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1.
Front Microbiol ; 13: 923038, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35756030

RESUMO

Parageobacillus thermantarcticus strain M1 is a Gram-positive, motile, facultative anaerobic, spore forming, and thermophilic bacterium, isolated from geothermal soil of the crater of Mount Melbourne (74°22' S, 164°40' E) during the Italian Antarctic Expedition occurred in Austral summer 1986-1987. Strain M1 demonstrated great biotechnological and industrial potential owing to its ability to produce exopolysaccharides (EPSs), ethanol and thermostable extracellular enzymes, such as an xylanase and a ß-xylosidase, and intracellular ones, such as xylose/glucose isomerase and protease. Furthermore, recent studies revealed its high potential in green chemistry due to its use in residual biomass transformation/valorization and as an appropriate model for microbial astrobiology studies. In the present study, using a systems-based approach, genomic analysis of P. thermantarcticus M1 was carried out to enlighten its functional characteristics. The elucidation of whole-genome organization of this thermophilic cell factory increased our understanding of biological mechanisms and pathways, by providing valuable information on the essential genes related to the biosynthesis of nucleotide sugar precursors, monosaccharide unit assembly, as well as the production of EPSs and ethanol. In addition, gene prediction and genome annotation studies identified genes encoding xylanolytic enzymes that are required for the conversion of lignocellulosic materials to high-value added molecules. Our findings pointed out the significant potential of strain M1 in various biotechnological and industrial applications considering its capacity to produce EPSs, ethanol and thermostable enzymes via the utilization of lignocellulosic waste materials.

2.
Extremophiles ; 15(2): 213-20, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21287211

RESUMO

A novel haloalkaliphilic, facultative anaerobic and Gram-negative Salinivibrio-like microorganism (designated strain BAG(T)) was recovered from a saline lake in Ras Mohammed Park (Egypt). Cells were motile, curved rods, not spore-forming and occurred singly. Strain BAG(T) grew optimally at 35°C (temperature growth range 25-40°C) with 10.0% (w/v) NaCl [NaCl growth range 6.0-16.0% (w/v)] and at pH 9.0 (pH growth range 6.0-10.0). Strain BAG(T) had phosphatidylethanolamine (PEA) and phosphatidylglycerol (PG) as the main polar lipids, C16:0 (54.0%) and C16:1 (26.0%) as the predominant cellular fatty acids and Q-8 as the major respiratory quinone. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BAG(T) was a member of Salinivibrio genus, with the highest sequence similarities of 99.1, 98.4 and 98.1% to Salinivibrio siamensis JCM 14472(T), Salinivibrio proteolyticus DSM 19052(T) and Salinivibrio costicola subsp. alcaliphilus DSM 16359(T), respectively. DNA-DNA hybridization values of strain BAG(T) with members of Salinivibrio genus were lower than 55.0%. DNA G + C content was 51.0 mol%. On the basis of the polyphasic taxonomic results revealed in this study, strain BAG(T) should be classified as a novel species of Salinivibrio genus, for which the name Salinivibrio sharmensis sp. nov. is proposed, with the type strain BAG(T) (=ATCC BAA-1319(T) = DSM 18182(T)).


Assuntos
Vibrionaceae/genética , Carboidratos/química , DNA/química , DNA/genética , Concentração de Íons de Hidrogênio , Lipídeos/química , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fosfatidiletanolaminas/química , Fosfatidilgliceróis/química , Filogenia , Quinonas/química , RNA Ribossômico 16S/genética , Cloreto de Sódio/química , Temperatura , Microbiologia da Água
3.
Extremophiles ; 14(2): 233-40, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20155430

RESUMO

A novel thermophilic, anaerobic, rod-shaped bacterium strain, designated Buff, was isolated from buffalo-dung samples collected from a buffalo-farm located in Caserta (Campania, south of Italy). Strain Buff was Gram-positive, motile and no spore-forming. The growth temperature range was 40-65 degrees C with an optimum at 60 degrees C, while pH growth range at 60 degrees C was 5.5-8.0 with an optimum at about pH 6.5. NaCl growth concentration ranged from 0 to 2.0% with an optimum at 0.5% (w/v); no growth was observed with the presence of NaCl 3.0% (w/v). The strain produced ethanol, acetate, lactate, H(2), H(2)S and CO(2) by glucose fermentation. The DNA G + C content was 34.4 mol%. As determined by 16S rRNA sequence analysis, this organism belonged to the genus Thermoanaerobacterium. On the basis of the physiological and molecular properties, we propose for strain Buff the new species designation Thermoanaerobacterium thermostercus sp. nov. This novel organism represents the first species of the genus Thermoanaerobacterium isolated from buffalo-dung. The type strain is Buff (=DSM 22141 = ATCC BAA-1776).


Assuntos
Búfalos/microbiologia , Thermoanaerobacterium/isolamento & purificação , Thermoanaerobacterium/metabolismo , Animais , Composição de Bases , DNA Bacteriano/química , DNA Bacteriano/genética , Fezes/microbiologia , Itália , Dados de Sequência Molecular , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Thermoanaerobacterium/classificação , Thermoanaerobacterium/genética
4.
Extremophiles ; 13(2): 345-54, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19125220

RESUMO

This is the first report describing the purification and enzymatic properties of a native invertase (beta-D-fructosidase) in Thermotogales. The invertase of the hydrogen-producing thermophilic bacterium Thermotoga neapolitana DSM 4359 (hereby named Tni) was a monomer of about 47 kDa having an amino acid sequence quite different from other invertases studied up to now. Its properties and substrates specificity let us classify this protein as a solute-binding protein with invertase activity. Tni was specific for the fructose moiety and the enzyme released fructose from sucrose and raffinose and the fructose polymer inulin was hydrolyzed in an endo-type fashion. Tni had an optimum temperature of 85 degrees C at pH 6.0. At temperatures of 80-85 degrees C, the enzyme retained at least 50% of its initial activity during a 6 h preincubation period. Tni had a K(m) and k(cat)/K(m) values (at 85 degrees C and pH 6.0) of about 14 mM and 5.2 x 10(8) M(-1) s(-1), respectively.


Assuntos
Thermotoga neapolitana/enzimologia , beta-Frutofuranosidase/química , Concentração de Íons de Hidrogênio , Hidrólise , Inulina/química , Íons , Cinética , Metais/química , Modelos Químicos , Polímeros/química , Especificidade por Substrato , Temperatura
5.
Biotechnol Biofuels ; 12: 22, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30740143

RESUMO

BACKGROUND: Due to its wide range of applications in the food, pharmaceutical and chemical fields, microbial synthesis of succinic acid is receiving growing attention, generating already relevant industrial results, as well as fueling constant research for improvements. In order to develop a sustainable process, a special focus is now set on the exploitation and conversion of lignocellulosic biomasses into platform chemicals. RESULTS: In the present work we used Basfia succiniciproducens BPP7 in separated hydrolysis and fermentation experiments with Arundo donax as starting material. Fed-batch strategies showed a maximal production of about 37 g/L of succinic acid after 43 h of growth and a productivity of 0.9 g/L h on the pilot scale. Global mass balance calculations demonstrated a hydrolysis and fermentation efficiency of about 75%. Moreover, the application of a material flow analysis showed the obtainment of 88.5 and 52 % of succinic acid, per kg of virgin biomass and on the total generated output, respectively. CONCLUSIONS: The use of fed-batch strategies for the growth of B. succiniciproducens on A. donax improved the titer and productivity of succinic acid on pre-pilot scale. Process evaluation through material flow analysis showed successful results and predicted a yield of succinic acid of about 30% in a fed-batch process that uses A. donax as only carbon source also in the feed. Preliminary considerations on the possibility to achieve an energetic valorization of the residual solid coming from the fermentation process were also carried out.

6.
Syst Appl Microbiol ; 30(1): 31-8, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16621401

RESUMO

The taxomony of strain CRSS (DSM 15686(T)=ATCC BAA-848(T)) isolated from Cape Russell in Antarctica (Ross Sea, 74 52.35 S 163 53.03 E) was investigated in a polyphasic approach. The morphological, physiological and genetic characteristics were compared with that of related species of the genus Halomonas. The isolate grew optimally at pH 9.0, 10% NaCl at 30 degrees C. The cells were Gram-negative aerobic rods able to produce exopolysaccharide. They accumulated glycine-betaine, as a major osmolyte, with minor components ectoine and glutamate. The strain CRSS biosynthetised alpha-glucosidase. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as major components. Ubiquinone with nine repetitive unities (Q9) was the only quinone found and the fatty acid composition was dominated by C18:1 (53%). The G+C content of DNA was 55.0mol% and its phylogenetic position was established by 16S rRNA gene sequencing as a member of the genus Halomonas. For physiological, chemotaxonomic and genetic features (DNA-DNA hybridisation) it is proposed to classify the isolate as a new species for which we propose the name Halomonas alkaliantarctica sp. nov.


Assuntos
Sedimentos Geológicos/microbiologia , Halomonas/classificação , Halomonas/fisiologia , Polissacarídeos Bacterianos/metabolismo , Regiões Antárticas , Composição de Bases , Biodiversidade , DNA Bacteriano/química , DNA Ribossômico/genética , Genes de RNAr , Halomonas/química , Halomonas/isolamento & purificação , Concentração de Íons de Hidrogênio , Lipídeos/análise , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Cloreto de Sódio/metabolismo
7.
Microorganisms ; 5(2)2017 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-28509857

RESUMO

Extreme marine environments have been the subject of many studies and scientific publications. For many years, these environmental niches, which are characterized by high or low temperatures, high-pressure, low pH, high salt concentrations and also two or more extreme parameters in combination, have been thought to be incompatible to any life forms. Thanks to new technologies such as metagenomics, it is now possible to detect life in most extreme environments. Starting from the discovery of deep sea hydrothermal vents up to the study of marine biodiversity, new microorganisms have been identified, and their potential uses in several applied fields have been outlined. Thermophile, halophile, alkalophile, psychrophile, piezophile and polyextremophile microorganisms have been isolated from these marine environments; they proliferate thanks to adaptation strategies involving diverse cellular metabolic mechanisms. Therefore, a vast number of new biomolecules such as enzymes, polymers and osmolytes from the inhabitant microbial community of the sea have been studied, and there is a growing interest in the potential returns of several industrial production processes concerning the pharmaceutical, medical, environmental and food fields.

8.
Res Microbiol ; 157(6): 531-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16797930

RESUMO

Species of Alicyclobacillus, Bacillus and Thermus genera were selected in order to study the possible presence of the (ADP-ribosyl)ation system. These bacteria are thermophilic, aerobic, and were isolated from different geothermal sources. Both activity and expression of (ADP-ribosyl)ating proteins were tested in cells at different growth phases, and evidence of an active system was obtained in all analyzed microorganisms, with comparable enzymatic levels. Immunochemical analyses with polyclonal antibodies against both eukaryotic anti-(ADP-ribose) transferase and anti-poly(ADP-ribose) polymerase revealed, for all tested organisms, an immunosignal localized in the range of molecular masses between 43-53 kD. Several proteins of various molecular masses were found as ADP-ribose acceptors. Reaction product analyses showed mono(ADP-ribose) to be the only synthesized compound.


Assuntos
ADP Ribose Transferases/metabolismo , Bactérias/enzimologia , Poli(ADP-Ribose) Polimerases/metabolismo , Adenosina Difosfato Ribose/metabolismo , Bacillus/enzimologia , Bacillus/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Ativação Enzimática , Thermus/enzimologia , Thermus/crescimento & desenvolvimento
9.
Syst Appl Microbiol ; 29(4): 300-7, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16682297

RESUMO

A new thermophilic spore-forming strain MR3CT was isolated from geothermal soil located on Mount Rittmann in Antarctica. Strain MR3CT was Gram-positive, rod-shaped, occurring in pairs or filamentous. Growth was observed between 45 and 65 degrees C (optimum 61 degrees C) and at pH 5.0-6.5 (optimum pH 5.6). It was capable of utilizing galactose, trehalose, maltose and sucrose. The microorganism produced an exopolysaccharide and synthesized an extracellular constitutive amylolytic activity. The G + C content of DNA was 43.5 mol%. On the basis of 16S rRNA gene sequence similarity, strain MR3CT was shown to be related most closely to Anoxybacillus species. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid-iso-C15:0 and iso-C17:0) supported the affiliation of strain MR3C1T to the genus Anoxybacillus. The results of DNA-DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain MR3CT from the validly published Anoxybacillus species. MR3CT therefore represents a new species, for which the name Anoxybacillus amylolyticus sp. nov., is proposed, with the type strain MR3CT (= ATCC BAA-872T = DSM 15939T = CIP 108338T).


Assuntos
Amilases/biossíntese , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/isolamento & purificação , Microbiologia do Solo , Regiões Antárticas , Composição de Bases , Metabolismo dos Carboidratos , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Ácidos Graxos/isolamento & purificação , Genes de RNAr/genética , Bactérias Gram-Positivas/citologia , Bactérias Gram-Positivas/fisiologia , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Filogenia , Polissacarídeos Bacterianos/biossíntese , Quinonas/análise , Quinonas/isolamento & purificação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Temperatura , Terpenos/análise
10.
J Gen Appl Microbiol ; 52(6): 339-48, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17325447

RESUMO

A halotolerant and alkaliphilic Gram-negative bacterium, strain 18bAG(T), that grows aerobically at the optimum temperature of 37 degrees C, and at pH 7.5-10 (optimum 9.0), was isolated from a salt pool located in Montefredane in Campania Region (South of Italy). The isolate tolerated high concentration of NaCl up to 20%. Strain 18bAG(T) accumulated osmolytes and polyhydroxybutyrate, produced exopolysaccharide and possessed alpha-glucosidase activity. The predominant respiratory quinones were ubiquinones, Q8 and Q6(6H); phosphoethanolamine, phosphatidylglycerol and diphosphatidylglycerol were the predominant polar lipids. Major fatty acids were C16 : 1, C16 : 0, and C18 : 0. On the basis of 16S rRNA gene sequence similarity, 18bAG(T) was shown to belong to Halomonas genus. Analysis of 16S rRNA gene revealed a high similarity of strain 18bAG(T) to Halomonas venusta (DSM 4743(T)) and Halomonas hydrothermalis (DSM 15725(T)). Level of DNA-DNA relatedness between strain 18bAG(T) and the most related species Halomonas venusta and Halomonas hydrothermalis was 56.0% and 41.2%, respectively. The G+C content (mol%) of DNA was 53.0. The RiboPrinting patterns of Halomonas venusta and 18AG(T) showed a pattern similarity of 0.50. On the basis of genomic information and phenotypic characteristics strain 18bAG(T) represents a new species, for which the name Halomonas alkaliphila sp. nov. is proposed. The type strain is 18bAG(T) (=DSM 16354T =ATCC BAA-953T).


Assuntos
Halomonas/classificação , Halomonas/isolamento & purificação , Microbiologia da Água , Aerobiose , Álcalis/química , Composição de Bases , Sequência de Bases , Metabolismo dos Carboidratos , DNA Ribossômico/análise , Halomonas/genética , Concentração de Íons de Hidrogênio , Hidroxibutiratos/metabolismo , Itália , Dados de Sequência Molecular , Filogenia , Polissacarídeos Bacterianos/metabolismo , RNA Ribossômico 16S/genética , Sais/toxicidade
11.
J Gen Appl Microbiol ; 52(4): 223-34, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17116971

RESUMO

A thermophilic, spore-forming bacterial strain L1(T) was isolated from hot compost "Pomigliano Environment" s.p.a., Pomigliano, Naples, Italy. The strain was identified by using a polyphasic taxonomic approach. L1(T) resulted in an aerobic, gram-positive, rod-shaped, thermophilic with an optimum growth temperature of 68 degrees C chemorganotrophic bacterium which grew on hydrocarbons as unique carbon and energy sources and was resistant to heavy metals. The G+C DNA content was 43.5 mol%. Phylogenetic analysis of 16S rRNA gene sequence and Random Amplified Polymorphic DNA-PCR (RAPD-PCR) analysis of L1(T) and related strains showed that it forms within Geobacillus toebii, a separate cluster in the Geobacillus genus. The composition of cellular fatty acids analyses by Gas-Mass Spectroscopy differed from that typical for the genus Geobacillus in that it is lacking in iso-C15 fatty acid, while iso-C16 and iso-C17 were predominant. Isolates grew on a rich complex medium at temperatures between 55-75 degrees C and presented a doubling time (t(d)) of 2 h and 6 h using complex media and hydrocarbon media, respectively. Among hydrocarbons tested, n-decane (2%) was the more effective to support the growth (1 g/L of wet cells). The microorganism showed resistance to heavy metal tested during the growth. Furthermore, intracellular alpha-galactosidase and alpha-glucosidase enzymatic activities were detectable in the L1(T) strain. Based on phenotypic, phylogenetic, fatty acid analysis and results from DNA-DNA hybridization, we propose assigning a novel subspecies of Geobacillus toebii, to be named Geobacillus toebii subsp. decanicus subsp. nov., with the type strain L1(T) (=DSM 17041=ATCC BAA 1004).


Assuntos
Bacillaceae/efeitos dos fármacos , Bacillaceae/metabolismo , Hidrocarbonetos/metabolismo , Metais Pesados/farmacologia , Solo , Bacillaceae/genética , Bacillaceae/isolamento & purificação , Ácidos Graxos/metabolismo , Filogenia , RNA Ribossômico 16S/metabolismo , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Microbiologia do Solo
12.
Bioresour Technol ; 222: 355-360, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27741473

RESUMO

In the present work the recently isolated strain Basfia succiniciproducens BPP7 was evaluated for the production of succinic acid up to the pilot fermentation scale in separate hydrolysis and fermentation experiments on Arundo donax, a non-food dedicated energy crop. An average concentration of about 17g/L of succinic acid and a yield on consumed sugars of 0.75mol/mol were obtained demonstrating strain potential for further process improvement. Small scale experiments indicated that the concentration of acetic acid in the medium is crucial to improve productivity; on the other hand, interestingly, short-term (24h) adaptation to higher acetic acid concentrations, and strain recovery, were also observed.


Assuntos
Microbiologia Industrial/métodos , Pasteurellaceae/metabolismo , Poaceae/química , Ácido Succínico/metabolismo , Ácido Acético , Anaerobiose , Meios de Cultura/química , Fermentação , Hidrólise , Projetos Piloto
13.
Res Microbiol ; 156(4): 478-84, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15862445

RESUMO

An extracellular protease produced at the end of the exponential growth phase was purified to homogeneity and characterized from the new isolate haloalkaliphilic strain 18AG, phylogenetically related to Salinivibrio costicola subsp. costicola. The protease molecular mass was about 38 kDa. The enzyme was dependent on salt concentration for activity and stability, and it showed optimal activity at 60 degrees C in the presence of 2.0% NaCl and 2.0 mM CaCl2, while in the absence of CaCl2 the optimum temperature was 50 degrees C. The enzyme was stable for 24 h at 30 degrees C, whereas at 50 degrees C in the presence of CaCl2 the half life was about 5 h. The enzyme had an optimum pH of 8.0 with 80% of residual activity at pH 9.0. The protease was strongly inhibited by phenylmethyl sulfonylfluoride (PMSF), slightly activated by denaturing agents such as SDS and urea, and partially inhibited by thiol-containing reducing agents. The synthesis of the enzyme in culture media was influenced by the medium composition: it was specifically dependent upon the NaCl concentration and was induced by the presence of gelatin.


Assuntos
Peptídeo Hidrolases/isolamento & purificação , Vibrionaceae/enzimologia , Meios de Cultura , Ativação Enzimática , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Peso Molecular , Peptídeo Hidrolases/química , Peptídeo Hidrolases/metabolismo , Inibidores de Proteases/farmacologia , Cloreto de Sódio , Especificidade por Substrato , Temperatura , Vibrionaceae/crescimento & desenvolvimento
14.
Syst Appl Microbiol ; 28(1): 34-42, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15709363

RESUMO

Phenotypic and phylogenetic studies were performed on unidentified Gram-negative staining, haloalkaliphilic aerobe and protease producer Salinivibrio-like organism recovered from a saltish spring with algal mat in the "Pozzo del Sale" site (Salt's Well) in the Campania Region (South Italy). Phylogenetic analysis based on comparison of 16S rRNA gene sequences demonstrated that the isolate was related to species of Salinivibrio genus. The DNA-DNA hybridization of the type strain 18AG(T) with the most related Salinivibrio costicola subsp. costicola showed a reassociation value of 72%. Based on the phenotypic distinctiveness of 18AG(T) strain and molecular, chemical and genetic evidence, it is proposed that strain 18AG(T) can be classified as S. costicola subsp. alcaliphilus, subsp. nov. The type strain of S. costicola subsp. alcaliphilus, is ATCC BAA-952(T); DSM 16359(T).


Assuntos
Vibrionaceae/classificação , Microbiologia da Água , Aerobiose , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , Genes de RNAr , Violeta Genciana , Itália , Lipídeos/análise , Lipídeos/isolamento & purificação , Dados de Sequência Molecular , Movimento , Hibridização de Ácido Nucleico , Peptídeo Hidrolases/biossíntese , Fenazinas , Filogenia , Quinonas/análise , Quinonas/isolamento & purificação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio/farmacologia , Vibrionaceae/citologia , Vibrionaceae/isolamento & purificação , Vibrionaceae/fisiologia
15.
Syst Appl Microbiol ; 28(7): 610-8, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16156119

RESUMO

A Gram-negative, aerobic, motile and rod-shaped haloalkaliphilic bacterial strain 5AGT (DSM 15293 and ATCC BAA-966) was isolated from water with algal mat of a mineral pool in Malvizza site (Campania-Italy) and was subjected to a polyphasic study. The isolate grew at temperature of 10.0-43.0 degrees C with an optimum at 37.0 degrees C. Strain 5AGT grew optimally in the presence of 10% NaCl and grew also in the absence of salt. The isolate grew in the pH range 7.0-10.0 with an optimum at pH 9.0. It accumulated glycine-betaine, ectoine, and glutamate, as osmoprotectants. Strain 5AGT was also characterized chemotaxonomically by having ubiquinone-8 (Q8) as the predominant isoprenoid quinone, phosphoethanolamine (PEA), phosphatidylglycerol (PG) and diphosphatidylglycerol (DPG), as major polar lipids and aiC16:0 and C18:1cis as the major fatty acids. The DNA G+C content was 63.7mol%. Phylogenetic analyses based on 16S rRNA gene sequence showed that the isolate belonged to the genus Halomonas. The DNA-DNA hybridization of the type strain 5AGT with the most related Halomonas campisalis showed a re-association value of 35.0%. On the basis of phenotypic properties and phylogeny, strain 5AGT should be placed in the genus Halomonas as a member of a novel species for which we propose the name Halomonas campaniensis sp. nov.


Assuntos
Água Doce/microbiologia , Halomonas/classificação , Ácidos Graxos/análise , Água Doce/química , Genes Bacterianos , Genes de RNAr , Halomonas/química , Halomonas/genética , Halomonas/metabolismo , Itália , Lipídeos/análise , Minerais , Dados de Sequência Molecular , Fenótipo , Filogenia , RNA Ribossômico 16S/genética
16.
J Gen Appl Microbiol ; 51(3): 183-9, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16107756

RESUMO

A novel thermophilic, aerobic, endospore-forming bacterium, designated strain PizzoT, was isolated from geothermal volcanic environment. Samples were collected from the Pizzo sopra la Fossa site at Stromboli Island (Eolian Islands, south of Italy) at the high altitude of 918 m. Cells of strain PizzoT were rod-shaped and stained Gram-positive. Growth was observed between 50 and 75 degrees C (optimum 70 degrees C) and at pH 5.0-8.0 (optimum pH 7.0). NaCl (0.4%, w/v) supported growth and among the hydrocarbons tested none induced growth. The G+C content of the DNA was 54.1 mol% and the sequence analysis of the 16S rRNA gene showed that the new isolate was phylogenetically closely related to the members of the Bacillus rRNA Group 5. DNA-DNA hybridization studies revealed a borderline similarity between the new isolate and Geobacillus thermoleovorans DSM 5366T (69.8%) and Geobacillus kaustophilus DSM 7263T (63.4%). On the basis of phylogenetic analysis and physiological traits of the isolate, it should be described as a new member of the Geobacillus thermoleovorans species and it is proposed that strain PizzoT can be classified as Geobacillus thermoleovorans subsp. stromboliensis, subsp. nov. (ATCC BAA-979T; DSM 15393T).


Assuntos
Bacillaceae/classificação , Microbiologia do Solo , Erupções Vulcânicas , Bacillaceae/genética , Bacillaceae/isolamento & purificação , Bacillaceae/metabolismo , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , DNA Ribossômico/análise , Genes de RNAr , Temperatura Alta , Itália , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie
17.
Res Microbiol ; 155(4): 283-9, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15142626

RESUMO

Bacillus thermantarcticus, a thermophilic bacterium isolated from Antarctic geothermal soil near the crater of Mount Melbourne, produced extracellular xylanase (1,4-beta-D-xylan xylanohydrolase; E.C. 3.2.1.8) and beta-xylosidase (1,4-beta-D-xylan xylohydrolase; E.C. 3.2.1.37). Each extracellular enzyme was separated by gel filtration with Sephacryl S-200 and further purified to homogeneity (119-fold for xylanase and 160-fold for beta-xylosidase). The optimum temperatures were 80 degrees C for xylanase at pH 5.6 and 70 degrees C for beta-xylosidase at pH 6.0. The isoelectric points and molecular masses were 4.8 and 45 kDa for xylanase and 4.2 and 150 kDa for beta-xylosidase, respectively. Xylanase was stable at 60 degrees C for 24 h, whereas it showed a half life at 70 degrees C of 24 h and at 80 degrees C for 50 min. beta-xylosidase activity did not decrease after 1 h at 60 degrees C. Km of xylanase for xylan was 1.6 mg/ml, Km of beta-xylosidase for p-nitrophenyl-beta-D-xylopyranoside was 0.5 mM and for o-nitrophenyl-beta-D-xylopyranoside was 1.28 mM. The action of two enzymes on xylan gave only xylose.


Assuntos
Geobacillus stearothermophilus/enzimologia , Glicosídeo Hidrolases/isolamento & purificação , Xilosidases/isolamento & purificação , Geobacillus stearothermophilus/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/metabolismo , Temperatura Alta , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Peso Molecular , Xilanos/metabolismo , Xilosidases/metabolismo
18.
Syst Appl Microbiol ; 26(3): 357-66, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14529178

RESUMO

The taxomony of strain M8, isolated from algal mat formed at the origin of a sulfurous spring in Rifieto (Savignano Irpino, Campania, Italy), was investigated in a polyphasic approach. The morphological, physiological and genetic characteristics were compared with of Planococcus and Planomicrobium species. The isolate grew optimally at pH 9.0, 1.8 M NaCl at 37 degrees C. The cells were Gram-positive cocci that form pairs, tetrads and aggregates of several cells. The isolate was aerobic/microaerophilic and accumulated glycine-betaine, as a major osmolyte, with minor components glutamate and an unknown compound. M8 was able to hydrolyse X-Glc (5-bromo-4-chloro-3-indoyl beta-d-glucopyranoside). The polar lipid profile consisted of phosphatidylglycerol and diphosphatidylglycerol as major components, and phosphocholine as a minor compound. MK8 was the only quinone found and the fatty acid composition was dominated by branched acids, mainly aiC15:0. The G+C content of DNA was 47.9% and its phylogenetic position was established by 16S rRNA gene sequencing as a member of the genus Planococcus. The DNA/DNA similarity of M8 to the type species Planococcus citreus was less than 55%. For this reason and for physiological and chemotaxonomic features, it is proposed to create a new species Planococcus rifietensis sp. nov.


Assuntos
Sedimentos Geológicos/microbiologia , Cocos Gram-Positivos/classificação , Cocos Gram-Positivos/isolamento & purificação , Microbiologia da Água , Aerobiose , Composição de Bases , Sequência de Bases , Benzoquinonas/análise , Betaína/metabolismo , Cardiolipinas/análise , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , Eucariotos/crescimento & desenvolvimento , Eucariotos/microbiologia , Ácidos Graxos/análise , Cocos Gram-Positivos/citologia , Cocos Gram-Positivos/fisiologia , Concentração de Íons de Hidrogênio , Itália , Lipídeos/análise , Dados de Sequência Molecular , Fosfatidilgliceróis/análise , Fosforilcolina/análise , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Cloreto de Sódio/metabolismo , Temperatura
19.
Syst Appl Microbiol ; 25(3): 319-25, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12421069

RESUMO

Thermophilic microorganisms (4001-4014), described as aerobic or facultatively anaerobic, endospore forming with growth optima temperatures in the range of 60 to 80 degrees C, have been isolated from hot marine springs around Ischia and from hydrothermal vents in the gulf of Naples. Mucous colonies are been selected for the recovery of new strains producing exopolysaccharides (EPS). To induce the biosynthesis of new exopolysaccharides, different sugars were tested as carbon sources in the media. The production of EPS in the strain 4009 reached 60 mg/l using trehalose as carbon source, increasing the yield of about 1000 fold. The 4001-EPS was a mannan with a molecular weight of 380.000 D and with a complex primary structure. In fact, the analysis of the permethylated polysaccharide in GC-MS, showed the presence of mannose, glucose, galactose, mannosamine in the relative ratio of 1:0.1:tr :tr, respectively. Nuclear magnetic resonance spectrum of the exopolysaccharide confirmed the presence of a repetitive unity formed by seven monosaccharides, six with alpha gluco/galacto configuration and one residue with beta conformation.


Assuntos
Bacillus/metabolismo , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/química , Água do Mar/microbiologia , Temperatura , Thermus/metabolismo , Bacillus/crescimento & desenvolvimento , Meios de Cultura , Itália , Espectroscopia de Ressonância Magnética , Mananas/química , Thermus/crescimento & desenvolvimento , Trealose/metabolismo
20.
AMB Express ; 4: 55, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25024928

RESUMO

Polysaccharidases from extremophiles are remarkable for specific action, resistance to different reaction conditions and other biotechnologically interesting features. In this article the action of crude extracts of thermophilic microorganisms (Thermotoga neapolitana, Geobacillus thermantarcticus and Thermoanaerobacterium thermostercoris) is studied using as substrate hemicellulose from one of the most interesting biomass crops, the giant reed (Arundo donax L.). This biomass can be cultivated without competition and a huge amount of rhizomes remains in the soil at the end of cropping cycle (10-15 years) representing a further source of useful molecules. Optimization of the procedure for preparation of the hemicellulose fraction from rhizomes of Arundo donax, is studied. Polysaccharidases from crude extracts of thermophilic microorganisms revealed to be suitable for total degradative action and/or production of small useful oligosaccharides from hemicelluloses from A. donax. Xylobiose and interesting tetra- and pentasaccharide are obtained by enzymatic action in different conditions. Convenient amount of raw material was processed per mg of crude enzymes. Raw hemicelluloses and pretreated material show antioxidant activity unlike isolated tetra- and pentasaccharide. The body of results suggest that rhizomes represent a useful raw material for the production of valuable industrial products, thus allowing to increase the economic efficiency of A. donax cultivation.

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