Biomassa do fungo filamentoso Lasiodiplodia theobromae: composição química e utilização como nutriente para bioprocesso
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Data
2016-04-04
Autores
Bueno, Yara Cristina [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A riqueza nutricional da biomassa de Lasiosiplodia theobromae, resíduo do bioprocesso que tem como finalidade a produção de exopolissacarídeo (EPS), foi estudada neste trabalho, bem como a produção de EPS pelo mesmo fungo, em cultivos suplementados com esse biomaterial. Inicialmente, o microrganismo foi cultivado em condição padrão (sacarose 50 g/L, sais mínimos de Vogel (SMV) e nitrato de amônio 2 g/L, 28 °C, 72 h), e o EPS e a biomassa (Biomassa A), provenientes deste cultivo, foram separados e quantificados por gravimetria. Parte da biomassa foi lavada, por duas vezes, com solução de NaCl 0,15 mol/L, autoclavada, liofilizada, tamisada e analisada quanto à composição bromatológica (Weende e Kjeldahl) e de minerais (Absorção Atômica), e utilizada como suplemento aos meios de cultivo. A biomassa A apresentou 332 g/kg de C e 51 g/kg de N, além de sais minerais, como Zn, Fe, Cu, Mn, K, Mg, Ca, S e P. Para avaliar a adição de biomassa em meio de cultivo para produção de EPS, foram realizados 18 experimentos, com 6 diferentes composições (meios BSVN, BSV, BVN, BV, BN e B), identificados de acordo com a composição de nutrientes: Biomassa A 20, 40 ou 60 g/L (B), sacarose 50 g/L (S), SMV (V) e nitrato de amônio 2 g/L (N). Houve produção de EPS em 16 experimentos, sendo que em apenas três condições experimentais a produção de EPS foi inferior à condição padrão de cultivo. Destaque para os resultados obtidos em meios BV, compostos por biomassa 40 e 60 g/L e SMV, sendo 3,22 e 3,99 g/L de EPS, respectivamente, enquanto que na condição padrão de cultivo, houve produção de 1,3 g/L de EPS. A biomassa resultante do primeiro cultivo com adição de Biomassa A, identificada como Biomassa B (Biomassa A residual + biomassa de novo crescimento microbiano), também foi avaliada quanto à composição bromatológica e de minerais. Observou-se 414 g/kg de C e 46 g/kg de N. Cultivos na condição BV com 40g/L de biomassa foram realizados em ciclos subsequentes, a fim de se verificar por quantos cultivos a biomassa poderia ser utilizada para a produção de EPS pelo fungo. Observou-se produção de EPS até o 3° ciclo, obtendo-se 2,1, 1,4 e 1,1 g/L, entre o 1° e o 3° ciclos, respectivamente, enquanto que, na condição padrão de cultivo, foram obtidos 1,4 g/L de EPS. O EPS produzido em meio BV foi caracterizado estruturalmente por Ressonância Magnética Nuclear (RMN), após fracionamento por gelo e degelo. Observou-se a presença de uma β-glucana-(1→3)-(1→6) insolúvel em água fria, e uma β-glucana-(1→6), solúvel em água fria. Os resultados confirmam a possibilidade de utilização de biomassa de L. theobromae como suplemento para meios de cultivo.
The nutritional value of Lasiodiplodia theobromae’ biomass, waste of the bioprocess used for the production of exopolysaccharide (EPS) was studied in this work, as well as the production of EPS by the same fungus when grown in cultures supplemented with this biomaterial. Initially the microorganism was cultured in standard conditions (Sucrose 50 g/L, Vogel minimal salts (SMV) and ammonium nitrate 2 g/L, 28 °C, 72 h) and the EPS and the biomass (A Biomass) from this culture were separated and quantified by gravimetry. Part of the biomass was rinsed twice with NaCl 0.15 mol/L solution, autoclaved, lyophilized, sieved and analyzed for chemical composition (Weende and Kjeldahl) and minerals (Atomic Absorption) and used as a supplement to culture medium. Biomass A presented 332 g/kg C and 51 g/kg of N, and minerals such as Zn, Fe, Cu, Mn, Mg, Ca, S and P. In order to evaluate the addition of biomass in the culture medium for EPS production, 18 experiments were conducted with six different compositions (BSVN, BSV, BVN, BV, BN and B growth mediums), identified accordingly to the nutritional components: A Biomass 20, 40 or 60 g/L (B), Sucrose 50 g/L (S), SMV (V) and ammonium nitrate 2 g/L (N). EPS production occurred in 16 experiments, and in only three experimental conditions EPS production was lower than on the standard cultivation condition. Emphasis to the results obtained in BV medium, composed by biomass 40 and 60 g / L and SMV, being 3.22 and 3.99 g/L EPS, respectively, while the standard conditions of cultivation, production occurred of 1.3 g/L EPS. The biomass resulting this first cultivation with addition of A Biomass, identified as B Biomass (A Biomass waste + the biomass new microbial growth) was also evaluated for their chemical and mineral composition. As result 414 g/kg C and 46 g/kg N. Cultivations on BV condition with 40g/L of biomass were carried out in subsequent cycles, in order to check for how many cultivations the same biomass could be used in other to enable the fungus to produce EPS. It was observed EPS production until the 3rd cycle, producing 2.1, 1.4 and 1.1 g/L, respectively, while the standard cultivation condition produced 1.4 g/L EPS. The EPS produced in BV medium was structurally characterized by nuclear magnetic resonance (NMR), after fractionation by freezing and thawing. It was observed the presence of a β-(1 → 3) - (1 → 6)-glucan, insoluble in cold water, and a β-(1 → 6)-glucan, soluble in cold water. The results confirm the possibility of use of L. theobromae biomass as supplement for culture mediuns.
The nutritional value of Lasiodiplodia theobromae’ biomass, waste of the bioprocess used for the production of exopolysaccharide (EPS) was studied in this work, as well as the production of EPS by the same fungus when grown in cultures supplemented with this biomaterial. Initially the microorganism was cultured in standard conditions (Sucrose 50 g/L, Vogel minimal salts (SMV) and ammonium nitrate 2 g/L, 28 °C, 72 h) and the EPS and the biomass (A Biomass) from this culture were separated and quantified by gravimetry. Part of the biomass was rinsed twice with NaCl 0.15 mol/L solution, autoclaved, lyophilized, sieved and analyzed for chemical composition (Weende and Kjeldahl) and minerals (Atomic Absorption) and used as a supplement to culture medium. Biomass A presented 332 g/kg C and 51 g/kg of N, and minerals such as Zn, Fe, Cu, Mn, Mg, Ca, S and P. In order to evaluate the addition of biomass in the culture medium for EPS production, 18 experiments were conducted with six different compositions (BSVN, BSV, BVN, BV, BN and B growth mediums), identified accordingly to the nutritional components: A Biomass 20, 40 or 60 g/L (B), Sucrose 50 g/L (S), SMV (V) and ammonium nitrate 2 g/L (N). EPS production occurred in 16 experiments, and in only three experimental conditions EPS production was lower than on the standard cultivation condition. Emphasis to the results obtained in BV medium, composed by biomass 40 and 60 g / L and SMV, being 3.22 and 3.99 g/L EPS, respectively, while the standard conditions of cultivation, production occurred of 1.3 g/L EPS. The biomass resulting this first cultivation with addition of A Biomass, identified as B Biomass (A Biomass waste + the biomass new microbial growth) was also evaluated for their chemical and mineral composition. As result 414 g/kg C and 46 g/kg N. Cultivations on BV condition with 40g/L of biomass were carried out in subsequent cycles, in order to check for how many cultivations the same biomass could be used in other to enable the fungus to produce EPS. It was observed EPS production until the 3rd cycle, producing 2.1, 1.4 and 1.1 g/L, respectively, while the standard cultivation condition produced 1.4 g/L EPS. The EPS produced in BV medium was structurally characterized by nuclear magnetic resonance (NMR), after fractionation by freezing and thawing. It was observed the presence of a β-(1 → 3) - (1 → 6)-glucan, insoluble in cold water, and a β-(1 → 6)-glucan, soluble in cold water. The results confirm the possibility of use of L. theobromae biomass as supplement for culture mediuns.
Descrição
Palavras-chave
Biomassa fúngica, Fungi biomass, Exopolissacarídeo, Viabilidade econômica, Capacidade nutricional, Exopolysaccharide, Economic viability, Nutritional capacity