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Paramasivam Murugan, Lizhu Han, Chee-Yuen Gan, Frans H J Maurer, Kumar Sudesh
Bacterial polyhydroxyalkanoates (PHA) are expensive partly due to the recovery and purification processes. Thus, many studies have been carried out in order to minimize the cost. Here we report on the use of mealworm, which is the larva of mealworm beetle (Tenebrio molitor) to recover PHA granules from Cupriavidus necator. Mealworms were shown to readily consume the freeze-dried C. necator cells and excrete the PHA granules in the form of whitish feces. Further purification using water, detergent and heat resulted in almost 100% pure PHA granules...
October 13, 2016: Journal of Biotechnology
Yoong Kit Leong, John Chi-Wei Lan, Hwei-San Loh, Tau Chuan Ling, Chien Wei Ooi, Pau Loke Show
Polyhydroxyalkanoates (PHAs), a class of renewable and biodegradable green polymers, have gained attraction as a potential substitute for the conventional plastics due to the increasing concern towards environmental pollution as well as the rapidly depleting petroleum reserve. Nevertheless, the high cost of downstream processing of PHA has been a bottleneck for the wide adoption of PHAs. Among the options of PHAs recovery techniques, aqueous two-phase extraction (ATPE) outshines the others by having the advantages of providing a mild environment for bioseparation, being green and non-toxic, the capability to handle a large operating volume and easily scaled-up...
October 10, 2016: Journal of Bioscience and Bioengineering
C Kourmentza, M Kornaros
Mixed microbial cultures that undergo successful enrichment, following eco-biotechnological approaches, to form a community dominant in polyhydroxyalkanoates (PHA) forming bacteria, represent an attractive economic alternative towards the production of those biopolymers. In the present study, an enriched mixed culture was investigated for the production of PHA at different initial pH values under non-controlled conditions in order to minimize process control and operational costs. Short-chain fatty acids were provided as PHA precursors and they were tested as sole carbon sources and as mixtures under nitrogen deficiency...
October 6, 2016: Bioresource Technology
Pei-Shze Mok, Diana Hooi-Ean Ch'ng, Soo-Peng Ong, Keiji Numata, Kumar Sudesh
Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] is one of the polyhydroxyalkanoate (PHA) copolymers which can be degraded by lipases. In this study, the depolymerizing activity of different known commercial lipases was investigated via microassay using P(3HB-co-92 mol % 4HB) thin film as substrate. Non-enzymatic hydrolysis occurred under conditions in which buffers with pH 12 and 13 were added or temperature of 50 °C and above. Different concentrations of metal ions or detergents alone did not cause the film hydrolysis...
December 2016: AMB Express
Stephanie Karmann, Stéphanie Follonier, Monica Bassas-Galia, Sven Panke, Manfred Zinn
Poly(3-hydroxyalkanoates) (PHAs) are bio-based and biodegradable polyesters which have been considered as a promising alternative to petrol-based plastics. Its bacterial production is a dynamic process in which intracellular polymerization and depolymerization are closely linked and depend on the availability of carbon substrates and other nutrients. These dynamics require a fast and quantitative method to determine the optimal harvest-time of PHA containing cells or to adjust carbon supply. In principle, flow cytometry (FCM) is an ideal tool that suits these requirements and, in addition, provides data on the PHA content of different cell populations...
October 6, 2016: Journal of Microbiological Methods
Misty R Riddle, Erik A Spickard, Angela Jevince, Ken C Q Nguyen, David H Hall, Pradeep M Joshi, Joel H Rothman
The differentiated cell identities and structure of fully formed organs are generally stable after their development. In contrast, we report here that development of the C. elegans proximal somatic gonad (hermaphrodite uterus and spermathecae, and male vas deferens) can be redirected into intestine-like organs by brief expression of the ELT-7 GATA transcription factor. This process converts one developing organ into another and can hence be considered "transorganogenesis." We show that, following pulsed ELT-7 expression, cells of the uterus activate and maintain intestine-specific gene expression and are transformed at the ultrastructural level to form an epithelial tube resembling the normal intestine formed during embryogenesis...
October 4, 2016: Developmental Biology
Maider Muñoz-Culla, Matías Sáenz-Cuesta, Maier J Guereca-Barandiaran, Marcelo L Ribeiro, David Otaegui
Yerba mate (YM) has been shown to have anti-inflammatory properties in several studies. However, this effect has been found mainly in obesity-related inflammation. The aim of this work was to study the effect of YM on cultured peripheral blood mononuclear cells to see whether it has anti-inflammatory properties. We stimulated peripheral blood mononuclear cells in vitro with phytohemagglutinin (PHA) in the presence of yerba mate and determined their activation by measuring the expression of CD25 by flow cytometry...
October 7, 2016: Food & Function
S Vigneswari, V Murugaiyah, G Kaur, H P S Abdul Khalil, A A Amirul
Polyhydroxyalkanoate (PHA) is a microbial polymer that has been at the forefront of many attempts at tissue engineering. However, the surface of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) is hydrophobic with few recognition sites for cell attachment. Various concentrations of fish-scale collagen peptides (FSCPs) were incorporated into P(3HB-co-4HB) copolymer by aminolysis. Later, FSCPs were introduced onto the aminolyzed P(3HB-co-4HB) scaffolds. Introduction of the FSCP groups was verified using Fourier transform infrared spectroscopy and the ninhydrin method...
October 6, 2016: Biomedical Materials
Mieko Higuchi-Takeuchi, Kumiko Morisaki, Keiji Numata
Polyhydroxyalkanoates (PHAs) are a family of biopolyesters accumulated by a variety of microorganisms as carbon and energy storage under starvation conditions. We focused on marine purple non-sulfur photosynthetic bacteria as host microorganisms for PHA production and developed a method for their isolation from natural seawater. To identify novel PHA-producing marine purple non-sulfur photosynthetic bacteria, natural seawaters were cultured in nutrient-rich medium for purple non-sulfur photosynthetic bacteria, and twelve pink- or red-pigmented colonies were picked up...
2016: Frontiers in Microbiology
Hongna Yang, Jinhua Sun, Feng Wang, Yan Li, Jianzhong Bi, Tingyu Qu
The immunoregulatory function of T regulatory cells (Tregs) is impaired in multiple sclerosis (MS). Recent studies have shown that umbilical cord-derived mesenchymal stem cells (UC-MSCs) exert regulatory effect on the functions of immune cells. Thus, we investigated whether UC-MSCs could improve the impaired function of Tregs from MS patients. Co-cultures of UC-MSCs with PBMCs of MS patients were performed for 3 days. Flow cytometry was used to determine the frequency of Tregs. A cell proliferation assay was used to evaluate the suppressive capacity of Tregs...
September 29, 2016: Oncotarget
Piming Ma, Tianfeng Shen, Long Lin, Weifu Dong, Mingqing Chen
Comb-like nanocrystal cellulose graft poly (d-lactide) (PDLA), i.e., NCC-g-PDLA nanohybrids were synthesized and compounded with poly (l-lactide) (PLLA) and poly (hydroxyalkanoate)s (PHA) to make fully biobased nanocomposites. Surprisingly, the complex viscosity of the PLLA/PHA melts was reduced by more than one order of magnitudes, viz. from 4000 to 100Pas by incorporation of 2-4wt% of the NCC-g-PDLA nanohybrids. Meanwhile, the crystallization of the PLLA component was accelerated by the NCC-g-PDLA nanohybrids due to the strong interaction between PDLA and PLLA macromolecules...
January 2, 2017: Carbohydrate Polymers
Erik R Coats, Benjamin S Watson, Cynthia K Brinkman
Polyhydroxyalkanoates (PHAs) are biodegradable polymers that can substitute for petroleum-based plastics in a variety of applications. One avenue to commercial PHA production involves coupling waste-based synthesis with the use of mixed microbial consortia (MMC). In this regard, production requires maximizing the enrichment of a MMC capable of feast-famine PHA synthesis, with the metabolic response induced through imposition of aerobic-dynamic feeding (ADF) conditions. However, the concept of PHA production in complex matrices remains unrefined; process operational improvements are needed, along with an enhanced understanding of the MMC...
September 21, 2016: Water Research
Denis Vadlja, Martin Koller, Mario Novak, Gerhart Braunegg, Predrag Horvat
Statistical distribution of cell and poly[3-(R)-hydroxybutyrate] (PHB) granule size and number of granules per cell are investigated for PHB production in a five-stage cascade (5CSTR). Electron microscopic pictures of cells from individual cascade stages (R1-R5) were converted to binary pictures to visualize footprint areas for polyhydroxyalkanoate (PHA) and non-PHA biomass. Results for each stage were correlated to the corresponding experimentally determined kinetics (specific growth rate μ and specific productivity π)...
October 3, 2016: Applied Microbiology and Biotechnology
Andrea V Bagdadi, Maryam Safari, Prachi Dubey, Pooja Basnett, Panagiotis Sofokleous, Eleanor Humphrey, Ian Locke, Mohan Edirisinghe, Cesare Terracciano, Aldo R Boccaccini, Jonathan C Knowles, Sian E Harding, Ipsita Roy
Cardiac tissue engineering (CTE) is currently a prime focus of research due to an enormous clinical need. In this work, a novel functional material, Poly(3-hydroxyoctanoate), P(3HO), a medium chain length polyhydroxyalkanoate (PHA), produced using bacterial fermentation, was studied as a new potential material for CTE. Engineered constructs with improved mechanical properties, crucial for supporting the organ during new tissue regeneration, and enhanced surface topography, to allow efficient cell adhesion and proliferation, were fabricated...
September 30, 2016: Journal of Tissue Engineering and Regenerative Medicine
Lu-Hong Lan, Han Zhao, Jin-Chun Chen, Guo-Qiang Chen
Halomonas spp. have been studied as a low cost production host for producing bulk materials such as polyhydroxyalkanoates (PHA) bioplastics, since they are able to grow at high pH and high NaCl concentration under unsterile and continuous conditions without microbial contamination. In this paper, Halomonas strain TD was used as a host to produce a protein named PHA phasin or PhaP which has a potential to be developed into a bio-surfactant. Four Halomonas TD expression strains were constructed based on a strong T7-family expression system...
September 30, 2016: Biotechnology Journal
Peter James Strong, Bronwyn Laycock, Syarifah Nuraqmar Syed Mahamud, Paul Douglas Jensen, Paul Andrew Lant, Gene Tyson, Steven Pratt
Polyhydroxyalkanoate (PHA) biopolymers are widely recognised as outstanding candidates to replace conventional petroleum-derived polymers. Their mechanical properties are good and can be tailored through copolymer composition, they are biodegradable, and unlike many alternatives, they do not rely on oil-based feedstocks. Further, they are the only commodity polymer that can be synthesised intracellularly, ensuring stereoregularity and high molecular weight. However, despite offering enormous potential for many years, they are still not making a significant impact...
February 3, 2016: Microorganisms
Olga Revelles, Daniel Beneroso, J Angel Menéndez, Ana Arenillas, J Luis García, M Auxiliadora Prieto
The massive production of urban and agricultural wastes has promoted a clear need for alternative processes of disposal and waste management. The potential use of municipal solid wastes (MSW) as feedstock for the production of polyhydroxyalkanoates (PHA) by a process known as syngas fermentation is considered herein as an attractive bio-economic strategy to reduce these wastes. In this work, we have evaluated the potential of Rhodospirillum rubrum as microbial cell factory for the synthesis of PHA from syngas produced by microwave pyrolysis of the MSW organic fraction from a European city (Seville)...
September 28, 2016: Microbial Biotechnology
L M Bedoya, M Beltrán, P Obregón-Calderón, J García-Pérez, E de la Torre, N González, M Pérez-Olmeda, D Auñón, L Capa, E Gómez-Acebo, J Alcami
OBJECTIVE: To investigate the toxicity and activity against HIV of 5-hydroxytyrosol (5-HT) as a potential microbicide. DESIGN: The anti-HIV-1 activity of 5-HT, a polyphenolic compound, was tested against wild-type HIV-1 and viral clones resistant to NRTIs, NNRTIs, PIs and INIs. Besides, its activity against founder viruses, different viral subtypes and potential synergy with TDF, 3TC and FTC was also tested. 5-HT toxicity was evaluated in vivo in rabbit vaginal mucosa...
September 24, 2016: AIDS
Dublu Lal Gupta, Sanjeev Bhoi, Teena Mohan, Sagar Galwnkar, D N Rao
INTRODUCTION: Multiple organ dysfunction syndrome (MODS) developed due to the insult of trauma is a leading cause of death. The high mortality rate in these patients with and without sepsis has been reported up to 50%, throughout the world and thus required an urgent insight to overcome this problem. OBJECTIVE: The aim of this study is to examine the differential changes in subsets of T cells, imbalance in cytokine profile, immune-paralysis (T cell anergy) in Trauma hemorrhagic shock (THS) and post traumatic sepsis patients...
December 2016: Cytokine
S Mohapatra, D P Samantaray, S M Samantaray, B B Mishra, S Das, S Majumdar, S K Pradhan, S N Rath, C C Rath, J Akthar, K G Achary
In this investigation an attempt has been made to characterize and identify Lysinibacillus sp. 3HHX by 16S-rDNA sequencing. The bacterium exhibited occurrence of PHAs granules on an average 11±1 per cell of 1.0μm length and breadth 0.72μm, revealed from TEM studies. Under optimized condition, 4.006gm/L of PHAs was extracted using hypochlorite digestion and multi-solvent extraction process. PhaC gene of ∼540bp and higher PHA synthase activity was detected at 48h of cultivation. The extracted PHAs was structurally characterized by GC-MS and (1)H NMR reported to be P(3HB-co-3HDD-co-3HTD) and amorphous in nature with 112°C melting point, -11...
September 22, 2016: International Journal of Biological Macromolecules
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