Potencial bioquímico e perfil de crescimento de isolados de Streptomyces spp
Data
2020-11-05
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Universidade Federal de Viçosa
Resumo
Bactérias do gênero Streptomyces pertencentes ao filo Actinobacteria são Gram-positivas com alto conteúdo GC no seu DNA. São predominantes no solo e há uma estimativa de que cerca de 80% das substâncias bioativas naturais do mundo, como antibióticos, substâncias antitumorais, imunossupressores, pesticidas, pigmentos e diversas enzimas de interesse industrial sejam produzidas por Streptomyces spp. O rastreamento de novas fontes de enzimas com capacidade de catalisar diferentes reações é um aspecto atraente para indústria biotecnológica. Uma forma de encontrar novas fontes, é a partir da triagem de um grande número de microrganismos, aumentando a probabilidade de se encontrar fontes promissoras para uma ampla gama de enzimas. O objetivo desse trabalho foi caracterizar isolados de Streptomyces spp. em relação à produção de diversas enzimas de interesse biotecnológico e investigar o perfil de crescimento de alguns dos isolados considerados mais promissores. Na primeira etapa, foi realizada análise qualitativa para atividade das enzimas: amilase, celulase, protease, lipase, L-asparaginase e L-glutaminase. Os isolados de Streptomyces spp. investigados foram capazes de expressar atividade de diferentes enzimas nas condições analisadas. Assim, 5% dos isolados apresentaram atividade de todas as 6 enzimas investigadas, 30% foram capazes de expressar atividade para 5 diferentes enzimas, 30% (4), 19% (3) e 16% apenas um único perfil de atividade. Três isolados foram investigados quanto ao perfil de crescimento. Para isso, os isolados identificados como CAB25, CAB50 e CAB66 foram inoculados nos caldos BD (Batata Dextrose) e ISP-2 (International Streptomyces Project), por 12 dias a 28 °C e 150 RPM, e o crescimento acompanhado por massa seca, consumo de glicose e variação do pH ao longo do período de análise. A partir dos resultados obtidos, pôde-se observar que houve relação entre variação de pH e aumento de massa seca, sendo a tendência de incremento de biomassa ao longo do tempo significativamente diferente entre os dois meios de cultura e para todos os isolados testados. A escolha do meio de cultura apropriado é importante para análise de isolados de Streptomyces, visto que o potencial de produção de compostos bioativos é influenciado pelas condições culturais. A análise do pH do sobrenadante 9 das culturas em meio ISP-2, de neutro a alcalino, revelou que os isolados de Streptomyces possuem características interessantes para aplicação em solos ácidos. Portanto, com este trabalho, foi possível selecionar isolados de Streptomyces spp. produtores de enzimas de interesse biotecnológico e com taxa de crescimento rápido, o que permite desenvolver plataformas ou chassis biotecnológicos de Streptomyces spp. Palavras-chave: Actinobacteria. Potencial enzimático. Crescimento microbiano.
Bacteria of the genus Streptomyces belonging to the phylum Actinobacteria are Gram-positive with high GC content in their DNA. They are prevalent in the soil and it is estimated that about 80% of the world's natural bioactive substances, such as antibiotics, antitumor substances, immunosuppressants, pesticides, pigments and various enzymes of industrial interest are produced by Streptomyces spp. The screening of new sources of enzymes capable of catalyzing different reactions is an attractive aspect for the biotechnology industry. One way to find new sources is by screening a large number of microorganisms, increasing the probability of finding promising sources for a wide range of enzymes. The objective of this work was to characterize isolates of Streptomyces spp. regarding the production of several enzymes of biotechnological interest and to investigate the growth profile of some of the isolates considered most promising. In the first stage, a qualitative analysis was performed for enzyme activity: amylase, cellulase, protease, lipase, L-asparaginase and L-glutaminase. The isolates of Streptomyces spp. investigated were able to express activity of different enzymes under the conditions analyzed. Thus, 5% of the isolates showed activity of all 6 investigated enzymes, 30% were able to express activity for 5 different enzymes, 30% (4), 19% (3) and 16% only a single activity profile. Three isolates were investigated for growth profile. For this, the isolates identified as CAB25, CAB50 and CAB66 were inoculated in BD (Potato Dextrose) and ISP-2 (International Streptomyces Project) broths, for 12 days at 28 ° C and 150 RPM, and the growth verified by dry mass, glucose consumption and pH variation over the analysis period. From the results obtained, it was observed that the pH variation and increase in dry mass were related, with the tendency of increasing biomass over time significantly different between the two culture media and for all tested isolates. The choice of the appropriate culture medium is important for the analysis of Streptomyces isolates, since the production potential of bioactive compounds is influenced by cultural conditions. The analysis of the pH of the cultures supernatant in ISP-2 medium, from neutral to alkaline, indicated that the Streptomyces isolates have interesting characteristics for application in acidic soils. Therefore, with this work, it was possible to select 11 isolates of Streptomyces spp. producers of enzymes of biotechnological interest and with a rapid growth rate, which allows the development of biotechnological platforms or chassis of Streptomyces spp. Keywords: Actinobacteria. Enzymatic potential. Microbial growth.
Bacteria of the genus Streptomyces belonging to the phylum Actinobacteria are Gram-positive with high GC content in their DNA. They are prevalent in the soil and it is estimated that about 80% of the world's natural bioactive substances, such as antibiotics, antitumor substances, immunosuppressants, pesticides, pigments and various enzymes of industrial interest are produced by Streptomyces spp. The screening of new sources of enzymes capable of catalyzing different reactions is an attractive aspect for the biotechnology industry. One way to find new sources is by screening a large number of microorganisms, increasing the probability of finding promising sources for a wide range of enzymes. The objective of this work was to characterize isolates of Streptomyces spp. regarding the production of several enzymes of biotechnological interest and to investigate the growth profile of some of the isolates considered most promising. In the first stage, a qualitative analysis was performed for enzyme activity: amylase, cellulase, protease, lipase, L-asparaginase and L-glutaminase. The isolates of Streptomyces spp. investigated were able to express activity of different enzymes under the conditions analyzed. Thus, 5% of the isolates showed activity of all 6 investigated enzymes, 30% were able to express activity for 5 different enzymes, 30% (4), 19% (3) and 16% only a single activity profile. Three isolates were investigated for growth profile. For this, the isolates identified as CAB25, CAB50 and CAB66 were inoculated in BD (Potato Dextrose) and ISP-2 (International Streptomyces Project) broths, for 12 days at 28 ° C and 150 RPM, and the growth verified by dry mass, glucose consumption and pH variation over the analysis period. From the results obtained, it was observed that the pH variation and increase in dry mass were related, with the tendency of increasing biomass over time significantly different between the two culture media and for all tested isolates. The choice of the appropriate culture medium is important for the analysis of Streptomyces isolates, since the production potential of bioactive compounds is influenced by cultural conditions. The analysis of the pH of the cultures supernatant in ISP-2 medium, from neutral to alkaline, indicated that the Streptomyces isolates have interesting characteristics for application in acidic soils. Therefore, with this work, it was possible to select 11 isolates of Streptomyces spp. producers of enzymes of biotechnological interest and with a rapid growth rate, which allows the development of biotechnological platforms or chassis of Streptomyces spp. Keywords: Actinobacteria. Enzymatic potential. Microbial growth.
Descrição
Palavras-chave
Actinobacteria, Micro-organismos biotecnológicos, Enzimas microbianas, Ativadores enzimáticos
Citação
ABREU, Dâmaris Simões Gomes. Potencial bioquímico e perfil de crescimento de isolados de Streptomyces spp. 2020. 69 f. Dissertação (Mestrado em Microbiologia Agrícola) - Universidade Federal de Viçosa, Viçosa. 2020.