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Sena D'Anna L.,Fundacion Institute Estudios Avanzados IDEA | De Sisto A.,Fundacion Institute Estudios Avanzados IDEA | Duque Z.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit | Rojas D.,Fundacion Institute Estudios Avanzados IDEA | Naranjo L.,Fundacion Institute Estudios Avanzados IDEA
Acta Microscopica | Year: 2013

Arthrospira sp is a filamentous cyanobacterium that has biotechnological importance due to its high protein content and bioactive elements used in the industry.The difficult elimination of bacteria that cohabit with Arthrospira sp. indicates that they could be attached to the surface of the filaments or embedded in the mucilaginous cover of Arthrospira sp., and deterioration of axenic cultures of Arthrospira sp. could imply that these cohabitant bacteria are important for Arthrospira sp. subsistence. In this paper, we use Scanning Electron Microscopy (SEM) to determine the morphology and location of cohabitant bacteria with Arthrospira sp. Lefevre 1963/M-132-1 strain. Cultivable bacteria were obtained from Arthrospira sp. cultures previously washed by filtration (AO sterile culture medium), treated at pH 12 for 72 hours (physic-chemical treatment), and observed (sampled) at two different times: one week after the physic-chemical treatment, and two months after the physic-chemical treatment. The micrographs evidenced that the morphologies of five (5) cultivable isolated bacteria match with the morphology of their molecular identification: Bacillus sp. AP1 (rod-shaped), Halomonas desiderata (rod-shaped), Indibacter alkaliphilus (rod-shaped), Rhodobaca bogoriensis (spherical) and Bacillus akibai (rod-shaped). The SEM of Arthrospira sp. culture gave the following results: in T1 we observed in the culture a pedunculated ovoid bacterial morphology that does not match any of the cultivable bacteria, implying that it is an uncultivable bacterium. The Arthrospira sp. culture observed in T2 effectively showed that the cohabitant bacteria get attached to the surface of the filaments or embedded in the mucilaginous cover of the cyanobacterium. Source


Gonzalez M.,Venezuelan Institute for Scientific Research | Alvarado Y.,Venezuelan Institute for Scientific Research | Restrepo J.,Venezuelan Institute for Scientific Research | Bruno-Colmenarez J.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit
Avances en Quimica | Year: 2013

The title compound, (E)-2-(4-methoxybenzylidene)-1-(2-nitrophenyl)hydrazine (I), C14H13N3O3, has been synthesized and characterized by IR and NMR spectroscopy, and X-ray diffraction. The compound crystallizes in the monoclinic system, space group P21/c, with unit-cell parameters a=12.7671(18)Å, b= 5.3718(7)Å, c= 19.887(3)Å, β=104.138(4), V=1322.6(3)Å3. Compound 1 shows two intermolecular hydrogen bonds patterns which are described by the graph set symbol R22(12) and R12(6). The molecules are stacked alternately along the b -axis through N3-O2···Cg (1) interactions. Source


Salcedo J.G.,University of Sucre | Rios J.M.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit | Ferrer A.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit | Lopez J.E.,University of Valle | And 2 more authors.
Acta Microscopica | Year: 2013

Lignocellulosic materials account for about 71% of the total biomass in the planet. Given their abundance, they are being considered as a potential feedstock for bioethanol production which can reduce the use of fossil fuel consumption. An alternative is the use of leaves and buds which are crop residues from sugar cane, and can be converted into ethanol by pretreatment, hydrolysis and fermentation. In this study, we evaluated the effect of two delignification pretreatments, enzymatic and organosolv of four substrates (S1: untreated, S2: enzymatic treatment, S3: organosolv and S4: organosolv followed by alkaline bleaching) on the crystallinity and sugars production by enzymatic hydrolysis measured as crystallinity index (CrI), relative intensity number (Ir), global hydrolysis rate (IGS) and ultrastructural changes, by means of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction and scanning electron microscopy (SEM). The results showed that substrates with the lowest residual lignin content and Kappa number, have the highest CrI and IGS values, showing that changes in the crystalline structure of cellulose as well as delignification enhance enzymatic hydrolysis. SEM micrographs of substrates S2 and S3 show slight surface modifications with respect to S1, while destruction of the substrate cell walls and great defibrillation, typical of a large delignification, validated by the FTIR spectra, are observed in S4. Source


De Sisto A.,Fundacion Institute Estudios Avanzados IDEA | Duque Z.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit | Garcia D.,Fundacion Institute Estudios Avanzados IDEA | Garcia D.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit | Naranjo Briceno L.,Fundacion Institute Estudios Avanzados IDEA
Acta Microscopica | Year: 2013

Bacterial corrosion is recognized as a worldwide problem that affects different industries. In oil industries, 40% of the internal damage in transporting pipeline distribution is attributed to microbially-induced corrosion. Several studies have been focused on anaerobic corrosion influenced by sulfate-reducing bacteria and few advances related to the MIC by aerobic microorganisms have been described. In this study, two aerobic bacterial strains isolated from naphtha distribution system of Venezuelan Oil Industries with corrosion damage were tested using Scanning Electron Microscope in order to determine their morphological characteristics and their possible corrosivity on coupons steel surfaces API 5L. Morphological analysis allowed to discriminate that bacterial strains have different morphotypes (cocco and bacilli). The fluorescence microscopy quantification revealed the same sessile cell density values for the both strains. MEB analysis on the metal surface allowed to detect opposed effect produced by the bacterial strains: bacilli type strain generated a protective effect while the cocco type strain did not inhibit corrosion. Instead, in the presence or absence of the cocco type strain, localized corrosion (pitting) like control were obtained, suggesting the prevalence of abiotic corrosion in the condition studied. The results obtained are discussed. Source


Alciaturi C.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit | Alciaturi C.,University of Zulia | Escobar M.,University of Zulia | Esteves I.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit | Duque Z.,Fundacion Instituto Zuliano Of Investigaciones Tecnologicas Inzit
Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia | Year: 2010

Chemometrics has been defined as "The discipline that uses mathematical and statistical methods for selection or design of optimal experimental conditions, and to provide relevant information from chemical data". This is an area of intense activity, with ample applications in the chemical, energy, and process industry, and in environmental studies. The fast progress in its applications has received impulse from the advances in electronics and computers, which have made possible the acquisition, transmission and processing of data with great efficiency. This paper explains the advantages provided by coupling chemometrics with process analytical chemistry (PAT). Some examples are presented of the use of chemometric methods for material characterization, detection of deviations, process optimization, and instrumental data interpretation. Source

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