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Elahe Bahremandi Toloue, Saeed Karbasi, Hossein Salehi, Mohammad Rafienia
The choice of material types for tissue engineering scaffolds and the design of methods are contributive in yielding the proper result. In this study, 1-5% wt. Alumina nanowires are added to (Polyhydroxybutyrate-Chitosan) PHB-CTS alloy solution, and the scaffolds are prepared by electrospinning method. The fiber diameters, porosity percentages and uniform distribution of Alumina nanowires are assessed by SEM, EDS and TEM. The surface roughness of the fibers is confirmed by FESEM and AFM. The crystallinity of nanofibers is calculated by DSC and verified by FTIR...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
Mercy Temitope Bankole, Ambali Saka Abdulkareem, Ishaq Alhassan Mohammed, Stephen Shaibu Ochigbo, Jimoh Oladejo Tijani, Oladiran Kamaldeen Abubakre, Wiets Daniel Roos
This research investigated the removal of heavy metals (As, Pb, Cr, Cd, Ni, Cu, Fe, and Zn) via batch adsorption process from industrial electroplating wastewater using two different nano-adsorbents; purified carbon nanotubes (P-CNTs) and polyhydroxylbutyrate functionalized carbon nanotubes (PHB-CNTs), both produced through catalytic chemical vapour deposition (CCVD) method. HRSEM, HRTEM, XRD, DLS, BET, FTIR, XPS, TGA, pH drift and Raman spectroscopy were used to characterize the developed nano-adsorbents. In the batch adsorption process, the effects of contact time, dosage, temperature and pH were studied...
March 14, 2019: Scientific Reports
Daniel Pfeiffer, Mauricio Toro-Nahuelpan, Marc Bramkamp, Jürgen M Plitzko, Dirk Schüler
Magnetotactic bacteria (MTB) are of special scientific interest due to the formation of magnetosomes, intracellular membrane-enveloped magnetite crystals arranged into a linear chain by a dedicated cytoskeleton. Magnetotaxis relies on the formation and proper inheritance of these unique magnetic organelles, both of which need to be coordinated with the segregation of other cellular content such as chromosomes or motility and chemotaxis related structures. Thus, elaborated mechanisms are required in MTB to coordinate and maintain a high level of spatial and temporal subcellular organization during cytokinesis...
March 12, 2019: MBio
Pietro Carlozzi, Maurizia Seggiani, Antonella Capperucci, Damiano Tanini, Patrizia Cinelli, Andrea Lazzeri
This study disserts on the exploitation of olive mill wastewater (OMW) for the production of both bio-based poly-β-hydroxybutyrate (PHB) and hydrogen (H2 ) by using the residual effluent as feedstock for growing purple bacteria after the recovery of hydroxytyrosol-rich mixtures. In particular, Rhodopseudomonas sp. S16-FVPT5 was fed with either the virgin OMW or dephenolized-OMW (d-OMW). For polyphenols removal, the OMW was treated with activated carbon; subsequently, acidified ethanol (pH = 3.1) at 50 °C was used as extractor solvent for obtaining hydroxytyrosol-rich mixtures...
March 7, 2019: Journal of Biotechnology
Takahiro Yamaguchi, Joemark Narsico, Takanori Kobayashi, Akira Inoue, Takao Ojima
A novel alginolytic bacterium Hydrogenophaga sp. strain UMI-18 that produces poly(3-hydroyxybutylate) (PHB) in the alginate-mineral salt (AMS) medium containing 1% (w/v) sodium alginate as a sole carbon source was isolated from a decayed brown seaweed litter. The yield of PHB produced by strain UMI-18 was 1.1 ± 0.15 g/L of AMS and the PHB content in dried cell pellet was 58 ± 4% (w/w). Glucose, fructose, galactose, mannose, mannitol, sucrose and lactose were also available for the production of PHB by strain UMI-18...
March 7, 2019: Journal of Bioscience and Bioengineering
Rijuta Ganesh Saratale, Ganesh Dattatraya Saratale, Si Kyung Cho, Dong Su Kim, Gajanan S Ghodake, Avinash Kadam, Gopalakrishanan Kumar, Ram Naresh Bharagava, Rajesh Banu, Han Seung Shin
Kenaf biomass (KB) was employed as feedstock for the synthesis of polyhydroxybutyrate (PHB) using Ralstonia eutropha to replace conventional petroleum-derived polymers. Various pretreatments followed by enzymatic saccharification were applied to release monomeric sugars from KB for PHB production. The effects of increasing concentration of Na2 CO3  + Na2 SO3 (NaC + NaS) pretreated KB hydrolysates (20-40 g/L) on PHB production were investigated. NaC + NaS pretreated KB hydrolysates (30 g/L) exhibited maximum 70...
February 19, 2019: Bioresource Technology
Sung-Ho Park, Gi Bae Kim, Hyun Uk Kim, Si Jae Park, Jong-Il Choi
During microbial production of target product, accumulation of by-products and target product itself may be toxic to host strain. Thus, development of abiotic stress tolerant strains are essential to achieve high productivity of target product with sustained metabolism. Expression of DR1558 from Deinococcus radiodurans, a response regulator in two-component signal transduction system, was reported to increase the tolerance against oxidative stress in Escherichia coli. In this study, the effect of overexpression of DR1558 was examined on poly‑3‑hydroxybutyrate (PHB) production in recombinant E...
March 6, 2019: International Journal of Biological Macromolecules
Nguyen Van Hung, Peter Bossier, Nguyen Thi X Hong, Christine Ludeseve, Linsey Garcia-Gonzalez, Nancy Nevejan, Peter De Schryver
The natural amorphous polymer poly-β-hydroxybutyrate (PHB-A: lyophilized Ralstonia eutropha containing 75% PHB) was used as a biological agent to control bacterial pathogens of blue mussel (Mytilus edulis) larvae. The larvae were supplied with PHB-A at a concentration of 1 or 10 mg/L for 6 or 24 hr, followed by exposure to either the rifampicin-resistant pathogen Vibrio splendidus or Vibrio coralliilyticus at a concentration of 105 CFU/ml. Larvae pretreated 6 hr with PHB-A (1 mg/L) survived a Vibrio challenge better relative to 24 hr pretreatment...
March 8, 2019: Journal of Fish Diseases
Amita Sharma, Manisha Thakur, Munna Bhattacharya, Tamal Mandal, Saswata Goswami
Cellulose is the biosynthetic product from plants, animals and bacteria. Cellulose is the most abundant polymer having long linear chain like structure composed of (1,4) linked β-D glucopyranosyl units assembled into hierarchical structures of microfibrils with excellent strength and stiffness. And 'nanocellulose' refers to the cellulosic materials with defined nano-scale structural dimensions. They may be cellulose nanocrystal (CNC or NCC), cellulose nanofibers (CNF) or bacterial nanocellulose. Nanocellulose is non-toxic, biodegradable and biocompatible with no adverse effects on health and environment...
March 2019: Biotechnology Reports
Baoxia Tian, Mohsin Shah, Mun Hwan Choi, Jong Kook Rho, Sang Yeol Lee, Sung Chul Yoon
Soil bacteria accumulate polyesters (typically poly([R]-3-hydroxybutyrate (PHB), in which one end of the chain terminates with a carboxyl group) in the form of hydrated, amorphous nanogranules in cells. However, it is not clear what drives the structure of these biomaterials inside bacterial cells. Here, we determined that calcium guides intracellular formation of PHB nanogranules. Our systematic study using the surface zeta potential measurement and the carboxyl-specific SYTO-62 dye binding assay showed that the terminal carboxyl is not exposed to the granule surface but is buried inside native "unit-granules" comprising the mature granule...
March 5, 2019: Scientific Reports
Aditi Singh, Mriganko Das, Abhinav Grover
Polyhydroxyalkanoates are gaining importance due to their biodegradable nature and close analogy to plastics. Polyhydroxybutyrate (PHB) is the most widely used bioplastic from polyalkanoate family, which is produced by a legion of bacterial species via phbCAB operon encoding β-ketothiolase (PhaA), NADPH-dependent acetoacetyl-coenzyme A (acetoacetyl-CoA) reductase (PhaB) and polyhydroxyalkanoate synthase (PhaC). Augmentation in the activity of these enzymes is promising for increased PHB production which is achieved by enzyme engineering strategies including non-structural and structural approaches...
March 5, 2019: Journal of Biomolecular Structure & Dynamics
Abhranil Biswas, Arkady Ellern, Aaron D Sadow
The rhodium dicarbonyl {PhB(OxMe2 )2 ImMes }Rh(CO)2 (1) and primary silanes react by oxidative addition of a nonpolar Si-H bond and, uniquely, a thermal dissociation of CO. These reactions are reversible, and kinetic measurements model the approach to equilibrium. Thus, 1 and RSiH3 react by oxidative addition at room temperature in the dark, even in CO-saturated solutions. The oxidative addition reaction is first-order in both 1 and RSiH3 , with rate constants for oxidative addition of PhSiH3 and PhSiD3 revealing kH / kD ∼ 1...
March 1, 2019: Inorganic Chemistry
Viviana Urtuvia, Pamela Villegas, Sebastián Fuentes, Myriam González, Michael Seeger
Polyhydroxyalkanoates (PHAs) are biodegradable bioplastics that are synthesized by diverse bacteria. In this study, the synthesis of PHAs by the model aromatic-degrading strain Burkholderia xenovorans LB400 was analyzed. Twelve pha genes including three copies of phaC and five copies of the phasin-coding phaP genes are distributed among the three LB400 replicons. The phaC1ABR gene cluster that encodes the enzymes of the PHA anabolic pathway is located at chromosome 1 of strain LB400. During the growth of strain LB400 on glucose under nitrogen limitation, the expression of the phaC1, phaA, phaP1, phaR, and phaZ genes was induced...
June 2018: International Microbiology: the Official Journal of the Spanish Society for Microbiology
Jyumpei Kobayashi, Akihiko Kondo
BACKGROUND: Due to various environmental problems, biodegradable polymers such as poly (3-hydroxybutyrate) (PHB) have gained much attention in recent years. Purple non-sulfur (PNS) bacteria have various attractive characteristics useful for environmentally harmless PHB production. However, production of PHB by PNS bacteria using genetic engineering has never been reported. This study is the first report of a genetically engineered PNS bacterial strain with a high PHB production. RESULTS: We constructed a poly (3-hydroxyalkanoate) depolymerase (phaZ) gene-disrupted Rhodobacter sphaeroides HJ strain...
February 26, 2019: Microbial Cell Factories
Mengxing Li, Kent Eskridge, Enshi Liu, Mark Wilkins
In this study, Plackett-Burman and central composite designs were applied to improve polyhydroxybutyrate (PHB) production from alkaline pretreatment liquor (APL) by Cupriavidus necator DSM 545 using a supplement system consisting of oxidative enzymes (laccase, aryl alcohol oxidase (AAO)), mediators (ABTS, HOBT), DMSO, silica nanoparticle Aerosol R816 and surfactant Tween 80. First, screening experiments under Plackett-Burman design showed R816, ABTS and Tween 80 could significantly enhance PHB production. Additional experiments showed that HOBT and DMSO could be removed, and laccase and AAO were needed to remain in the system...
February 16, 2019: Bioresource Technology
Joshua Avossa, Roberto Paolesse, Corrado Di Natale, Emiliano Zampetti, Giovanni Bertoni, Fabrizio De Cesare, Giuseppe Scarascia-Mugnozza, Antonella Macagnano
Structural and functional properties of polymer composites based on carbon nanomaterials are so attractive that they have become a big challenge in chemical sensors investigation. In the present study, a thin nanofibrous layer, comprising two insulating polymers (polystyrene (PS) and polyhydroxibutyrate (PHB)), a known percentage of nanofillers of mesoporous graphitized carbon (MGC) and a free-base tetraphenylporphyrin, was deposited onto an Interdigitated Electrode (IDE) by electrospinning technology. The potentials of the working temperature to drive both the sensitivity and the selectivity of the chemical sensor were studied and described...
February 17, 2019: Nanomaterials
Adriane Cherpinski, Piotr K Szewczyk, Adam Gruszczyński, Urszula Stachewicz, Jose M Lagaron
The main goal of this study was to obtain, for the first time, highly efficient water barrier and oxygen-scavenging multilayered electrospun biopaper coatings of biodegradable polymers over conventional cellulose paper, using the electrospinning coating technique. In order to do so, poly(3-hydroxybutyrate) (PHB) and polycaprolactone (PCL) polymer-containing palladium nanoparticles (PdNPs) were electrospun over paper, and the morphology, thermal properties, water vapor barrier, and oxygen absorption properties of nanocomposites and multilayers were investigated...
February 14, 2019: Nanomaterials
McKenna K Goetz, John S Anderson
C-H activation by transition metal oxo complexes is a fundamental reaction in oxidative reactivity by both biological and synthetic systems. This centrality has motivated efforts to understand the patterns and mechanisms of such reactivity. We have therefore thoroughly examined the C-H activation reactivity of the recently synthesized and characterized late transition metal oxo complex PhB(tBuIm)3CoIIIO. Accurate values for the pKa and BDFEO-H of the conjugates of this com-plex have been experimentally determined and provide insight into the observed reactivity...
February 9, 2019: Journal of the American Chemical Society
Kyle Mason-Jones, Callum C Banfield, Michaela A Dippold
RATIONALE: Many bacteria synthesize carbon (C) and energy storage compounds, including water-insoluble polyester lipids composed mainly or entirely of poly(3-hydroxybutyrate) (PHB). Despite the potential significance of C and energy storage for microbial life and C cycling, few measurements of PHB in soil have been reported. METHODS: A new protocol was implemented, based on an earlier sediment extraction and derivatization procedure, with quantification by gas chromatography-mass spectrometry (GC/MS) and 13 C isotopic analysis by GC-combustion-isotope ratio mass spectrometry (GC/C/IRMS)...
February 4, 2019: Rapid Communications in Mass Spectrometry: RCM
Marcel V Alavi
The mitochondrial inner membrane proteins OMA1 and OPA1 belong to the BAX/BAK1-dependent apoptotic signaling pathway, which can be regulated by tumor protein p53 and the prohibitins PHB and PHB2 in the context of neoplastic disease. For the most part these proteins have been studied separate from each other. Here, I argue that the OMA1 mechanism of action represents the missing link between p53 and cytochrome c release. The mitochondrial fusion protein OPA1 is cleaved by OMA1 in a stress-dependent manner generating S-OPA1...
February 4, 2019: International Journal of Cancer. Journal International du Cancer
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