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1.
PLoS One ; 15(7): e0235560, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614907

RESUMO

The present study investigated the effects of four woody forages (Moringa oleifera Lam (MOL), fermented MOL, Folium mori (FM) and fermented FM) on biodiversity and bioactivity of aerobic culturable gut bacteria of tilapia (Oreochromis niloticus) by a traditional culture-dependent method. A total of 133 aerobic culturable isolates were recovered and identified from the gut of tilapia, belonging to 35 species of 12 genera in three bacterial phyla (Firmicutes, Actinobacteria and Proteobacteria). Among them, 6 bacterial isolates of Bacillus baekryungensis, Bacillus marisflavi, Bacillus pumilus, Bacillus methylotrophicus, Proteus mirabilis and Pseudomonas taiwanensis were isolated from all the five experimental groups. The Bray-Curtis analysis showed that the bacterial communities among the five groups displayed obvious differences. In addition, this result of bioactivity showed that approximate 43% of the aerobic culturable gut bacteria of tilapia displayed a distinct anti-bacterial activity against at least one of four fish pathogens Streptococcus agalactiae, Streptococcus iniae, Micrococcus luteus and Vibrio parahemolyticus. Furthermore, Bacillus amyloliquefaciens and Streptomyces rutgersensis displayed strong activity against all four indicator bacteria. These results contribute to our understanding of the intestinal bacterial diversity of tilapia when fed with woody forages and how certain antimicrobial bacteria flourished under such diets. This can aid in the further exploitation of new diets and probiotic sources in aquaculture.


Assuntos
Bactérias/isolamento & purificação , Ciclídeos/microbiologia , Microbioma Gastrointestinal , Aerobiose , Animais , Antibacterianos/farmacologia , Bacillus/efeitos dos fármacos , Bacillus/genética , Bacillus/isolamento & purificação , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Biodiversidade , Dieta/veterinária , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/microbiologia , Testes de Sensibilidade Microbiana , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/metabolismo , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Streptococcus/isolamento & purificação
2.
Ecotoxicol Environ Saf ; 201: 110798, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32526591

RESUMO

Despite constant progress in the understanding of the mechanisms related to the effects of biosurfactants in the bioremediation processes of oily residues, the possibility of antagonist effects on microbial growth and the production in situ of these compounds must be elucidated. The aims of this work were a) to evaluate the effects of the addition of a homemade biosurfactant of Bacillus methylotrophicus on the microbial count in soil in order to determine the possibility of inhibitory effects, and b) to accomplish biostimulation using media prepared with whey and bioaugmentation with B. methylotrophicus, analyzing the effects on the bioremediation of diesel oil and evidencing the in situ production of biosurfactants through effects on surface tension. The homemade bacterial biosurfactant did not present inhibitory effects acting as a biostimulant until 4000 mg biosurfactant/kg of soil. The biostimulation and bioaugmentation presented similar better results (p > 0.05) with the degradation of oil (~60%) than natural attenuation due to the low quantities of biostimulants added. For bioaugmentated and biostimulated soils, a decrease of surface tension between 30 and 60 days was observed, indicating the production of tensoactives in the soil, which was not observed in natural attenuation or a control treatment.


Assuntos
Bacillus/efeitos dos fármacos , Argila/química , Petróleo/análise , Poluentes do Solo/análise , Solo/química , Tensoativos/farmacologia , Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Biodegradação Ambiental , Petróleo/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Tensoativos/química
3.
Bull Environ Contam Toxicol ; 104(6): 820-827, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32424434

RESUMO

Di-(2-ethylhcxyl) phthalate (DEHP) is applied as plasticizer, which results in the pollution of environment. In this study, the effects of DEHP on soil microbial functions, structure and genetic diversity were investigated. The concentration of DEHP in the soil were 0, 0.1, 1, 10 and 50 mg/kg, and the experimental period were 28 days. DEHP reduced the quantity, abundance, species dominance and homogeneity of soil microbes during the first 14 days. In addition, microbial utilization efficiency of carbon (carbohydrates, aliphatics, amino acids, metabolites) was impacted after 28 days, though the effects gradually weakened. Based on denaturing gradient gel electrophoresis and clone library analysis, in the presence of DEHP, the dominant microbes in the DEHP-contaminated soil were Sphingomonas and Bacillus, which belonged to the Acidobacteria and Proteobacteriav, respectively. With 0.1 or 1 mg/kg of DEHP, the relative abundances of Acidobacteria were higher, and with 10 or 50 mg/kg of DEHP, the relative abundances of Proteobacteria were higher.


Assuntos
Dietilexilftalato/toxicidade , Microbiota/efeitos dos fármacos , Plastificantes/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo/química , Bacillus/efeitos dos fármacos , Bacillus/metabolismo , Carbono/metabolismo , Dietilexilftalato/análise , Plastificantes/análise , Poluentes do Solo/análise , Sphingomonas/efeitos dos fármacos , Sphingomonas/metabolismo
4.
Arch Microbiol ; 202(7): 1817-1829, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32440759

RESUMO

Today, industrial activities lead to the accumulation of heavy metals in the soil, water, and air due to mine deposits and operations, fertilizers, and drugs used in agriculture, and urban wastes. Using microorganism bioremediation of metals is an important technique in solving these problems. Herein, a rhizoid bacterium isolated from orchids that grow in Ovit plateau was defined as Bacillus sp. 5O5Y11 by conventional and molecular methods and the bioremediation properties of strain were investigated. It was capable of growth at high salt (10-15%) concentration, wide temperature (10-45 °C) and pH range (pH 4.5-8.0), and was observed to have strong lecithinase, gelatinase activity, and nitrate reduction. When the plant growth-promoting properties of this strain were examined, strong siderophore and ammonium production were observed in in vitro conditions. Bacillus sp. 5O5Y11 was found to have high tolerance to a group of heavy metals [iron (Fe), copper (Cu), lead (Pb), silver (Ag), zinc (Zn)]. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of copper metal on Bacillus sp. 5O5Y11 were determined as 12.5 mM and 50 mM, respectively. The effectiveness of this bacterium on the germination and growth of maize plant in the presence and absence of copper were investigated. These results suggest that Bacillus sp. 5O5Y11 is a microorganism, which has potential in metal bioremediation and plant growth promotion.


Assuntos
Bacillus/efeitos dos fármacos , Biodegradação Ambiental , Cobre/toxicidade , Microbiologia do Solo , Zea mays/efeitos dos fármacos , Zea mays/microbiologia , Bacillus/isolamento & purificação , Bacillus/metabolismo , Metais Pesados/toxicidade , Desenvolvimento Vegetal/efeitos dos fármacos , Poluentes do Solo/toxicidade
5.
PLoS One ; 15(4): e0231274, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32271828

RESUMO

We evaluated the minimum inhibitory concentrations of clindamycin and erythromycin toward 98 Bacillus licheniformis strains isolated from several types of fermented soybean foods manufactured in several districts of Korea. First, based on recent taxonomic standards for bacteria, the 98 strains were separated into 74 B. licheniformis strains and 24 B. paralicheniformis strains. Both species exhibited profiles of erythromycin resistance as an acquired characteristic. B. licheniformis strains exhibited acquired clindamycin resistance, while B. paralicheniformis strains showed unimodal clindamycin resistance, indicating an intrinsic characteristic. Comparative genomic analysis of five strains showing three different patterns of clindamycin and erythromycin resistance identified 23S rRNA (adenine 2058-N6)-dimethyltransferase gene ermC and spermidine acetyltransferase gene speG as candidates potentially involved in clindamycin resistance. Functional analysis of these genes using B. subtilis as a host showed that ermC contributes to cross-resistance to clindamycin and erythromycin, and speG confers resistance to clindamycin. ermC is located in the chromosomes of strains showing clindamycin and erythromycin resistance and no transposable element was identified in its flanking regions. The acquisition of ermC might be attributable to a homologous recombination. speG was identified in not only the five genome-analyzed strains but also eight strains randomly selected from the 98 test strains, and deletions in the structural gene or putative promoter region caused clindamycin sensitivity, which supports the finding that the clindamycin resistance of Bacillus species is an intrinsic property.


Assuntos
Bacillus licheniformis/genética , Bacillus/genética , Clindamicina/farmacologia , Farmacorresistência Bacteriana/genética , Genes Bacterianos , Genômica , Bacillus/efeitos dos fármacos , Bacillus/crescimento & desenvolvimento , Bacillus licheniformis/classificação , Bacillus licheniformis/efeitos dos fármacos , Bacillus licheniformis/crescimento & desenvolvimento , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/genética , Bacillus subtilis/crescimento & desenvolvimento , Sequência de Bases , Farmacorresistência Bacteriana/efeitos dos fármacos , Eritromicina/farmacologia , Testes de Sensibilidade Microbiana
6.
J Biosci Bioeng ; 130(1): 48-53, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32224010

RESUMO

Macrolactins (MLNs) have attracted considerable attention due to their antibacterial and antiviral properties. Here, the MLN production of Bacillus sp. strain IMDGX0108 was improved using a breeding strategy of atmospheric room temperature plasma (ARTP) technique. Combining with a selection procedure based on the colony morphology and specific growth rate index (SGRI), two genetically stable mutants A29 and A72 were identified. The MLN production of A29 and A72 was 35.2% and 52.8% greater than that of the parent strain, respectively. The best-performing mutant A72 was subjected to RNA-sequence analysis. Five pathways were significantly enriched, and fatty acid bioprocesses might play an important role in improving the production of MLNs. The combined strategy developed herein (i.e., ARTP mutation plus an efficient screening procedure) might be an appropriate method by which to obtain strains overproducing MLNs.


Assuntos
Bacillus/efeitos dos fármacos , Bacillus/crescimento & desenvolvimento , Alcaloides Indólicos/metabolismo , Gases em Plasma/farmacologia , Bacillus/química , Bacillus/genética , Ácidos Graxos/metabolismo , Cinética , Mutação
7.
Arch Microbiol ; 202(6): 1477-1488, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32193579

RESUMO

Shallow hydrothermal systems are extreme environments. The sediments and fluids emitted from the vents present unusual physical and chemical conditions compared to other marine areas, which promotes unique biodiversity that has been of great interest for biotechnology for some years. In this work, a bioprospective study was carried out to evaluate the capacity of bacteria associated with shallow hydrothermal vents to produce biofilm-inhibiting compounds. Degradation assays of N-acyl homoserine lactone (AHL) autoinducers (C6HSL) involved in the quorum sensing process were carried out on 161 strains of bacteria isolated from three shallow hydrothermal systems located in Baja California Sur (BCS), Mexico. The biosensor Chromobacterium violaceum CV026 was used. Twenty-three strains showed activity, and organic extracts were obtained with ethyl acetate. The potential of the extracts to inhibit the formation of biofilms was tested against two human pathogenic strains (Pseudomonas aeruginosa PAO1 and Aeromonas caviae ScH3), a shrimp pathogen (Vibrio parahaemolyticus M8), and two marine strains identified as producing biofilms on submerged surfaces (Virgibacillus sp C29 and Vibrio alginolyticus C96). The results showed that Vibrio alginolyticus and Brevibacillus thermoruber, as well as some thermotolerant strains (mostly Bacillus), produce compounds that inhibit bacterial biofilms (B. licheniformis, B. paralicheniformis, B. firmus, B. oceanizedimenis, B. aerius and B. sonorensis).


Assuntos
Antibacterianos/metabolismo , Antibiose/fisiologia , Biofilmes/crescimento & desenvolvimento , Chromobacterium/metabolismo , Fontes Hidrotermais/microbiologia , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Aeromonas caviae/efeitos dos fármacos , Bacillus/efeitos dos fármacos , Brevibacillus/efeitos dos fármacos , Chromobacterium/isolamento & purificação , Chromobacterium/fisiologia , México , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/fisiologia , Vibrio alginolyticus/efeitos dos fármacos
8.
Appl Biochem Biotechnol ; 190(2): 391-409, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31363982

RESUMO

Microorganisms that survive in the high salt environment have been shown to be a potential source for metabolites with pharmaceutical importance. In the present study, we have investigated the effect of 5 and 10% (w/v) NaCl on growth, biochemical changes, and metabolite production in seven moderately halophilic bacteria isolated from the salterns/mangrove area of South India. Metabolite production by Bacillus VITPS3 increased by 3.18-fold in the presence of 10% (w/v) NaCl concentration. Total phenolic and flavonoid content increased in Bacillus VITPS5 (11.3-fold) and Planococcus maritimus VITP21 (5.99-fold) whereas ß-carotene content was less at higher NaCl concentrations. VITP21 and VITPS5, in response to NaCl, produced metabolites with higher (6.72- and 4.91-fold) DPPH and ABTS radical scavenging activity. UV/visible spectrophotometry of the extracts confirmed the presence of flavonoids, phenolics, and related compounds. 1H-NMR spectra indicated substantial changes in the metabolite production in response to salt concentration. Principal component analysis (PCA) revealed that VITP21 extracts exhibited the highest antioxidant activity compared with other extracts. The present study presents the first report on the comparative analysis of pigment production by moderate halophilic bacteria, in response to the effect of salt and their relation to radical scavenging property.


Assuntos
Antioxidantes/farmacologia , Bacillus/efeitos dos fármacos , Pigmentos Biológicos/biossíntese , Planococcus (Bactéria)/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Compostos de Bifenilo/metabolismo , Depuradores de Radicais Livres/farmacologia , Picratos/metabolismo , Planococcus (Bactéria)/crescimento & desenvolvimento , Planococcus (Bactéria)/metabolismo
9.
J Appl Microbiol ; 128(4): 920-933, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31758752

RESUMO

AIMS: In case of biological hazards and pandemics, personal protective equipment of rescue forces is currently manually decontaminated with harmful disinfectants, primarily peracetic acid. To overcome current drawbacks regarding supply, handling and disposal of chemicals, the use of plasma processed air (PPA) represents a promising alternative for surface decontamination on site. In this study, the sporicidal efficiency of a portable plasma system, designed for field applications, was evaluated. METHODS AND RESULTS: The developed plasma device is based on a dielectric barrier discharge (DBD) and operated with ambient air as process gas. PPA from the plasma nozzle was flushed into a treatment chamber (volume: 300 l) and bacterial endospores (Bacillus subtilis and Bacillus atrophaeus) dried on different surfaces were treated under variable conditions. Reductions in spores by more than 4 log10 were found within 3 min of PPA exposure. However, the presence of endospores in agglomerates or in an organic matrix as well as the complexity of the respective surface microstructure negatively affected the inactivation efficiency. When endospores were embedded in a dried protein matrix, mechanical wiping with swabs during exposure to PPA increased the inactivation effect significantly. Gaseous ozone alone did not provide a sporicidal effect. Significant spore inactivation was only obtained when water vapour was injected into the PPA stream. CONCLUSION: The results show that endospores dried on surfaces can be reduced by several orders of magnitude within few minutes in a treatment chamber which is flushed with PPA from of a DBD plasma nozzle. SIGNIFICANCE AND IMPACT OF THE STUDY: Plasma processed air generated on site by DBD plasma nozzles could be a suitable alternative for the disinfection of various surfaces in closed rooms.


Assuntos
Descontaminação/métodos , Desinfetantes/farmacologia , Contaminação de Equipamentos/prevenção & controle , Gases em Plasma/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Bacillus/efeitos dos fármacos , Bacillus/fisiologia , Descontaminação/instrumentação , Umidade , Propriedades de Superfície
10.
J Microbiol Biotechnol ; 30(3): 404-416, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-31693829

RESUMO

Bacteria that are resistant to high temperatures and alkaline environments are essential for the biological repair of damaged concrete. Alkaliphilic and halotolerant Bacillus sp. AK13 was isolated from the rhizosphere of Miscanthus sacchariflorus. Unlike other tested Bacillus species, the AK13 strain grows at pH 13 and withstands 11% (w/v) NaCl. Growth of the AK13 strain at elevated pH without urea promoted calcium carbonate (CaCO3) formation. Irregular vateritelike CaCO3 minerals that were tightly attached to cells were observed using field-emission scanning electron microscopy. Energy-dispersive X-ray spectrometry, confocal laser scanning microscopy, and X-ray diffraction analyses confirmed the presence of CaCO3 around the cell. Isotope ration mass spectrometry analysis confirmed that the majority of CO32- ions in the CaCO3 were produced by cellular respiration rather than being derived from atmospheric carbon dioxide. The minerals produced from calcium acetate-added growth medium formed smaller crystals than those formed in calcium lactate-added medium. Strain AK13 appears to heal cracks on mortar specimens when applied as a pelletized spore powder. Alkaliphilic Bacillus sp. AK13 is a promising candidate for self-healing agents in concrete.


Assuntos
Bacillus/genética , Carbonato de Cálcio/farmacologia , Genoma Bacteriano , Álcalis/química , Bacillus/efeitos dos fármacos , Precipitação Química , Filogenia
11.
Med Chem ; 16(1): 104-118, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30398118

RESUMO

OBJECTIVE: Due to the incidence of resistance, a series of sulfonamide-derived 1,2,4- triazoles were synthesized and evaluated. METHOD: The novel sulfonamide-derived 1,2,4-triazoles were prepared starting from commercial acetaniline and chlorosulfonic acid by sulfonylation, aminolysis, N-alkylation and so on. The antimicrobial activity of the synthesized compounds were evaluated in vitro by two-fold serial dilution technique. RESULTS: In vitro antimicrobial evaluation found that 2-chlorobenzyl sulfonamide 1,2,4-triazole 7c exhibited excellent antibacterial activities against MRSA, B. subtilis, B. typhi and E. coli with MIC values of 0.02-0.16 µmol/mL, which were comparable or even better than Chloromycin. The preliminary mechanism suggested that compound 7c could effectively bind with DNA, and also it could bind with human microsomal heme through hydrogen bonds in molecular docking. Computational chemical studies were performed on compound 7c to understand the structural features that are essential for activity. Additionally, compound 7c could generate a small amount of reactive oxygen species (ROS). CONCLUSION: Compound 7c could serve as a potential clinical antimicrobial candidate.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Sulfonamidas/farmacologia , Triazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Bacillus/efeitos dos fármacos , Relação Dose-Resposta a Droga , Desenho de Fármacos , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Saccharomyces cerevisiae/efeitos dos fármacos , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Triazóis/síntese química , Triazóis/química
12.
Food Chem ; 311: 126057, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31869636

RESUMO

Fermented foods have been consumed for centuries in various parts of the world and are known to be rich resources of functionally important microorganisms. This study documents the antioxidative, anticancer and enzyme-inhibiting properties of potential probiotic Bacillus strains isolated from fermented brine mango pickle. Antioxidant activity was determined through in-vitro assays namely, DPPH•, ABTS•+, hydroxyl radical scavenging ability, reducing activity, superoxide anion scavenging ability, linoleic acid and plasma lipid peroxidation ability. Both intact cells (IC) and intracellular cell-free extracts (CFE) from most of the strains exhibited prominent antioxidant activity. Likewise, CFE and intracellular cell-free supernatants (CFS) exhibited potential inhibitory activities towards α-amylase, α-glucosidase and tyrosinase. Interestingly, CFS and crude ethyl acetate extracts of PUFSTP35 (Bacillus licheniformis KT921419) displayed strong anticancer activity against HT-29 colon cancer cell line. Hence, these probiotic strains have been showed to exhibit unique functional properties and could be further commercially exploited.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Mangifera/química , Probióticos/farmacologia , Bacillus/efeitos dos fármacos , Fermentação , Células HT29 , Humanos , Mangifera/microbiologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Sais , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases
13.
Environ Monit Assess ; 192(1): 20, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31820108

RESUMO

The concept of the study resulted from the lack of accurate data on the toxicity of bisphenol F (BPF) coinciding with the need for immediate changes in the global economic policy eliminating the effects of environmental contamination with bisphenol A (BPA). The aim of the experiment was to determine the scale of the previously unstudied inhibitory effect of BPF on soil biochemical activity. To this end, in a soil subjected to increasing BPF pressure at three contamination levels of 0, 5, 50 and 500 mg BPF kg-1 DM, responses of soil enzymes, dehydrogenases, catalase, urease, acid phosphatase, alkaline phosphatase, arylsulphatase and ß-glucosidase, were examined. Moreover, the study suggested a potentially effective way of biostimulating the soil by means of bioaugmentation with a consortium of four bacterial species: Pseudomonas umsongensis, Bacillus mycoides, Bacillus weihenstephanensis and Bacillus subtilis, and the following fungal species: Mucor circinelloides, Penicillium daleae, Penicillium chrysogenum and Aspergillus niger. It was found that BPF was a controversial BPA analogue due to the fact that it contributed to the inhibition of all the enzyme activities. Dehydrogenases proved to be the most sensitive to bisphenol contamination of the soil. The addition of 5 mg BPF kg-1 DM of soil triggered an escalation of the inhibition comparable to that for the other enzymes only after exposing them to the effects of 50 and 500 mg BPF kg-1 DM of soil. Moreover, BPF generated low activity of urease, acid phosphatase, alkaline phosphatase and ß-glucosidase. Bacterial inoculum increased the activity of urease, ß-glucosidase, catalase and alkaline phosphatase. Seventy-six percent of BPF underwent biodegradation during the 5 days of the study.


Assuntos
Compostos Benzidrílicos/análise , Biodegradação Ambiental , Monitoramento Ambiental , Fenóis/análise , Microbiologia do Solo , Poluentes do Solo/análise , Arilsulfatases , Bacillus/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Oxirredutases , Solo , Estrobilurinas , Urease
14.
Biosens Bioelectron ; 143: 111628, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31476599

RESUMO

A combined calorimetric gas- and spore-based biosensor array is presented in this work to monitor and evaluate the sterilization efficacy of gaseous hydrogen peroxide in aseptic filling machines. H2O2 has been successfully measured under industrial conditions. Furthermore, the effect of H2O2 on three different spore strains , namely Bacillus atrophaeus, Bacillus subtilis and Geobacillus stearothermophilus, has been investigated by means of SEM, AFM and impedimetric measurements. In addition, the sterilization efficacy of a spore-based biosensor and the functioning principle are addressed and discussed: the sensor array is convenient to be used in aseptic food industry to guarantee sterile packages.


Assuntos
Técnicas Biossensoriais , Calorimetria , Peróxido de Hidrogênio/isolamento & purificação , Esporos Bacterianos/efeitos dos fármacos , Bacillus/efeitos dos fármacos , Bacillus/crescimento & desenvolvimento , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Desinfetantes/química , Desinfetantes/isolamento & purificação , Gases/química , Gases/isolamento & purificação , Geobacillus stearothermophilus/efeitos dos fármacos , Geobacillus stearothermophilus/crescimento & desenvolvimento , Humanos , Peróxido de Hidrogênio/farmacologia , Infertilidade , Esporos Bacterianos/crescimento & desenvolvimento , Esterilização
15.
Food Microbiol ; 84: 103244, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421772

RESUMO

Today, there is no effective non-thermal method to inactivate unwanted bacterial spores in foods. High-Pressure (HP) process has been shown to act synergistically with moderate heating and the bacteriocin nisin to inactivate spores but the mechanisms have not been elucidated. The purpose of the present work was to investigate in depth the synergy of HP and nisin on various foodborne spore species and to bring new elements of understandings. For this purpose, spores of Bacillus pumilus, B. sporothermodurans, B. licheniformis, B. weihenstephanensis, and Clostridium sp. were suspended in MES buffer, in skim milk or in a liquid medium simulating cooked ham brine and treated by HP at 500 MPa for 10 min at 50 °C or 20 °C. Nisin (20 or 50 IU/mL) was added at three different points during treatment: during HP, during and or in the plating medium of enumeration. In the latter two cases, a high synergy was observed with the inhibition of the spores of Bacillus spp. The evaluation of the germinated fraction of Bacillus spp. spores after HP revealed that this synergy was likely due to the action of nisin on HP-sensitized spores, rather than on HP-germinated spores. Thus, the combination of nisin and HP can lead to Bacillus spp. spore inhibition at 20 °C. And Nisin can act on HP-treated spores, even if they are not germinated. This paper provides new information about the inhibition of spores by the combination of HP and nisin. The high synergy observed at low temperature has not been reported yet and could allow food preservation without the use of any thermal process.


Assuntos
Pressão Atmosférica , Viabilidade Microbiana/efeitos dos fármacos , Nisina/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Bacillus/efeitos dos fármacos , Bacillus/crescimento & desenvolvimento , Clostridium/efeitos dos fármacos , Clostridium/crescimento & desenvolvimento , Conservação de Alimentos , Temperatura Alta
16.
J Basic Microbiol ; 59(10): 979-991, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31469183

RESUMO

This study investigates the effect of metals (cadmium, lead, mercury, and tellurium) and organic pollutants (benzene, diesel, lindane, and xylene) on a dinoflagellate-Prorocentrum sigmoides Böhm-and its associated culturable bacteria. Two bacterial cultures (Bacillus subtilis strain PD005 and B. xiamensis strain PD006) were isolated from P. sigmoides and characterized by scanning electron microscopy, 16S ribosomal RNA sequencing, biochemical analyses, and growth curve studies. This study points to a mutualistic relationship between P. sigmoides and its associated Bacillus isolates. P. sigmoides enhanced the growth of its associated Bacillus spp., through the secretion of extracellular exudates. In return, both Bacillus isolates contributed to the resistance of P. sigmoides to metals and organic pollutants. P. sigmoides and both Bacillus isolates exhibited concentration-dependent responses to metals and organic pollutants. An intriguing feature was the similar response of P. sigmoides and its associated Bacillus isolates to mercury and cadmium, indicating a co-selection of mercury and cadmium resistance. This provides support to the "dinoflagellate host-phycosphere bacteria" behaving as a single functional unit. However, the sensitivity profiles of P. sigmoides and its associated Bacillus isolates are different with respect to metals versus organic pollutants. These aspects need to be addressed in future studies to unravel the effect of metal and organic pollutants on dinoflagellates, an important component of the phytoplankton community, and to discern the influence of associated "phycosphere" bacteria on the response of dinoflagellates to pollutants.


Assuntos
Bacillus/efeitos dos fármacos , Dinoflagelados/efeitos dos fármacos , Dinoflagelados/microbiologia , Hidrocarbonetos/farmacologia , Metais/farmacologia , Poluentes Químicos da Água/farmacologia , Bacillus/genética , Bacillus/crescimento & desenvolvimento , Bacillus/ultraestrutura , Coevolução Biológica , DNA Bacteriano/genética , Dinoflagelados/metabolismo , Resistência a Medicamentos , Microscopia Eletrônica de Varredura , RNA Ribossômico 16S/genética , Simbiose
17.
Biotechnol Appl Biochem ; 66(5): 900-910, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400027

RESUMO

Synergistic effects of metallic nanoparticles (NPs) with commonly used antibiotics have encouraged the exploration of novel biological entities, including bacteria and weed plants. The present study for the first time reports the capability of an extracellular fraction of Bacillus sp. isolated from effluents of a glass-manufacturing unit to biosynthesis silver nanoparticles (AgNPs) without hazardous materials. Besides, the biosynthesis of AgNPs using an aqueous extract of herbaceous weed plant (Amaranthus sp.), as a low-cost natural source, has been addressed in this study. Our findings confirmed the fabrication of microbial and plant-sourced AgNPs, being thoroughly characterized by UV-vis, transmission electron microscopy, X-ray diffraction, dynamic light scattering, energy dispersive X-ray spectroscopy, and zeta potential measurements. Further, biological activities of the plant- and bacterium-derived AgNPs were investigated against several pathogenic bacteria, in combination with streptomycin. The antibacterial effectiveness of the antibiotic coated with 400 µg/disk of AgNPs increased over 50% toward all the pathogenic bacteria. The data presented here demonstrate that both industrial wastewater-adapted Bacillus sp. and wild-growing Amaranthus sp. are efficient natural sources with excellent capabilities for creating biologically active AgNPs, which would be of considerable interest for circumventing bacterial resistance to current antibiotics.


Assuntos
Amaranthus/efeitos dos fármacos , Antibacterianos/biossíntese , Bacillus/efeitos dos fármacos , Vidro , Resíduos Industriais , Nanopartículas Metálicas/química , Prata/farmacologia , Amaranthus/crescimento & desenvolvimento , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus/crescimento & desenvolvimento , Indústrias , Testes de Sensibilidade Microbiana , Prata/química , Prata/metabolismo
18.
Int J Nanomedicine ; 14: 2693-2703, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354260

RESUMO

Background: Silver, incorporation with natural or synthetic polymers, has been used as an effective antibacterial agent since decades. Silver has potential applications in healthcare especially in nanoparticles form but silver sulfadiazine (AgSD) is the most efficient antibacterial agent especially for burn wound dressings. Method: In this report, mechanical, structural, and antibacterial properties of PAN nanofibers incorporation with silver sulfadiazine are mainly focused. AgSD was loaded for the first time on electrospinning as well as self-synthesized AgSD on PAN nanofibers by solution immersion method and then compared the results of both. Results: Occurrence of chemical reaction among the functional groups of AgSD and PAN were analyzed using FTIR, for both types of specimen. Morphological and surface properties of prepared nanofiber mats were characterized by scanning electron microscope, and it resulted in uniform nanofibers without bead formation. Diameter of nanofibers was slightly increased with addition of AgSD by in situ and immersion methods respectively. Nanoparticles distribution was analyzed by transmission electron microscopy. Thermal properties were analyzed by thermo-gravimetric analyzer and it was observed that AgSD decreased thermal stability of PAN which is better from biomedical perspective. X-ray diffraction declared crystalline structure of nanofiber mats. Presence of Ag and S contents in nanofiber mats was analyzed by X-ray photo spectroscopy. Antibacterial properties of nanofiber mats were investigated by disc diffusion method was carried out. E. coli and Bacillus bacteria strain were used as gram-negative and gram-positive respectively. Zone inhibition of the bacteria was used as a tool to determine effectiveness of AgSD released from PAN nanofiber mats. The antibacterial properties of PAN nanofibers impregnated with AgSD were determined with both types of bacteria strains to compare with control one. Conclusion: On the basis of characterization results it is concluded that PAN/AgSD (immersion) nanofiber mats have better structural and antibacterial properties than that of PAN/AgSD (in situ) nanofiber mats. So, from our point of view, self-synthesized AgSD is recommended for further production of nanofiber mats for antibacterial applications.


Assuntos
Resinas Acrílicas/química , Antibacterianos/farmacologia , Nanofibras/química , Sulfadiazina de Prata/farmacologia , Bacillus/efeitos dos fármacos , Módulo de Elasticidade , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanofibras/ultraestrutura , Espectroscopia Fotoeletrônica , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Resistência à Tração , Termogravimetria , Difração de Raios X
19.
Arch Microbiol ; 201(10): 1369-1383, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31332474

RESUMO

Tanneries are the primary source of toluene pollution in the environment and toluene due to its hazardous effects has been categorized as persistent organic pollutant. Present study was initiated to trace out metabolic fingerprints of three toluene-degrading bacteria isolated from tannery effluents of Southern Punjab. Using selective enrichment and serial dilution methods followed by biochemical, molecular and antibiotic resistance analysis, isolated bacteria were subjected to metabolomics analysis. GC-MS/LC-MS analysis of bacterial metabolites helped to identify toluene transformation products and underlying pathways. Three toluene-metabolizing bacteria identified as Bacillus paralicheniformis strain KJ-16 (IUBT4 and IUBT24) and Brevibacillus agri strain NBRC 15538 (IUBT19) were found tolerant to toluene and capable of degrading toluene. Toluene-degrading potential of these isolates was detected to be IUBT4 (10.35 ± 0.084 mg/h), IUBT19 (14.07 ± 3.14 mg/h) and IUBT24 (11.1 ± 0.282 mg/h). Results of GC-MS analysis revealed that biotransformation of toluene is accomplished not only through known metabolic routes such as toluene 3-monooxygenase (T3MO), toluene 2-monooxygenase (T2MO), toluene 4-monooxygenase (T4MO), toluene methyl monooxygenase (TOL), toluene dioxygenase (Tod), meta- and ortho-ring fission pathways. But additionally, confirmed existence of a unique metabolic pathway that involved conversion of toluene into intermediates such as cyclohexene, cyclohexane, cyclohexanone and cyclohexanol. LC-MS analysis indicated the presence of fatty acid amides, stigmine, emmotin A and 2, 2-dinitropropanol in supernatants of bacterial cultures. As the isolated bacteria transformed toluene into relatively less toxic molecules and thus can be preferably exploited for the eco-friendly remediation of toluene.


Assuntos
Bacillus/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Brevibacillus/metabolismo , Oxigenases/metabolismo , Tolueno/metabolismo , Bacillus/efeitos dos fármacos , Bacillus/enzimologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Brevibacillus/efeitos dos fármacos , Brevibacillus/enzimologia , Cromatografia Gasosa-Espectrometria de Massas , Oxigenases de Função Mista , Tolueno/toxicidade
20.
Molecules ; 24(13)2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31261837

RESUMO

To explore the flavonoids from Morus alba L. leaves (MLF), the process of extracting was optimized by a response surface methodology and the antimicrobial and antioxidant activities were evaluated in vitro. The yield of flavonoids reached 50.52 mg g-1 under the optimized extraction conditions (i.e., extraction temperature, 70.85 °C; solvent concentration, 39.30%; extraction time, 120.18 min; and liquid/solid ratio, 34.60:1). The total flavonoids were extracted in organic solvents with various polarities, including petroleum ether (MLFp), ethyl acetate (MLFe), and n-butanol (MLFb). In vitro, the four MLF samples exhibited good antioxidant activities for scavenging of 2, 2'-azinobis-(3-ethylbenz-thiazoline-6-sulphonate) radical, 1, 1-diphenyl-2-picrylhydrazyl radical, and total reducing power. Regarding antimicrobial efficacy, the MLF samples suppressed the development of Staphylococcus aureus, Bacillus subtilis, and Bacillus pumilus. The MLF samples inhibited α-amylase activity to a certain extent. The analytical hierarchy process (AHP) was used to evaluate comprehensively the bioactivities of the MLF samples. The AHP results revealed that the bioactivity comprehensive score (78.83 µg mL-1) of MLFe was optimal among the four MLF samples. Morus alba L. leaves also exhibited non-hemolytic properties. All bioactivities suggested the potential of MLFe as a candidate resource in the food and drug industries.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Flavonoides/farmacologia , Morus/química , alfa-Amilases/antagonistas & inibidores , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Bacillus/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Flavonoides/química , Flavonoides/isolamento & purificação , Testes de Sensibilidade Microbiana , Extratos Vegetais , Folhas de Planta/química , Staphylococcus aureus/efeitos dos fármacos
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