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1.
Chemosphere ; 238: 124689, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524624

RESUMO

Pharmaceutical effluents released from industries are accountable to deteriorate the aquatic and soil environment through indirect toxic effects. Microbes are adequately been used to biodegrade pharmaceutical industry wastewater and present study was envisaged to determine biodegradation of pharmaceutical effluent by Micrococcus yunnanensis. The strain showed 42.82% COD (Chemical oxygen demand) reduction before optimization. After applying Taguchi's L8 array as an optimization technique, the biodegradation rate was enhanced by 82.95% at optimum conditions (dextrose- 0.15%, peptone 0.1%, inoculum size 4% (wv-1), rpm 200, pH 8 at 25 °C) within 6 h. The confirmation of pharmaceuticals degradation was done by 1H NMR (Nuclear magnetic resonance) studies followed by elucidation of transformation pathways of probable drugs in the effluent through Q-Tof-MS (Quadrupole Time of Flight- Mass Spectrometry). The cytotoxicity evaluation of treated and untreated wastewater was analyzed on Human Embryonic Kidney (HEK 293) cells using Alamar Blue assay, which showed significant variance.


Assuntos
Biodegradação Ambiental , Resíduos Industriais/análise , Micrococcus/metabolismo , Preparações Farmacêuticas/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Análise da Demanda Biológica de Oxigênio , Linhagem Celular , Indústria Farmacêutica , Células HEK293 , Humanos
2.
Int J Biol Macromol ; 131: 343-352, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30844458

RESUMO

An exopolysaccharide (EPS) producing strain FSW-25 was isolated from the Rasthakaadu beach Kanyakumari, Tamil Nadu India. Based on polyphasic taxonomy, the strain FSW-25 was assigned to the genus Microbacterium and found to be the closest relative of the species aurantiacum. Large quantity of EPS (7.81 g/l) was secreted by the strain upon fermentation using Reasoner's 2A medium enriched with 2.5% glucose and was designated as Mi-25. FT-IR spectrum revealed presence of hydroxyl, carbonyl, carboxyl, methyl and sulfate functional groups in purified EPS. The EPS Mi-25 has a molecular weight of 7.0 × 106 Da and mainly comprises of glucuronic acid followed by glucose, mannose and fucose. Rheological study revealed that Mi-25 possesses significant viscosity with pseudoplastic nature. Interestingly, it was observed that the EPS Mi-25 has higher antioxidant activity as compared to xanthan. The characteristics of EPS Mi-25 suggested that, it can be used as a potential antioxidant with viscosifier properties in diverse industrial sectors.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Micrococcus/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Fenômenos Químicos , Genômica/métodos , Micrococcus/classificação , Micrococcus/genética , Micrococcus/metabolismo , Peso Molecular , Filogenia , RNA Ribossômico 16S/genética , Reologia , Análise Espectral , Termogravimetria
3.
Colloids Surf B Biointerfaces ; 172: 10-16, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30118959

RESUMO

A fast and single-step procedure is reported for the preparation of stable solutions of spherical-shaped silver nanoparticles (AgNPs) coated with lysozyme (LZ). The preparation of the AgNP@LZ nanocomposites was based on the reduction of Ag+ with ketyl radicals photo-generated by the UVA-photolysis of the benzoin I-2959. Both reaction precursors bind to LZ, modifying its superficial charge and conformational structure. The photo-induced kinetics of formation of the AgNPs as a function of the LZ concentration was monitored in-situ by UV-vis absorption spectroscopy. The multivariate curve resolution-alternating least square (MCR-ALS) method was used for the deconvolution of the kinetic curves for each transient species formed before the growth of the final AgNPs colloids. The Kolmogorov-Johnson-Mehl-Avrami (KJMA) model to describe the formation of the AgNPs was used, and the respective first-order rate constants for the growth of the AgNPs as a function of the lysozyme concentration were calculated and the role of the protein capping in the growth kinetics was evaluated. Despite the protein being partially oxidized by the photo-generated radicals, it was strongly adsorbed onto the silver surface forming a tight coating shell around the AgNPs of approximately 30-60 protein molecules. As a result of the partial denaturation and crowded packing, its intrinsic lytic activity was strongly reduced.


Assuntos
Luz , Nanopartículas Metálicas/química , Muramidase/metabolismo , Prata/química , Difusão Dinâmica da Luz , Cinética , Nanopartículas Metálicas/ultraestrutura , Micrococcus/metabolismo , Tamanho da Partícula , Fotólise , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Biosci Biotechnol Biochem ; 82(8): 1327-1334, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29629656

RESUMO

In Archaea and Bacteria, surface layer (S-layer) proteins form the cell envelope and are involved in cell protection. In the present study, a putative S-layer protein was purified from the crude extract of Pyrococcus horikoshii using affinity chromatography. The S-layer gene was cloned and expressed in Escherichia coli. Isothermal titration calorimetry analyses showed that the S-layer protein bound N-acetylglucosamine and induced agglutination of the gram-positive bacterium Micrococcus lysodeikticus. The protein comprised a 21-mer structure, with a molecular mass of 1,340 kDa, as determined using small-angle X-ray scattering. This protein showed high thermal stability, with a midpoint of thermal denaturation of 79 °C in dynamic light scattering experiments. This is the first description of the carbohydrate-binding archaeal S-layer protein and its characteristics.


Assuntos
Acetilglucosamina/metabolismo , Proteínas Arqueais/metabolismo , Pyrococcus horikoshii/metabolismo , Sequência de Aminoácidos , Proteínas Arqueais/química , Proteínas Arqueais/genética , Proteínas Arqueais/isolamento & purificação , Calorimetria/métodos , Cromatografia de Afinidade/métodos , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Genes Arqueais , Proteínas de Fluorescência Verde/metabolismo , Temperatura Alta , Micrococcus/metabolismo , Ligação Proteica , Conformação Proteica , Desnaturação Proteica , Estabilidade Proteica , Espalhamento a Baixo Ângulo , Difração de Raios X
5.
Chemosphere ; 201: 511-518, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29529578

RESUMO

This work mainly aims to explore the potential of synergistic use of cadmium-resistant bacteria and Napier grass to promote cadmium phytoremediation and the possibility of using the harvested Napier grass for biomass fuel. A pot experiment was carried out by transplanting Napier grass with and without bacterial inoculation in cadmium contaminated soil for 6 months. The results found that Micrococcus sp. significantly promoted the shoot biomass of Napier grass but not the root biomass. Micrococcus sp. and Arthrobacter sp. stimulated cadmium accumulation in the root and the shoot. Cadmium was retained more in the root than the shoot at all plantation periods. The maximum cadmium content in a whole plant was found in plants inoculated with Micrococcus sp. at six months. The values of phytoextraction coefficient and bioaccumulation factor in plants with bacterial inoculation were higher than those in the uninoculated control. Translocation factor was very low. Napier grass could be considered as a candidate plant for cadmium phytostabilization. The calorific value of Napier grass transplanted in cadmium-contaminated soil was similar to that in uncontaminated soil, but cadmium was still retained in the ash and some was emitted into the air. In conclusion, these cadmium-resistant bacteria enhanced the performance of Napier grass on cadmium phytoremediation. The harvested Napier grass can be used for biomass fuel under controlled ash and air emission from the combustion process.


Assuntos
Biodegradação Ambiental , Biocombustíveis , Cádmio/metabolismo , Micrococcus/metabolismo , Poaceae/microbiologia , Arthrobacter/metabolismo , Biomassa , Cádmio/análise , Cádmio/farmacologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Poaceae/crescimento & desenvolvimento , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Poluentes do Solo/farmacologia
6.
FEMS Microbiol Lett ; 364(11)2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28460054

RESUMO

Utilization of rhizobacteria that have associated with plant roots in harsh environments could be a feasible strategy to deal with limits to agricultural production caused by soil salinity. Halophytes occur naturally in high-salt environments, and their roots may be associated with promising microbial candidates for promoting growth and salt tolerance in crops. This study aimed to isolate efficient halotolerant plant-growth-promoting rhizobacterial strains from halophytes and evaluate their activity and effects on sugar beet (Beta vulgaris L.) growth under salinity stress. A total of 23 isolates were initially screened for their ability to secrete 1-aminocyclopropane-1-carboxylate deaminase (ACD) as well as other plant-growth-promoting characteristics and subsequently identified by sequencing the 16S rRNA gene. Three isolates, identified as Micrococcus yunnanensis, Planococcus rifietoensis and Variovorax paradoxus, enhanced salt stress tolerance remarkably in sugar beet, resulting in greater seed germination and plant biomass, higher photosynthetic capacity and lower stress-induced ethylene production at different NaCl concentrations (50-125 mM). These results demonstrate that salinity-adapted, ACD-producing bacteria isolated from halophytes could promote sugar beet growth under saline stress conditions.


Assuntos
Alphaproteobacteria/classificação , Beta vulgaris/microbiologia , Raízes de Plantas/microbiologia , Plantas Tolerantes a Sal/microbiologia , Estresse Fisiológico , Alphaproteobacteria/genética , Alphaproteobacteria/isolamento & purificação , Beta vulgaris/crescimento & desenvolvimento , Biomassa , Carbono-Carbono Liases/metabolismo , Etilenos/metabolismo , Micrococcus/isolamento & purificação , Micrococcus/metabolismo , Planococcus (Bactéria)/isolamento & purificação , Planococcus (Bactéria)/metabolismo , RNA Ribossômico 16S/genética , Salinidade , Solo/química , Microbiologia do Solo
7.
Br Poult Sci ; 58(3): 319-328, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28097888

RESUMO

1. The main aim of this work is to develop a robust method to generate a microbial mixture which can successfully degrade poultry feathers to overcome environmental problems. 2. Four different alkaliphilic microbes were isolated and shown to degrade poultry feathers. 3. Two of the isolates were phylogenetically identified as Lysinibacillus and the others were identified as Nocardiopsis and Micrococcus. 4. The best microbial co-culture for white and black feather degradation was optimised for pH, temperature and relative population of the isolates to achieve almost 96% of degradation compared with a maximum of 31% when applying each isolate individually. 5. The maximum activity of keratinase was estimated to be 1.5 U/ml after 3 d for white feathers and 0.6 U/ml after 4 d for black feathers in a basal medium containing feather as the main carbon source. Additionally, non-denaturing polyacrylamide gel electrophoresis showed 4 and 3 protease activity bands for white and black feather, respectively. 6. This study provides a robust method to develop potential new mixtures of microorganisms that are able to degrade both white and black feathers by applying a Central Composite Design.


Assuntos
Criação de Animais Domésticos/métodos , Proteínas de Bactérias/metabolismo , Galinhas , Plumas , Bactérias Gram-Positivas/metabolismo , Peptídeo Hidrolases/metabolismo , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/metabolismo , Animais , Bacillaceae/classificação , Bacillaceae/genética , Bacillaceae/metabolismo , Biodegradação Ambiental , Plumas/química , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/genética , Resíduos Industriais , Micrococcus/classificação , Micrococcus/genética , Micrococcus/metabolismo , Filogenia , Pigmentação , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Análise de Sequência de DNA/veterinária
8.
Appl Microbiol Biotechnol ; 101(5): 2033-2041, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27858137

RESUMO

Psychrophilic enzymes display efficient activity at moderate or low temperatures (4-25 °C) and are therefore of great interest in biotechnological industries. We previously examined the crystal structure of BglU, a psychrophilic ß-glucosidase from the bacterium Micrococcus antarcticus, at 2.2 Å resolution. In structural comparison and sequence alignment with mesophilic (BglB) and thermophilic (GlyTn) counterpart enzymes, BglU showed much lower contents of Pro residue and of charged amino acids (particularly positively charged) on the accessible surface area. In the present study, we investigated the roles of specific amino acid residues in the cold adaptedness of BglU. Mutagenesis assays showed that the mutations G261R and Q448P increased optimal temperature (from 25 to 40-45 °C) at the expense of low-temperature activity, but had no notable effects on maximal activity or heat lability. Mutations A368P, T383P, and A389E significantly increased optimal temperature (from 25 to 35-40 °C) and maximal activity (~1.5-fold relative to BglU). Thermostability of A368P and A389E increased slightly at 30 °C. Mutations K163P, N228P, and H301A greatly reduced enzymatic activity-almost completely in the case of H301A. Low contents of Pro, Arg, and Glu are important factors contributing to BglU's psychrophilic properties. Our findings will be useful in structure-based engineering of psychrophilic enzymes and in production of mutants suitable for a variety of industrial processes (e.g., food production, sewage treatment) at cold or moderate temperatures.


Assuntos
Adaptação Fisiológica/genética , Proteínas de Bactérias/genética , Micrococcus/enzimologia , Micrococcus/metabolismo , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Sequência de Aminoácidos , Aminoácidos/genética , Proteínas de Bactérias/metabolismo , Temperatura Baixa , Estabilidade Enzimática , Micrococcus/genética , Mutagênese Sítio-Dirigida , Conformação Proteica , Alinhamento de Sequência
9.
Environ Sci Pollut Res Int ; 23(1): 756-64, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26336850

RESUMO

Cadmium-resistant Micrococcus sp. TISTR2221, a plant growth-promoting bacterium, has stimulatory effects on the root lengths of Zea mays L. seedlings under toxic cadmium conditions compared to uninoculated seedlings. The performance of Micrococcus sp. TISTR2221 on promoting growth and cadmium accumulation in Z. mays L. was investigated in a pot experiment. The results indicated that Micrococcus sp. TISTR2221significantly promoted the root length, shoot length, and dry biomass of Z. mays L. transplanted in both uncontaminated and cadmium-contaminated soils. Micrococcus sp. TISTR2221 significantly increased cadmium accumulation in the roots and shoots of Z. mays L. compared to uninoculated plants. At the beginning of the planting period, cadmium accumulated mainly in the shoots. With a prolonged duration of cultivation, cadmium content increased in the roots. As expected, little cadmium was found in maize grains. Soil cadmium was significantly reduced with time, and the highest percentage of cadmium removal was found in the bacterial-inoculated Z. mays L. after transplantation for 6 weeks. We conclude that Micrococcus sp. TISTR2221 is a potent bioaugmenting agent, facilitating cadmium phytoextraction in Z. mays L.


Assuntos
Biodegradação Ambiental , Cádmio , Micrococcus/efeitos dos fármacos , Poluentes do Solo , Biomassa , Cádmio/metabolismo , Micrococcus/metabolismo , Desenvolvimento Vegetal , Raízes de Plantas/crescimento & desenvolvimento , Plântula , Solo , Zea mays/crescimento & desenvolvimento
10.
J Appl Microbiol ; 120(3): 671-83, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26666740

RESUMO

AIMS: The technological properties of 22 micrococcus strains from traditional fermented Kedong sufu were evaluated in order to develop autochthonous starter cultures. METHODS AND RESULTS: The proteolytic, autolytic and lipolytic activity, salt tolerance, production and degradation of the biogenic amines of six Micrococcus luteus, nine Kocuria kristinae and seven Kocuria rosea were evaluated. The results indicated that these micrococcus strains exhibited a certain technological diversity, and the results also indicated the best properties to be used in mixed starter cultures. Based on the above findings, two sets of autochthonous starters were formulated. Considering the physicochemical properties and sensory characteristics of sufu, the maturation period of sufu was shortened by 30 days. The profiles of free amino acids and peptides partly revealed the mechanism of sensory quality and shorter ripening time of sufu manufactured using autochthonous mixed starters. Compared to back-slopping fermentation, sufu manufactured with selected autochthonous starter cultures exhibited lower levels of total biogenic amines. CONCLUSIONS: The selected strains could be used as starter to avoid the accumulation of high concentrations of biogenic amines while also maintaining typical sensory characteristics and preserving the autochthonous strains of the traditional Kedong sufu. The maturation times of Kedong sufu were shortened by 30 days with application of the autochthonous starter. SIGNIFICANCE AND IMPACT OF THE STUDY: Autochthonous mixed starters can reduce the generation of biogenic amines, speed up the sufu maturation process and preserve typical sensory quality. Furthermore, the rotation of two sets of mixed starter cultures can effectively resist phage attack during the production of sufu.


Assuntos
Micrococcaceae/metabolismo , Alimentos de Soja/microbiologia , Soja/microbiologia , Aminoácidos/metabolismo , Aminas Biogênicas/metabolismo , Fermentação , Microbiologia de Alimentos , Micrococcaceae/classificação , Micrococcus/classificação , Micrococcus/metabolismo , Peptídeos/metabolismo
11.
Int J Pharm ; 498(1-2): 96-109, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26656302

RESUMO

The prilling process proposes a microparticle formulation easily transferable to the pharmaceutical production, leading to monodispersed and highly controllable microspheres. PLGA microspheres were used for carrying an encapsulated protein and adhered stem cells on its surface, proposing a tool for regeneration therapy against injured tissue. This work focused on the development of the production of PLGA microspheres by the prilling process without toxic solvent. The required production quality needed a complete optimization of the process. Seventeen parameters were studied through experimental designs and led to an acceptable production. The key parameters and mechanisms of formation were highlighted.


Assuntos
Química Farmacêutica/métodos , Ácido Láctico/síntese química , Micrococcus , Microesferas , Muramidase/química , Polietilenoglicóis/síntese química , Ácido Poliglicólico/síntese química , Animais , Galinhas , Desenho de Drogas , Ácido Láctico/farmacocinética , Micrococcus/metabolismo , Muramidase/farmacocinética , Tamanho da Partícula , Polietilenoglicóis/farmacocinética , Ácido Poliglicólico/farmacocinética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
12.
J Sci Food Agric ; 96(9): 2990-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26391435

RESUMO

BACKGROUND: The camel is an excellent source of high quality meat and camel meat might be a potential alternative for beef. This study aimed to manipulate the raw camel meat for the production of stable and acceptable emulsion sausage, as well as to study the effect of cooking at different core temperatures on the tenderness, sensory quality and microstructure of produced sausage. RESULTS: Increasing the cooking temperature of sausages resulted in reduction of the shear force values from 2.67 kgf after cooking at 85 °C to 1.57 kgf after cooking at 105 °C. The sensory scores of sausages have been improved by increasing the cooking core temperature of meat batter. The light and scanning electron microscope micrographs revealed solubilisation of the high quantity of connective tissue of camel meat. High emulsion stability values for the camel meat batter associated with high values of water-holding capacity for raw camel meat and meat batter have been recorded. CONCLUSION: Stable and acceptable camel meat emulsion can be developed from camel meat. Increasing the cooking core temperature of meat batter improved the quality of produced sausages. Therefore, camel meat emulsion sausages might be a potential alternative for beef particularly in Asian and African countries. © 2015 Society of Chemical Industry.


Assuntos
Camelus , Culinária , Qualidade dos Alimentos , Produtos da Carne/análise , Carne/análise , Animais , Tecido Conjuntivo/química , Tecido Conjuntivo/ultraestrutura , Egito , Emulsões , Fermentação , Preferências Alimentares/etnologia , Armazenamento de Alimentos , Temperatura Alta/efeitos adversos , Humanos , Carne/microbiologia , Produtos da Carne/microbiologia , Fenômenos Mecânicos , Micrococcus/crescimento & desenvolvimento , Micrococcus/metabolismo , Microscopia Eletrônica de Varredura , Músculo Esquelético/química , Músculo Esquelético/ultraestrutura , Refrigeração , Sensação , Resistência ao Cisalhamento , Água/análise
13.
Bull Environ Contam Toxicol ; 96(2): 210-6, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26602566

RESUMO

Eight chromium resistant bacteria were isolated from a dry fly ash sample of DVC-MTPS thermal power plant located in Bankura, West Bengal, India. These isolates displayed different degrees of chromate reduction under aerobic conditions. According to 16S rDNA gene analysis, five of them were Staphylococcus, two were Bacillus and one was Micrococcus. The minimum inhibitory concentration towards chromium and the ability to reduce hexavalent chromium to trivalent chromium was highest in Staphylococcus haemolyticus strain HMR17. All the strains were resistant to multiple heavy metals (As, Cu, Cd, Co, Zn, Mn, Pb and Fe) and reduced toxic hexavalent chromium to relatively non toxic trivalent chromium even in the presence of these multiple heavy metals. All of them showed resistance to different antibiotics. In a soil microcosm study, S. haemolyticus strain HMR17 completely reduced 4 mM hexavalent chromium within 7 days of incubation.


Assuntos
Bacillus/metabolismo , Bactérias/metabolismo , Cromo/farmacologia , Cinza de Carvão/química , Centrais Elétricas , Antibacterianos/farmacologia , Bacillus/efeitos dos fármacos , Bacillus/isolamento & purificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Cromo/metabolismo , Farmacorresistência Bacteriana , Índia , Metais Pesados/metabolismo , Metais Pesados/farmacologia , Testes de Sensibilidade Microbiana , Micrococcus/efeitos dos fármacos , Micrococcus/isolamento & purificação , Micrococcus/metabolismo , Solo , Staphylococcus/efeitos dos fármacos , Staphylococcus/isolamento & purificação , Staphylococcus/metabolismo
14.
Zhongguo Zhong Yao Za Zhi ; 40(12): 2367-71, 2015 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-26591527

RESUMO

To investigate cytotoxic secondary metabolites of Micrococcus sp. R21, an actinomycete isolated from a deep-sea sediment (-6 310 m; 142 degrees 19. 9' E, 10 degrees 54. 6' N) of the Western Pacific Ocean, column chromatography was introduced over silica gel, ODS, and Sephadex LH-20. As a result, eight compounds were obtained. By mainly detailed analysis of the NMR data, their structures were elucidated as cyclo(4-hydroxy-L-Pro-L-leu) (1), cyclo(L-Pro-L-Gly) (2), cyclo( L-Pro-L-Ala) (3), cyclo( D-Pro-L-Leu) (4), N-ß-acetyltryptamine (5), 2-hydroxybenzoic acid (6), and phenylacetic acid (7). Compound 1 exhibited weak cytotoxic activity against RAW264. 7 cells with IC50 value of 9.1 µmol x L(-1).


Assuntos
Fatores Biológicos/química , Micrococcus/química , Micrococcus/metabolismo , Água do Mar/microbiologia , Metabolismo Secundário , Animais , Fatores Biológicos/isolamento & purificação , Fatores Biológicos/metabolismo , Fatores Biológicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Camundongos , Micrococcus/genética , Micrococcus/isolamento & purificação , Estrutura Molecular , Filogenia , Células RAW 264.7
15.
Braz J Microbiol ; 46(3): 667-72, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26413046

RESUMO

Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken cultures. PUF-immobilized cells showed higher degradation of cypermethrin (10 mM and 20 mM) than freely suspended cells and cells immobilized in other matrices. The PUF-immobilized cells of Micrococcus sp. strain CPN 1 were retain their degradation capacity. Thus, they can be reused for more than 32 cycles, without losing their degradation capacity. Hence, the PUF-immobilized cells of Micrococcus sp. could potentially be used in the bioremediation of cypermethrin contaminated water.


Assuntos
Biodegradação Ambiental , Células Imobilizadas/metabolismo , Inseticidas/metabolismo , Micrococcus/metabolismo , Piretrinas/metabolismo , Alginatos , Ácido Glucurônico , Ácidos Hexurônicos , Micrococcus/classificação , Poliuretanos
16.
Braz. j. microbiol ; 46(3): 667-672, July-Sept. 2015. ilus
Artigo em Inglês | LILACS | ID: lil-755816

RESUMO

Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken cultures. PUF-immobilized cells showed higher degradation of cypermethrin (10 mM and 20 mM) than freely suspended cells and cells immobilized in other matrices. The PUF-immobilized cells of Micrococcus sp. strain CPN 1 were retain their degradation capacity. Thus, they can be reused for more than 32 cycles, without losing their degradation capacity. Hence, the PUF-immobilized cells of Micrococcus sp. could potentially be used in the bioremediation of cypermethrin contaminated water.

.


Assuntos
Biodegradação Ambiental , Células Imobilizadas/metabolismo , Inseticidas/metabolismo , Micrococcus/metabolismo , Piretrinas/metabolismo , Alginatos , Ácido Glucurônico , Ácidos Hexurônicos , Micrococcus/classificação , Poliuretanos
17.
Bioresour Technol ; 193: 274-80, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26141288

RESUMO

The hypothesis that extracellular polymeric substances (EPS) affect the formation of biofilms for subsequent enhanced biodegradation of polycyclic aromatic hydrocarbons was tested. Controlled formation of biofilms on humin particles and biodegradation of phenanthrene and pyrene were performed with bacteria and EPS-extracted bacteria of Micrococcus sp. PHE9 and Mycobacterium sp. NJS-P. Bacteria without EPS extraction developed biofilms on humin, in contrast the EPS-extracted bacteria could not attach to humin particles. In the subsequent biodegradation of phenanthrene and pyrene, the biodegradation rates by biofilms were significantly higher than those of EPS-extracted bacteria. Although, both the biofilms and EPS-extracted bacteria showed increases in EPS contents, only the EPS contents in biofilms displayed significant correlations with the biodegradation efficiencies of phenanthrene and pyrene. It is proposed that the bacterial-produced EPS was a key factor to mediate bacterial attachment to other surfaces and develop biofilms, thereby increasing the bioavailability of poorly soluble PAH for enhanced biodegradation.


Assuntos
Biofilmes/crescimento & desenvolvimento , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Polímeros/metabolismo , Biodegradação Ambiental , Disponibilidade Biológica , Substâncias Húmicas/microbiologia , Micrococcus/crescimento & desenvolvimento , Micrococcus/metabolismo , Mycobacterium/crescimento & desenvolvimento , Mycobacterium/metabolismo , Fenantrenos/metabolismo , Pirenos/metabolismo
18.
Environ Sci Pollut Res Int ; 22(24): 19317-25, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25940486

RESUMO

A soil habitat consists of a significant number of bacteria that cannot be cultivated by conventional means, thereby posing obvious difficulties in their classification and identification. This difficulty necessitates the need for advanced techniques wherein a well-compiled biomolecular database consisting of the already cultivable bacteria can be used as a reference in an attempt to link the noncultivable bacteria to their closest phylogenetic groups. Raman spectroscopy has been successfully applied to taxonomic studies of many systems like bacteria, fungi, and plants relying on spectral differences contributed by the variation in their overall biomolecular composition. However, these spectral differences can be obscured due to Raman signatures from photosensitive microbial pigments like carotenoids that show enormous variation in signal intensity hindering taxonomic investigations. In this study, we have applied laser-induced photobleaching to expel the carotenoid signatures from pigmented cocci bacteria. Using this method, we have investigated 12 species of pigmented bacteria abundant in soil habitats belonging to three genera mainly Micrococcus, Deinococcus, and Kocuria based on their Raman spectra with the assistance of a chemometric tool known as the radial kernel support vector machine (SVM). Our results demonstrate the potential of Raman spectroscopy as a minimally invasive taxonomic tool to identify pigmented cocci soil bacteria at a single-cell level.


Assuntos
Deinococcus/classificação , Micrococcus/classificação , Microbiologia do Solo , Carotenoides/metabolismo , Deinococcus/metabolismo , Micrococcus/metabolismo , Filogenia , Padrões de Referência , Análise Espectral Raman , Máquina de Vetores de Suporte
19.
Chemosphere ; 130: 34-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25747304

RESUMO

BTEX compounds (benzene, toluene, ethylbenzene and xylenes) and methyl tert-butyl ether (MTBE) are some of the main constituents of gasoline and can be accidentally released in the environment. In this work the effect of bioaugmentation on the microbial communities in a bench scale aerobic biobarrier for gasoline contaminated water treatment was studied by 16S rRNA gene sequencing. Catabolic genes (tmoA and xylM) were quantified by qPCR, in order to estimate the biodegradation potential, and the abundance of total bacteria was estimated by the quantification of the number of copies of the 16S rRNA gene. Hydrocarbon concentration was monitored over time and no difference in the removal efficiency for the tested conditions was observed, either with or without the microbial inoculum. In the column without the inoculum the most abundant genera were Acidovorax, Bdellovibrio, Hydrogenophaga, Pseudoxanthomonas and Serpens at the beginning of the column, while at the end of the column Thauera became dominant. In the inoculated test the microbial inoculum, composed by Rhodococcus sp. CE461, Rhodococcus sp. CT451 and Methylibium petroleiphilum LMG 22953, was outcompeted. Quantitative PCR results showed an increasing in xylM copy number, indicating that hydrocarbon degrading bacteria were selected during the treatment, although only a low increase of the total biomass was observed. However, the bioaugmentation did not lead to an increase in the degradative potential of the microbial communities.


Assuntos
Biodegradação Ambiental , Gasolina/análise , Água Subterrânea/análise , Hidrocarbonetos/metabolismo , Poluentes Químicos da Água/análise , Benzeno/análise , Micrococcus/genética , Micrococcus/metabolismo , Análise de Componente Principal , RNA Ribossômico 16S/genética , Rhodococcus/genética , Rhodococcus/metabolismo , Tolueno/análise , Purificação da Água/métodos , Xilenos/análise
20.
Chemistry ; 21(12): 4655-63, 2015 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-25676609

RESUMO

Advanced functional materials incorporating well-defined multiscale architectures are a key focus for multiple nanotechnological applications. However, strategies for developing such materials, including nanostructuring, nano-/microcombination, hybridization, and so on, are still being developed. Here, we report a facile, scalable biomineralization process in which Micrococcus lylae bacteria are used as soft templates to synthesize 3D hierarchically structured magnetite (Fe3O4) microspheres for use as Li-ion battery anode materials and in water treatment applications. Self-assembled Fe3O4 microspheres with flower-like morphologies are systematically fabricated from biomineralized 2D FeO(OH) nanoflakes at room temperature and are subsequently subjected to post-annealing at 400 °C. In particular, because of their mesoporous properties with a hollow interior and the improved electrical conductivity resulting from the carbonized bacterial templates, the Fe3 O4 microspheres obtained by calcining the FeO(OH) in Ar exhibit enhanced cycle stability and rate capability as Li-ion battery anodes, as well as superior adsorption of organic pollutants and toxic heavy metals.


Assuntos
Fontes de Energia Elétrica , Lítio/química , Microesferas , Purificação da Água , Adsorção , Carbono/química , Condutividade Elétrica , Óxido Ferroso-Férrico/química , Íons/química , Metais Pesados/química , Metais Pesados/isolamento & purificação , Micrococcus/metabolismo , Porosidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
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