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Qian Wang, Jiasheng Xu, Zhijie Sun, Yaqi Luan, Ying Li, Junshu Wang, Quanfeng Liang, Qingsheng Qi
The low carbon yield from native metabolic machinery produces unfavorable process economics during the biological conversion of substrates to desirable bioproducts. To obtain higher carbon yields, we constructed a carbon conservation pathway named EP-bifido pathway in Escherichia coli by combining Embden-Meyerhof-Parnas Pathway, Pentose Phosphate Pathway and "bifid shunt", to generate high yield acetyl-CoA from glucose. 13 C-Metabolic flux analysis confirmed the successful and appropriate employment of the EP-bifido pathway...
August 10, 2018: Metabolic Engineering
Mananya Martla, Kamontam Umsakul, Kumar Sudesh
Polyhydroxyalkanoates (PHAs) has been paid great attention because of its useful thermoplastic properties and complete degradation in various natural environments. But, at industrial level, the successful commercialization of PHAs is limited by the high production cost due to the expensive carbon source and recovery processes. Pseudomonas mendocina PSU cultured for 72 h in mineral salts medium (MSM) containing 2% (v/v) biodiesel liquid waste (BLW) produced 79.7 wt% poly(3-hydroxybutyrate) (PHB) at 72 h...
August 10, 2018: Journal of Basic Microbiology
Tugba Ozgoren, Orkun Pinar, Gulnihal Bozdag, Aziz Akin Denizci, Oguzhan Gunduz, Pinar Cakir Hatir, Dilek Kazan
In this study, poly(3-hydroxybutyrate) (PHB) production from a newly isolated obligate alkaliphilic Bacillus marmarensis DSM 21297 was investigated to evaluate the ability of obligate alkaliphilic strain to produce a biopolymer. Additionally, electrospun nanofibers from B. marmarensis PHB (Bm-PHB) were generated using Bm-PHB/polycaprolactone (PCL) blend to evaluate the applicability of Bm-PHB. According to the experimental results, the metabolic activity of B. marmarensis decreased the pH of the medium by generating H+ ions to initiate Bm-PHB production, which was achieved at pH below 9...
August 6, 2018: International Journal of Biological Macromolecules
Bruna Matturro, Lucia Pierro, Emanuela Frascadore, Marco Petrangeli Papini, Simona Rossetti
This study investigated the organohalide-respiring bacteria (OHRB) and the supporting microbial populations operating in a pilot scale plant employing poly-3-hydroxybutyrate (PHB), a biodegradable polymer produced by bacteria from waste streams, for the in situ bioremediation of groundwater contaminated by chlorinated solvents. The bioremediation was performed in ground treatment units, including PHB reactors as slow release source of electron donors, where groundwater extracted from the wells flows through before the re-infiltration to the low permeability zones of the aquifer...
2018: Frontiers in Microbiology
A P Bonartsev, I I Zharkova, V V Voinova, E S Kuznetsova, V A Zhuikov, T K Makhina, V L Myshkina, D M Potashnikova, D V Chesnokova, D D Khaydapova, G A Bonartseva, K V Shaitan
Development of biocompatible 3D scaffolds is one of the most important challenges in tissue engineering. In this study, we developed polymer scaffolds of different design and microstructure to study cell growth in them. To obtain scaffolds of various microstructure, e.g., size of pores, we used double- and one-stage leaching methods using porogens with selected size of crystals. A composite of poly(3-hydroxybutyrate) (PHB) with poly(ethylene glycol) (PEG) (PHB/PEG) was used as polymer biomaterial for scaffolds...
August 2018: 3 Biotech
Jorge A Zaldívar Carrillo, Lisa Y Stein, Dominic Sauvageau
Methane and methanol are common industrial by-products that can be used as feedstocks for the production of value-added products by methylotrophic bacteria. Alphaproteobacterial methanotrophs are known to produce and accumulate the biopolymer polyhydroxybutyrate (PHB) under conditions of nutrient starvation. The present study determined optimal production of biomass and PHB by Methylosinus trichosporium OB3b as a function of carbon source (methane or methanol), nitrogen source (ammonium or nitrate), and nitrogen-to-carbon ratio during growth...
2018: Frontiers in Microbiology
Vibhavee Sukruansuwan, Suchada Chanprateep Napathorn
Background: Pineapple is the third most important tropical fruit produced worldwide, and approximately 24.8 million tons of this fruit are produced annually throughout the world, including in Thailand, which is the fourth largest pineapple producer in the world. Pineapple wastes (peel and core) are generated in a large amount equal to approximately 59.36% based on raw material. In general, the anaerobic digestion of pineapple wastes is associated with a high biochemical oxygen demand and high chemical oxygen demand, and this process generates methane and can cause greenhouse gas emissions if good waste management practices are not enforced...
2018: Biotechnology for Biofuels
C Kourmentza, J Costa, Z Azevedo, C Servin, C Grandfils, V De Freitas, M A M Reis
The present work assessed the feasibility of used cooking oil as a low cost carbon source for rhamnolipid biosurfactant production employing the strain Burkholderia thailandensis. According to the results, B. thailandensis was able to produce rhamnolipids up to 2.2 g/L, with the dominant congener being the di-rhamnolipid Rha-Rha-C14 -C14 . Rhamnolipids had the ability to reduce the surface tension to 37.7 mN/m and the interfacial tension against benzene and oleic acid to 4.2 and 1.5 mN/m, while emulsification index against kerosene reached up to 64%...
January 2018: Bioresource Technology
Ulrike Buehler, Katharina Schulenburg, Hajime Yurugi, Maja Šolman, Daniel Abankwa, Alexander Ulges, Stefan Tenzer, Tobias Bopp, Bernd Thiede, Frauke Zipp, Krishnaraj Rajalingam
T helper (Th)17 cells represent a unique subset of CD4+ T cells and are vital for clearance of extracellular pathogens including bacteria and fungi. However, Th17 cells are also involved in orchestrating autoimmunity. By employing quantitative surface proteomics, we found that the evolutionarily conserved prohibitins (PHB1/2) are highly expressed on the surface of both murine and human Th17 cells. Increased expression of PHBs at the cell surface contributed to enhanced CRAF/MAPK activation in Th17 cells. Targeting surface-expressed PHBs on Th17 cells with ligands such as Vi polysaccharide (Typhim vaccine) inhibited CRAF-MAPK pathway, reduced interleukin (IL)-17 expression and ameliorated disease pathology with an increase in FOXP3+ -expressing Tregs in an animal model for multiple sclerosis (MS)...
July 26, 2018: EMBO Journal
Leidy Patricia Bedoya-Pérez, Luis Felipe Muriel-Millán, Soledad Moreno, Elva Quiroz-Rocha, Nancy Rivera-Gómez, Guadalupe Espín
In bacteria, the 5'-end-dependent RNA degradation is triggered by the RNA pyrophosphohydrolase RppH converting tri/diphosphate to monophosphate transcripts. This study shows that in the soil bacterium Azotobacter vinelandii, inactivation of rppH gene negatively affected the production of bioplastic poly-β-hydroxybutyrate (PHB) by reducing the expression at the translational level of PhbR, the specific transcriptional activator of the phbBAC biosynthetic operon. The effect of RppH on the translation of phbR seemed to be exerted through the translational repressor RsmA, as the inactivation of rsmA in the rppH mutant restored the phbR expression...
September 2018: Microbiological Research
Siew Yin Chan, Benjamin Qi Yu Chan, Zengping Liu, Bhav Harshad Parikh, Kangyi Zhang, Qianyu Lin, Xinyi Su, Dan Kai, Wee Sim Choo, David James Young, Xian Jun Loh
Natural polysaccharide pectin has for the first time been grafted with polyhydroxybutyrate (PHB) via ring-opening polymerization of β-butyrolactone. This copolymer, pectin-polyhydroxybutyrate (pec-PHB), was blended with PHB in various proportions and electrospun to produce nanofibers that exhibited uniform and bead-free nanostructures, suggesting the miscibility of PHB and pec-PHB. These nanofiber blends exhibited reduced fiber diameters from 499 to 336-426 nm and water contact angles from 123.8 to 88.2° on incorporation of pec-PHB...
December 31, 2017: ACS Omega
Eman M Saied, Hanan Alsaeid Alshenawy
Background: Prostatic carcinoma ranks as the second most common malignant tumor and the fifth cause of cancer-related deaths in men. Many studies now focus on the different molecules involved in prostatic carcinogenesis. Maspin and prohibitin (PHB) are suggested to play crucial roles in the development and progression of many cancers; however, their roles in prostatic carcinogenesis have not been fully elucidated. Aim: This work was designed to study the immunohistochemical expression of maspin and PHB in prostatic carcinoma in comparison to their expression in benign prostatic hyperplasia (BPH) to give more insights about their roles in prostatic carcinogenesis...
January 2018: Journal of microscopy and ultrastructure
Souha Tohme, Gül Gülenay Hacıosmanoğlu, Mehmet Sayip Eroğlu, Ceyda Kasavi, Seval Genç, Zehra Semra Can, Ebru Toksoy Oner
Levan is a fructan type polysaccharide that has long been considered as an industrially important biopolymer however its limited availability is mainly due to the bottlenecks associated with its large-scale production. To overcome such bottlenecks in the commercialization of this very promising polysaccharide, co-production of levan with polyhydroxyalkanoates (PHAs) by halophilic Halomonas smyrnensis cultures has been proposed in this study for the first time. After in silico and in vitro assessment of PHA accumulation, fermentation profiles for levan and PHA concentrations were obtained in the presence of sucrose and glucose and the PHA granules observed by TEM were found to be poly(3-hydroxybutyrate) (PHB) after detailed structural characterization by GC-MS, DSC, FTIR and NMR...
July 3, 2018: International Journal of Biological Macromolecules
Tatiana B Eronina, Valeriya V Mikhaylova, Natalia A Chebotareva, Vladimir V Shubin, Boris I Kurganov
In this work the effect of ionic strength and arginine on the kinetics of aggregation of UV-irradiated muscle glycogen phosphorylase b (UV-Phb) was studied using dynamic light scattering at 37 °C at various ionic strengths (0.02-0.7 M). Under these conditions the rate-limiting stage of the overall aggregation process is the structural reorganization of UV-Phb, which can be characterized by the first order rate constant kI . It was shown that an increase in NaCl concentration caused a decrease in the kI value, suggesting a slowdown of the UV-Phb structural reorganization...
July 2, 2018: International Journal of Biological Macromolecules
Daisuke Toda, Keiko Tsukasaki, Tomoya Itatani, Kaoru Kyota, Shoryoku Hino, Tatsuru Kitamura
BACKGROUND: Potentially harmful behaviour (PHB) by caregivers is detrimental to the physical and psychological well-being of care recipients. In Japan, few studies have investigated caregivers' PHB towards dementia patients. This study examined PHB in family caregivers of dementia patients with behavioural and psychological symptoms of dementia (BPSD) and identified factors related to PHB. METHODS: Following primary consultations at an elderly psychiatric patient department, we enrolled 133 pairs of dementia patients and their family caregivers...
July 10, 2018: Psychogeriatrics: the Official Journal of the Japanese Psychogeriatric Society
Mandana Akia, Nataly Salinas, Cristobal Rodriguez, Robert Gilkerson, Luis Materon, Karen Lozano
Fine fibers of polyhydroxybutyrate (PHB), a biopolymer, were developed via a centrifugal spinning technique. The developed fibers have an average diameter of 1.8 µm. Texas sour orange juice (SOJ) was applied as a natural antibacterial agent and infiltrated within the fibrous membranes. The antibacterial activity against common Gram-positive and Gram-negative bacteria ( Staphylococcus aureus and Escherichia coli , respectively) was evaluated as well as cell adhesion and viability. The PHB/SOJ scaffolds showed antibacterial activity of up to 152% and 71% against S...
July 4, 2018: Membranes
Sean M M Quinlan, Natalia Rodriguez-Alvarez, Eleanor J Molloy, Stephen F Madden, Geraldine B Boylan, David C Henshall, Eva M Jimenez-Mateos
Seizures in neonates, mainly caused by hypoxic-ischemic encephalopathy, are thought to be harmful to the brain. Phenobarbital remains the first line drug therapy for the treatment of suspected neonatal seizures but concerns remain with efficacy and safety. Here we explored the short- and long-term outcomes of phenobarbital treatment in a mouse model of hypoxia-induced neonatal seizures. Seizures were induced in P7 mice by exposure to 5% O2 for 15 minutes. Immediately after hypoxia, pups received a single dose of phenobarbital (25 mg...
July 3, 2018: Scientific Reports
Donya Kamravamanesh, Tamas Kovacs, Stefan Pflügl, Irina Druzhinina, Paul Kroll, Maximilian Lackner, Christoph Herwig
Photosynthetic Poly-β-hydroxybutyrate (PHB) productivity in cyanobacteria needs to be increased to make cyanobacterial derived bioplastics economically feasible and competitive with petroleum-based plastics. In this study, high PHB yielding mutants of Synechocystis sp. PCC 6714 have been generated by random mutagenesis, using UV light as a mutagen. The selection of strains was based on PHB content induced by nitrogen and phosphorus starvation. The fast growing mutant MT_a24 exhibited more than 2.5-fold higher PHB productivity than that of the wild-type, attaining values of 37 ± 4% dry cell weight PHB...
June 20, 2018: Bioresource Technology
Adriane Cherpinski, Melike Gozutok, Hilal Turkoglu Sasmazel, Sergio Torres-Giner, Jose M Lagaron
This paper reports on the development and characterization of oxygen scavenging films made of poly(3-hydroxybutyrate) (PHB) containing palladium nanoparticles (PdNPs) prepared by electrospinning followed by annealing treatment at 160 °C. The PdNPs were modified with the intention to optimize their dispersion and distribution in PHB by means of two different surfactants permitted for food contact applications, i.e., hexadecyltrimethylammonium bromide (CTAB) and tetraethyl orthosilicate (TEOS). Analysis of the morphology and characterization of the chemical, thermal, mechanical, and water and limonene vapor barrier properties and the oxygen scavenging capacity of the various PHB materials were carried out...
June 27, 2018: Nanomaterials
Diana Isabel Martínez-Tobón, Maryam Gul, Anastasia Leila Elias, Dominic Sauvageau
The biodegradation of polyhydroxybutyrate (PHB) has been broadly investigated, but studies typically focus on a single strain or enzyme and little attention has been paid to comparing the interaction of different PHB depolymerase (PhaZ)-producing strains with this biopolymer. In this work, we selected nine bacterial strains-five with demonstrated and four with predicted PhaZ activity-to compare their effectiveness at degrading PHB film provided as sole carbon source. Each of the strains with demonstrated activity were able to use the PHB film (maximum mass losses ranging from 12% after 2 days for Paucimonas lemoignei to 90% after 4 days for Cupriavidus sp...
June 27, 2018: Applied Microbiology and Biotechnology
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