Bioprospecção de leveduras para produção de carotenoides microbianos
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Data
2018-04-13
Autores
Machado, Whallans Raphael Couto
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A bioprospecção é uma ferramenta valiosa, que possibilita a busca de novos micro-organismos com potencial biotecnológico. O Brasil apresenta vários biomas, dentre eles o Cerrado, com 2 milhões de quilômetros quadrados, ocupando 25% do território nacional, com uma estimativa de 70 a 100 mil espécies de fungos/leveduras. Entretanto, é pouco explorado em termos biotecnológicos. O objetivo desse trabalho, foi isolar e selecionar cepas de leveduras com capacidade de produção de carotenoides a partir da biodiversidade presente em amostras ambientais (folhas, solo, flores, frutos silvestres e insetos) coletadas do bioma Cerrado, bem como outro espaço, do campus universitário da UNESP, localizando em São José do Rio Preto - SP. Foram encontrados 69 micro-organismos no bioma Cerrado que apresentaram coloração, com destaque para quatro leveduras, Rhodotorula lactosa, Rhodotorula glutinis, Rhodotorula graminis e Rhodotorula aurantiaca, e oito leveduras, para o bioma do campus universitário, com destaque para Rhodotorula mucilaginosa. Todas as cepas destacadas foram identificadas por análise de DNA (PCR). A produção microbiana de carotenoides foi influenciada pelas condições experimentais de cultivo submerso, tais como agitação (130 rpm a 230 rpm) e temperatura (25 °C a 35 °C). Para as leveduras isoladas R. lactosa, R. glutinis, R. graminis e R. aurantiaca, a melhor forma de cultivar foi a 130 rpm e 25 °C. Entretanto, existem outros fatores no cultivo submerso que devem ser considerados, como as componentes do meio de cultivo como o extrato de levedura (1 a 10 g/L), a peptona (1 a 10 g/L), a glicose (10 a 30 g/L), o extrato de malte (1 a 10 g/L) e o pH inicial (4,5 a 6,5), que apresentam influência na síntese de carotenoides, aumentando sua produção. Dentre os micro-organismos estudados (R. lactosa, R. glutinis e R. mucilaginosa), a levedura R. mucilaginosa apresentou uma produção de carotenoides de 4164,45 µg/L (252,99 µg/g) com 16,46 g/L em biomassa. Na tentativa de substituição do agente de ruptura (DMSO – Dimetilsulfóxido) por outro método mais brando, o ácido acético com pérola de vidro apresentou uma extração de apenas 63,29 µg/g. Na batelada intermitente, é possível produzir quantidades semelhantes de carotenoides (2,8 mg/L) a cada 3 dias de cultivo, removendo 50% do meio. O uso de coproduto como substratos promoveu uma produção de carotenoides de 1829,81, 416,50 e 351,24 µg/L, respectivamente, com melaço (40 g/L), glicerol (10 g/L) e manipueira (40 g/L)
Bioprospecting is now a valuable tool, enabling the search for new microorganisms with biotechnological potential. Brazil has several biomes, including the Cerrado, with 2 million square kilometers, occupying 25% of the national territory, with an estimated 70 to 100 thousand species of fungi/yeasts. However, it is little explored in biotechnology terms. The objective of this work was to isolate and select yeast strains with the capacity to produce carotenoids from the biodiversity present in environmental samples (leaves, soil, flowers, wild fruits and insects) collected from the Cerrado biome, as well as another space, the university campus of UNESP, located in São José do Rio Preto - SP. A total of 69 microorganisms were found in the Cerrado biome, with four yeasts, Rhodotorula lactosa, Rhodotorula glutinis, Rhodotorula graminis and Rhodotorula aurantiaca, and eight microorganisms, with emphasis on Rhodotorula mucilaginosa. All strains highlighted were identified by DNA analysis (PCR). The microbial production of carotenoids was influenced by the experimental conditions of cultivation, such as agitation (130 rpm at 230 rpm) and temperature (25 °C to 35 °C). For the isolated yeasts R. lactosa, R. glutinis, R. graminis and R. aurantiaca, the best way to cultivate was at 130 rpm and 25 °C. However, there are other factors in the submerged culture that must be considered, such as the components of the culture medium (yeast extract, peptone, glucose, malt extract and initial pH), which influence the synthesis of carotenoids, increasing their production. Among the studied microorganisms (R. lactosa, R. glutinis and R. mucilaginosa), yeast R. mucilaginosa presented a carotenoid production of 4164.45 μg/L (252.99 μg/g) with 16.46 g/L in biomass. In an attempt to substitute the DMSO with a milder method, the acetic acid with glass pearl presented an extraction of only 63.29 μg/g. In the intermittent batch, it is possible to produce similar quantities of carotenoids (2.8 mg/L) every 3 days of cultivation, removing 50% of the medium The use of co-product as substrates promoted a carotenoid production of 1829.81, 416.50 and 351.24 μg/L respectively with molasses (40 g/L), glycerol (10 g/L) and cassava wastewater (40 g/L).
Bioprospecting is now a valuable tool, enabling the search for new microorganisms with biotechnological potential. Brazil has several biomes, including the Cerrado, with 2 million square kilometers, occupying 25% of the national territory, with an estimated 70 to 100 thousand species of fungi/yeasts. However, it is little explored in biotechnology terms. The objective of this work was to isolate and select yeast strains with the capacity to produce carotenoids from the biodiversity present in environmental samples (leaves, soil, flowers, wild fruits and insects) collected from the Cerrado biome, as well as another space, the university campus of UNESP, located in São José do Rio Preto - SP. A total of 69 microorganisms were found in the Cerrado biome, with four yeasts, Rhodotorula lactosa, Rhodotorula glutinis, Rhodotorula graminis and Rhodotorula aurantiaca, and eight microorganisms, with emphasis on Rhodotorula mucilaginosa. All strains highlighted were identified by DNA analysis (PCR). The microbial production of carotenoids was influenced by the experimental conditions of cultivation, such as agitation (130 rpm at 230 rpm) and temperature (25 °C to 35 °C). For the isolated yeasts R. lactosa, R. glutinis, R. graminis and R. aurantiaca, the best way to cultivate was at 130 rpm and 25 °C. However, there are other factors in the submerged culture that must be considered, such as the components of the culture medium (yeast extract, peptone, glucose, malt extract and initial pH), which influence the synthesis of carotenoids, increasing their production. Among the studied microorganisms (R. lactosa, R. glutinis and R. mucilaginosa), yeast R. mucilaginosa presented a carotenoid production of 4164.45 μg/L (252.99 μg/g) with 16.46 g/L in biomass. In an attempt to substitute the DMSO with a milder method, the acetic acid with glass pearl presented an extraction of only 63.29 μg/g. In the intermittent batch, it is possible to produce similar quantities of carotenoids (2.8 mg/L) every 3 days of cultivation, removing 50% of the medium The use of co-product as substrates promoted a carotenoid production of 1829.81, 416.50 and 351.24 μg/L respectively with molasses (40 g/L), glycerol (10 g/L) and cassava wastewater (40 g/L).
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Corantes microbianos, coprodutos, otimização, Microbial dyes, co-products, optimization