Consulta: subjectFacets:"Biopolymer"
Registros recuperados: 15
Data/hora: 11/06/2024 08:20:06

Bioconversion of mixed free fatty acids to poly-3-hydroxyalkanoates by Pseudomonas putida BET001 and modeling of its fermentation in shake flasks
Provedor de dados: 69
Autores: Makhdum Munawar,Khalil Munawar; Simarani,Khanom; Annuar,Mohamad Suffian Mohamad.
Background: The paper reports on the utilization of palm kernel oil (PKO) as a low cost renewable substrate for medium-chain-length poly-3-hydroxyalkanoates (mcl-PHA) production by Pseudomonas putida BET001. Investigation on the effects of selected key variables on growth, mixed free fatty acids consumption and mcl-PHA production by the bacterial culture in the shaken flask system were carried out along with its kinetic modeling. Results: The biomass production, fatty acids consumption and mcl-PHA production were found favorable when the strain was cultured in mineral medium at pH 6-7,28°C, aeration surface-to-volume ratio of 0.4 x 10(6) m-1, 250 rpm agitation rate for 48 h. Mcl-PHA production by this strain showed mixed growth and non-growth associated...
Tipo: Journal article
Palavras-chave: Biopolymer; Fermentation; Medium-chain-length PHA; Palm kernel oil; Pseudomonas putida.
Ano: 2016
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000100008

Biodegradation of a blended starch/natural rubber foam biopolymer and rubber gloves by Streptomyces coelicolor CH13
Provedor de dados: 69
Autores: Watcharakul,Sirimaporn; Umsakul,Kamontam; Hodgson,Brian; Chumeka,Wannapa; Tanrattanakul,Varaporn.
Background: The growing problem of environmental pollution caused by synthetic plastics has led to the search for alternative materials such as biodegradable plastics. Of the biopolymers presently under development, starch/natural rubber is one promising alternative. Several species of bacteria and fungi are capable of degrading natural rubber and many can degrade starch. Results: Streptomyces coelicolor CH13 was isolated from soil according to its ability to produce translucent halos on a mineral salts medium, MSM, supplemented with natural rubber and to degrade starch. Scanning electron microscope studies showed that it colonized the surfaces of strips of a new starch/natural rubber biopolymer and rubber gloves and caused degradation by forming holes,...
Tipo: Journal article
Palavras-chave: Biodegradation; Biopolymer; Natural rubber; Starch; Streptomyces coelicolor.
Ano: 2012
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582012000100008

Bioconversion of cassava starch by-product into Bacillus and related bacteria polyhydroxyalkanoates
Provedor de dados: 69
Autores: Krueger,Cristhiane L; Radetski,Claudemir M; Bendia,Amanda G; Oliveira,Ida M; Castro-Silva,Marcus A; Rambo,Carlos R; Antonio,Regina V; Lima,André O.S.
Background: Unlike petroleum-based synthetic plastics, biodegradable biopolymer generation from industrial residue is a key strategy to reduce costs in the production process, as well as in the waste management, since efficient industrial wastewater treatment could be costly. In this context, the present work describes the prospection and use of bacterial strains capable to bioconvert cassava starch by-product into biodegradable polyhydroxyalkanoates (PHAs). Results: The first step of this study was the bacterial competence screening which was conducted with 72 strains covering 21 Bacillus and related species. The microorganism growth in a medium with a starch substrate was measured by an innovative MTT assay, while the ability of the bacteria to secrete...
Tipo: Journal article
Palavras-chave: Bacillus megaterium; Biodegradable plastics; Biopolymer; MTT assay; Starch substrates.
Ano: 2012
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582012000300008

Reduction of potential ennoblement of stainless steel in natural seawater by an ecofriendly biopolymer
Provedor de dados: 5
Autores: Abi Nassif, L.; Rioual, S.; Farah, W.; Hellio, C.; Fauchon, M.; Trepos, R; Abboud, M.; Diler, E.; Thierry, D.; Lescop, B.
The effect of biofilm formation on passive stainless steel in seawater environments is of primary importance since it leads to potential ennoblement of surfaces and subsequently to localized corrosion such as pitting and crevice corrosion. This study aims at developing an ecofriendly alginate biopolymer containing both non-toxic calcium and a limited amount of biocidal zinc ions which inhibits this effect. For this purpose, calcium alginate containing less than 1 % of zinc ions localized in the vicinity of the steel surface in natural and renewed seawater is demonstrated to reduce significantly the ennoblement process of steel. After 1 month of immersion, a mass loss of only 4 % of the active material is observed authorizing thereby long-term protection of...
Tipo: Text
Palavras-chave: Biopolymer; Steel; Ennoblement; Antimicrobial; Alginate; Biofilm.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00604/71607/73083.pdf

Interfacial bonding of Flax fibre/Poly(L-lactide) bio-composites
Provedor de dados: 5
Autores: Le Duigou, Antoine; Davies, Peter; Baley, Christophe.
The use of glass fibre reinforced polyester composites raises many health and safety and environmental questions. One alternative is the development of high performance bio-based bio-composites with low environmental impact. Improved understanding of interfacial properties is essential to optimise the mechanical properties and durability of these materials, but so far few data are available. The present work describes the interfacial characterization of Flax fibre/Poly(lactic) acid (PLLA) system at the micro-scale using the microbond test. Different thermal treatments have been carried out (cooling rate and annealing) in order to evaluate the influence of matrix and interfacial morphologies as well as residual stress on interfacial properties....
Tipo: Text
Palavras-chave: Flax fibre; Biopolymer; Biocomposite; Interfacial properties; Microbond test.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00000/11161/7808.pdf

Seawater ageing of flax/poly(lactic acid) biocomposites
Provedor de dados: 5
Autores: Le Duigou, A.; Davies, Peter; Baley, C.
Natural fibre reinforced biopolymer composites, or biocomposites, are an alternative to the glass fibre reinforced thermoset composites widely used today in marine applications. Biocomposites offer good mechanical properties and total biodegradability, but if they are to be adopted for marine structures their durability in a seawater environment must be demonstrated. In the present study unreinforced PLLA (Poly(L-Lactic acid)), injected and film stacked flax composites with the same PLLA matrix have been examined. All the samples were aged in natural seawater at different temperatures in order to accelerate hygrothermal ageing. Changes to physico-chemical and mechanical behaviour have been followed by weight measurements, thermal and gel permeation...
Tipo: Text
Palavras-chave: Mechanical properties; Hygrothermal ageing; Biopolymer; Natural fibre; Composites.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6639.pdf

An overview of lignin metabolism and its effect on biomass recalcitrance
Provedor de dados: 88
Autores: Cesarino,Igor; Araújo,Pedro; Domingues Júnior,Adilson Pereira; Mazzafera,Paulo.
Lignin, after cellulose, is the second most abundant biopolymer on Earth, accounting for 30% of the organic carbon in the biosphere. It is considered an important evolutionary adaptation of plants during their transition from the aquatic environment to land, since it bestowed the early tracheophytes with physical support to stand upright and enabled long-distance transport of water and solutes by waterproofing the vascular tissue. Although essential for plant growth and development, lignin is the major plant cell wall component responsible for biomass recalcitrance to industrial processing. The fact that lignin is a non-linear aromatic polymer built with chemically diverse and poorly reactive linkages and a variety of monomer units precludes the ability of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biopolymer; Genetic engineering; Phenylpropanoids; Wall components.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042012000400003

Quality and microbiological protection of table eggs by ultrasonic application of acidic electrolyzed water and chitosan
Provedor de dados: 109
Autores: Cabanillas-Beltrán,Héctor; González-Estrada,Ramsés R; Gutiérrez-Martínez,Porfirio; Hernández-López,Silvia María.
Abstract Ultrasonic nebulization was used as a novel method of chitosan (CH) and acidic electrolyzed water (AEW) application on table eggs; effects on preservation, quality and antimicrobial properties were investigated. The effect of the application of CH and AEW alone or in combination on eggs quality was evaluated in terms of weight loss, shell thickness, yolk colour, Haugh units and shell strength. Additionally, the application of CH and AEW as antimicrobial agent was investigated in order to evaluate their efficacy against Salmonella enteritidis and Escherichia coli (ATCC 25922). A negative effect was observed by the sole application of AEW on eggshell thickness and strength. Conversely, the combination of AEW and CH improve eggshell strength, as well...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antimicrobial; Biopolymer; Fogging; Sanitizer.
Ano: 2020
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122020000200097

Xanthan gum production by Xanthomonas axonopodis pv. mangiferaeindicae from glycerin of biodiesel in different media and addition of glucose
Provedor de dados: 3
Autores: Gondim, Tayssa Santos; Pereira, Roberto Guimarães; Fiaux, Sorele Batista.
Biodiesel production has been increasing yearly in Brazil. A large amount of glycerin is generated in this process and needs a correct destination. One possible use of this glycerin in crude form is in biotechnological processes. Xanthan gum is a commercial gum used primarily in the pharmaceutical and food industries as thickener, emulsifier and stabilizer. It is synthetized by species of the bacterium Xanthomonas generally from glucose. However, current research shows that species of this bacterium have the capacity to grow and synthesize the gum using glycerin from biodiesel. The aim of this study was to produce xanthan gum using glycerin from biodiesel production in medium with different nitrogen content, named complex and simple media. The kinetics of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ciências biológicas; Bioprocessos residue; Biopolymer; Biotechnological process. Bioprocessos.
Ano: 2019
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/43661

β-galactosidase Encapsulated in Carrageenan, Pectin and Carrageenan/Pectin: Comparative Study, Stability and Controlled Release
Provedor de dados: 42
Autores: SILVA,RENATA CRISTINA; TREVISAN,MARCELLO G.; GARCIA,JERUSA SIMONE.
Abstract  The present study investigated the encapsulation of β-galactosidase in carrageenan, pectin and its hybrid hydrogels by using the ionotropic gelation method. The material obtained was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG/DTG) and scanning electron microscopy (SEM). The effects of pH, temperature and storage time were evaluated in terms of the catalytic activity of the free and encapsulated enzyme. Addition studies were conducted evaluating the performance of catalytic activity in vitro conditions. Carrageenan, pectin and hybrid hydrogels presented encapsulation efficiency of 58 ± 1%, 72 ± 1% and 77 ± 2%, respectively. The pectin hydrogel showed the higher β-galactosidase activity in pH and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biopolymer; Encapsulation; Enzymatic activity; Ionotropic gelation; Lactase.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652020000100905

Synthesis and physicochemical characterization of chemically modified chitosan by succinic anhydride
Provedor de dados: 52
Autores: Mello,Karine Gargioni Pereira Correa de; Bernusso,Leandra de Cássia; Pitombo,Ronaldo Nogueira de Moraes; Polakiewicz,Bronislaw.
The N-succinil-chitosan is a chemically modified derivative of the biopolymer chitosan. The succinic anhydride attached to the free amino groups presented along the chitosan's polymer chain imparts to the molecule different physicochemical properties not exhibited before the modification. These chemical modifications enhance chitosan's solubility in slightly acid, neutral and alkaline media. These properties are related to the long alkyl chains attached to hydrophilic parts. In this case the hydrophilic part of D-glucosamine promotes stronger interactions with the water molecules, and consequently, enhances the solubility of the chitosan polymer. Non-modified free chitosan is soluble only in acidic medium (pH &lt; 5.5). These modifications made possible...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: N-succinil-chitosan; Succinic anhydride; Biopolymer; Solubility.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000500017

Mixed Cultures Fermentation for the Production of Poly-ß-hydroxybutyrate
Provedor de dados: 52
Autores: Shalin,Thomas; Sindhu,Raveendran; Binod,Parameswaran; Soccol,Carlos Ricardo; Pandey,Ashok.
Poly-ß-hydroxybutyrate (PHB) is a biodegradable intracellular microbial product produced by many bacteria and it is comparable to some of the petrochemical derived thermoplastics such as polypropylene. One of the main barriers for the commercial exploitation is the high cost of the substrate for the production of biopolymer. The utilization of mixed microbial cultures facilitates the use of complex substrates thereby reducing the cost of PHB production. In the present study, mixed culture systems were evaluated for PHB production. Bacillus firmus NII 0830 was used for the production of PHB since it accumulates a large amount of PHB and a second organism Lactobacillus delbrueckii NII 0925 was used to provide lactic acid. FTIR and 1H NMR analyses revealed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Poly-3-hydroxybutyrate; Biopolymer; Mixed culture; Bacillus firmus; Lactobacillus delbrueckii; Biodegradation.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000500644

Semi-scale production of PHAs from waste frying oil by Pseudomonas fluorescens S48
Provedor de dados: 58
Autores: Gamal,Rawia F.; Abdelhady,Hemmat M.; Khodair,Taha A.; El-Tayeb,Tarek S.; Hassan,Enas A.; Aboutaleb,Khadiga A.
The present study aimed at developing a strategy to improve the volumetric production of PHAs by Pseudomonas fluorescens S48 using waste frying oil (WFO) as the sole carbon source. For this purpose, several cultivations were set up to steadily improve nutrients supply to attain high cell density and high biopolymer productivity. The production of PHAs was examined in a 14 L bioreactor as one-stage batch, two-stage batch, and high-cell-density fed-batch cultures. The highest value of polymer content in one-stage bioreactor was obtained after 60 h (33.7%). Whereas, the two-stage batch culture increased the polymer content to 50.1% after 54 h. High-cell-density (0.64 g/L) at continuous feeding rate 0.55 mL/l/h of WFO recorded the highest polymer content after...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pseudomonas fluorescens S48; Biopolymer; PHAs; Batch; Two-stage batch; High-celldensity fed batch; Bioreactor; Recovery.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822013000200034

Industrial wastewater as raw material for exopolysaccharide production by Rhizobium leguminosarum
Provedor de dados: 58
Autores: Sellami,Mohamed; Oszako,Tomasz; Miled,Nabil; Ben Rebah,Faouzi.
The objective of this study was to evaluate the exopolysaccharide (EPS) production by Rhizobium leguminosarum cultivated in wastewater generated by oil companies (WWOC1 and WWOC2) and fish processing industry (WWFP). The results obtained in Erlenmeyer flasks indicated that the rhizobial strain grew well in industrial wastewater. Generally, wastewater composition affected the growth and the EPS production. WWFP allowed good bacterial growth similar to that obtained with the standard medium (YMB). During growth, various quantities of EPS were produced and yields varied depending on the media. Growing in YMB, EPS production did not exceed 9.7 g/L obtained after 72 h of growth. In wastewater, the maximum EPS value reached 11.1 g/L obtained with the fish...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Industrial wastewater; Biopolymer; Exopolysaccharide; Rhizobium.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000200407

Biodegradable films of starch/PVOH/alginate in packaging systems for minimally processed lettuce (Lactuca sativa L.)
Provedor de dados: 64
Autores: Brandelero,Renata Paula Herrera; Brandelero,Evandro Martin; Almeida,Fábio Mendonça de.
ABSTRACT Biodegradable packaging may replace non-biodegradable materials when the shelf life of the packaged product is relatively short, as in minimally processed foods. The objective of this work was to evaluate the efficiency of biodegradable films comprising starch/polyvinyl alcohol (PVOH)/alginate with the addition of 0 or 0.5% of essential oil of copaiba (EOCP) or lemongrass (EOLM) compared to poly-vinyl chloride (PVC) films in the storage of minimally processed lettuce. Lettuce samples cut into 1-cm strips were placed in polypropylene trays wrapped with biodegradable films and stored at 6 ± 2 °C for 8 days. PVC films were used as controls. The biofilms presented 11.43-8.11 MPa resistance and 11.3-13.22% elongation, with water vapor permeability...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Active packaging; Biopolymer; Copaiba oil; Lemongrass oil.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542016000500510