A, B and C) inhibited the survival of CT26 cells in a concentration- and time-dependent manner. The hydrolysates induced characteristic DNA fragmentation of the CT26 cells. These results suggested that the hydrolysates from chitinous materials are potent apoptosis-inducing agents for CT26 cells.

An antifungal protease produced by Pseudomonas aeruginosa M-1001 with shrimp and crab shell powder as a carbon source

Wed, 27 Feb 2013 01:39:35 GMT

title: An antifungal protease produced by Pseudomonas aeruginosa M-1001 with shrimp and crab shell powder as a carbon source abstract: Pseudomonas aeruginosa M-1001 produced a protease when it was grown in a medium containing shrimp and crab shell powder (SCSP) of marine wastes. An antifungal protease was purified from the culture supernatant to homology. The protease had a molecular weight of 38,000 and a pI of 5.7. The optimum pH, optimum temperature, and pH stability of the protease were pH 7, 37 °C, and pH 5–8, respectively. Antifungal activity of the protease was found when using assay based upon inhibition of spores germination and hyphal extension of the fungal Fusarium solani.

Bioconversion of shellfish chitin wastes for the production of Bacillus subtilis W-118 chitinase

Wed, 27 Feb 2013 01:39:22 GMT

title: Bioconversion of shellfish chitin wastes for the production of Bacillus subtilis W-118 chitinase

Purification and characterization of a chitosanase from Serratia marcescens TKU011

Wed, 27 Feb 2013 01:39:18 GMT

title: Purification and characterization of a chitosanase from Serratia marcescens TKU011

A solvent stable metalloprotease produced by Bacillus sp. TKU004 and its application in the deproteinization of squid pen for β-chitin preparation

Wed, 27 Feb 2013 01:39:12 GMT

title: A solvent stable metalloprotease produced by Bacillus sp. TKU004 and its application in the deproteinization of squid pen for β-chitin preparation abstract: A protease-producing bacterium was isolated and identified as Bacillus sp. TKU004. It thus can be used for deproteinization of squid pen in the preparation of β-chitin. The optimized condition for protease production was found when the culture was shaken at 30 °C for 4 days in 100 mL of medium containing 2% squid pen powder (SPP) (w/v), 0.1% K2HPO4, and 0.05% MgSO4. Under such condition, both the production of protease by Bacillus sp. TKU004 and the resulted protein removal of squid pen attained the optimum. They were 0.065 U/mL and 73%, respectively. An extracellular protease was purified from the culture supernatant of Bacillus sp. TKU004. The molecular weight of TKU004 protease was 27 and 57 kDa assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively. The optimum pH, optimum temperature, pH stability, thermal stability, Km, Vmax, and activation energy of TKU004 protease were 6–8, 60 °C, pH 5–8, 50 °C, 2.98 mg/mL, 0.14 U/mL, 8.31 J/(mol K), respectively. It was concluded that TKU004 protease is a Zn-containing metalloenzyme, and its dimeric structure contains at least one disulfide bond. The unique characteristic of TKU004 protease is that it retained more than 60% of its original activity after preincubation for 10 days at 25 °C in the presence of tested organic solvents (25%, v/v). This is also the first report of a strain being able to use squid pen as the sole carbon/nitrogen source for proteases production and being used for the reclamation of β-chitin from squid pen.

Reclamation of chitinous materials by bromelain for the preparation of antitumor and antifungal materials

Wed, 27 Feb 2013 01:39:08 GMT

title: Reclamation of chitinous materials by bromelain for the preparation of antitumor and antifungal materials

Microbial reclamation of squid pen for the production of a novel extracellular serine protease by Lactobacillus paracasei subsp paracasei TKU012

Wed, 27 Feb 2013 01:39:04 GMT

title: Microbial reclamation of squid pen for the production of a novel extracellular serine protease by Lactobacillus paracasei subsp paracasei TKU012

Bioconversion of squid pen by Lactobacillus paracasei subsp paracasei TKU010 for the production of proteases and lettuce growth enhancing biofertilizers

Wed, 27 Feb 2013 01:39:00 GMT

title: Bioconversion of squid pen by Lactobacillus paracasei subsp paracasei TKU010 for the production of proteases and lettuce growth enhancing biofertilizers

Two novel surfactant-stable alkaline proteases from Vibrio fluvialis TKU005 and their applications

Wed, 27 Feb 2013 01:38:56 GMT

title: Two novel surfactant-stable alkaline proteases from Vibrio fluvialis TKU005 and their applications

Production of a surfactant- and solvent-stable alkaliphilic protease by bioconversion of shrimp shell wastes fermented by Bacillus subtilis TKU007

Wed, 27 Feb 2013 01:38:52 GMT

title: Production of a surfactant- and solvent-stable alkaliphilic protease by bioconversion of shrimp shell wastes fermented by Bacillus subtilis TKU007

Microbial reclamation of shellfish wastes for the production of chitinases

Wed, 27 Feb 2013 01:38:47 GMT

title: Microbial reclamation of shellfish wastes for the production of chitinases abstract: Shrimp and crab shell powder (SCSP), prepared by treating shellfish processing waste with boiling and crushing, was used as a substrate for isolating chitinolytic microorganisms. Three potential strains (E1, J1, and J1-1) were isolated and identified as Bacillus cereus, B. alvei, and B. sphaericus, respectively. Three extracellular chitinases (FB1, FB2, and FB3) were purified from the culture supernatants of Bacillus cereus E1, B. alvei J1, and B. sphaericus J1-1, respectively. The molecular weights of FB1, FB2, and FB3 were 71,000, 71,000, and 65,000, respectively, by SDS-PAGE. The pIs for FB1, FB2, and FB3 were 7.1, 7.2, and 7.4, respectively. The optimum pH, optimum temperature, pH stability, and thermal stability of FB1 were pH 9, 50°C, pH 7 to 10, and 70°C; those of FB2 were pH 9, 60°C, pH 5 to 9, and 70°C; and those of FB3 were pH 7, 50°C, pH 5 to 9, and 60°C. The activities of all enzymes were strongly inhibited by Hg2+ and completely inhibited by glutathione, dithiothreitol, and 2-mercaptoethanol.

Purification and characterization of a novel catechol 1,2-dioxygenase from Pseudomonas aeruginosa with benzoic acid as a carbon source

Wed, 27 Feb 2013 01:38:43 GMT

title: Purification and characterization of a novel catechol 1,2-dioxygenase from Pseudomonas aeruginosa with benzoic acid as a carbon source abstract: Pseudomonas aeruginosa TKU002, capable of growing significantly on acidic side pH 5.5 and benzoic acid as a sole carbon source, was isolated from enrichment culture accumulation of catechol. An intracellular catechol 1,2-dioxygenase (CD) produced by P. aeruginosa TKU002 was purified and characterized. The TKU002 CD was found to have unique characteristics different to other microbial CDs. The unique characteristics include the smallest molecular mass of 22 kDa, the most acidic pI value of lower than 4, and the highest cleavage activity to the substrate, pyrogallol. Different to other CD producing strains, P. aeruginosa TKU002 produced CD at a lower pH of 5.5 when benzoate was used as the sole carbon source. The TKU002 CD was a monomer with a Km of 5.9 μM. The TKU002 CD showed 36% and 14% sequence coverage rate with protocatechuate 3,4-dioxygenase β-subunit of P. aeruginosa UCBPP-COG3485 and catechol 1,2-dioxygenase of P. aeruginosa PA01, respectively, and possessed one matched peptide (YLWDDFAYATR). In conclusion, this is the first report of a microbial CD with the smallest molecular mass, the most acidic pI value, the highest specific activity to the substrate pyrogallol, and the most acidic medium for CD production.

Biodegradation of shellfish wastes and production of chitosanases by a squid pen-assimilating bacterium, Acinetobacter calcoaceticus TKU024

Wed, 16 Jan 2013 06:37:47 GMT

title: Biodegradation of shellfish wastes and production of chitosanases by a squid pen-assimilating bacterium, Acinetobacter calcoaceticus TKU024 abstract: Two chitosanases (CHSA1 and CHSA2) were purified from the culture supernatant of Acinetobacter calcoaceticus TKU024 with squid pen as the sole carbon/nitrogen source. The molecular masses of CHSA1 and CHSA2 determined by SDS-PAGE were approximately 27 and 66 kDa, respectively. The optimum pH, optimum temperature, pH stability, and thermal stability of CHSA1 and CHSA2 were (pH 6, 50°C, pH 4–10, ＜90°C) and (pH 7, 60°C, pH 6–11, ＜70°C), respectively. CHSA1 and CHSA2 had broad pH and thermal stability. CHSA1 and CHSA2 were both inhibited by EDTA and were inhibited completely by 5 mM Mn2+. CHSA1 and CHSA2 degraded chitosan with DD ranging from 60 to 98%, and also degraded some chitin. The most susceptible substrate was 60% deacetylated chitosan. Furthermore, TKU024 culture supernatant (1.5% SPP) incubated for 5 days has the most reducing sugars (0.63 mg/ml). With this method, we have shown that shellfish wastes may have a great potential for the production of bioactive materials.

Cellular Uptake of a Polypyridyl Ruthenium Complex Revealed Using a Fluorescent Rhodamine-modified Ruthenium Complex

Tue, 08 Jan 2013 05:05:13 GMT

title: Cellular Uptake of a Polypyridyl Ruthenium Complex Revealed Using a Fluorescent Rhodamine-modified Ruthenium Complex abstract: A fluorescent polypyridyl ruthenium complex was successfully prepared using an amide bond linkage to link two rhodamine moieties through bipyridine groups. Although photo-induced electron transfer (PET) quenched the fluorescent intensity, the quantum yield of the rhodamine-modified Ru(II) complex was 0.17 in water, sufficient for observing the fluorophore behaviour in biological systems. The rhodaminemodified Ru(II) complex was found to inhibit the bacterial growth of E. coli. In vitro fluorescence images of human hepatoma cells (SK-Hep1) showed that a fluorescent polypyridyl ruthenium complex not only supported the above observation but also preferably accumulated in the cytoplasmic region inside the cell. These observations suggest that in addition to strong Ru–DNA interactions, Ru-protein interactions in the cytoplasmic regions are strong and are therefore important to the development of metallopharmaceuticals.

Embryonic exposure to diclofenac disturbs actin organization and leads to myofibril misalignment

Thu, 24 May 2012 03:17:34 GMT

title: Embryonic exposure to diclofenac disturbs actin organization and leads to myofibril misalignment abstract: The objective of this study was to investigate the embryotoxicity of diclofenac. Zebrafish (Danio rerio) embryos at 12 hpf were treated with different dosages of diclofenac (0–2,000 ppm) for different time courses (12–72 hr). Results showed no evident differences in survival rates or morphological changes between the mock-treated control (0 ppm) zebrafish embryos and those with 1-ppm diclofenac-exposure (12–24, 12–36 hpf). In contrast, after higher doses (5 and 10 ppm) of exposure, embryos displayed some defective phenotypes, including malformed somite boundary, a twisted body axis, and shorter body length. In addition, diclofenac-treated embryos exhibited significantly reduced frequencies of spontaneous in-chorion contractions in comparison with mock-control littermates (mock-control: 13.20±2.24 vs. 5–10 ppm diclofenac: 6.66±1.35–3.03±1.84). Subtle changes were easily observed by staining with specific monoclonal antibodies F59 and phalloidin to detect morphological changes in muscle fibers and formation of F-actin, respectively. Our data show that diclofenac treatment disturbs actin organization and muscle fiber alignment, thus causing malformed somite phenotypes.
description: 100學年度研究獎補助論文

Inhibition of the P2X7 Receptor Reduces Cystogenesis in PKD

Thu, 24 May 2012 03:15:43 GMT

title: Inhibition of the P2X7 Receptor Reduces Cystogenesis in PKD abstract: The P2X7 receptor participates in purinergic signaling, which may promote the progression of ADPKD. We examined the effects of a P2X7 receptor antagonist and a P2X7 receptor agonist on cyst development in a zebrafish model of polycystic kidney disease in which we knocked down pkd2 by morpholinos. We used live wt-1b pronephric-specific GFP-expressing zebrafish embryos to directly observe changes in the pronephros. Exposure of pkd2-morphant zebrafish to a P2X7 receptor antagonist (oxidized ATP [OxATP]) significantly reduced the frequency of the cystic phenotype compared with either exposure to a P2X7 receptor agonist (BzATP) or with no treatment (P ＜ 0.01). Histology confirmed improvement of glomerular cysts in OxATP-treated pkd2 morphants. OxATP also reduced p-ERK activity and cell proliferation in pronephric kidneys in pkd2 morphants. Inhibition of P2X7 with an additional specific antagonist (A-438079), and through morpholino-mediated knockdown of p2rx7, confirmed these effects. In conclusion, blockade of the P2X7 receptor reduces cyst formation via ERK-dependent pathways in a zebrafish model of polycystic kidney disease, suggesting that P2X7 antagonists may have therapeutic potential in ADPKD.

UV-induced fin damage in zebrafish as a system for evaluating the chemopreventive potential of broccoli and cauliflower extracts

Thu, 24 May 2012 03:13:43 GMT

title: UV-induced fin damage in zebrafish as a system for evaluating the chemopreventive potential of broccoli and cauliflower extracts abstract: This study applied broccoli and cauliflower extracts (whole, floret, and stem) to zebrafish larvae in parallel to receive 100 mJ/cm2 of UVB six times, and recorded their fin malformation phenotypes. Chemopreventive effects of each group, including UVB, whole-, floret-, and stem-extracts of broccoli and cauliflower on fin development were evaluated using Kaplan-Meier analysis, log-rank test, and Cox proportional hazards regression. Results showed that (1) zebrafish fins in the UVB + whole broccoli extract group are 6.20~9.32-times more likely to return to normal fins than ones in the UVB only group, but fins in the UVB + whole cauliflower extract group are only 5.13~11.10-times more likely to recover, indicated that whole broccoli and cauliflower extract had similar chemopreventive ability on fin development; and (2) the broccoli stem has the highest antioxidant capacity among other groups. In conclusion, zebrafish can be used as a system for evaluating the efficacy of other UVB protective compounds.
description: 100學年度研究獎補助論文

Taro α-galactosidase: A new gene product for blood conversion

Wed, 23 May 2012 06:30:09 GMT

title: Taro α-galactosidase: A new gene product for blood conversion abstract: The N-terminal sequence and internal sequences of the purified taro α-galactosidase (α-Gal) were determined using tandem mass spectrometry. By using reverse transcriptase PCR (RT-PCR), 5′ and 3′ rapid amplification of cDNA ends (RACE) with designed, degenerate primers, a novel cDNA sequence was obtained. The recombinant taro α-Gal not only hydrolyzes α1→4 linked galactosyl residues, which are accumulated in the tissues from patients with Fabry disease, but also hydrolyzes the α1→3 linked galactoside of B red blood cells (RBC). The recombinant taro α-Gal provides an ideal enzyme source for biomedical systems.

Yeast Ribosomal Protein L12 Is a Substrate of Protein-arginine Methyltransferase 2*

Sun, 16 Oct 2011 17:01:38 GMT

title: Yeast Ribosomal Protein L12 Is a Substrate of Protein-arginine Methyltransferase 2*