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1.
J Basic Microbiol ; 60(9): 809-815, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32602226

RESUMO

The aim of this study was to select and identify thermophilic bacteria from Caatinga biome (Brazil) able to produce thermoactive keratinases and characterize the keratinase produced by the selected isolate. After enrichment in keratin culture media, an Anoxybacillus caldiproteolyticus PC2 was isolated. This thermotolerant isolate presents a remarkable feature producing a thermostable keratinase at 60°C. The partially purified keratinase, identified as a thermolysin-like peptidase, was active at a pH range of 5.0-10.0 with maximal activity at a temperature range of 50-80°C. The optimal activity was observed at pH 7.0 and 50-60°C. These characteristics are potentially useful for biotechnological purposes such as processing and bioconversion of keratin.


Assuntos
Anoxybacillus/metabolismo , Extremófilos/metabolismo , Peptídeo Hidrolases/metabolismo , Anoxybacillus/classificação , Anoxybacillus/isolamento & purificação , Anoxybacillus/fisiologia , Brasil , Estabilidade Enzimática , Extremófilos/classificação , Extremófilos/isolamento & purificação , Extremófilos/fisiologia , Concentração de Íons de Hidrogênio , Queratinas/metabolismo , Peptídeo Hidrolases/química , Peptídeo Hidrolases/isolamento & purificação , Temperatura , Termolisina/química , Termolisina/metabolismo , Termotolerância
2.
Bioelectrochemistry ; 133: 107450, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31978857

RESUMO

Common alloys used for the manufacture of aircrafts are subject to different forms of environmental deterioration. A major one is corrosion, and there is a strong body of evidence suggesting that environmental microorganisms initiate and accelerate it. The development of an appropriate strategy to reduce this process depends on the knowledge concerning the factors involved in corrosion. In this work, a biofilm forming bacterial consortium was extracted in situ from the corrosion products formed in an aircraft exposed to Antarctic media. Two thermophilic bacteria, an Anoxybacillus and a Staphylococcus strain, were successfully isolated from this consortium. Two extracellular enzymes previously speculated to participate in corrosion, catalase and peroxidase, were detected in the extracellular fraction of the consortium. Additionally, we assessed the individual contribution of those thermophilic microorganisms on the corrosion process of 7075-T6 aluminum alloy, which is widely used in aeronautical industry, through electrochemical methods and surface analysis techniques.


Assuntos
Ligas/química , Alumínio/química , Anoxybacillus/fisiologia , Biofilmes , Anoxybacillus/enzimologia , Anoxybacillus/isolamento & purificação , Regiões Antárticas , Corrosão , Oxirredução , Staphylococcus/enzimologia , Staphylococcus/isolamento & purificação , Staphylococcus/fisiologia , Propriedades de Superfície
3.
Biofouling ; 35(5): 551-560, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31273998

RESUMO

Anoxybacillus (A. flavithermus, A. kamchatkensis subsp. asachharedens, A. caldiproteolyticus and A. tepidamans) and Geobacillus (two strains of G. thermodenitrificans, G. thermoglucosidans and G. vulcanii) isolates and reference strains in whole milk were evaluated for their biofilm production on six different abiotic surfaces. G. thermodenitrificans DSM 465T had the highest cell counts (>4 log10 CFU cm-2) on glass and stainless steel (SS) at 55 and 65 °C, respectively. G. thermodenitrificans D195 had the highest counts on SS at 55 °C (>5 log10 CFU cm-2) and polyvinyl chloride (PVC) at 65 °C (>4 log10 CFU cm-2), indicating the existence of strain variation. The ideal surfaces for all strains were SS and glass at 55 °C, but their preferences were polystyrene and SS at 65 °C. Moreover, Anoxybacillus members were more prone to form biofilms in skim milk than in semi-skim and whole milk, whereas the results were the opposite for Geobacillus. Both the attachment and sporulation of Geobacillus in whole milk was higher than in semi-skim or skim milk. This study proposes that the surface material, temperature and milk type had a cumulative effect on biofilm formation.


Assuntos
Anoxybacillus/fisiologia , Biofilmes , Indústria de Laticínios , Geobacillus/fisiologia , Leite , Animais , Contagem de Células , Aço Inoxidável , Temperatura
4.
Ultrason Sonochem ; 51: 325-331, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30322767

RESUMO

The vegetative cells and spores of Geobacillus spp. and Anoxybacillus flavithermus were subjected to 20 kHz ultrasound with a power ∼8 W. Ultrasonication had considerable effect on vegetative cells (5-log reduction in Geobacillus spp. and 1.6-log reduction in A.flavithermus). TEM imaging of the ultrasonicated vegetative cells showed an extensive damage both internally and externally. However, spores showed high resistance towards ultrasound treatment in the absence of NaOH and H2O2, although the outer layers such as the exosporium and the outer coat layer were disrupted, resulting in the reduced resistance of spores towards sonication. The combination of 0.12 M NaOH and 10 min ultrasonication inactivated 6 log spores of Geobacillus spp. A 7 log spore reduction of A.flavithermus was achieved by combining 0.17 M NaOH with 10 min ultrasonication. Ultrasonication combined with 1% H2O2 inactivated ∼7 log Geobacillus spp. spores in 6 min and ∼7 log A.flavithermus spores in 3 min. These ultrasound treatments in the presence of NaOH and H2O2 are synergistic as they showed a greater spore reduction when compared to NaOH combined with high temperature (85 °C), where only 1 and 3 log reduction was achieved in Geobacillus spp. and A.flavithermus spores, respectively.


Assuntos
Anoxybacillus/fisiologia , Geobacillus/fisiologia , Peróxido de Hidrogênio/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Hidróxido de Sódio/farmacologia , Ondas Ultrassônicas , Anoxybacillus/efeitos dos fármacos , Geobacillus/efeitos dos fármacos , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/fisiologia
5.
J Microbiol Biotechnol ; 26(6): 1087-97, 2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-27012240

RESUMO

An intracellular lipase from Anoxybacillus flavithermus HBB 134 was purified to 7.4-fold. The molecular mass of the enzyme was found to be about 64 kDa. The maximum activity of the enzyme was at pH 9.0 and 50°C. The enzyme was stable between pH 6.0 and 11.0 at 25°C, 40°C, and 50°C for 24 h. The Km and Vmax of the enzyme for pNPL substrate were determined as 0.084 mM and 500 U/mg, respectively. Glycerol, sorbitol, and mannitol enhanced the enzyme thermostability. The enzyme was found to be highly stable against acetone, ethyl acetate, and diethyl ether. The presence of PMSF, NBS, DTT and ß-mercaptoethanol inhibited the enzyme activity. Hg(2+), Fe(3+), Pb(2+), Al(3+), and Zn(2+) strongly inhibited the enzyme whereas Li(+), Na(+), K(+), and NH4(+) slightly activated it. At least 60% of the enzyme activity and stability were retained against sodium deoxycholate, sodium taurocholate, n-octyl-ß-D-glucopyranoside, and CHAPS. The presence of 1% Triton X-100 caused about 34% increase in the enzyme activity. The enzyme is thought to be a true lipase since it has preferred the long-chain triacylglycerols. The lipase of HBB 134 cleaved triolein at the 1- or 3-position.


Assuntos
Anoxybacillus/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Lipase/química , Lipase/isolamento & purificação , Lipase/metabolismo , Álcalis/farmacologia , Anoxybacillus/fisiologia , Proteínas de Bactérias/genética , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Glicerol/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Lipase/genética , Manitol/metabolismo , Mercaptoetanol/farmacologia , Peso Molecular , Sorbitol/metabolismo , Especificidade por Substrato , Temperatura
6.
Appl Environ Microbiol ; 81(15): 5115-22, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26002898

RESUMO

This study investigated the effects of varied sodium, calcium, and magnesium concentrations in specialty milk formulations on biofilm formation by Geobacillus spp. and Anoxybacillus flavithermus. The numbers of attached viable cells (log CFU per square centimeter) after 6 to 18 h of biofilm formation by three dairy-derived strains of Geobacillus and three dairy-derived strains of A. flavithermus were compared in two commercial milk formulations. Milk formulation B had relatively high sodium and low calcium and magnesium concentrations compared with those of milk formulation A, but the two formulations had comparable fat, protein, and lactose concentrations. Biofilm formation by the three Geobacillus isolates was up to 4 log CFU cm(-2) lower in milk formulation B than in milk formulation A after 6 to 18 h, and the difference was often significant (P ≤ 0.05). However, no significant differences (P ≤ 0.05) were found when biofilm formations by the three A. flavithermus isolates were compared in milk formulations A and B. Supplementation of milk formulation A with 100 mM NaCl significantly decreased (P ≤ 0.05) Geobacillus biofilm formation after 6 to 10 h. Furthermore, supplementation of milk formulation B with 2 mM CaCl2 or 2 mM MgCl2 significantly increased (P ≤ 0.05) Geobacillus biofilm formation after 10 to 18 h. It was concluded that relatively high free Na(+) and low free Ca(2+) and Mg(2+) concentrations in milk formulations are collectively required to inhibit biofilm formation by Geobacillus spp., whereas biofilm formation by A. flavithermus is not impacted by typical cation concentration differences of milk formulations.


Assuntos
Anoxybacillus/efeitos dos fármacos , Anoxybacillus/fisiologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Cátions/metabolismo , Geobacillus/efeitos dos fármacos , Geobacillus/fisiologia , Animais , Cálcio/metabolismo , Contagem de Colônia Microbiana , Magnésio/metabolismo , Leite/microbiologia , Cloreto de Sódio/metabolismo , Fatores de Tempo
7.
J Appl Microbiol ; 116(2): 350-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24119100

RESUMO

AIMS: To determine whether strains of Geobacillus stearothermophilus isolated from a milk powder manufacturing plant were different in their ability to form biofilms and produce spores. In addition, this study evaluated whether there were other physiological characteristics that could differentiate these strains. METHODS AND RESULTS: Ten G. stearothermophilus strains and one Anoxybacillus species were isolated from a milk powder manufacturing plant. A microtitre plate assay was used to show that these strains differed in their abilities to form biofilms and produce spores. Scanning electron microscopy showed differences in the biofilm morphologies of three of the G. stearothermophilus strains. Biochemical profiling, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and fatty acid profiling further showed that they had distinct characteristics. CONCLUSIONS: These G. stearothermophilus strains, isolated from the same environment, showed differences in their ability to form biofilms and produce endospores. Based on the multiple characterization methods used in this study, these strains of G. stearothermophilus isolated from one manufacturing plant are diverse. SIGNIFICANCE AND IMPACT OF THE STUDY: Differences in the ability of G. stearothermophilus to form biofilms and produce spores may influence the cleaning method used to control the growth of thermophilic bacilli in a dairy processing environment.


Assuntos
Anoxybacillus/fisiologia , Biofilmes/crescimento & desenvolvimento , Indústria de Processamento de Alimentos , Geobacillus stearothermophilus/fisiologia , Leite/microbiologia , Animais , Anoxybacillus/classificação , Anoxybacillus/isolamento & purificação , Anoxybacillus/ultraestrutura , Bacillus , DNA Ribossômico/química , Ácidos Graxos/metabolismo , Indústria de Processamento de Alimentos/instrumentação , Indústria de Processamento de Alimentos/normas , Geobacillus stearothermophilus/classificação , Geobacillus stearothermophilus/isolamento & purificação , Geobacillus stearothermophilus/ultraestrutura , Microscopia Eletrônica de Varredura , Leite/química , Filogenia , Pós , RNA Ribossômico 16S/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Esporos Bacterianos
8.
Appl Environ Microbiol ; 79(13): 4186-90, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23645192

RESUMO

Preconditioning of Anoxybacillus flavithermus E16 and Geobacillus sp. strain F75 with cations prior to attachment often significantly increased (P ≤ 0.05) the number of viable cells that attached to stainless steel (by up to 1.5 log CFU/cm(2)) compared with unconditioned bacteria. It is proposed that the transition of A. flavithermus and Geobacillus spp. from milk formulations to stainless steel product contact surfaces in milk powder manufacturing plants is mediated predominantly by bacterial physiological factors (e.g., surface-exposed adhesins) rather than the concentrations of cations in milk formulations surrounding bacteria.


Assuntos
Anoxybacillus/fisiologia , Aderência Bacteriana/fisiologia , Biofilmes/crescimento & desenvolvimento , Cátions/metabolismo , Geobacillus/fisiologia , Adesinas Bacterianas/metabolismo , Cálcio/metabolismo , Caseínas , Contagem de Células , Magnésio/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Aço Inoxidável , Fatores de Tempo
9.
J Bacteriol ; 194(23): 6684-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23144421

RESUMO

Anoxybacillus kamchatkensis G10 is a spore-forming thermophilic bacterium isolated from a hot spring in Indonesia. Here, we report the draft genome sequence of A. kamchatkensis G10 that may reveal insights into aerobic/anaerobic metabolisms and carbon utilization in moderate thermophiles.


Assuntos
Anoxybacillus/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Análise de Sequência de DNA , Aerobiose , Anaerobiose , Anoxybacillus/isolamento & purificação , Anoxybacillus/metabolismo , Anoxybacillus/fisiologia , Carbono/metabolismo , Fontes Termais/microbiologia , Indonésia , Dados de Sequência Molecular
10.
Int J Syst Evol Microbiol ; 61(Pt 1): 118-122, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20173008

RESUMO

Two novel thermophilic, spore-forming bacterial strains, T-11(T) and E-112(T), were isolated from hot springs in Tengchong and Eryuan counties of Yunnan province in south-west China. The strains were Gram-stain-positive rods, occurring singly or in chains. Growth of strain T-11(T) was observed between 30 and 75 °C (optimum 50 °C) and at pH 7-11 (optimum pH 8.5), while the temperature range for strain E-112(T) was 35-70 °C (optimum 55 °C) and the pH range was 7.0-11.0 (optimum pH 8.0). The DNA G+C contents of strains T-11(T) and E-112(T) were 41.1 and 42.6 mol%, respectively. On the basis of 16S rRNA gene sequence similarity, the two strains were shown to be related most closely to Anoxybacillus species. The chemotaxonomic characteristics [predominant isoprenoid quinone menaquinone 7 (MK-7); major fatty acids iso-C(15 : 0) and iso-C(17 : 0)] also supported the affiliation of strains T-11(T) and E-112(T) to the genus Anoxybacillus. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strains T-11(T) and E-112(T) from Anoxybacillus species with validly published names. Strains T-11(T) and E-112(T) therefore represent two novel species, for which the names Anoxybacillus tengchongensis sp. nov. (type strain T-11(T) =CCTCC AB209237(T) =KCTC 13721(T)) and Anoxybacillus eryuanensis sp. nov. (type strain E-112(T) =CCTCC AB209236(T) =KCTC 13720(T)) are proposed.


Assuntos
Anoxybacillus/classificação , Anoxybacillus/isolamento & purificação , Fontes Termais/microbiologia , Anoxybacillus/genética , Anoxybacillus/fisiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos/citologia , Temperatura
11.
J Ind Microbiol Biotechnol ; 37(11): 1111-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20574738

RESUMO

The aim of the present study was to investigate the attachment mechanisms that enable the thermophile Anoxybacillus flavithermus (B12) to attach to stainless-steel surfaces. Passing a B12 culture through a column of stainless-steel chips, collecting the first cells to pass through, re-culturing, and repeating the process six times, resulted in the isolation of a mutant, labeled X7, with tenfold reduced ability to attach to stainless steel as well as a reduced ability to attach to plastic. A comparison of bacterial cell-surface properties indicated that X7 was less hydrophobic than its parental strain B12. Cell-surface charge measurements also suggest that X7 had a lower net-negative surface charge. Disruption of extracellular polysaccharides and DNA appeared to have no effect on the attachment process. Removal of surface proteins caused a reduction in attachment of both B12 and X7, suggesting surface protein involvement in attachment.


Assuntos
Anoxybacillus/isolamento & purificação , Anoxybacillus/fisiologia , Aderência Bacteriana , Biofilmes , Laticínios/microbiologia , Proteínas de Bactérias/análise , Contagem de Colônia Microbiana , Interações Hidrofóbicas e Hidrofílicas , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/metabolismo , Plásticos , Técnica de Amplificação ao Acaso de DNA Polimórfico , Aço Inoxidável , Propriedades de Superfície
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