Síntese biogênica de nanopartículas de prata por fungos marinhos
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2019-02-19
Autores
Silva, Victória Corrêa da
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Universidade Estadual Paulista (Unesp)
Resumo
As nanopartículas de prata (AgNP) oriundas da síntese biológica são descritas na atualidade como os novos agentes nanobiotecnológicos com potencial aplicação industrial e ambiental, principalmente devido a reconhecida atividade antimicrobiana. Dentre os diferentes organismos capazes de biossintetizar AgNP, os fungos filamentosos (Ff) se destacam, devido ao rápido crescimento e fácil escalonamento. Neste sentido, o presente estudo objetivou selecionar Ff marinhos, capazes de biossintetizar AgNP, assim como, otimizar o processo de síntese avaliando a influência de da concentração de AgNO3, biomassa, agitação, temperatura e pH. Também foi avaliada capacidade antimicrobiana e potencial efeito tóxico em camarão de água doce Palaemon pandaliformis. Dentre 12 linhagens Ff selecionadas, 10 apresentaram capacidade em biossintetizar AgNP. As AgNP produzidas pelas linhagens Penicillium citrinum IB-CLP11, Penicillium sclerotigenum IB-CLP17, Aspergillus niger IB-CLP20 e Penicillium polonicum IB-CLP22 apresentaram banda de ressonância plasmônica superficial no espectro em comprimento de onda compreendido entre 410-450 nm, tamanho compreendido entre 1-100 nm, carga com valor em módulo até o limite de 30 mV, índice de polidispersão inferior a 0,3. Nos estudos de ação antibacteriana, todas as 4 AgNP apresentaram capacidade em inibir o crescimento de Pseudomonas aeruginosa IPT322, Staphylococcus aureus IPT246 e Klebsiella pneumoniae IPT412 em concentração igual ou superior a 50 μg·mL-1 . Com relação a ação antifúngica, Aspergillus niger IPT295 e Penicillium funiculosum IPT423 foram os mais sensíveis, apresentando as Concentrações inibitórias mínimas entre 20 a 40 µg·mL-1 .Com relação a influência de diferentes parâmetros na biossíntese de AgNP, concentrações de AgNO3 superiores a 1,0 mM desencadearam o aumento de tamanho dos nanomateriais e a AgNP IB-CLP22 apresentou instabilidade em um tempo inferior a 1 mês de armazenamento. Todas as linhagens apresentaram capacidade de biossintetizar os nanomateriais quando o valor de biomassa foi compreendido entre 75,0- 150,0 g·L-1 . Na avaliação da influência da agitação no processo de formação de AgNP, tanto em modo estático como em agitado as 4 linhagens produziram AgNP, contudo, as AgNP biossintetizadas em modo estático apresentaram maior tamanho quando comparadas a processos realizados com agitação de até 150 rpm. Também foi detectado um maior estado de agregação das AgNP produzidas a 200 rpm. Em adição, as AgNP IB-CLP11, IB-CLP17 e IBCLP22 produzidas em 200 rpm precipitaram após 3 meses de armazenamento. Ocorreu formação de todas as AgNP em temperaturas compreendidas entre 25-35 ºC. Contudo, foi observada uma instabilidade dos nanomateriais AgNP IB-CLP11 e IB-CLP22 em temperaturas superiores a 30 ºC. Em pH acima de 5,5 não ocorreu formação de AgNP para nenhuma das linhagens selecionadas. As AgNP produzidas em pH 4,5 apresentaram uma melhor estabilidade. De todas as AgNPs, a IB-CLP 11 apresentou um melhor conjunto de resultados sendo selecionada para os testes in vivo no metabolismo de rotina em Palaemon pandaliformis. Por fim, a exposição da AgNP IB-CLP11 em Palaemon pandaliformis apresentou alterações no metabolismo de rotina do organismo, quando compara ao grupo controle. Contudo, são necessários estudos complementares com AgNP sintéticas para efetivamente termos uma visão clara dos diferentes efeitos gerados no metabolismo de rotina do organismo supracitado.
Silver nanoparticles (AgNP) from biological synthesis are currently described as the new nanobiotechnological agents with potential industrial and environmental application, mainly due to their recognized antimicrobial activity. Among the different organisms capable of biosynthesizing AgNP, filamentous fungi (Ff) stand out because of the rapid growth and easy staggering. Thus, the present study aimed to select marine fungi from the collection of culture of the Institute of Biosciences- Campus littoral Paulista (IB-CLP) of the state of São Paulo, which is able to biosynthesize AgNP, as well as optimize the synthesis process by evaluating the influence of different physico-chemical parameters, such, as variations concentrations in AgNO3, biomass, agitation, temperature and pH. An antimicrobial capacity and potential toxic effect were also evaluated in freshwater shrimp Palaemon pandaliformis. Among 12 selected strains of fungi, 10 were able to biosynthesize AgNP. All AgNP were characterized according to the proposed parameters and after 6 months of stability analysis, 4 presented a set of promising characteristics for the accomplishment of the second stage of the study. The AgNP produced by the Penicillium citrinum IB-CLP11, Penicillium sclerotigenum IB-CLP17, Aspergillus niger IB-CLP20 and Penicillium polonicum IB-CLP22 strains have surface plasmonic resonance band (SPR) in the wavelength range of 410-450 nm, size between 1-100 nm, load with module value up to the limit of 30 mV, and polidispersity index (PDI) less than 0,3. In the antibacterial action studies, all 4 AgNPs were able to inhibit the growth of Pseudomonas aeruginosa IPT322, Staphylococcus aureus IPT246 and Klebsiella pneumoniae IPT412 in concentrations equal to or greater than 50 μg mL-1 . In relation to the antifungal action, Aspergillus niger IPT295 and Penicillium funiculosum IPT423 were the most sensitive, presenting minimum inhibitory concentration (MICs) from 20 to 40 μg mL-1 . Regarding the influence of different parameters on AgNP biosynthesis, AgNO3 concentrations higher than 1,0 mM triggered the increase of nanomaterials size and the AgNP IB-CLP22 presented instability once to infer to 1 month of storage. All strains presented biosynthesis capabilities when the biomass value was between 75.0-150.0 g L-1 . In the evaluation of the agitation influence in the process of AgNP formation, in both static and agitated mode the four lines produced AgNP, however, the AgNP biosynthesized in static mode presented larger size when compared to processes carried out with agitation of up to 150 rpm. A higher aggregation state of AgNP produced at 200 rpm was also detected. In addition, AgNP IB-CLP11, IB-CLP17 and IB-CLP22 produced at 200 rpm precipitated after 3 months of storage. All AgNP formation occurred at temperatures between 25-35 ° C. However, an instability of AgNP IB-CLP11 and IB-CLP22 nanomaterials was observed at temperatures above 30 ° C. At pH above 5.5, no AgNP formation occurred for any of the selected strains. AgNPs produced at pH 4.5 showed better stability. Of all AgNP, the IB-CLP 11 demonstrated better stability according to data in Zeta Potential, therefore this was chosen for in vivo tests in routine metabolism in Palaemon pandaliformis. Finally, the exposure of AgNP IB-CLP11 to Palaemon pandaliformis presented alterations in the routine metabolism of the organism when compared to the control group. However, further studies with synthetic AgNP are needed to effectively have a clear view of the different effects generated in the routine metabolism of the aforementioned organism.
Silver nanoparticles (AgNP) from biological synthesis are currently described as the new nanobiotechnological agents with potential industrial and environmental application, mainly due to their recognized antimicrobial activity. Among the different organisms capable of biosynthesizing AgNP, filamentous fungi (Ff) stand out because of the rapid growth and easy staggering. Thus, the present study aimed to select marine fungi from the collection of culture of the Institute of Biosciences- Campus littoral Paulista (IB-CLP) of the state of São Paulo, which is able to biosynthesize AgNP, as well as optimize the synthesis process by evaluating the influence of different physico-chemical parameters, such, as variations concentrations in AgNO3, biomass, agitation, temperature and pH. An antimicrobial capacity and potential toxic effect were also evaluated in freshwater shrimp Palaemon pandaliformis. Among 12 selected strains of fungi, 10 were able to biosynthesize AgNP. All AgNP were characterized according to the proposed parameters and after 6 months of stability analysis, 4 presented a set of promising characteristics for the accomplishment of the second stage of the study. The AgNP produced by the Penicillium citrinum IB-CLP11, Penicillium sclerotigenum IB-CLP17, Aspergillus niger IB-CLP20 and Penicillium polonicum IB-CLP22 strains have surface plasmonic resonance band (SPR) in the wavelength range of 410-450 nm, size between 1-100 nm, load with module value up to the limit of 30 mV, and polidispersity index (PDI) less than 0,3. In the antibacterial action studies, all 4 AgNPs were able to inhibit the growth of Pseudomonas aeruginosa IPT322, Staphylococcus aureus IPT246 and Klebsiella pneumoniae IPT412 in concentrations equal to or greater than 50 μg mL-1 . In relation to the antifungal action, Aspergillus niger IPT295 and Penicillium funiculosum IPT423 were the most sensitive, presenting minimum inhibitory concentration (MICs) from 20 to 40 μg mL-1 . Regarding the influence of different parameters on AgNP biosynthesis, AgNO3 concentrations higher than 1,0 mM triggered the increase of nanomaterials size and the AgNP IB-CLP22 presented instability once to infer to 1 month of storage. All strains presented biosynthesis capabilities when the biomass value was between 75.0-150.0 g L-1 . In the evaluation of the agitation influence in the process of AgNP formation, in both static and agitated mode the four lines produced AgNP, however, the AgNP biosynthesized in static mode presented larger size when compared to processes carried out with agitation of up to 150 rpm. A higher aggregation state of AgNP produced at 200 rpm was also detected. In addition, AgNP IB-CLP11, IB-CLP17 and IB-CLP22 produced at 200 rpm precipitated after 3 months of storage. All AgNP formation occurred at temperatures between 25-35 ° C. However, an instability of AgNP IB-CLP11 and IB-CLP22 nanomaterials was observed at temperatures above 30 ° C. At pH above 5.5, no AgNP formation occurred for any of the selected strains. AgNPs produced at pH 4.5 showed better stability. Of all AgNP, the IB-CLP 11 demonstrated better stability according to data in Zeta Potential, therefore this was chosen for in vivo tests in routine metabolism in Palaemon pandaliformis. Finally, the exposure of AgNP IB-CLP11 to Palaemon pandaliformis presented alterations in the routine metabolism of the organism when compared to the control group. However, further studies with synthetic AgNP are needed to effectively have a clear view of the different effects generated in the routine metabolism of the aforementioned organism.
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Palavras-chave
Fungo marinho, Nanopartícula de prata, otimização de processo, Pseudomonas aeroginosa, Aspergillus fumigatus, Palaemon pandaliformis