RESUMO
Statistical experimental designs were used to formulate a culture medium for zeaxanthin production by an Antarctic Flavobacterium sp. P8 strain. Eleven nutritional factors were assayed in shaken flasks. The effect of temperature on zeaxanthin and carotenoid production was also studied. Peptone, yeast extract, and sodium chloride were the nutrients that caused the principal impact on the biomass growth. These components were further studied to enhance zeaxanthin and total carotenoid concentrations. Although a high production rate of zeaxanthin and carotenoids was achieved, the aerobic characteristics of the bacterial strain and the oxygen requirements for zeaxanthin biosynthesis incorporate a factor that requires additional consideration. Scaling up the process to a 5â¯L-bioreactor that increased dissolved oxygen availability resulted in a 4.5-fold increase in the total carotenoid content and an almost 9-fold increase in zeaxanthin, which represented 98% of the total carotenoids produced. The results reveal that Flavobacterium sp. P8 is a promising strain for zeaxanthin production.
Assuntos
Reatores Biológicos/microbiologia , Flavobacterium/metabolismo , Zeaxantinas , Carotenoides/análise , Carotenoides/metabolismo , Meios de Cultura/química , Meios de Cultura/metabolismo , Temperatura , Zeaxantinas/análise , Zeaxantinas/metabolismoRESUMO
Flavobacterium sp. AUG42 is a cellulase-producing bacterium isolated from the Antarctic oligochaete Grania sp. (Annelida). In this work, we report that AUG42 produces a glycoside hydrolase cocktail with CMCase, PASCase and cellobiase activities (optimum pHs and temperatures ranging from 5.5 to 6.5 and 40 to 50 °C, respectively). The time-course analyses of the bacterial growth and cellulase production showed that the cocktail has maximal activity at the stationary phase when growing at 16 °C with filter paper as a cellulosic carbon source, among the tested substrates. The analyses of the CAZome and the identification of secreted proteins by shotgun Mass Spectrometry analysis showed that five glycoside hydrolyses are present in the bacterial secretome, which probably cooperate in the degradation of the cellulosic substrates. Two of these glycoside hydrolyses may harbor putative carbohydrate binding modules, both with a cleft-like active site. The cellulolytic cocktail was assayed in saccharification experiments using carboxymethylcellulose as a substrate and results showed the release of glucose (a fermentable sugar) and other reducing-sugars, after 24 h incubation. The ecological relevance of producing cellulases in the Antarctic environment, as well as their potential use in the bio-refinery industry, are discussed.
Assuntos
Celulases/biossíntese , Celulases/química , Flavobacterium/enzimologia , Flavobacterium/metabolismo , Regiões Antárticas , Sequência de Bases , Carbono/metabolismo , Ciclo do Carbono , Carboximetilcelulose Sódica/metabolismo , Domínio Catalítico , Celulase , Celulases/genética , Celulose , Ensaios Enzimáticos , Fermentação , Flavobacterium/genética , Flavobacterium/crescimento & desenvolvimento , Glucose/metabolismo , Glicosídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , Especificidade por Substrato , Temperatura , beta-Glucosidase/metabolismoRESUMO
Ornithine lipids (OLs) are phosphorus-free membrane lipids that can be formed by many bacteria but that are absent from archaea and eukaryotes. A function for OLs in stress conditions and in host-bacteria interactions has been shown in some bacteria. Some bacterial species have been described that can form OLs, but lack the known genes (olsBA) involved in its biosynthesis, which implied the existence of a second pathway. Here we describe the bifunctional protein OlsF from Serratia proteamaculans involved in OL formation. Expression of OlsF and its homologue from Flavobacterium johnsoniae in Escherichia coli causes OL formation. Deletion of OlsF in S. proteamaculans caused the absence of OL formation. Homologues of OlsF are widely distributed among γ-, δ- and ε-Proteobacteria and in the Cytophaga-Flavobacterium-Bacteroidetes group of bacteria, including several well-studied pathogens for which the presence of OLs has not been suspected, such as for example Vibrio cholerae and Klebsiella pneumonia. Using genomic data, we predict that about 50% of bacterial species can form OLs.
Assuntos
Aciltransferases/metabolismo , Lipídeos/genética , Lipídeos de Membrana/metabolismo , Ornitina/análogos & derivados , Serratia/enzimologia , Bacteroidetes/metabolismo , Cytophaga/metabolismo , Flavobacterium/metabolismo , Deleção de Genes , Lipídeos/biossíntese , Ornitina/biossíntese , Ornitina/genética , Proteobactérias/metabolismo , Serratia/metabolismoRESUMO
Thirty nine isolates of Flavobacterium columnare from Brazilian fish farms had their carbohydrate composition of EPS evaluated by high efficiency liquid chromatography, using the phenol-sulfuric acid method of EPS. The occurrence of capsules on F. columnare cells was not directly related to biofilm formation, and the predominant monosaccharide is glucose.
Assuntos
Animais , Peixes/microbiologia , Flavobacterium/isolamento & purificação , Flavobacterium/metabolismo , Monossacarídeos/análise , Polissacarídeos Bacterianos/química , Brasil , Cromatografia LíquidaRESUMO
Thirty nine isolates of Flavobacterium columnare from Brazilian fish farms had their carbohydrate composition of EPS evaluated by high efficiency liquid chromatography, using the phenol-sulfuric acid method of EPS. The occurrence of capsules on F. columnare cells was not directly related to biofilm formation, and the predominant monosaccharide is glucose.
Assuntos
Peixes/microbiologia , Flavobacterium/isolamento & purificação , Flavobacterium/metabolismo , Monossacarídeos/análise , Polissacarídeos Bacterianos/química , Animais , Brasil , Cromatografia LíquidaRESUMO
Three Gram-staining-negative non-endospore-forming strains were isolated from farmed fish in Chile: one (LM-09-Fp(T)) from a rainbow trout (Oncorhynchus mykiss) and the others (LM-19-Fp(T) and LM-20-Fp) from two Atlantic salmon (Salmo salar). Phylogenetic analyses based on 16S rRNA gene sequences indicated that all three isolates belonged to the genus Flavobacterium. In these analyses, strain LM-09-Fp(T) appeared most closely related to the type strains of Flavobacterium chungangense (98.5 % sequence similarity), Flavobacterium glaciei (98.2 %), Flavobacterium aquidurense (97.6 %), Flavobacterium saccharophilum (97.6 %) and Flavobacterium hercynium (97.6 %). The 16S rRNA gene sequences of strains LM-19-Fp(T) and LM-20-Fp were found to be identical and most similar to the corresponding sequences of the type strains of Flavobacterium aquidurense (98.6 %), Flavobacterium frigidimaris (98.5 %), Flavobacterium hercynium (97.9 %), Flavobacterium saccharophilum (97.7 %) and Flavobacterium pectinovorum (97.7 %). For each of the three novel strains, menaquinone (MK-6) was the predominant respiratory quinone and the major compounds in the polar lipid profile were phosphatidylethanolamine, an unidentified aminolipid, phosphatidylserine and two or three unknown lipids. The fatty acid profile of each strain, which comprised major amounts of iso-C(15:0), C(15:0) and summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH) as well as smaller amounts of various hydroxylated fatty acids (e.g. iso-C(16:0) 3-OH, iso-C(17:0) 3-OH, C(16:0) 3-OH and C(15:0) 3-OH), indicated that each belonged to the genus Flavobacterium. Based on their physiological and biochemical characteristics and the results of DNA-DNA hybridizations, which showed relatively low levels of relatedness between the novel strains and the most closely related Flavobacterium species, strain LM-09-Fp(T) ( = LMG 26360(T) = CCM 7940(T)) represents a novel species within the genus Flavobacterium, for which the name Flavobacterium chilense sp. nov. is proposed, and strains LM-19-Fp(T) ( = LMG 26359(T) = CCM 7939(T)) and LM-20-Fp ( = LMG 26331) represent a second novel species within the same genus, for which the name Flavobacterium araucananum sp. nov. is proposed.
Assuntos
Doenças dos Peixes/microbiologia , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/classificação , Flavobacterium/isolamento & purificação , Oncorhynchus mykiss/microbiologia , Animais , Chile , DNA Bacteriano/genética , Ácidos Graxos/metabolismo , Infecções por Flavobacteriaceae/microbiologia , Flavobacterium/genética , Flavobacterium/metabolismo , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
Surfactants and inorganic ligands are pointed as efficient to simultaneous removal of heavy metals and hydrophobic organic pollutants from soil. However, the biosurfactants are potentially less toxic to soil organisms than other chemical agents. Thus, in this study the efficiency of combinations of iodide (I(-)) ligand and surfactants produced by different bacterial species in the simultaneous removal of cadmium (Cd(2+)) and phenanthrene in a Haplustox soil sample was investigated. Four microbial surfactants and the synthetic surfactant Triton X-100 were tested with different concentrations of ligand. Soil samples contaminated with Cd(2+) and phenanthrene underwent consecutive washings with a surfactant/ligand solution. The removal of Cd(2+) increased with increased ligand concentration, particularly in solutions containing biosurfactants produced by the bacterial strains Bacillus subtilis LBBMA155 (lipopeptide) and Flavobacterium sp. LBBMA168 (mixture of flavolipids) and Triton X-100. Maximum Cd(2+) removal efficiency was 99.2% for biosurfactant produced by Arthrobacter oxydans LBBMA 201 (lipopeptide) and 99.2% for biosurfactant produced by Bacillus sp. LBBMA111A (mixed lipopeptide) in the presence of 0.336 mol iodide l(-1), while the maximum efficiency of Triton X-100 removal was 65.0%. The biosurfactant solutions removed from 80 to 88.0% of phenanthrene in soil, and the removal was not influenced by the presence of the ligand. Triton X-100 removed from 73 to 88% of the phenanthrene and, differently from the biosurfactants, iodide influenced the removal efficiency. The results indicate that the use of a single washing agent, called surfactant-ligand, affords simultaneous removal of organic contaminants and heavy metals.
Assuntos
Bacillus subtilis/metabolismo , Cádmio/metabolismo , Recuperação e Remediação Ambiental/métodos , Flavobacterium/metabolismo , Fenantrenos/metabolismo , Poluentes do Solo/metabolismo , Tensoativos/química , Biodegradação Ambiental , Iodetos/química , Octoxinol/química , Microbiologia do SoloRESUMO
Prospective sampling activities of intertidal invertebrates in the Ancon Bay (Lima, Peru) were done in order to select marine bacteria producing antimicrobial substances. The study included the isolation of bacteria in marine agar, in vitro antimicrobial susceptibility testing and electronic microscopic observations. We report the isolation, phenotypical characterization and antimicrobial properties of 10 strains of marine bacteria including the genus Vibrio, Pseudomonas, and Flavobacterium, and the order Actinomycetae that inhibit human pathogens. The results indicate that the marine invertebrates would be sources of bacteria producing antibiotic substances.
Assuntos
Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Antibacterianos/biossíntese , Flavobacterium/isolamento & purificação , Flavobacterium/metabolismo , Invertebrados/microbiologia , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Vibrio/isolamento & purificação , Vibrio/metabolismo , Animais , Testes de Sensibilidade Microbiana , Peru , Ondas de MaréRESUMO
Heap leaching is an effective and widely used method of recovering metals from low-grade ores. However, the heap leaching technique has not yet been used in other biotechnological processes such as bioremediation. This work describes biostimulation of the native microbial consortium as a novel application of the heap leaching technique to bioremediate mining soils contaminated with hydrocarbons. Microorganisms present in the polluted soil were isolated in a liquid mineral solution using diesel fuel as the sole energy and carbon source. Biodegradation activity was evaluated and two genera, Flavobacterium and Aspergillus, were identified as the primary microorganisms that degraded hydrocarbons in the polluted soil. In order to simulate the heap leaching process on a laboratory scale, using both columns and piles, the contaminated soil was mixed with different sand concentrations and was agglomerated before it was used. Three flow rates, of the mineral solution, were evaluated. Of the rates tested, biodegradation was most efficient at a flow rate of 200 ml h(-1). The heap leaching technique demonstrated good efficiency in the column and pile, with a 2% soil-sand mixture lowering the TPH concentration from 61,000 to 1800 mg kg(-1) (98.5%) in 15 d.
Assuntos
Aspergillus/metabolismo , Biodegradação Ambiental , Flavobacterium/metabolismo , Hidrocarbonetos/metabolismo , Poluentes do Solo/metabolismo , Reatores Biológicos , Hidrocarbonetos/química , Mineração , Poluentes do Solo/química , Fatores de TempoRESUMO
Metallo-beta-lactamases (MbetaLs) are zinc-dependent enzymes able to hydrolyze and inactivate most beta-lactam antibiotics. The large diversity of active site structures and metal content among MbetaLs from different sources has limited the design of a pan-MbetaL inhibitor. Here we report the biochemical and biophysical characterization of a novel MbetaL, GOB-18, from a clinical isolate of a Gram-negative opportunistic pathogen, Elizabethkingia meningoseptica. Different spectroscopic techniques, three-dimensional modeling, and mutagenesis experiments, reveal that the Zn(II) ion is bound to Asp120, His121, His263, and a solvent molecule, i.e. in the canonical Zn2 site of dinuclear MbetaLs. Contrasting all other related MbetaLs, GOB-18 is fully active against a broad range of beta-lactam substrates using a single Zn(II) ion in this site. These data further enlarge the structural diversity of MbetaLs.
Assuntos
Zinco/química , beta-Lactamases/fisiologia , Sítios de Ligação , Clonagem Molecular , DNA/química , Flavobacterium/metabolismo , Vetores Genéticos , Hidrólise , Concentração Inibidora 50 , Cinética , Modelos Químicos , Dados de Sequência Molecular , Mutagênese , Mutagênese Sítio-Dirigida , Espectrofotometria , beta-Lactamases/química , beta-Lactamases/metabolismoRESUMO
Marigold flowers are the main natural source of xanthophylls, and marigold saponified extract is used as an additive in several food and pharmaceutical industries. In this work, the use of a solid-state fermentation (ensilage) process for increasing the yield of xanthophylls extracted from fermented marigold flowers was examined. The process consisted of a mixed culture of three microorganisms (Flavobacterium IIb, Acinetobacter anitratus, and Rhizopus nigricans), part of the normal microbiota associated with the marigold flower. These microorganisms had been previously isolated, and were identified as relevant for the ensilage process due to their capacity to produce cellulolytic enzymes. Based on experimental design strategies, optimum operation values were determined for aeration, moisture, agitation, and marigold-to-inoculum ratio in the proposed solid-state fermentation equipment, leading to a xanthophylls yield of 17.8-g/kg dry weight. The optimum achieved represents a 65% increase with respect to the control. HPLC analysis indicated conservation of extracted oleoresin. Based on the experimental results, interactions were identified that could be associated with the heat and mass-transfer reactions taking place within the bioreactor. The insight gained allows conditions that limit growth and metabolic activity to be avoided.
Assuntos
Biotecnologia/métodos , Extratos Vegetais/isolamento & purificação , Tagetes/química , Xantofilas/isolamento & purificação , Acinetobacter/crescimento & desenvolvimento , Acinetobacter/isolamento & purificação , Acinetobacter/metabolismo , Reatores Biológicos , Fermentação , Flavobacterium/crescimento & desenvolvimento , Flavobacterium/isolamento & purificação , Flavobacterium/metabolismo , Extratos Vegetais/química , Rhizopus/crescimento & desenvolvimento , Rhizopus/isolamento & purificação , Rhizopus/metabolismo , Tagetes/microbiologia , Xantofilas/análiseRESUMO
A Flavobacterium sp. producing a high keratinolytic activity was isolated from a poultry industry after growth on selective feather meal agar. This bacterium grew on feather meal broth, producing keratinase, and was also capable of complete degradation of raw feathers. The proteolytic activity was assessed in the presence of specific protease inhibitors. The crude enzyme showed mainly metalloprotease character. This novel isolate would have potential biotechnological use in processes involving keratin hydrolysis.
Assuntos
Plumas/metabolismo , Flavobacterium/metabolismo , Queratinas/metabolismo , Animais , Biodegradação Ambiental , Biotecnologia , Flavobacterium/isolamento & purificação , Microbiologia Industrial , Carne , Peptídeo Hidrolases/biossíntese , Aves DomésticasRESUMO
An experiment was carried out in order to evaluate the effect of pH on Azospirillum sp. growth and survival in maize rhizosphere. Sterilized maize seeds were sown in a perlite substratum with addition of a nutritive medium. The pots were buffered at two different pHs: 5.8 (group one) and 7.0 (group two). Each group was divided in two treatments: inoculated with Azospirillum sp. Az-39 and non-inoculated. Experimental pots were incubated at 20 degrees C with a 14 hour photoperiod. Growth of non-inoculated roots was negligible. Inoculated roots showed a better response at pH 5.8 than at 7.0. Several accompanying bacteria were found. Azospirillum grew in both groups with a low penetration into roots. A set of nutritive relationships among microorganisms and maize roots was observed; Xanthomonas is a maize pathogenic bacteria, and it is a NO3- consumer, and uses this anion as hydrogen acceptor. The Gram (-) Diplococcus is a nitrate producer . Cytophaga and Flavobacterium are related with roots decomposition. It is concluded that Azospirillum improves the root growth, mainly at pH 5.8.
Assuntos
Azospirillum/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Microbiologia do Solo , Zea mays/microbiologia , Cytophaga/metabolismo , Flavobacterium/metabolismo , Nitratos/metabolismo , Raízes de Plantas/microbiologia , Simbiose , Xanthomonas/metabolismoRESUMO
1. This paper reports the structural analysis of proteoglycans and mucopolysaccharides extracted from a human multiple enchondroma (enchondromatosis), a benign cartilage tumor, where growth, but no calcification takes place. The tumors were located inside the phalanges of both hands of a 22-year-old patient and were obtained after surgery. 2. The proteoglycans of chondromas contain only a small amount of keratan sulfate (1.3% of total mucopolysaccharide) and the chondroitin sulfate is composed of 4- and 6-sulfated disaccharide units in approximately equivalent amounts, forming hybrid polymeric chains. Furthermore, the electrophoretic mobility of these proteoglycans in agarose-polyacrylamide large-pore gel indicates that they may occur as a single polydisperse component. This structural pattern is very similar to that of the proteoglycans present in the articular cartilage of normal human newborn and young. In contrast, the proteoglycans of adult articular cartilage contain higher amounts of keratan sulfate (25% of the total mucopolysaccharide) and very small amounts of 4-sulfated disaccharide units (7%) in the chondroitin sulfate molecules. The multiple zones observed in agarose/polyacrylamide large-pore gel electrophoresis indicate the presence of more than one polydisperse component. These findings suggest a correlation between the structural characteristics of the proteoglycans and the occurrence of growth in the cartilage tissue. 3. Although the amounts of proteoglycans extractable from chondromas and from normal young and adult articular cartilages were almost the same, the chondroma proteoglycans interacted with hyaluronic acid to a lesser extent than those from the normal cartilages. This effect may be due to structural changes in the hyaluronic acid-binding region of the proteoglycan monomers.