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1.
Int J Syst Evol Microbiol ; 69(10): 3001-3008, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31145676

RESUMO

A rod-shaped, spore-forming, thermophilic, chemoorganotrophic, aerobic or facultatively anaerobic bacterial strain, 1017T, was isolated from production water sampled at the Dagang oilfield (PR China), and was characterized by using a polyphasic approach. The strain is capable of anaerobic glucose fermentation. Nitrate is reduced to nitrite. Optimal growth was observed at 60-65 °C, at pH between pH 7.0 and 7.5, and with 1-2 % (w/v) NaCl. The major cellular fatty acids were iso-C17 : 0, anteiso-C17 : 0, iso-C15 : 0, iso-C16 : 0 and C16 : 0. The predominant polar lipids were diphosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analysis based on the 16S rRNA, gyrB and parE gene sequences indicated that the isolate belonged to the genus Geobacillus and was most closely related to Geobacillus thermoleovorans KCTC 3570T (99.5, 96.1 and 97.9 % sequence similarity, respectively). Genome sequencing revealed a genome size of 3.57495 Mb and a DNA G+C content of 51.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between the genomes of strain 1017T and G. thermoleovorans KCTC 3570T were 95.9 and 64.9 %, respectively. Results of phylogenomic metrics analysis of the genome and 1172 core genes of strain 1017T and its physiological and biochemical characteristics confirmed that strain 1017T represented a novel species of the genus Geobacillus, for which the name Geobacillusproteiniphilus sp. nov. is proposed. The type strain is 1017T (=VKM B-3132T=KCTC 33986T).


Assuntos
Geobacillus/classificação , Campos de Petróleo e Gás/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Geobacillus/isolamento & purificação , Temperatura Alta , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
2.
Appl Microbiol Biotechnol ; 103(20): 8339-8350, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31501940

RESUMO

Bacteria from the genus Geobacillus are generally obligately thermophilic, with a unique bioenergy production capacity and unique enzymes. Geobacillus species were isolated primarily from hot springs, oilfields, and associated soils. They often exhibit unique survival patterns in these extreme oligotrophic environments. With the development of the microbial resources found in oilfields, Geobacillus spp. have been proven as valuable bacteria in many reports related to oilfields. After the isolation of Geobacillus by culture methods, more evidence was found that they possess the abilities of hydrocarbon utilization and bioemulsifier production. This paper mainly summarizes some characteristics of the Geobacillus species found in the oilfield environment, focusing on the inference and analysis of hydrocarbon degradation and bioemulsifier synthesis based on existing research, which may reveal their potential value in microbial enhanced oil recovery. It also provides references for understanding microbes in extreme environments.


Assuntos
Emulsificantes/metabolismo , Geobacillus/crescimento & desenvolvimento , Geobacillus/metabolismo , Hidrocarbonetos/metabolismo , Campos de Petróleo e Gás/microbiologia , Geobacillus/isolamento & purificação
3.
Lett Appl Microbiol ; 68(3): 226-233, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30489645

RESUMO

Medicago sativa L. (alfalfa) is an important forage crop throughout the world. Despite the abiotic nutritional components of alfalfa having been extensively studied, there is only limited information on alfalfa endophytes. In this study, thirteen endophytic bacteria were isolated from alfalfa seeds. Bacillus (76·9%) was the most abundant genus, followed by Enterobacter (15·4%), Brevibacterium (7·7%), Geobacillus (7·7%) and Staphylococcus (7·7%). Four of the 13 endophytic bacteria, including Bacillus amyloliquefaciens EnB-alf1, Bacillus subtilis EnB-alf3, EnB-alf5 and EnB-alf13, were capable of significantly extending the lifespan of Caenorhabditis elegans. In addition, B. amyloliquefaciens EnB-alf1 enhanced the resistance of C. elegans to thermal stress whereas B. subtilis EnB-alf3 enhanced the resistance to oxidative stress. Further studies demonstrated that the enhanced lifespan of the worm was depended on the function of DAF-2/DAF-16 and was associated with the colonization of strain in the worms' intestines when strain EnB-alf1 or strain EnB-alf3 was presented to the worms as food sources. Our results suggest that some endophytic Bacillus strains isolated from alfalfa are beneficial on C. elegans health. SIGNIFICANCE AND IMPACT OF THE STUDY: Medicago sativa L. (alfalfa) is an important forage crop throughout the world. Despite the abiotic nutritional components of alfalfa having been extensively studied, there is only limited information available on alfalfa endophytes. Beneficial bacteria residing in the host intestine have been shown to affect host longevity. However, there is limited information available on the functions of alfalfa seed endophytes to nematodes. In this study, four endophytic Bacillus strains isolated from alfalfa seeds were found to significantly extend the lifespan of Caenorhabditis elegans and enhance resistance to thermal and oxidative stress. Our results suggest that some endophytic Bacillus strains isolated from alfalfa seeds can promote good health in C. elegans.


Assuntos
Bacillus subtilis/metabolismo , Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Endófitos/isolamento & purificação , Fatores de Transcrição Forkhead/genética , Longevidade/fisiologia , Medicago sativa/microbiologia , Receptor de Insulina/genética , Animais , Bacillus subtilis/classificação , Bacillus subtilis/isolamento & purificação , Brevibacterium/isolamento & purificação , Enterobacter/isolamento & purificação , Geobacillus/isolamento & purificação , Estresse Oxidativo/fisiologia , Sementes/microbiologia , Staphylococcus/isolamento & purificação
4.
Exp Dermatol ; 27(3): 295-298, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29283459

RESUMO

Previously, we determined that genetic and environmental factors contributed equally towards rosacea in twins. To assess an environmental factor, we characterized the malar cheek bacterial microbiome from twins discordant for rosacea. We found no significant difference in facial microbiome alpha and beta diversity between related twins discordant for rosacea. However, the relative percentage abundance of Gordonia and Geobacillus, low-abundant genera, was positively and negatively associated with rosacea severity, respectively. Our data demonstrate a significant correlation between facial microbiome and severity of rosacea in genetically matched twins and importantly that overall microbiome composition is largely unchanged.


Assuntos
Bochecha/microbiologia , Disbiose/complicações , Microbiota , Rosácea/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Firmicutes/isolamento & purificação , Geobacillus/isolamento & purificação , Bactéria Gordonia/isolamento & purificação , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Proteobactérias/isolamento & purificação , Índice de Gravidade de Doença , Adulto Jovem
5.
Int J Syst Evol Microbiol ; 68(11): 3430-3434, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30222099

RESUMO

A thermophilic, spore-forming, rod-shaped bacterium isolated from the Yumthang hot spring in North Sikkim, India was subjected to taxonomic studies. The thermophilic bacterial isolate was designated as strain AYN2T. Cells were Gram-stain-positive, aerobic, motile, rod-shaped, catalase-positive and methyl red-negative. Strain AYN2T was able to grow in the pH range from 6 to 10 (optimum, pH 7.5-8.0), at 40-70 °C (60 °C) and in NaCl concentrations of 0-4 % (1 %). The major cellular fatty acids were iso-C15 : 0 (12.8 %), iso-C16 : 0 (13.9 %) and iso-C17 : 0 (13.8 %). No matches were found in the rtsba6 Sherlock libraries. The G+C content of the genomic DNA was 42.11 mol%. Based on phylogenetic analysis of the 16S rRNA gene sequences, strain AYNT showed highest sequence similarity to the type strain of Geobacillus toebii (96 %). However, the phenotypic properties of strain AYN2T were clearly distinct from those of G. toebii and related species. On the basis of polyphasic analysis, strain AYN2T represents a novel species in the genus Geobacillus, for which the name Geobacillus yumthangensis sp. nov. is proposed. The type strain is AYN2T(MTCC=12749=KCTC=33950= JCM 32596).


Assuntos
Geobacillus/classificação , Fontes Termais/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Geobacillus/genética , Geobacillus/isolamento & purificação , Índia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
6.
Extremophiles ; 22(5): 725-737, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29779131

RESUMO

The thermal ecosystems, including geothermal springs, are proving to be source of thermophiles able to produce extracellular polysaccharides (EPSs). Among the sixteen thermophilic bacilli isolated from sediment sampled from Arzakan geothermal spring, Armenia, two best EPSs producer strains were identified based on 16S rRNA gene sequence analysis and phenotypic characteristics, and designated as Geobacillus thermodenitrificans ArzA-6 and Geobacillus toebii ArzA-8 strains. EPSs production was investigated under different time, temperature and culture media's composition. The highest specific EPSs production yield (0.27 g g-1 dry cells and 0.22 g g-1 dry cells for strains G. thermodenitrificans ArzA-6 and G. toebii ArzA-8, respectively) was observed after 24 h when fructose was used as sole carbon source at 65 °C and pH 7.0. Purified EPSs displayed a high molecular mass: 5 × 105 Da for G. thermodenitrificans ArzA-6 and 6 × 105 Da for G. toebii ArzA-8. Chemical composition and structure of the biopolymers, determined by GC-MS, HPAE-PAD and NMR, showed that both the two EPSs are heteropolymers composed by mannose as major monomer unit. Optical rotation values [α] D25 °C of the two EPSs (2 mg ml-1 H2O) were - 142,135 and - 128,645 for G. thermodenitrificans ArzA-6 and G. toebii ArzA-8, respectively.


Assuntos
Geobacillus/metabolismo , Fontes Termais/microbiologia , Polissacarídeos Bacterianos/biossíntese , Armênia , Carbono/metabolismo , Frutose/metabolismo , Geobacillus/genética , Geobacillus/isolamento & purificação , Microbiologia Industrial/métodos , Polissacarídeos Bacterianos/química , RNA Ribossômico 16S/genética
7.
Appl Microbiol Biotechnol ; 102(4): 1869-1887, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29305694

RESUMO

We have characterized a broad collection of extremophilic bacterial isolates from a deep subsurface mine, compost dumping sites, and several hot spring ecosystems. Spore-forming strains isolated from these environments comprised both obligate thermophiles/thermotolerant species (growing at > 55 °C; 240 strains) and mesophiles (growing at 15 to 40 °C; 12 strains). An overwhelming abundance of Geobacillus (81.3%) and Bacillus (18.3%) species was observed among the tested isolates. 16S rRNA sequence analysis documented the presence of 24 species among these isolates, but the 16S rRNA gene was shown to possess insufficient resolution to reliably discern Geobacillus phylogeny. gyrB-based phylogenetic analyses of nine strains revealed the presence of six known Geobacillus and one novel species. Multilocus sequence typing analyses based on seven different housekeeping genes deduced from whole genome sequencing of nine strains revealed the presence of three novel Geobacillus species. The vegetative cells of 41 Geobacillus strains were exposed to UVC254, and most (34 strains) survived 120 J/m2, while seven strains survived 300 J/m2, and cells of only one Geobacillus strain isolated from a compost facility survived 600 J/m2. Additionally, the UVC254 inactivation kinetics of spores from four Geobacillus strains isolated from three distinct geographical regions were evaluated and compared to that of a spacecraft assembly facility (SAF) clean room Geobacillus strain. The purified spores of the thermophilic SAF strain exhibited resistance to 2000 J/m2, whereas spores of two environmental Geobacillus strains showed resistance to 1000 J/m2. This study is the first to investigate UV resistance of environmental, obligately thermophilic Geobacillus strains, and also lays the foundation for advanced understanding of necessary sterilization protocols practiced in food, medical, pharmaceutical, and aerospace industries.


Assuntos
Ambientes Extremos , Geobacillus/isolamento & purificação , Viabilidade Microbiana/efeitos da radiação , Microbiologia do Solo , Raios Ultravioleta , Microbiologia da Água , Bacillus/classificação , Bacillus/genética , Bacillus/isolamento & purificação , Análise por Conglomerados , DNA Girase/genética , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Geobacillus/classificação , Geobacillus/genética , Geobacillus/efeitos da radiação , Tipagem de Sequências Multilocus , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Temperatura
8.
J Dairy Sci ; 101(2): 1013-1019, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29153522

RESUMO

Thermophilic bacilli such as Anoxybacillus and Geobacillus are important contaminants in dairy powder products. Remarkably, one of the common contaminants, Geobacillus thermoglucosidans, showed poor growth in skim milk, whereas significant growth of G. thermoglucosidans was observed in the presence of an Anoxybacillus flavithermus dairy isolate. In the present study, we investigated the underlying reason for this growth dependence of G. thermoglucosidans. Whole-genome sequences of 4 A. flavithermus strains and 4 G. thermoglucosidans strains were acquired, with special attention given to carbohydrate utilization clusters and proteolytic enzymes. Focusing on traits relevant for dairy environments, comparative genomic analysis revealed that all G. thermoglucosidans strains lacked the genes necessary for lactose transport and metabolism, showed poor growth in skim milk, and produced white colonies on X-gal plates, indicating the lack of ß-galactosidase activity. The A. flavithermus isolates scored positive in these tests, consistent with the presence of a putative lactose utilization gene cluster. All tested isolates from both species showed proteolytic activity on milk plate count agar plates. Adding glucose or galactose to liquid skim milk supported growth of G. thermoglucosidans isolates, in line with the presence of the respective monosaccharide utilization gene clusters in the genomes. Analysis by HPLC of A. flavithermus TNO-09.006 culture filtrate indicated that the previously described growth dependence of G. thermoglucosidans in skim milk was based on the supply of glucose and galactose by A. flavithermus TNO-09.006.


Assuntos
Anoxybacillus/metabolismo , Geobacillus/isolamento & purificação , Lactose/metabolismo , Leite/microbiologia , Animais , Bovinos , Laticínios/microbiologia , Geobacillus/genética , Geobacillus/crescimento & desenvolvimento , Geobacillus/metabolismo
9.
World J Microbiol Biotechnol ; 33(5): 85, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28378223

RESUMO

Sulfamethazine (SM2) is an antimicrobial drug that is frequently detected in manure compost, is difficult to degrade at high temperatures and is potentially threatening to the environment. In this study, a thermophilic bacterium was isolated from the activated sludge of an antibiotics pharmaceutical factory; this bacterium has the ability to degrade SM2 at 70 °C, which is higher than the traditional manure composting temperature. The strain S-07 is closely related to Geobacillus thermoleovorans based on its 16S rRNA gene sequence. The optimal conditions for the degradation of SM2 are 70 °C, pH 6.0, 50 rpm rotation speed and 50 mL of culture volume. More than 95% of the SM2 contained in media was removed via co-metabolism within 24 h, which was a much higher percentage than that of the type strain of G. thermoleovorans. The supernatant from the S-07 culture grown in SM2-containing media showed slightly attenuated antibacterial activity. In addition, strain S-07 was able to degrade other sulfonamides, including sulfadiazine, sulfamethoxazole and sulfamerazine. These results imply that strain S-07 might be a new auxiliary bacterial resource for the biodegradation of sulfonamide residue in manure composting.


Assuntos
Geobacillus/classificação , Geobacillus/isolamento & purificação , Esgotos/microbiologia , Sulfametazina/metabolismo , Biodegradação Ambiental , DNA Bacteriano/genética , DNA Ribossômico/genética , Geobacillus/genética , Temperatura Alta , Concentração de Íons de Hidrogênio , Filogenia , RNA Ribossômico 16S/genética
10.
Metab Eng ; 33: 148-157, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26100076

RESUMO

Thermophiles are increasingly used as versatile hosts in the biotechnology industry. One of the key advantages of thermophiles is the potential to achieve high rates of feedstock conversion at elevated temperatures. The recently isolated Geobacillus strain LC300 grows extremely fast on xylose, with a doubling time of less than 30 min. In the accompanying paper, the genome of Geobacillus LC300 was sequenced and annotated. In this work, we have experimentally validated the metabolic network model using parallel (13)C-labeling experiments and applied (13)C-metabolic flux analysis to quantify precise metabolic fluxes. Specifically, the complete set of singly labeled xylose tracers, [1-(13)C], [2-(13)C], [3-(13)C], [4-(13)C], and [5-(13)C]xylose, was used for the first time. Isotopic labeling of biomass amino acids was measured by gas chromatography mass spectrometry (GC-MS). Isotopic labeling of carbon dioxide in the off-gas was also measured by an on-line mass spectrometer. The (13)C-labeling data was then rigorously integrated for flux elucidation using the COMPLETE-MFA approach. The results provided important new insights into the metabolism of Geobacillus LC300, its efficient xylose utilization pathways, and the balance between carbon, redox and energy fluxes. The pentose phosphate pathway, glycolysis and TCA cycle were found to be highly active in Geobacillus LC300. The oxidative pentose phosphate pathway was also active and contributed significantly to NADPH production. No transhydrogenase activity was detected. Results from this work provide a solid foundation for future studies of this strain and its metabolic engineering and biotechnological applications.


Assuntos
Proteínas de Bactérias/metabolismo , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Geobacillus/classificação , Geobacillus/metabolismo , Análise do Fluxo Metabólico/métodos , Xilose/metabolismo , Proliferação de Células/fisiologia , Ciclo do Ácido Cítrico/fisiologia , Geobacillus/isolamento & purificação , Glicólise/fisiologia , Via de Pentose Fosfato/fisiologia , Especificidade da Espécie
11.
Int J Syst Evol Microbiol ; 65(Pt 3): 864-869, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25514918

RESUMO

A Gram-reaction-positive, motile, thermophilic spore-forming strain, G1w1(T), was isolated from a hot spring of the Valley of Geysers, Kamchatka (Russia). Based on data from the present polyphasic taxonomic study, including phylogenetic analysis of 16S rRNA and spo0A gene sequences, the strain is considered to represent a novel species of the genus Geobacillus, for which the name Geobacillus icigianus sp. nov. is proposed. The type strain is G1w1(T) ( = VKM B-2853(T) = DSM 28325(T)).


Assuntos
Geobacillus/classificação , Fontes Termais/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Geobacillus/genética , Geobacillus/isolamento & purificação , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Federação Russa , Análise de Sequência de DNA
12.
Appl Microbiol Biotechnol ; 99(19): 8101-11, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25994257

RESUMO

Small metabolites can participate in the virus-host interactions in eukaryotes. However, little is known about roles of metabolites in the interactions between bacteria and bacteriophages. In this study, the metabolomic profilings of bacteriophage GVE2-infected and virus-free Geobacillus sp. E263, a thermophilic bacterium isolated from a deep-sea hydrothermal vent, were characterized. The results showed that metabolites tryptophol, adenine, and hydroxybenzylalcohol were significantly elevated in Geobacillus sp. E263 in response to the GVE2 infection. Furthermore, our data indicated that tryptophol was involved in the bacteriophage infection. Tryptophol could inhibit the infection/replication of GVE2 by interacting with the host's Clp protease. Therefore, our study revealed novel aspects of metabolites during the bacteriophage infection in high-temperature environment.


Assuntos
Bacteriófagos/fisiologia , Geobacillus/metabolismo , Geobacillus/virologia , Indóis/metabolismo , Geobacillus/genética , Geobacillus/isolamento & purificação , Interações Hospedeiro-Patógeno , Temperatura Alta , Fontes Hidrotermais/química , Fontes Hidrotermais/microbiologia
13.
J Basic Microbiol ; 55(10): 1219-31, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26175347

RESUMO

A new lipolytic enzyme gene was cloned from a thermophile Geobacillus sp. JM6. The gene contained 750 bp and encoded a 249-amino acid protein. The recombinant enzyme was expressed and purified from Escherichia coli BL21 (DE3) with a molecular mass of 33.6 kDa. Enzyme assays using p-nitrophenyl esters with different acyl chain lengths as the substrates confirmed its esterase activity, yielding the highest activity with p-nitrophenyl butyrate. When p-nitrophenyl butyrate was used as a substrate, the optimum reaction temperature and pH for the enzyme were 60 °C and pH 7.5, respectively. Geobacillus sp. JM6 esterase showed excellent thermostability with 68% residual activity after incubation at 100 °C for 18 h. A theoretical structural model of strain JM6 esterase was developed with a monoacylglycerol lipase from Bacillus sp. H-257 as a template. The predicted core structure exhibits an α/ß hydrolase fold, and a putative catalytic triad (Ser97, Asp196, and His226) was identified. Inhibition assays with PMSF indicated that serine residue is involved in the catalytic activity of strain JM6 esterase. The recombinant esterase showed a relatively good tolerance to the detected detergents and denaturants, such as SDS, Chaps, Tween 20, Tween 80, Triton X-100, sodium deoxycholate, urea, and guanidine hydrochloride.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Esterases/genética , Esterases/metabolismo , Geobacillus/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/química , Butiratos/metabolismo , China , Clonagem Molecular , Estabilidade Enzimática , Esterases/química , Regulação Bacteriana da Expressão Gênica , Geobacillus/genética , Geobacillus/isolamento & purificação , Fontes Termais/microbiologia , Temperatura Alta , Modelos Moleculares , Dados de Sequência Molecular , Peso Molecular , Monoacilglicerol Lipases/química , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA
14.
Pol J Microbiol ; 64(3): 253-63, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26638533

RESUMO

An obligately thermophilic strain ZY-10 was isolated from the crude oil in a high-temperature oilfield, which was capable of degrading heavy crude oil. Phenotypic and phylogenetic analysis demonstrated that the isolate should be grouped in the genus Geobacillus, which shared thd highest similarity (99%) of the 16S rDNA sequence to Geobacillus stearothermophilus. However, the major cellular fatty acid iso-15:0 (28.55%), iso-16:0 (24.93%), iso-17:0 (23.53%) and the characteristics including indole production, tolerance to NaN3 and carbohydrate fermentation showed some difference from the recognized species in the genus Geobacillus. The isolate could use tridecane, hexadecane, octacosane and hexatridecane as sole carbon source for cell growth, and the digesting rate of long-chain alkane was lower than that of short-chain alkane. When the isolate was cultured in the heavy crude oil supplement with inorganic salts and trace yeast extract, the concentration of short-chain alkane was significantly increased and the content of long-chain alkane was decreased, suggesting that the larger hydrocarbon components in crude oil were degraded into shorter-chain alkane. Strain ZY-10 would be useful for improving the mobility of crude oil and upgrading heavy crude oil in situ.


Assuntos
Geobacillus/isolamento & purificação , Geobacillus/metabolismo , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Microbiologia do Solo , Biodegradação Ambiental , DNA Bacteriano/genética , DNA Ribossômico/genética , Geobacillus/classificação , Geobacillus/genética , Hidrocarbonetos/química , Dados de Sequência Molecular , Petróleo/análise , Filogenia , RNA Ribossômico 16S/genética
15.
Microbiology (Reading) ; 160(Pt 1): 1-11, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24085838

RESUMO

The genus Geobacillus comprises endospore-forming obligate thermophiles. These bacteria have been isolated from cool soils and even cold ocean sediments in anomalously high numbers, given that the ambient temperatures are significantly below their minimum requirement for growth. Geobacilli are active in environments such as hot plant composts, however, and examination of their genome sequences reveals that they are endowed with a battery of sensors, transporters and enzymes dedicated to hydrolysing plant polysaccharides. Although they appear to be relatively minor members of the plant biomass-degrading microbial community, Geobacillus bacteria have achieved a significant population with a worldwide distribution, probably in large part due to adaptive features of their spores. First, their morphology and resistance properties enable them to be mobilized in the atmosphere and transported long distances. Second, their longevity, which in theory may be extreme, enables them to lie quiescent but viable for long periods of time, accumulating gradually over time to achieve surprisingly high population densities.


Assuntos
Microbiologia Ambiental , Geobacillus/isolamento & purificação , Geobacillus/fisiologia , Geobacillus/crescimento & desenvolvimento , Geobacillus/efeitos da radiação , Viabilidade Microbiana , Temperatura
16.
Food Microbiol ; 43: 41-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24929881

RESUMO

The presence of thermophilic bacilli in dairy products is indicator of poor hygiene. Their rapid detection and identification is fundamental to improve the industrial reactivity in the implementation of corrective and preventive actions. In this study a rapid and reliable identification of Geobacillus stearothermophilus and Anoxybacillus flavithermus was achieved by species-specific PCR assays. Two primer sets, targeting the ITS 16S-23S rRNA region and the rpoB gene sequence of the target species respectively, were employed. Species-specificity of both primer sets was evaluated by using 53 reference strains of DSMZ collection; among them, 13 species of the genus Geobacillus and 15 of the genus Anoxybacillus were represented. Moreover, 99 wild strains and 23 bulk cells collected from 24 infant formula powders gathered from several countries worldwide were included in the analyses. Both primer sets were highly specific and the expected PCR fragments were obtained only when DNA from G. stearothermophilus or A. flavithermus was used. After testing their specificity, they were combined in a Multiplex-PCR assay for the simultaneous identification of the two target species. The specificity of the Multiplex-PCR was evaluated by using both wild strains and bulk cells. Every analysis confirmed the reliable identification results provided by the single species-specific PCR methodology. The easiness, the rapidity (about 4 h from DNA isolation to results) and the reliability of the PCR procedures developed in this study highlight the advantage of their application for the specific detection and identification of the thermophilic species G. stearothermophilus and A. flavithermus.


Assuntos
Anoxybacillus/isolamento & purificação , Contaminação de Alimentos/análise , Geobacillus/isolamento & purificação , Leite/microbiologia , Reação em Cadeia da Polimerase Multiplex/métodos , Animais , Anoxybacillus/classificação , Anoxybacillus/genética , Bovinos , Primers do DNA/genética , DNA Bacteriano/genética , Geobacillus/classificação , Geobacillus/genética , Fórmulas Infantis/química , RNA Ribossômico 16S/genética
17.
Microb Cell Fact ; 12: 75, 2013 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-23919572

RESUMO

BACKGROUND: The use of microorganisms in the synthesis of nanoparticles emerges as an eco-friendly and exciting approach, for production of nanoparticles due to its low energy requirement, environmental compatibility, reduced costs of manufacture, scalability, and nanoparticle stabilization compared with the chemical synthesis. RESULTS: The production of gold nanoparticles by the thermophilic bacterium Geobacillus sp. strain ID17 is reported in this study. Cells exposed to Au3+ turned from colourless into an intense purple colour. This change of colour indicates the accumulation of intracellular gold nanoparticles. Elemental analysis of particles composition was verified using TEM and EDX analysis. The intracellular localization and particles size were verified by TEM showing two different types of particles of predominant quasi-hexagonal shape with size ranging from 5-50 nm. The mayority of them were between 10‒20 nm in size. FT-IR was utilized to characterize the chemical surface of gold nanoparticles. This assay supports the idea of a protein type of compound on the surface of biosynthesized gold nanoparticles. Reductase activity involved in the synthesis of gold nanoparticles has been previously reported to be present in others microorganisms. This reduction using NADH as substrate was tested in ID17. Crude extracts of the microorganism could catalyze the NADH-dependent Au3+ reduction. CONCLUSIONS: Our results strongly suggest that the biosynthesis of gold nanoparticles by ID17 is mediated by enzymes and NADH as a cofactor for this biological transformation.


Assuntos
Geobacillus/química , Ouro/química , Nanopartículas Metálicas/química , Regiões Antárticas , Cloretos/química , Cloretos/metabolismo , Geobacillus/isolamento & purificação , Geobacillus/metabolismo , Compostos de Ouro/química , Compostos de Ouro/metabolismo , Microscopia Eletrônica de Transmissão e Varredura , Oxirredução , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Biodegradation ; 24(1): 57-67, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22639115

RESUMO

A thermophilic bacterium capable of degrading acrylamide, AUT-01, was isolated from soil collected from a hot spring area in Montana, USA. The thermophilic strain grew with 0.2 % glucose as the sole carbon source and 1.4 mM acrylamide as the sole nitrogen source. The isolate AUT-01 was identified as Geobacillus thermoglucosidasius based on 16S rDNA sequence. An enzyme from the strain capable of transforming acrylamide to acrylic acid was purified by a series of chromatographic columns. The molecular weight of the enzyme was estimated to be 38 kDa by SDS-PAGE. The enzyme activity had pH and temperature optima of 6.2 and 70 ºC, respectively. The influence of different metals and amino acids on the ability of the purified protein to transform acrylamide to acrylic acid was evaluated. The gene from G. thermoglucosidasius encoding the acrylamidase was cloned, sequenced, and compared to aliphatic amidases from other bacterial strains. The G. thermoglucosidasius gene, amiE, encoded a 38 kDa, monomeric, heat-stable amidase that catalysed the cleavage of carbon-nitrogen bonds in acrylamide. Comparison of the amino acid sequence to other bacterial amidases revealed 99 and 82 % similarity to the amino acid sequences of Bacillus stearothermophilus and Pseudomonas aeruginosa, respectively.


Assuntos
Amidoidrolases/química , Amidoidrolases/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Clonagem Molecular , Geobacillus/enzimologia , Fontes Termais/microbiologia , Acrilamida/metabolismo , Acrilatos/metabolismo , Amidoidrolases/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Estabilidade Enzimática , Geobacillus/química , Geobacillus/genética , Geobacillus/isolamento & purificação , Temperatura Alta , Dados de Sequência Molecular
19.
Environ Technol ; 34(13-16): 1895-904, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24350443

RESUMO

Switchgrass is considered as a good candidate for biofuel, especially ethanol production due to its huge biomass output and high cellulose content. In a search for novel microorganisms capable of using and degrading switchgrass to produce sugars and ethanol, enrichment experiments were established to screen for microorganisms from soil samples obtained at the University of Tennessee Agricultural Research Station, Jackson, Tennessee. Three enrichments were prepared and incubated at different pH and temperatures: (1) 30 degrees C, pH 5, (2) 30 degrees C, pH 8 and (3) 60 degrees C, pH5. Bulk community DNA was directly extracted from the enrichments. Microbial community structures were determined by phylogenetic analysis of 16S rRNA gene sequences retrieved from the enrichment cultures containing switchgrass as the carbon source. The mesophilic enrichments were dominated by Sarcina, Anaerobacter, and Clostrium, which were not found in the thermophilic enrichment. The thermophilic enrichment selected for two types of bacteria belonging to the class Bacilli (Geobacillus and Saccharococcus). The thermophilic enrichments were dominated by the Geobacillus spp. (Firmicutes, class Bacilli), and Saccharococcus (Firmicutes, class Bacilli); both containing thermophilic microorganisms with some cellulolytic members. Enzymatic assays detected the presence of enzymes involved in cellulose (beta-glucosidase and cellobiohydrolase) and hemicellulose degradations (beta-xylosidase); and the activity tends to be higher in the enrichments incubated at 30 degrees C.


Assuntos
Bactérias/isolamento & purificação , Biocombustíveis/microbiologia , Biomassa , Panicum/microbiologia , Bactérias/classificação , Bactérias/genética , Proteínas de Bactérias/metabolismo , Celulases/metabolismo , Celulose/metabolismo , DNA Bacteriano/classificação , DNA Bacteriano/genética , Geobacillus/classificação , Geobacillus/genética , Geobacillus/isolamento & purificação , Consórcios Microbianos , Filogenia , RNA Ribossômico 16S , Microbiologia do Solo , Temperatura
20.
J Bacteriol ; 194(5): 1239, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22328744

RESUMO

Geobacillus thermoleovorans CCB_US3_UF5 is a thermophilic bacterium isolated from a hot spring in Malaysia. Here, we report the complete genome of G. thermoleovorans CCB_US3_UF5, which shows high similarity to the genome of Geobacillus kaustophilus HTA 426 in terms of synteny and orthologous genes.


Assuntos
DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Geobacillus/genética , Geobacillus/isolamento & purificação , Fontes Termais/microbiologia , Malásia , Dados de Sequência Molecular , Análise de Sequência de DNA
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