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1.
Environ Monit Assess ; 191(7): 469, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31243556

RESUMO

Sapanca Lake is important as a source of drinking water. In this study, we aimed to detect the bacterial quality, the frequency of bacterial antibiotic and heavy metal resistance, and bioindicator bacteria in the water samples taken from Sapanca Lake in the period between 2008 and 2010. The resistance of bacterial isolates to certain antibiotics and heavy metal salts was investigated using disc diffusion and minimum inhibitory concentration techniques. Bacterial metabolic reactions were tested using the VITEK 2 Compact 30 micro identification system for identification of cultivable bacteria. Twenty-seven bacteria species belonging to three classes-Gammaproteobacteria, Bacilli, Flavobacteria-were recorded for the first time in Sapanca Lake. The highest indicator bacteria were recorded as 71 ± 3.1 × 104 CFU/100 ml in the summer season. The highest bacterial resistance was recorded as 90.47% against vancomycin in a total of 84 strains. Ampicillin (88.10%) and amoxicillin-clavulanate (64.29%) followed them. The resistance varied between 10.71 and 59.52% against cefuroxime, kanamycin, aztreonam, ceftazidime, cefotaxime, and oxacillin. The highest frequency against heavy metal salts was recorded as 74.19% against NiCl2. The heavy metal resistance against Cu, Zn, Hg, and Cd detected as 52.38%, 46.42%, 33.33%, and 26.19%, respectively. The results showed that the occurrence of heavy metals and antibiotic sources in Sapanca Lake induced a tolerance in bacteria for the metal salts and antibiotic derivatives tested. The fluctuations in the indicator bacteria and the occurrence of pathogenic bacteria also showed the possibility that the coastal areas of Sapanca Lake had been exposed to contamination due to inadequate sewage treatment.


Assuntos
Antibacterianos/farmacologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/fisiologia , Monitoramento Ambiental/métodos , Metais Pesados/farmacologia , Bacillus/isolamento & purificação , Bactérias/isolamento & purificação , Água Potável/química , Água Potável/microbiologia , Flavobacteriaceae/isolamento & purificação , Gammaproteobacteria/isolamento & purificação , Lagos , Testes de Sensibilidade Microbiana , Turquia , Poluentes Químicos da Água/farmacologia , Poluição da Água
2.
Chemosphere ; 232: 243-253, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31154185

RESUMO

This study faces the characterization of the culturable microbiota of the facultative Ni-hyperaccumulator Alyssoides utriculata to obtain a collection of bacterial and fungal strains for potential applications in Ni phytoextraction. Rhizosphere soil samples and adjacent bare soil associated with A. utriculata from serpentine and non-serpentine sites were collected together with plant roots and shoots. Rhizobacteria and fungi were isolated and characterized genotypically and phenotypically. Plants and soils were analyzed for total element concentration using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Serpentine and non-serpentine sites differ in terms of elements concentration in soil, plant roots and shoots. Ni and Co are significantly higher on serpentine site, while Ca is more abundant in non-serpentine site. Bacteria and fungi were significantly more abundant in rhizosphere than in bare soil and were dominated by genera Arthrobacter, Bacillus and Streptomyces, Penicillium and Mucor. The genus Pseudomonas was only found in rhizospheric serpentine soils (<2% of total serpentine isolates) and with Streptomyces sp. showed highest Ni-tolerance up to 15 mM. The same occurred for Trichoderma strain, belonging to the harzianum group (<2% of the total microfungal count) and Penicillium ochrochloron (<10% of the total microfungal count, tolerance up to Ni 20 mM). Among serpentine bacterial isolates, 8 strains belonging to 5 genera showed at least one PGPR activity (1-Aminocyclopropane-1-Carboxylic Acid (ACC) deaminase activity, production of indole-3-acetic acid (IAA), siderophores and phosphate solubilizing capacity), especially genera Pantoea, Pseudomonas and Streptomyces. Those microorganisms might thus be promising candidates for employment in bioaugmentation trials.


Assuntos
Níquel/análise , Rizosfera , Poluentes do Solo/análise , Aminoácidos Cíclicos , Bacillus/isolamento & purificação , Bactérias , Brassicaceae/microbiologia , Ácidos Indolacéticos , Raízes de Plantas/química , Pseudomonas , Sideróforos/análise , Solo/química , Microbiologia do Solo
3.
World J Microbiol Biotechnol ; 35(6): 83, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31134356

RESUMO

Bacterial metabolites have been observed to be important in new drug formulation for both plant, animals and human beings. The aim of this study was to identify the different bioactive compounds found in three rhizobacterial isolates (B. amyloliquefaciens, B. thuringiensis and Bacillus sp.) from the rhizosphere of Bambara groundnut and to assay for their antibacterial properties. Gas chromatography mass spectrometry (GC-MS) was used to carry out the analysis using seven extraction solvents. In the GC-MS analysis, 68 compounds were identified based on peak area percentage, retention time and structure. From the bioactive compounds in B. amyloliquefaciens and B. thuringiensis, the peak area percentage shows that dimethylfuvene from ethyl acetate extraction had the highest relative abundance with 89.11% while Formic acid 2-methylpropyl ester from hexane extraction had the lowest with 6.25%. Others are tridecane, acetic acid butyl ester, paraldehyde, s-(+)-1,2 propanediol, tropone, phthalan and p-xylene with relative abundance of 61.72%, 60.41%, 83.79%, 71.53%, 24.06%, 86.72% and 64.33% respectively. These extracts inhibited the growth of the four test organisms, Bacillus cereus, Pseudomonas aeruginosa, Micrococcus cryophilus and Enterococcus feacalis. Butanol extract from B. amyloliquefaciens had 28 mm zone of inhibition against B. cereus compared to 18 mm and 16 mm by Bacillus sp. and B. thuringiensis respectively. Its zone of inhibition was 24 mm zone against M. cryophilus compared to 12 mm and 19 mm by Bacillus sp. and B. thuringiensis respectively. Butanol extract from B. thuringiensis suppressed E. feacalis and P. aeruginosa having 23 mm and 26 mm zones of inhibition respectively. This was higher compared to Bacillus sp. and B. amyloliquefaciens having 18 mm/15 mm and 21 mm/15 mm against E. feacalis and P. aeruginosa respectively. Hexane and ethyl acetate extract from Bacillus sp. suppressed P. aeruginosa with 12 mm and 17 mm inhibition zones respectively compared to no inhibition zones from hexane extract of B. amyloliquefaciens and B. thuringiensis. Zones of inhibition of 2 mm and 6 mm were observed against P. aeruginosa from ethyl acetate extract of B. amyloliquefaciens and B. thuringiensis respectively. These results suggest that the three isolates are quite rich in the production of bioactive compounds that are also very effective antibacterial agents. These volatile organic compounds are promising compounds for more antibacterial bioactivity development.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Cromatografia Gasosa-Espectrometria de Massas/métodos , Rhizobium/metabolismo , Vigna/microbiologia , Compostos Orgânicos Voláteis/análise , Bacillus/classificação , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/metabolismo , Bacillus cereus/efeitos dos fármacos , DNA Ribossômico/genética , Enterococcus faecalis/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Micrococcus/efeitos dos fármacos , Extratos Vegetais/química , Pseudomonas aeruginosa/efeitos dos fármacos , Microbiologia do Solo , África do Sul , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/farmacologia
4.
Huan Jing Ke Xue ; 40(4): 1680-1687, 2019 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-31087908

RESUMO

Size distribution and microbial population structure are typical characteristics of bioaerosols that are relevant to human health. The concentrations and population structure of bioaerosols associated with size-segregated airborne particulate matter at human average respiratory height were studied using a 6-stage Andersen impactor during and after fog-haze days in the area of Beijing. The results showed that the size distribution of the cultured microbial populations was uneven during fog-haze days, and that the microbial concentration and the difference in the population structure of the size-segregated airborne particulate matter were higher during than after the fog-haze days. During the fog-haze days, Bacillus sp. was the dominant bacteria present in bioaerosols of >3.3 µm, whereas Bacillus sp. and Bacillus amyloliquefaciens were the dominant bacteria in bioaerosols of <3.3 µm. In contrast, after the fog-haze days, Bacillus amyloliquefaciens was dominant in all the bioaerosol sizes. Five species (Alternaria sp., Penicillium italicum, Talaromyces stollii, Cladosporium sp., and Davidiella sp.) were detected as the dominant fungi in the bioaerosols >3.3 µm during the fog-haze days, and only Alternaria sp. was detected in the bioaerosols >3.3 µm after fog-haze. Penicillium italicum and Talaromyces stollii were also detected in the bioaerosols of <3.3 µm during and after the fog-haze. There were significant differences in the concentration and population structure of the size-segregated airborne particulate matter at human average respiratory height collected during and after the fog-haze days. The high concentration of microorganisms and the relatively complex population at human average respiratory height on haze days indicate that the potential risks of the microbiological characteristics of the bioaerosols to human health cannot be ignored.


Assuntos
Aerossóis , Microbiologia do Ar , Poluentes Atmosféricos/análise , Bacillus/isolamento & purificação , Pequim , Monitoramento Ambiental , Fungos/isolamento & purificação , Humanos , Tamanho da Partícula , Material Particulado
5.
Mar Drugs ; 17(5)2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31058830

RESUMO

The secondary metabolite Tyrian purple, also known as shellfish purple and royal purple, is a dye with historical importance for humans. The biosynthetic origin of Tyrian purple in Muricidae molluscs is not currently known. A possible role for symbiotic bacteria in the production of tyrindoxyl sulphate, the precursor to Tyrian purple stored in the Australian species, Dicathais orbita, has been proposed. This study aimed to culture bacterial symbionts from the purple producing hypobranchial gland, and screen the isolates for bromoperoxidase genes using molecular methods. The ability of bromoperoxidase positive isolates to produce the brominated indole precursor to Tyrian purple was then established by extraction of the culture, and analysis by liquid chromatography-mass spectrometry (LC-MS). In total, 32 bacterial isolates were cultured from D. orbita hypobranchial glands, using marine agar, marine agar with hypobranchial gland aqueous extracts, blood agar, thiosulphate citrate bile salts sucrose agar, and cetrimide agar at pH 7.2. These included 26 Vibrio spp., two Bacillus spp., one Phaeobacter sp., one Shewanella sp., one Halobacillus sp. and one Pseudoalteromonas sp. The two Bacillus species were the only isolates found to have coding sequences for bromoperoxidase enzymes. LC-MS analysis of the supernatant and cell pellets from the bromoperoxidase producing Bacillus spp. cultured in tryptone broth, supplemented with KBr, confirmed their ability to produce the brominated precursor to Tyrian purple, tyrindoxyl sulphate. This study supports a potential role for symbiotic Bacillus spp. in the biosynthesis of Tyrian purple.


Assuntos
Bacillus/genética , Bactérias/genética , Gastrópodes/microbiologia , Peroxidases/genética , Animais , Bacillus/isolamento & purificação , Bacillus/metabolismo , Bactérias/isolamento & purificação , Bactérias/metabolismo , Região Branquial/metabolismo , Região Branquial/microbiologia , Indóis/análise , Moluscos , Análise de Sequência de RNA , Simbiose
6.
J Agric Food Chem ; 67(24): 6828-6836, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31136163

RESUMO

Verticillium wilt, caused by Verticillium dahliae, results in a dramatic loss of cotton yields in China. There is great potential for biocontrol to manage this destructive crop disease. In this study, we obtained the endophytic bacterium Bacillus halotolerans Y6 from Verticillium wilt-resistant cotton Gossypium barbadense Xinhai15; this bacterium possesses strong antagonistic abilities that inhibit V. dahliae spore germination and mycelial growth. The results of the enzyme activity assay, heterologous expression, and gene knockdown showed that the key virulence factor of Y6 for antagonizing V. dahliae was ß -glucanase Bgy6. To facilitate field tests of biological control, we constructed the homologous Bgy6-overexpression strain OY6. Compared with the wild-type Y6 strain, the ß-glucanase activity of OY6 was increased by 91.79%, and the inhibition rate of OY6 against V. dahliae V991 exceeded 96.7%. Moreover, the spores of V. dahliae V991 treated with OY6 showed more mucus and larger holes on the surface, as observed by scanning electron microscopy. Potting test results illustrated that both OY6 and Y6 could improve the resistance of upland cotton to Verticillium wilt. With the inoculation of V. dahliae V991 for 45 days, the disease index of G. hirsutum TM-1 treated with OY6 was only 8.33, which was significantly lower than that in plants treated with the wild-type strain Y6 (17.86) or the controls without bacteria (35.94). Our research provides a new idea for the control of Verticillium wilt in upland cotton via transforming endophytic bacteria of Verticillium wilt-resistant cotton and proposes a new solution to prevent and control Verticillium wilt.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/genética , Endo-1,3(4)-beta-Glucanase/genética , Endófitos/enzimologia , Gossypium/microbiologia , Doenças das Plantas/imunologia , Verticillium/fisiologia , Fatores de Virulência/genética , Antibiose , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/fisiologia , Proteínas de Bactérias/metabolismo , Resistência à Doença , Endo-1,3(4)-beta-Glucanase/metabolismo , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/fisiologia , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Gossypium/imunologia , Doenças das Plantas/microbiologia , Fatores de Virulência/imunologia
7.
Environ Monit Assess ; 191(5): 314, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31037401

RESUMO

The use of pesticides has been increasing due to the great agricultural production worldwide. The pesticides are used to eradicate pests and weeds; however, these compounds are classified as toxic to non-target organisms. Atrazine and diuron are herbicides widely used to control grassy and broadleaf weeds and weed control in agricultural crops and non-crop areas. Heavy metals are also important environmental contaminants that affect the ecological system. This study aimed to investigate the presence of herbicides-degrading genes and heavy metal resistance genes in bacterial isolates from two different soil samples from two Brazilian regions and to determine the genetic location of these genes. In this study, two isolates were obtained and identified as Escherichia fergusonii and Bacillus sp. Both isolates presented atzA, atzB, atzC, atzD, atzE, atzF, puhA, and copA genes and two plasmids each, being the major with ~ 60 Kb and a smaller with ~ 3.2 Kb. Both isolates presented the atzA-F genes inside the larger plasmid, while the puhA and copA genes were detected in the smaller plasmid. Digestion reactions were performed and showed that the ~ 60-Kb plasmid presented the same restriction profile using different restriction enzymes, suggesting that this plasmid harboring the complete degradation pathway to atrazine was found in both isolates. These results suggest the dispersion of these plasmids and the multi-herbicide degradation potential in both isolates to atrazine and diuron, which are widely used in different culture types worldwide.


Assuntos
Atrazina/metabolismo , Bacillus/genética , Bacillus/metabolismo , Diurona/metabolismo , Escherichia/genética , Escherichia/metabolismo , Herbicidas/metabolismo , Metais Pesados/toxicidade , Plasmídeos/genética , Bacillus/isolamento & purificação , Biodegradação Ambiental , Brasil , Farmacorresistência Bacteriana/genética , Monitoramento Ambiental , Escherichia/isolamento & purificação , Plasmídeos/efeitos dos fármacos , Microbiologia do Solo
8.
Ann Lab Med ; 39(5): 470-477, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31037866

RESUMO

BACKGROUND: The emergence of carbapenem resistance among gram-negative bacilli (GNB), mediated by carbapenemase production, has necessitated the development of a simple and accurate device for detecting minimum inhibitory concentrations (MICs) and resistance mechanisms, especially carbapenemase production. We evaluated the performance of the BD Phoenix NMIC-500 panel (BD Diagnostic Systems, Sparks, MD, USA) for antimicrobial susceptibility testing (AST) and carbapenemase-producing organism (CPO) detection. METHODS: We used 450 non-duplicate clinical GNB isolates from six general hospitals in Korea (409 Enterobacteriaceae and 41 glucose non-fermenting bacilli [GNFB] isolates). AST for meropenem, imipenem, ertapenem, ceftazidime, and ceftazidime/avibactam, and CPO detection were performed using the Phoenix NMIC-500 panel. Broth microdilution was used as the reference method for AST. The rates of categorical agreement (CA), essential agreement (EA), minor error (mE), major error (ME), and very major error (VME) were calculated in each antimicrobial. In addition, PCR and sequencing were performed to evaluate the accuracy of CPO detection by the BD Phoenix NMIC-500 panel, and the rate of correct identification was calculated. RESULTS: The CA rates were >90% for all antimicrobials tested with the Enterobacteriaceae isolates, except for imipenem (87.2%). The GNFB CA rates ranged from 92.7% to 100% for all antimicrobials. The ME rates were 1.7% for Enterobacteriaceae and 0% for GNFB. The panel identified 97.2% (243/250) of the carbapenemase-producing isolates. CONCLUSIONS: The BD Phoenix NMIC-500 panel shows promise for AST and CPO detection.


Assuntos
Bactérias Gram-Negativas/isolamento & purificação , Testes de Sensibilidade Microbiana/métodos , Antibacterianos/farmacologia , Bacillus/efeitos dos fármacos , Bacillus/isolamento & purificação , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , beta-Lactamases/genética
9.
Int J Syst Evol Microbiol ; 69(8): 2335-2339, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31125305

RESUMO

A Gram-stain-positive, strictly aerobic, rod-shaped, motile, endospore-forming strain, SYSU K30001T, was isolated from a soil sample collected from a cave in Xingyi county, Guizhou province, south-west China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU K30001T belonged to the genus Bacillus, with the highest sequence similarity to the type strain of Bacillus panaciterrae (98.1 %). Growth occurred at pH 6.0-9.0 (optimum, pH 7.0), at 28-55 °C (optimum, 28 °C) and in the presence of 0-3 % (w/v) NaCl (optimum in the absence of NaCl). Strain SYSU K30001T contained meso-2,6-diaminopimelic acid in the cell-wall peptidoglycan and MK-7 as the only isoprenoid quinone present. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified glycolipid. The major fatty acids were iso-C15 : 0, iso-C17 : 1ω10c, anteiso-C14 : 0 and iso-C17 : 0. The genome G+C content was 39.8 mol%. The average nucleotide identity values between SYSU K30001T and B. panaciterrae DSM 19096T were 72.1 % (ANIb) and 83.1 % (ANIm), which were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and molecular characterizations, strain SYSU K30001T represents a novel species of the genus Bacillus, for which the name Bacillus antri sp. nov. is proposed. The type strain is SYSU K30001T (=KCTC 33954T=CGMCC 1.13871T).


Assuntos
Bacillus/classificação , Cavernas/microbiologia , Filogenia , Microbiologia do Solo , Bacillus/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Glicolipídeos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfatidiletanolaminas , Fosfatidilgliceróis/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
10.
Int J Syst Evol Microbiol ; 69(6): 1714-1719, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30950781

RESUMO

A rod-shaped, endospore-forming, aerobic bacterium, designated FJAT-46582T, was isolated from a sediment sample of the coastal region in Xiapu County, Fujian Province in China. Growth was observed at 10-30 °C (optimum, 25 °C), in 0-7.0 % NaCl (0 %) and at pH 6.0-11.0 (pH 8.0), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK-7. The main fatty acids were anteiso-C17 : 0 (26.5 %), anteiso-C15 : 0 (19.6 %), iso-C15 : 0 (14.4 %) and C16 : 0 (10.5 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidyl ethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain FJAT-46582T with the genus Bacillus, and showed the highest sequence similarity to Bacillus thermotolerans SGZ-8T (97.6 %) and Bacillus ectoinformans (97.1 %). The average nucleotide identity and in silico DNA-DNA hybridization values between strain FJAT-46582T and the most closely related species were 72.3 and 22.9 %, respectively, which were much lower than the thresholds commonly used to define species (96 and 70 %, respectively) indicating that it belonged to a different taxon. The DNA G+C content was 44.2 mol%. The phenotypic characters and taxono-genomics study revealed that strain FJAT-46582T represents a novel Bacillus species, for which the name Bacillus xiapuensis sp. nov. is proposed. The type strain is FJAT-46582T (=JCM 33155=CCTCC AB 2017047T).


Assuntos
Bacillus/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Bacillus/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
11.
J Microbiol Biotechnol ; 29(5): 794-808, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31030454

RESUMO

Bacillus velezensis strain WRN014 was isolated from banana fields in Hainan, China. Bacillus velezensis is an important member of the plant growth-promoting rhizobacteria (PGPR) which can enhance plant growth and control soil-borne disease. The complete genome of Bacillus velezensis WRN014 was sequenced by combining Illumina Hiseq 2500 system and Pacific Biosciences SMRT high-throughput sequencing technologies. Then, the genome of Bacillus velezensis WRN014, together with 45 other completed genome sequences of the Bacillus velezensis strains, were comparatively studied. The genome of Bacillus velezensis WRN014 was 4,063,541bp in length and contained 4,062 coding sequences, 9 genomic islands and 13 gene clusters. The results of comparative genomic analysis provide evidence that (i) The 46 Bacillus velezensis strains formed 2 obviously closely related clades in phylogenetic trees. (ii) The pangenome in this study is open and is increasing with the addition of new sequenced genomes. (iii) Analysis of single nucleotide polymorphisms (SNPs) revealed local diversification of the 46 Bacillus velezensis genomes. Surprisingly, SNPs were not evenly distributed throughout the whole genome. (iv) Analysis of gene clusters revealed that rich gene clusters spread over Bacillus velezensis strains and some gene clusters are conserved in different strains. This study reveals that the strain WRN014 and other Bacillus velezensis strains have potential to be used as PGPR and biopesticide.


Assuntos
Bacillus/genética , Genes Bacterianos/genética , Sequenciamento Completo do Genoma/métodos , Bacillus/classificação , Bacillus/isolamento & purificação , Sequência de Bases , China , Mapeamento Cromossômico , DNA Bacteriano/análise , DNA Bacteriano/genética , Variação Genética , Genoma Bacteriano , Família Multigênica , Musa/microbiologia , Mutação , Filogenia , Desenvolvimento Vegetal , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Metabolismo Secundário/genética , Análise de Sequência de DNA
12.
Can J Microbiol ; 65(6): 405-420, 2019 Jun.
Artigo em Francês | MEDLINE | ID: mdl-30935210

RESUMO

In the dairy industry, bacterial contaminants persist on equipment surfaces due to spore and biofilm formation. These are involved in cross-contamination problems that affect the quality of processed products and limit their life. The pasteurization process, in which milk is submitted to moderate heat treatment, is inefficient against bacterial spores. The most prevalent sporulated bacteria belong to Bacillus and related genera. The situation is more complicated in countries where pasteurized milk is derived from imported milk powder originally contaminated by bacterial spores. Studies have shown biofilm formation on dairy equipment by mesophilic strains from the group Bacillus cereus and thermophilic strains from the genus Geobacillus. These biofilms are resistant to cleaning procedures and are sources of chronic contamination of pasteurized milk. This review analyzes the dairy situation in Algeria exposed to sporulated flora and derived biofilm problems, with the aim of proposing efficient solutions in the light of current knowledge. [Journal translation].


Assuntos
Biofilmes , Indústria de Laticínios , Leite/microbiologia , Argélia , Animais , Bacillus/isolamento & purificação , Esporos Bacterianos
13.
Appl Microbiol Biotechnol ; 103(9): 3669-3682, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30911788

RESUMO

Some members of the Bacillus velezensis (Bv) group (e.g., Bv FZB42T and AS3.43) were previously assigned grouping with B. subtilis and B. amyloliquefaciens, based on the fact that they shared a 99% DNA-DNA percentage phylogenetic similarity. However, hinging on current assessments of the pan-genomic reassignments, the differing phylogenomic characteristics of Bv from B. subtilis and B. amyloliquefaciens are now better understood. Within this re-grouping/reassignment, the various strains within the Bv share a close phylogenomic resemblance, and a number of these strains have received a lot of attention in recent years, due to their genomic robustness, and the growing evidence for their possible utilization in the agricultural industry for managing plant diseases. Only a few applications for their use medicinally/pharmaceutically, environmentally, and in the food industry have been reported, and this may be due to the fact that the majority of those strains investigated are those typically occurring in soil. Although the intracellular unique biomolecules of Bv strains have been revealed via in silico genome modeling and investigated using transcriptomics and proteomics, a further inquisition into the Bv metabolome using newer technologies such as metabolomics could elucidate additional applications of this economically relevant Bacillus species, beyond that of primarily the agricultural sector.


Assuntos
Bacillus/classificação , Bacillus/metabolismo , Filogenia , Bacillus/genética , Bacillus/isolamento & purificação , Microbiologia de Alimentos , Genoma Bacteriano , Genômica , Microbiologia Industrial , Metaboloma
14.
Int J Syst Evol Microbiol ; 69(6): 1591-1596, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30912738

RESUMO

A rod-shaped, endospore-forming, facultative anaerobic bacterium, designated FJAT-45385T, was isolated from soil collected from Devil City in the Xinjiang Autonomous Region in China. Growth was observed at 20-40 °C (optimum, 30 °C), pH 7.0-11.0 (pH 9.0) and in 0-10.0 % NaCl (4 %), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK-7. The main fatty acids were anteiso-C15 : 0 (37.4 %), iso-C15 : 0 (15.1 %) and C16 : 0 (12.6 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain FJAT-45385T to the genus Bacillus, and showed the highest sequence similarity to Bacillus wakoensis DSM 2521T (96.0 %). The average nucleotide identity and in silico DNA-DNA hybridization values between strain FJAT-45385T and its closest related species were 67.8 and 35.5 %, respectively, which were much lower than the thresholds commonly used to define species (96 and 70 %, respectively) indicating that it belong to a different taxon. The DNA G+C content was 38.1 mol%. The phenotypic characters and taxono-genomics study revealed that strain FJAT-45385T represents a novel Bacillus species, for which the name Bacillus urbisdiaboli sp. nov. is proposed. The type strain is FJAT-45385T (=DSM 104651T=CCTCC AB 2016263T).


Assuntos
Bacillus/classificação , Filogenia , Microbiologia do Solo , Bacillus/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
15.
Chemosphere ; 224: 272-279, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30825853

RESUMO

Microorganisms with the function of biological mineralization were isolated from a soil. The bacteria were identified by 16S rRNA as Bacillus sp and possessed a significant lead removal ability. Lead removal experiment indicated that the mathematical model of η=ηmax-ηcet/k fit the variation of removal rate with time well. Different from the previous studies, this work discovered that the culture medium had the ability to remove aqueous lead (Pb2+). At the same dosage, the removal rates of Pb2+ followed the order of: cells < culture medium < metabolites < bacterial suspension. The lead removal mechanism was further explored using the techniques of XRD, FTIR, and SEM. The results showed that during the fermentation, the bacteria decomposed phosphate-containing organic compounds in the culture medium to generate a large amount of phosphate groups on the surface of the bacterial cells. Pb2+ was precipitated in the form of Pb3(PO4)2 stable minerals.


Assuntos
Bacillus/isolamento & purificação , Chumbo/análise , Fosfatos/química , Microbiologia do Solo , Poluentes do Solo/análise , Solo/química , Bacillus/metabolismo , Biomineralização , Minerais
16.
World J Microbiol Biotechnol ; 35(4): 56, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30900044

RESUMO

Investigation of bacterial chromate tolerance has mostly focused on strains originating from polluted sites. In the present study, we isolated 33 chromate tolerant strains from diverse environments harbouring varying concentrations of chromium (Cr). All of these strains were able to grow on minimal media with at least 2 mM hexavalent chromium (Cr(VI)) and their classification revealed that they belonged to 12 different species and 8 genera, with a majority (n = 20) being affiliated to the Bacillus cereus group. Selected B. cereus group strains were further characterised for their chromate tolerance level and the ability to remove toxic Cr(VI) from solution. A similar level of chromate tolerance was observed in isolates originating from environments harbouring high or low Cr. Reference B. cereus strains exhibited the same Cr(VI) tolerance which indicates that a high chromate tolerance could be an intrinsic group characteristic. Cr(VI) removal varied from 22.9% (strain PCr2a) to 98.5% (strain NCr4). Strains NCr1a and PCr12 exhibited the ability to grow to the greatest extent in Cr(VI) containing media (maximum growth of 65.3% and 64.9% relative to that in the absence of Cr(VI), respectively) accompanied with high chromate removal activity (73.7% and 74.4%, respectively), making them prime candidates for the investigation of chromate tolerance mechanisms in Gram-positive bacteria and Cr(VI) bioremediation applications.


Assuntos
Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Cromatos/toxicidade , Cromo/toxicidade , Tolerância a Medicamentos , Microbiologia do Solo , Poluentes do Solo , Bacillus/classificação , Bacillus/efeitos dos fármacos , Bacillus/isolamento & purificação , Bactérias/genética , Biodegradação Ambiental , Meios de Cultura/química , Microbiologia Ambiental , Sedimentos Geológicos/microbiologia , Testes de Sensibilidade Microbiana , Oxirredução , Filogenia , RNA Ribossômico 16S/genética
17.
Int J Syst Evol Microbiol ; 69(4): 1155-1161, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30816840

RESUMO

A Gram-stain-positive, motile, rod-shaped bacterial strain, YN-1T, was isolated from a rice field in the town of Jietou, Yunnan Province, PR China. Colonies were circular, 1-2 mm in diameter, creamy white, with slightly irregular margins. The isolate grew optimally at 37 °C, pH 7.0 and with 1.0 % (w/v) NaCl. On the basis of the results of 16S rRNA gene sequence similarity comparisons, YN-1T clustered together with other species of the genus Bacillus and showed highest similarities with Bacillus onubensis 0911MAR22V3T (98.0 %), Bacillus humi LMG22167T (97.5 %), 'Bacillus timonensis' 10403023 (97.4 %) and 'Bacillussinesaloumensis' P3516 (97.1 %). However, the DNA-DNA hybridization values between YN-1T and closely related strains of species of the genus Bacillus were well below 47 %, indicating that they represent different taxa. The average nucleotide identity and the Genome-to-Genome Distance Calculator also revealed low relatedness (below 95 and 70 %, respectively) between YN-1T and type strains of closely related species of the genus Bacillus. The DNA G+C content of the strain was 40 mol%. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0, and C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids, three unidentified aminophospholipids and two other unidentified lipids. Physiological and biochemical test results were also different from those of the most closely related species. On the basis of the phenotypic, genetic and chemotaxonomic data, strain YN-1T is considered to represent a novel species of the genus Bacillus, for which the name Bacillusaciditolerans sp. nov. is proposed, with strain YN-1T (=CCTCC AB 2017280T=JCM 32973T) as the type strain.


Assuntos
Bacillus/classificação , Oryza/microbiologia , Filogenia , Microbiologia do Solo , Bacillus/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
18.
Bioengineered ; 10(1): 13-22, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30836830

RESUMO

The deep-sea bacterium strain FA13 was isolated from the sediment of the South Atlantic Ocean and identified as Bacillus circulans based on 16S ribosomal DNA sequence. Through liquid fermentation with five media, the cell-free supernatant fermented with ISP2 showed the highest inhibition activities against mycelial growth of Aspergillus parasiticus mutant strain NFRI-95 and accumulation of norsolorinic acid, a precursor for aflatoxin production. Based on ISP2, uniform design was used to optimize medium formula and fermentation conditions. After optimization, the inhibition efficacy of the 20-time diluted supernatant against A. parasiticus NFRI-95 mycelial growth and aflatoxin production was increased from 0-23.1% to 100%. Moreover, compared to the original protocol, medium cost and fermentation temperature were significantly reduced, and dependence on seawater was completely relieved, thus preventing the fermentor from corrosion. This is the first report of a deep-sea microorganism which can inhibit A. parasiticus NFRI-95 mycelial growth and aflatoxin production.


Assuntos
Aflatoxinas/antagonistas & inibidores , Antraquinonas/antagonistas & inibidores , Antitoxinas/isolamento & purificação , Aspergillus/efeitos dos fármacos , Bacillus/metabolismo , Micélio/efeitos dos fármacos , Aflatoxinas/biossíntese , Antraquinonas/metabolismo , Antitoxinas/farmacologia , Organismos Aquáticos , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Aspergillus/patogenicidade , Oceano Atlântico , Bacillus/classificação , Bacillus/genética , Bacillus/isolamento & purificação , Reatores Biológicos , Meios de Cultura/química , Análise Fatorial , Fermentação , Sedimentos Geológicos/microbiologia , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Micélio/patogenicidade , Filogenia , RNA Ribossômico 16S/genética , Temperatura Ambiente
19.
Arch Microbiol ; 201(5): 623-638, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30747263

RESUMO

Bisphenol A (BPA) is a synthetic chemical with known deleterious effects on biota. A genome sequencing project is an important starting point for designing a suitable BPA bioremediation process, because it provides valuable genomic information about the physiological, metabolic, and genetic potential of the microbes used for the treatment. This study explored genomic insights provided by the BPA-degrading strain Bacillus sp. GZB, previously isolated from electronic-waste-dismantling site. The GZB genome is a circular chromosome, comprised of a total of 4,077,007 bp with G+C content comprising 46.2%. Genome contained 23 contigs encoded by 3881 protein-coding genes with nine rRNA and 53 tRNA genes. A comparative study demonstrated that strain GZB bloomed with some potential features as compared to other Bacillus species. In addition, strain GZB developed spore cells and displayed laccase activity while growing at elevated stress levels. Most importantly, strain GZB contained many protein-coding genes associated with BPA degradation, as well as the degradation of several other compounds. The protein-coding genes in the genome revealed the genetic mechanisms associated with the BPA degradation by strain GZB. This study predicts four possible degradation pathways for BPA, contributing to the possible use of strain GZB to remediate different polluted environments in the future.


Assuntos
Bacillus/genética , Bacillus/metabolismo , Compostos Benzidrílicos/metabolismo , Biodegradação Ambiental , Resíduo Eletrônico , Lacase/metabolismo , Fenóis/metabolismo , Bacillus/isolamento & purificação , Composição de Bases/genética , Sequência de Bases , Mapeamento Cromossômico , Genoma Bacteriano/genética
20.
Environ Toxicol Pharmacol ; 67: 108-116, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30807915

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are recalcitrant hazardous environmental contaminants. Various strategies, including chemical and physical like oxidation, fixation, leaching, and electrokinetic or biological-based techniques are used for remediation of polluted sites. Bioremediation of PAHs, via PAH-degrading endophytic and rhizospheric microbes, represent a time-/cost-effective way for ecorestoration. Four bacterial strains were isolated from contaminated soil on MSM supplemented with anthracene, alpha-naphthalene or catechol as sole carbon sources. These isolates were identified with 16S rRNA as Bacillus anthracis, B. cereus, B. mojavensis and B. subtilis. The degradation efficiency on the selected aromatic compounds was tested by HPLC analysis. B. subtilis showed the highest degradation efficiency of anthracene (99%) after five days of incubation. B. subtilis showed the highest catechol 1, 2 dioxygenase activity in MSM supplemented with anthracene. The enzyme was purified by gel filtration chromatography and characterized (70 kD, Km 2.7 µg and Vmax 178U/mg protein). The catechol 1,2 dioxygenase gene from the identified four bacterial strains were isolated and submitted to GenBank (accession numbers MG255165-MG255168). The gene expression level of catechol 1,2 dioxygenase was upregulated 23.2-fold during the 72 h of incubation period. Furthermore, B. subtilis is a promising strain to be used in bioremediation of aromatic compounds-contaminated environments.


Assuntos
Bacillus/metabolismo , Proteínas de Bactérias/metabolismo , Catecol 1,2-Dioxigenase/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes do Solo/metabolismo , Bacillus/genética , Bacillus/isolamento & purificação , Proteínas de Bactérias/genética , Biodegradação Ambiental , Catecol 1,2-Dioxigenase/genética , DNA Bacteriano/genética , RNA Ribossômico 16S/genética , Microbiologia do Solo
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