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1.
Objective
To examine the activities of residual enzymes in dried shiitake mushrooms, which are a traditional foodstuff in Japanese cuisine, for possible applications in food processing.Results
Polysaccharide-degrading enzymes remained intact in dried shiitake mushrooms and the activities of amylase, β-glucosidase and pectinase were high. A potato digestion was tested using dried shiitake powder. The enzymes reacted with potato tuber specimens to solubilize sugars even under a heterogeneous solid-state condition and that their reaction modes were different at 38 and 50 °C.Conclusion
Dried shiitake mushrooms have a potential use in food processing as an enzyme preparation.2.
Songwen Tan Xuncai Chen Chunzhi Cui Yang Hou Weiguo Li Hong You 《Biotechnology letters》2017,39(1):91-96
Objective
To develop a method to treat saline phenolic wastewater in a biological contact oxidation reactor (BCOR) with immobilized cells of a marine microorganism, Oceanimonas sp., isolated from seawater.Results
Cells were immobilized on fibre carriers in the BCOR. Saline wastewater with phenol at 1.5 g/l and NaCl at 6 % (w/v) was treated. In continuous assays, 99 % removal of phenol was achieved and a kinetic model for the phenol degradation is presented based on Monod’s equation.Conclusion
The BOCR system using immobilized cells of Oceanimonas efficiently treats saline phenolic wastewaters without having decrease the salinity of the wastewater.3.
Objective
To protect the enzymes during fed-batch cellulase production by means of partial enzyme recovery at regular intervals.Results
Extracellular enzymes were partially recovered at the intervals of 1, 2, or 3 days. Mycelia were also removed to avoid contamination. Increases in the total harvested cellulase (24–62%) and β-glucosidase (22–76%) were achieved. In fermentor cultivation when the enzymes were recovered every day with 15% culture broth. The total harvested cellulase and β-glucosidase activity increased by 43 and 58%, respectively, with fungal cell concentration maintained at 3.5–4.5 g l?1.Conclusion
Enzyme recovery at regular intervals during fed-batch cellulase cultivation could protect the enzyme in the culture broth and enhance the enzyme production when the fungal cell concentration is maintained in a reasonable range.4.
Eugenio Spadoni Andreani Federica Villa Francesca Cappitelli Anna Krasowska Piotr Biniarz Marcin Łukaszewicz Francesco Secundo 《Biotechnology letters》2017,39(3):423-428
Objectives
To investigate the ability of the proteases, subtilisin and α-chymotrypsin (aCT), to inhibit the adhesion of Candida albicans biofilm to a polypropylene surface.Results
The proteases were immobilized on plasma-treated polypropylene by covalently linking them with either glutaraldehyde (GA) or N′-diisopropylcarbodiimide (DIC) and N-hydroxysuccinimide (NHS). The immobilization did not negatively affect the enzyme activity and in the case of subtilisin, the activity was up to 640% higher than that of the free enzyme when using N-acetyl phenylalanine ethyl ester as the substrate. The efficacies against biofilm dispersal for the GA-linked SubC and aCT coatings were 41 and 55% higher than the control (polypropylene coated with only GA), respectively, whereas no effect was observed with enzymes immobilized with DIC and NHS. The higher dispersion efficacy observed for the proteases immobilized with GA could be both steric (proper orientation of the active site) and dynamic (higher protein mobility/flexibility).Conclusions
Proteases immobilized on a polypropylene surface reduced the adhesion of C. albicans biofilms and therefore may be useful in developing anti-biofilm surfaces based on non-toxic molecules and sustainable strategies.5.
Objectives
Production of gluconic acid by using immobilized enzyme and continuous stirred tank reactor-plug flow tubular reactor (CSTR–PFTR) circulation reaction system.Results
A production system is constructed for gluconic acid production, which consists of a continuous stirred tank reactor (CSTR) for pH control and liquid storage and a plug flow tubular reactor (PFTR) filled with immobilized glucose oxidase (GOD) for gluconic acid production. Mathematical model is developed for this production system and simulation is made for the enzymatic reaction process. The pH inhibition effect on GOD is modeled by using a bell-type curve.Conclusions
Gluconic acid can be efficiently produced by using the reaction system and the mathematical model developed for this system can simulate and predict the process well.6.
Seyed Ziyae Aldin Samsam Shariat Fatemeh Borzouee Mohammad Reza Mofid Jaleh Varshosaz 《Biotechnology letters》2018,40(9-10):1343-1353
Objectives
The purpose of this study was to develop a facile and efficient method to enhance the stability and activity of lactoperoxidase (LPO) by using its immobilization on graphene oxide nanosheets (GO-NS).Methods
Following the LPO purification from bovine whey, it was immobilized onto functionalized GO-NS using glutaraldehyde as cross-linker. Kinetic properties and stability of free and immobilized LPO were investigated.Results
LPO was purified 59.13 fold with a specific activity of 5.78 U/mg protein. The successful immobilization of LPO on functionalized GO-NS was confirmed by using dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The overall results showed that the stability of the immobilized LPO was considerably improved compared to free LPO. Apparent Km and Vmax of LPO also indicated that the immobilized enzyme had greater affinity to the substrate than the native enzyme.Conclusions
Graphene oxide nanosheets are effective means for immobilization of LPO.7.
Objective
We explored the co-localization of multiple enzymes on a DNA backbone via a DNA-binding protein, Gene-A* (A*-tag) to increase the efficiency of cascade enzymatic reactions.Results
Firefly luciferase (FLuc) and pyruvate orthophosphate dikinase (PPDK) were genetically fused with A*-tag and modified with single-stranded (ss) DNA via A*-tag. The components were assembled on ssDNA by hybridization, thereby enhancing the efficiency of the cascading bioluminescent reaction producing light emission from pyrophosphate. The activity of A*-tag in each enzyme was investigated with dye-labeled DNA. Co-localization of the enzymes via hybridization was examined using a gel shift assay. The multi-enzyme complex showed significant improvement in the overall efficiency of the cascading reaction in comparison to a mixture of free enzymes.Conclusion
A*-tag is highly convenient for ssDNA modification of versatile enzymes, and it can be used for construction of functional DNA–enzyme complexes.8.
Background
The protein encoded by the gene ybgI was chosen as a target for a structural genomics project emphasizing the relation of protein structure to function.Results
The structure of the ybgI protein is a toroid composed of six polypeptide chains forming a trimer of dimers. Each polypeptide chain binds two metal ions on the inside of the toroid.Conclusion
The toroidal structure is comparable to that of some proteins that are involved in DNA metabolism. The di-nuclear metal site could imply that the specific function of this protein is as a hydrolase-oxidase enzyme.9.
Introduction
The efficient conversion of lignocellulosic feedstocks remains a key step in the commercialization of biofuels. One of the barriers to cost-effective conversion of lignocellulosic biomass to sugars remains the enzymatic saccharification process step. Here, we describe a novel hybrid processing approach comprising enzymatic pre-digestion with newly characterized hyperthermophilic enzyme cocktails followed by conventional saccharification with commercial enzyme preparations. Dilute acid pretreated corn stover was subjected to this new procedure to test its efficacy. Thermal tolerant enzymes from Acidothermus cellulolyticus and Caldicellulosiruptor bescii were used to pre-digest pretreated biomass at elevated temperatures prior to saccharification by the commercial cellulase formulation.Results
We report that pre-digestion of biomass with these enzymes at elevated temperatures prior to addition of the commercial cellulase formulation increased conversion rates and yields when compared to commercial cellulase formulation alone under low solids conditions.Conclusion
Our results demonstrating improvements in rates and yields of conversion point the way forward for hybrid biomass conversion schemes utilizing catalytic amounts of hyperthermophilic enzymes.10.
Ziqiang Wang Munan Su Yanliang Li Yunshan Wang Zhiguo Su 《Biotechnology letters》2017,39(12):1859-1863
Objective
To investigate the expression and immobilization of recombinant cis-epoxysuccinate hydrolase (ESH), and its application in the biological production of l-(+)-tartaric acid.Results
E. coli BL21 (DE3)/pET11a-ESH (His) was engineered to express recombinant ESH. The enzyme had an activity of 262 U mg?1. The recombinant ESH was immobilized on agarose Ni-IDA matrix with metal ion affinity interaction to improve its thermostability and pH stability. The immobilization efficiency and activity yield were 94 and 95%, respectively. The specific catalytic efficiency of immobilized ESH was 104 mg U?1 h?1 during the continuous enzymatic production process.Conclusion
ESH with a histidine tag was immobilized and used for the continuous production of l-(+)-tartaric acid.11.
Nicholas J. Bond Albert Koulman Julian L. Griffin Zoe Hall 《Metabolomics : Official journal of the Metabolomic Society》2017,13(11):128
Introduction
Mass spectrometry imaging (MSI) experiments result in complex multi-dimensional datasets, which require specialist data analysis tools.Objectives
We have developed massPix—an R package for analysing and interpreting data from MSI of lipids in tissue.Methods
massPix produces single ion images, performs multivariate statistics and provides putative lipid annotations based on accurate mass matching against generated lipid libraries.Results
Classification of tissue regions with high spectral similarly can be carried out by principal components analysis (PCA) or k-means clustering.Conclusion
massPix is an open-source tool for the analysis and statistical interpretation of MSI data, and is particularly useful for lipidomics applications.12.
Joon-Geun Ha Young Seok Song Sunghwan Jung Soohwan Jang Yong-Kweon Kim Seoung Jai Bai Jae-Hyoung Park Seung-Ki Lee 《Biotechnology letters》2017,39(6):849-855
Objective
To fabricate a novel microbial photobioelectrochemical cell using silicon microfabrication techniques.Results
High-density photosynthetic cells were immobilized in a microfluidic chamber, and ultra-microelectrodes in a microtip array were inserted into the cytosolic space of the cells to directly harvest photosynthetic electrons. In this way, the microbial photobioelectrochemical cell operated without the aid of electron mediators. Both short circuit current and open circuit voltage of the microbial photobioelectrochemical cell responded to light stimuli, and recorded as high as 250 pA and 45 mV, respectively.Conclusion
A microbial photobioelectrochemical cell was fabricated with potential use in next-generation photosynthesis-based solar cells and sensors.13.
Renato de Souza Pinto Lemgruber Kaspar Valgepea Mark P. Hodson Ryan Tappel Sean D. Simpson Michael Köpke Lars K. Nielsen Esteban Marcellin 《Metabolomics : Official journal of the Metabolomic Society》2018,14(3):35
Introduction
Quantification of tetrahydrofolates (THFs), important metabolites in the Wood–Ljungdahl pathway (WLP) of acetogens, is challenging given their sensitivity to oxygen.Objective
To develop a simple anaerobic protocol to enable reliable THFs quantification from bioreactors.Methods
Anaerobic cultures were mixed with anaerobic acetonitrile for extraction. Targeted LC–MS/MS was used for quantification.Results
Tetrahydrofolates can only be quantified if sampled anaerobically. THF levels showed a strong correlation to acetyl-CoA, the end product of the WLP.Conclusion
Our method is useful for relative quantification of THFs across different growth conditions. Absolute quantification of THFs requires the use of labelled standards.14.
Nadine Strehmel David Strunk Veronika Strehmel 《Metabolomics : Official journal of the Metabolomic Society》2017,13(11):135
Introduction
Aqueous–methanol mixtures have successfully been applied to extract a broad range of metabolites from plant tissue. However, a certain amount of material remains insoluble.Objectives
To enlarge the metabolic compendium, two ionic liquids were selected to extract the methanol insoluble part of trunk from Betula pendula.Methods
The extracted compounds were analyzed by LC/MS and GC/MS.Results
The results show that 1-butyl-3-methylimidazolium acetate (IL-Ac) predominantly resulted in fatty acids, whereas 1-ethyl-3-methylimidazolium tosylate (IL-Tos) mostly yielded phenolic structures. Interestingly, bark yielded more ionic liquid soluble metabolites compared to interior wood.Conclusion
From this one can conclude that the application of ionic liquids may expand the metabolic snapshot.15.
Ferran Casbas Pinto Srinivarao Ravipati David A. Barrett T. Charles Hodgman 《Metabolomics : Official journal of the Metabolomic Society》2017,13(7):81
Introduction
It is difficult to elucidate the metabolic and regulatory factors causing lipidome perturbations.Objectives
This work simplifies this process.Methods
A method has been developed to query an online holistic lipid metabolic network (of 7923 metabolites) to extract the pathways that connect the input list of lipids.Results
The output enables pathway visualisation and the querying of other databases to identify potential regulators. When used to a study a plasma lipidome dataset of polycystic ovary syndrome, 14 enzymes were identified, of which 3 are linked to ELAVL1—an mRNA stabiliser.Conclusion
This method provides a simplified approach to identifying potential regulators causing lipid-profile perturbations.16.
Korey J. Brownstein Mahmoud Gargouri William R. Folk David R. Gang 《Metabolomics : Official journal of the Metabolomic Society》2017,13(11):133
Introduction
Botanicals containing iridoid and phenylethanoid/phenylpropanoid glycosides are used worldwide for the treatment of inflammatory musculoskeletal conditions that are primary causes of human years lived with disability, such as arthritis and lower back pain.Objectives
We report the analysis of candidate anti-inflammatory metabolites of several endemic Scrophularia species and Verbascum thapsus used medicinally by peoples of North America.Methods
Leaves, stems, and roots were analyzed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and partial least squares-discriminant analysis (PLS-DA) was performed in MetaboAnalyst 3.0 after processing the datasets in Progenesis QI.Results
Comparison of the datasets revealed significant and differential accumulation of iridoid and phenylethanoid/phenylpropanoid glycosides in the tissues of the endemic Scrophularia species and Verbascum thapsus.Conclusions
Our investigation identified several species of pharmacological interest as good sources for harpagoside and other important anti-inflammatory metabolites.17.
Objectives
To increase the power generation of microbial fuel cells (MFCs), anode modification with carbon materials (activated carbon, carbon nanotubes, and carbon nanohorns) was investigated.Results
Maximum power densities of a stainless-steel anode MFC with a non-modified electrode (SS-MFC), an activated carbon-modified electrode (AC-MFC), a carbon nanotube-modified electrode (CNT-MFC) and a carbon nanohorn-modified electrode (CNH-MFC) were 72, 244, 261 and 327 mW m?2, respectively. The total polarization resistance measured by electrochemical impedance spectroscopy were 3610 Ω for SS-MFC, 283 Ω for AC-MFC, 231 Ω for CNTs-MFC, and 136 Ω for CNHs-MFC, consistent with the anode resistances obtained by fitting the anode polarization curves.Conclusions
Single-wall carbon nanohorns are better than activated carbon and carbon nanotubes as a new anode modification material for improving anode performance.18.
Yahya Mohammadzadeh Narges Rasouli Mohammad Hasan Samiee Aref Nasim Sadat Seyed Tabib Asghar Abdoli Peyvand Biglari Maryam Saleh Mansoureh Tabatabaeian Masoumeh Tavassoti Kheiri Abbas Jamali 《Biotechnology letters》2016,38(8):1321-1329
Objectives
To enhance the efficiency of influenza virosome-mediated gene delivery by engineering this virosome.Results
A novel chimeric influenza virosome was constructed containing the glycoprotein of Vesicular stomatitis virus (VSV-G), along with its own hemagglutinin protein. To optimize the transfection efficiency of both chimeric and influenza cationic virosomes, HEK cells were transfected with plasmid DNA and virosomes and the transfection efficiency was assessed by FACS analysis. The chimeric virosome was significantly more efficient in mediating transfection for all amounts of DNA and virosomes compared to the influenza virosome.Conclusions
Chimeric influenza virosome, including VSV-G, is superior to the conventional influenza virosome for gene delivery.19.
Thijs Welle Anna T. Hoekstra Ineke A. J. J. M. Daemen Celia R. Berkers Matheus O. Costa 《Metabolomics : Official journal of the Metabolomic Society》2017,13(7):83
Introduction
Swine dysentery caused by Brachyspira hyodysenteriae is a production limiting disease in pig farming. Currently antimicrobial therapy is the only treatment and control method available.Objective
The aim of this study was to characterize the metabolic response of porcine colon explants to infection by B. hyodysenteriae.Methods
Porcine colon explants exposed to B. hyodysenteriae were analyzed for histopathological, metabolic and pro-inflammatory gene expression changes.Results
Significant epithelial necrosis, increased levels of l-citrulline and IL-1α were observed on explants infected with B. hyodysenteriae.Conclusions
The spirochete induces necrosis in vitro likely through an inflammatory process mediated by IL-1α and NO.20.