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Asbjørn Toftgaard Pedersen, Teresa Melo de Carvalho, Euan Sutherland, Gustav Rehn, Robert Ashe, John M Woodley
Biocatalytic oxidation reactions employing molecular oxygen as the electron acceptor are difficult to conduct in a continuous flow reactor because of the requirement for high oxygen transfer rates. In this paper, the oxidation of glucose to glucono-1,5-lactone by glucose oxidase was used as a model reaction to study a novel continuous agitated cell reactor (ACR). The ACR consists of ten cells interconnected by small channels. An agitator is placed in each cell, which mixes the content of the cell when the reactor body is shaken by lateral movement...
February 10, 2017: Biotechnology and Bioengineering
Andrew Care, Kerstin Petroll, Emily S Y Gibson, Peter L Bergquist, Anwar Sunna
BACKGROUND: Solid-binding peptides (SBPs) bind strongly to a diverse range of solid materials without the need for any chemical reactions. They have been used mainly for the functionalisation of nanomaterials but little is known about their use for the immobilisation of thermostable enzymes and their feasibility in industrial-scale biocatalysis. RESULTS: A silica-binding SBP sequence was fused genetically to three thermostable hemicellulases. The resulting enzymes were active after fusion and exhibited identical pH and temperature optima but differing thermostabilities when compared to their corresponding unmodified enzymes...
2017: Biotechnology for Biofuels
Milan Polakovič, Juraj Švitel, Marek Bučko, Jaroslav Filip, Vilém Neděla, Marion B Ansorge-Schumacher, Peter Gemeiner
Viable microbial cells are important biocatalysts in the production of fine chemicals and biofuels, in environmental applications and also in emerging applications such as biosensors or medicine. Their increasing significance is driven mainly by the intensive development of high performance recombinant strains supplying multienzyme cascade reaction pathways, and by advances in preservation of the native state and stability of whole-cell biocatalysts throughout their application. In many cases, the stability and performance of whole-cell biocatalysts can be highly improved by controlled immobilization techniques...
February 8, 2017: Biotechnology Letters
Ke Li, Juxiang Wang, Kailin Wu, Daijun Zheng, Xiaojian Zhou, Wenyong Han, Nanwei Wan, Baodong Cui, Yongzheng Chen
A cascade biocatalysis system involving asymmetric hydroxylation and diastereoselective oxidation was developed using Rhodococcus equi ZMU-LK19, which gave chiral 2-substituted-1,2,3,4-tetrahydroquinoline-4-ols (2) (up to 57% isolated yield, 99 : 1 dr, and >99% ee) and chiral 2-substituted-2,3-dihydroquinolin-4(1H)-ones (3) (up to 25% isolated yield, and >99% ee) from (±)-2-substituted-tetrahydroquinolines (1). In addition, a possible mechanism for this cascade biocatalysis was tentatively proposed...
February 8, 2017: Organic & Biomolecular Chemistry
Yan Xu, Dong-Yang Zhang, Xiang-Yun Meng, Xi Liu, Sheng Sheng, Guo-Hua Wu, Jun Wang, Fu-An Wu
Today, continuous processing is regarded as an effective on-demand production technique of pharmaceuticals. Homemade microreactors packed with immobilized lipase under continuous-flow conditions were first applied to tailor the production of high-value caffeic acid phenethyl ester (CAPE) from methyl caffeate (MC) and 2-phenylethanol (PE) in cyclohexane via transesterification; however, this method is challenging due to the lack of a rapid platform for monitoring caffeates in microfluidic biocatalysis. The reactants were directly analyzed using Direct Analysis in Real Time Mass Spectrometry (DART-MS), and the corresponding ionization parameters were investigated...
January 29, 2017: Journal of Pharmaceutical and Biomedical Analysis
Nathalie Willems, Ainhoa Urtizberea, Andrea Francesco Verre, Maria Iliut, Mickael Lelimousin, Michael Hirtz, Aravind Vijayaraghavan, Mark S P Sansom
Supported phospholipid membrane patches stabilized on graphene surfaces have shown potential in sensor device functionalization, including biosensors and biocatalysis. Lipid dip-pen nanolithography (L-DPN) is a method useful in generating supported membrane structures that maintain lipid functionality, such as exhibiting specific interactions with protein molecules. Here, we have integrated L-DPN, atomic force microscopy, and coarse-grained molecular dynamics simulation methods to characterize the molecular properties of supported lipid membranes (SLMs) on graphene and graphene oxide supports...
February 6, 2017: ACS Nano
Joshua Britton, Rebekah P Dyer, Sudipta Majumdar, Colin L Raston, Gregory A Weiss
Nature applies enzymatic assembly lines to synthesize bioactive compounds. Inspired by such capabilities, we have developed a facile method for spatially segregating attached enzymes in a continuous-flow, vortex fluidic device (VFD). Fused Hisn -tags at the protein termini allow rapid bioconjugation and consequent purification through complexation with immobilized metal affinity chromatography (IMAC) resin. Six proteins were purified from complex cell lysates to average homogeneities of 76 %. The most challenging to purify, tobacco epi-aristolochene synthase, was purified in only ten minutes from cell lysate to near homogeneity (>90 %)...
January 30, 2017: Angewandte Chemie
Baptiste Thomas, Xiaojie Lu, William Birmingham, Kun Huang, Peter Both, Juana Reyes Martinez, Robert Young, Christopher Davie, Sabine Flitsch
DNA-encoded libraries are increasingly used for the discovery of bioactive lead compounds in high-throughput screening programmes against specific biological targets. Although a number of libraries are now available, they cover limited chemical space due to bias in ease of synthesis and the lack of chemical reactions that are compatible with DNA-tagging. For example, compound libraries rarely contain complex biomolecules such as carbohydrates with high level of functionality, stereochemistry and hydrophilicity...
January 26, 2017: Chembiochem: a European Journal of Chemical Biology
Liqiu Su, Yanbing Shen, Tian Gao, Jianmei Luo, Min Wang
In steroid biotransformation, soybean oil can improve the productivity of steroids by increasing substrate solubility and strengthen the cell membrane permeability. However, little is known of its role as oxygen carrier and its mechanism of promoting the steroid biotransformation. In this work, soybean oil used as oxygen vector for the enhancement of androst-4-ene-3,17-dione (AD) production by Mycobacterium neoaurum TCCC 11979 (MNR) was investigated. Upon the addition of 16% (v/v) soybean oil, the volumetric oxygen transfer coefficient (K L a) value increased by 44%, and the peak molar yield of AD (55...
January 24, 2017: Applied Biochemistry and Biotechnology
Theo Peschke, Kersten S Rabe, Christof M Niemeyer
We herein describe the engineering of E. coli strains that display orthogonal tags for immobilization on their surface and overexpress a functional heterologous "protein content" in their cytosol at the same time. Using the outer membrane protein Lpp-ompA, cell-surface display of the streptavidin-binding peptide, the SpyTag/SpyCatcher system, or a HaloTag variant allowed us to generate bacterial strains that can selectively bind to solid substrates, as demonstrated with magnetic microbeads. The simultaneous cytosolic expression of functional content was demonstrated for fluorescent proteins or stereoselective ketoreductase enzymes...
January 20, 2017: Angewandte Chemie
Kelly Dumorné, David Camacho Córdova, Marcia Astorga-Eló, Prabhaharan Renganathan
Extremophilic microorganisms have established a diversity of molecular strategies in order to survive in extreme conditions. Biocatalysts isolated by these organisms are termed extremozymes, possess extraordinary properties are salt allowance thermostability and cold adaptivity. Extremozymes are very resistant in extreme conditions due to their great solidity and they propose new opportunities for biocatalysis and biotransformations, also for the development of the economy and new line of research through their application...
January 20, 2017: Journal of Microbiology and Biotechnology
Yingbiao Zhou, Yueming Zhu, Yan Men, Caixia Dong, Yuanxia Sun, Juankun Zhang
There are excessive by-products in the biocatalysis process of this whole-cell biocatalytic production of melibiose from raffinose with current Saccharomyces cerevisiae strains. To solve this problem, we constructed engineered strains based on a liquor yeast (S. cerevisiae) via gene deletion (mel1 gene), heterologous integration (fsy1 or/and ffzi1 gene from Candida magnoliae), and gene overexpression (gcr1 gene). Functional verification showed that deletion of the mel1 gene led to elimination of the reactions catalyzed by α-galactosidase, as well as elimination of the degradation of melibiose and the formation of galactose by-product...
January 18, 2017: Journal of Industrial Microbiology & Biotechnology
Anisha N Patel, Agnès Anne, Arnaud Chovin, Christophe Demaille, Eric Grelet, Thierry Michon, Cécilia Taofifenua
Organizing active enzyme molecules on nanometer-sized scaffolds is a promising strategy for designing highly efficient supported catalytic systems for biosynthetic and sensing applications. This is achieved by designing model nanoscale enzymatic platforms followed by thorough analysis of the catalytic activity. Herein, the virus fd bacteriophage is considered as an enzyme nanocarrier to study the scaffolding effects on enzymatic activity. Nanoarrays of randomly oriented, or directionally patterned, fd bacteriophage virus are functionalized with the enzyme glucose oxidase (GOx), using an immunological assembly strategy, directly on a gold electrode support...
January 18, 2017: Small
Jan M Klenk, Bernd A Nebel, Joanne L Porter, Justyna K Kulig, Shaneela A Hussain, Sven M Richter, Michele Tavanti, Nicholas J Turner, Martin A Hayes, Bernhard Hauer, Sabine L Flitsch
P450 monooxygenases are able to catalyse the highly regio- and stereoselective oxidations of many organic molecules. However, the scale-up of such bio-oxidations remains challenging due to the often-low activity, level of expression and stability of P450 biocatalysts. Despite these challenges they are increasingly desirable as recombinant biocatalysts, particularly for the production of drug metabolites. Diclofenac is a widely used anti-inflammatory drug that is persistent in the environment along with the 4'- and 5-hydroxy metabolites...
January 18, 2017: Biotechnology Journal
Bettina M Nestl, Christopher Geinitz, Stephanie Popa, Sari Rizek, Robert J Haselbeck, Rosary Stephen, Michael A Noble, Max-Philipp Fischer, Erik C Ralph, Hoi Ting Hau, Henry Man, Muhiadin Omar, Johan P Turkenburg, Stephen van Dien, Stephanie J Culler, Gideon Grogan, Bernhard Hauer
The asymmetric dehydration of alcohols is an important process for the direct synthesis of alkenes. We report the structure and substrate specificity of the bifunctional linalool dehydratase isomerase (LinD) from the bacterium Castellaniella defragrans that catalyzes in nature the hydration of β-myrcene to linalool and the subsequent isomerization to geraniol. Enzymatic kinetic resolutions of truncated and elongated aromatic and aliphatic tertiary alcohols (C5-C15) that contain a specific signature motif demonstrate the broad substrate specificity of LinD...
March 2017: Nature Chemical Biology
Yuchen Zhou, Junjie Huang, Wei Sun, Yuanlai Ju, Pinghui Yang, Lingyun Ding, Zhong-Ren Chen, Julia A Kornfield
Patterned porous surfaces with responsive functionalities are fabricated by a thermoresponsive microgel-assisted breath figure (BF) process. When water droplets submerge into a polystyrene (PS) solution during formation of a porous surface by the bottom-up BF process, poly(N-isopropylacrylamide)-co-acrylic acid (PNIPAm-co-AA) microgels dispersed in the solution spontaneously assemble at the water-organic interfaces like "Pickering emulsions", reinforced by capillary flow. The conformal layer of PNIPAm-co-AA microgels lining the pores appears in images from a scanning electron microscope (SEM) either as a smooth surface layer (L) or as an array of domelike protrusions (D), depending on the conditions at which the sample was dried for SEM...
February 1, 2017: ACS Applied Materials & Interfaces
Holly A Reeve, Philip A Ash, HyunSeo Park, Ailun Huang, Michalis Posidias, Chloe Tomlinson, Oliver Lenz, Kylie A Vincent
The present study considers the ways in which redox enzyme modules are coupled in living cells for linking reductive and oxidative half-reactions, and then reviews examples in which this concept can be exploited technologically in applications of coupled enzyme pairs. We discuss many examples in which enzymes are interfaced with electronically conductive particles to build up heterogeneous catalytic systems in an approach which could be termed synthetic biochemistry We focus on reactions involving the H(+)/H2 redox couple catalysed by NiFe hydrogenase moieties in conjunction with other biocatalysed reactions to assemble systems directed towards synthesis of specialised chemicals, chemical building blocks or bio-derived fuel molecules...
January 15, 2017: Biochemical Journal
Nora Weber, Marie Gorwa-Grauslund, Magnus Carlquist
BACKGROUND: Whole-cell biocatalysis based on metabolically active baker's yeast with engineered transamination activity can be used to generate molecules carrying a chiral amine moiety. A prerequisite is though to express efficient ω-transaminases and to reach sufficient intracellular precursor levels. RESULTS: Herein, the efficiency of three different ω-transaminases originating from Capsicum chinense, Chromobacterium violaceum, and Ochrobactrum anthropi was compared for whole-cell catalyzed kinetic resolution of racemic 1-phenylethylamine to (R)-1-phenylethylamine...
January 3, 2017: Microbial Cell Factories
Guangda Han, Jin-Tao Wang, Xiaotian Ji, Li Liu, Hanying Zhao
Proteinosomes are a type of protein-based spherical capsules, which have potential applications in drug delivery, cell imaging, gene expression, and biocatalysis. In this research, a novel approach to the fabrication of proteinosomes entirely composed of protein molecules based on self-assembly of a supramolecular protein-polymer conjugate is proposed. A supramolecular protein-polymer conjugate was prepared by mixing βCD-modified bovine serum albumin (BSA) and adamantane-terminated poly(N-isopropylamide) (Ad-PNIPAM) in aqueous solution...
January 10, 2017: Bioconjugate Chemistry
Christian Gehring, Mirja Wessel, Steffen Schaffer, Oliver Thum
Microbially derived surfactants, so-called biosurfactants, have drawn much attention in recent years and are expected to replace current petrochemical surfactants, owing to their environmental and toxicological benefits. One strategy to support that goal is to reduce production costs by replacing relatively expensive sugars with cheaper raw materials, such as short-chain alkanes. Herein, we report the successful one-pot total synthesis of rhamnolipids, a class of biosurfactants with 12 stereocenters, from butane as sole carbon and energy source through the design of a tailored whole-cell biocatalyst...
December 2016: ChemistryOpen
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