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| Registros recuperados: 978 | |
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| Limberger,Renata Pereira; Aleixo,Adriana Mendes; Fett-Neto,Arthur Germano; Henriques,Amélia T. |
| This work describes the bioconversion of (-)- and (+)-alpha-pinene (2,6,6-trimethyl-bicyclo[3.1.1]hept-2-ene), targeted at the production of (-)- and (+)-verbenone (4,6,6-trimethyl-bicyclo (3.1.1) hept-3-en-2-one), respectively, using Psychotria brachyceras and Rauvolfia sellowii cell suspension cultures. P. brachyceras showed selectivity to (-)-alpha-pinene with 80.9% conversion (relative integrated area gas chromatography-mass spectrometry (GC-MS)) of (-)-verbenone in 10-day-incubation, whereas R. sellowii was able to convert both pinene enantiomers (37.6% conversion of (-)-verbenone in 7-day-incubation and 32.2% conversion of (+)-verbenone in 10-day-incubation). In both systems trans-verbenol was formed as main product and then slowly biocatalyzed to... |
| Tipo: Journal article |
Palavras-chave: Alpha-pinene; Biotransformation; Verbenol; Verbenone. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000400003 |
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| Zhong-Tao,Sun; Lin-Mao,Tian; Cheng,Liu; Jin-Hua,Du. |
| Apple pomace is a wasted resource produced in large quantities and its deposit has caused serious environmental problems, so it is significance to make the full utilization of the residues. The objectives of this work were to produce multienzyme bio-feed, biodegrade the anti-nutritional factors such as pectin and tannins in apple pomace, and obtain the nutritional enrichment of the fermented substrate. The mixture of apple pomace and cottonseed powder (1:1, w/w), supplemented with 1% (w/w) (NH4)2SO4 and 0.1% (w/w) KH2PO4, was proved to be the optimum medium for the mixed strains of Aspergillus niger M2 and M3 (2:1, w/w). The activities of pectinase, proteinase and cellulase achieved 21168 u/g, 3585 u/g and 1208u/g, and the biodegradation rates of pectin... |
| Tipo: Journal article |
Palavras-chave: Apple pomace; Aspergillus niger; Multienzyme bio-feed; Pectin; Solid state fermentation; Tannins. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000100002 |
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| 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 |
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| Mendonça,Elsa; Martins,Aida; Anselmo,Ana Maria. |
| The mycelium of Fusarium flocciferum was assayed for its ability to degrade aromatic compounds, namely, gallic, protocatechuic, vanillic, syringic, caffeic, and ferulic acids and syringic aldehyde, commonly found in agro-industrial wastes. The biodegradation assays were performed in liquid medium with the phenolic compounds as single substrates and as a synthetic mixture containing the seven aromatic compounds. The results with single substrates indicated that in 24 hrs of incubation the fungus was able to reduce the phenolic concentration from 200 mg/l to below detection limits, except for syringic acid, being the lowest degradation rates found for this acid and its aldehyde. The biodegradation experiments with the mixture of phenolic compounds showed... |
| Tipo: Journal article |
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| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000100005 |
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| Kopytko,Maria; Chalela,Graciela; Zauscher,Fernando. |
| The purpose of this project was to evaluate the biodegradation of two commercial herbicides (Gramoxone and Matancha) by the bacteria Pseudomonas putida. Gramoxones active ingredient is Paraquat (1,1-dimethyl-4,4-bipyridylium) and Matanchas is 2,4-D (2,4-dichlorophenoxiacetic acid). To carry out the biodegradation experiments, a factorial design 2³ was executed, where the independent variables were: herbicide concentration, nutrient concentration and the use or no use of activated charcoal (AC) in the same experiment with bacteria. Duplicate experiments were performed for a period of three days using 500 ml bioreactors. The best results obtained when no AC was used were: 47,29% degradation for Gramoxone (by UV/VIS) and 68.72% for Matancha (by HPLC). The... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000200013 |
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| Romero-Noguera,Julio; Martín-Sánchez,Inés; López-Miras,María del Mar; Ramos-López,José Miguel; Bolívar-Galiano,Fernando. |
| Since the middle of the XIX century, when dammar became popular in Occident, this natural resin is one of the most used in art painting techniques as final protective coating (varnish) as well as a component of pictorial media. The present work is the first approach to the study of the microbiological biodeterioration of this artistic material, which can seriously affect the appearance and integrity of works of art when bad conservation conditions -especially high humidity levels- take place. 12 microorganisms, fungi and bacteria, came from collection and from oil paintings affected by biodeterioration patterns, were inoculated on test specimens prepared with varnish dammar. These were incubated and analyzed by GC-MS to determine both the microbiological... |
| Tipo: Journal article |
Palavras-chave: Bacteria; Biodeterioration; Dammar; Fungi; GC-MS. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000300006 |
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| Saripan,Arunsri Fangkum; Reungsang,Alissara. |
| Background: Biological hydrogen production by microorganisms can be divided into two main categories i.e. photosynthetic organisms that produce hydrogen using light as energy source and anaerobic bacteria that produce hydrogen via dark fermentation. Dark fermentative hydrogen production by anaerobic bacteria has the advantages of a higher HPR without illumination and of the capability to convert various kinds of substrate. Results: Thermophilic hydrogen producer was isolated from elephant dung and identified as Thermoanaerobacterium thermosaccharolyticum KKU-ED1 by 16S rRNA gene analysis, which was further used to produce hydrogen from mixed pentose sugar i.e., xylose/arabinose. The optimum conditions for hydrogen production from mixed xylose/arabinose by... |
| Tipo: Journal article |
Palavras-chave: Arabinose; Biohydrogen; Elephant dung; Hydrolysate; Thermophilic; Xylose. |
| Ano: 2013 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582013000100001 |
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| Montealegre,Jaime; Valderrama,Luis; Sánchez,Soledad; Herrera,Rodrigo; Besoain,Ximena; Pérez,Luz María. |
| Biocontrol of Rhizoctonia solani in tomatoes cultivated under greenhouse and field conditions was analyzed using the Trichoderma harzianum mutants Th650-NG7, Th11A80.1, Th12A40.1, Th12C40.1 and Th12A10.1 and ThF2-1, respectively. Their innocuousness on tomato cultivars 92.95 and Gondola (greenhouse assays), and on cultivar Fortaleza (field assays) was established. Alginate pellets (1.7 g pellets/L soil) containing c.a1 x 10(5) colony forming units (cfu)/g pellet were applied to a soil previously inoculated with R. solani at transplant (greenhouse) or to a naturally infected soil (field). Controls considered parental wild strains, a chemical fungicide and no additions. Th11A 80.1, Th12A10.1 and Th650-NG7 prevented the 100% mortality of tomato plants cv.... |
| Tipo: Journal article |
Palavras-chave: Bioantagonism; Field assays; Greenhouse assays; Root rot; Tomato. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000200001 |
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| Vergara-Fernández,Alberto O; Quiroz,Erich F; Aroca,Germán E; Alarcón Pulido,Nelson A. |
| In this work the variation in the toluene elimination capacity of an airlift bioreactor as a function of the toluene inlet load, using compost as the support material for the microorganisms was studied. In order to evaluate the flexibility of the reactor under changing toluene load, the toluene biodegradation was measured for flows from 2.4 x 10-2 to 0.132 m³ h-1, and a concentration range from 1.4 to 0.8 g m-3. Results show a 100% removal efficiency (RE) for minor flows, however, for a flow increase of 450% the RE decreased 40%, reflecting the equipments weak flexibility in varying flows. Meanwhile the maximum elimination capacity obtained was 230 g m-3 h-1, for toluene loads of 550 g m-3 h-1, corresponding to a flow of 0.132 m³ h-1. It was found that a... |
| Tipo: Journal article |
Palavras-chave: Airlift bioreactors; Biofiltration; Bioscrubbers; Toluene. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000400003 |
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| Biological warfare is the intentional use of micro-organisms, and toxins, generally of microbial, plant or animal origin to produce disease and death in humans, livestock and crops. The attraction of bioweapons in war, and for use in terroristic attacks is attributed to easy access to a wide range of disease-producing biological agents, to their low production costs, to their non-detection by routine security systems, and to their easy transportation from one place to another. In addition, novel and accessible technologies give rise to proliferation of such weapons that have implications for regional and global security. In counteraction of such threats, and in securing the culture and defence of peace, the need for leadership and example in devising... |
| Tipo: Journal article |
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| Ano: 1999 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34581999000300001 |
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| Cauerhff,Ana; Castro,Guillermo R. |
| Background: In the past decade, considerable attention has been paid for the development of novel strategies for the synthesis of different kind of nano-objects. Most of the current strategies are usually working by the use physical or chemical principles to develop a myriad of nano-objects with multiple applications. Main fields of nanotechnology applications range from catalysis, micro- and nano-electronics (semiconductors, single electrons transistors), non-linear optic devices, photo-electrochemistry to biomedicine, diagnostics, foods and environment, chemical analysis and others. Results: Two main avenues for nanoparticles synthesis: cell-free extract and cell cultivation have been reported. The state of art of both biotechnological approaches for... |
| Tipo: Journal article |
Palavras-chave: Bacteria; Bionanoparticles; Fermentation; Fungi green chemistry; Plant extracts. |
| Ano: 2013 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582013000300011 |
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| Odisi,Estácio Jussie; Silvestrin,Marcela Bruschi; Takahashi,Rodrigo Yoji Uwamori; da Silva,Marcus Adonai Castro; Lima,André Oliveira de Souza. |
| Background: Cellulases and lipases have broad industrial application, which calls for an urgent exploration of microorganisms from extreme environments as valuable source of commercial enzyme. In this context, the present work describes the bioprospection and identification of deep-sea bacteria that produce cellulases and lipases, as well their optimal temperature of activity. Results: The first step of this study was the screening of cellulolytic and lipolytic deep-sea bacteria from sediment and water column, which was conducted with substrates linked with 4-Methylumbelliferyl. Among the 161 strains evaluated, 40 were cellulolytic, 23 were lipolytic and 5 exhibited both activities. Cellulolytic and lipolytic bacteria are more common in sediment than at... |
| Tipo: Journal article |
Palavras-chave: Bacteria; Cellulases; Deep-sea; Lipases. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582012000500018 |
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| Registros recuperados: 978 | |
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