Produção de biossurfactantes por Candida tropicalis utilizando resíduos do processamento do abacaxi (Ananas comosus) como substrato
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2019-05-08
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Universidade Estadual Paulista (Unesp)
Resumo
Biossurfactantes são grupos de compostos químicos produzidos por bactérias, fungos e leveduras através da biodegradação de matérias-primas renováveis. Tais compostos possuem característica anfipática, agindo como emulsificantes de hidrocarbonetos. São polímeros que formam micelas que se acumulam na interface entre líquidos de diferentes graus de polaridade. A utilização de biossurfactantes tornou-se uma alternativa bastante interessante em substituição aos surfactantes sintéticos, pois geram menor impacto ambiental devido à sua biodegradabilidade, diversidade estrutural e baixa toxicidade. O abacaxi é uma fruta tropical muito consumida no Brasil, principalmente o suco e a fruta “in natura”, gerando assim uma grande quantidade de resíduos como a casca e o talo de abacaxi. O presente trabalho teve como objetivo a produção de biossurfactante por meio da fermentação dos resíduos hidrolisados do processamento do abacaxi (Ananas comosus), por Candida tropicalis. A hidrólise foi realizada utilizando diferentes concentrações de ácido sulfúrico submetidas a diferentes tempos de aquecimento em autoclave. Foram realizadas análises de açúcares, composto fenólico e produção de biossurfactantes. Os resultados indicaram que a melhor concentração de ácido sulfúrico para realização da hidrólise foi 2,5% de H2SO4 com tempo de aquecimento de 15 minutos. A desintoxicação diminuiu a quantidade de compostos fenólicos. Foi determinada a melhor forma da produção de biossurfactantes por fermentação durante 12 horas e utilizando como fonte de carbono os hidrolisados da casca de abacaxi, talo de abacaxi e glicose na concentração de 5%. A partir destes resultados testou-se a capacidade de produção de biossurfactante utilizando o hidrolisado da casca e do talo de abacaxi e glicose. Os biossurfactantes produzidos após 2h, 4h, 6h e 8h em todos os substratos mantiveram um índice de emulsificação menor do que 50%, já os biossurfactantes produzido após 10 horas de fermentação tiveram valores próximos de 50% e mantiveram a estabilidade da emulsão acima das 24 horas. Os resultados obtidos para atividade emulsificante mostraram que quanto maior for a concentração de biossurfactante e maior o tempo de fermentação maior foi o valor de atividade emulsificante. Foram constatadas reduções da tensão superficial para os biossurfactantes produzidos a partir dos hidrolisados de todos os substratos. Deste, o biossurfactante obtido usando o hidrolisado do talo reduziu a tensão superficial até 30 mNm-1. A concentração micelar crítica teve seu valor menor também com o biossurfactante produzido pelo hidrolisado do talo de abacaxi, porém todos os substratos mantiveram valores baixos o que indica que os biossurfactantes produzidos foram eficazes. Foi analisado o índice de emulsificação em ensaios imitando um molho tipo francês. A formulação contendo 6 mL de biossurfactante estabilizou a mistura melhor. A análise em tempos de 15 em 15 dias verificou que com essa formulação há uma estabilização do molho, havendo pouca variação nos 120 dias analisados.
Biosurfactants are groups of chemical compounds produced by bacteria, fungi and yeasts through the biodegradation of renewable raw materials. Such compounds have amphipathic properties, acting as hydrocarbon emulsifiers. They are polymers that form micelles that accumulate at the interface between liquids of different degrees of polarity. The use of biosurfactants has become a rather interesting alternative to synthetic surfactants because they generate less environmental impact due to their biodegradability, structural diversity and low toxicity. Pineapple is a tropical fruit very consumed in Brazil, mainly the juice and the fruit "in natura", thus generating a great amount of residues like the pell and the stem of pineapple. The present work had as objective the production of biosurfactant by means of the fermentation of the hydrolyzed residues of the processing of the pineapple (Ananas comosus), by Candida tropicalis. The hydrolysis was performed using different concentrations of sulfuric acid submitted to different autoclaving times. Analyzes of sugars, phenolic compounds and biosurfactants production were carried out. The results indicated that the best sulfuric acid concentration for the hydrolysis was 2.5% H2SO4 with a heating time of 15 minutes. Detoxification decreased the amount of phenolic compounds. The best form of biosurfactant production was determined by fermentation for 12 hours and using the hydrolysates of pineapple peel, pineapple stem and glucose at 5% concentration as the carbon source. From these results the biosurfactant production capacity was tested using the hydrolyzate of the peel and the stem of pineapple and glucose. The biosurfactants produced after 2h, 4h, 6h and 8h in all substrates maintained an emulsification index of less than 50%, while the biosurfactants produced after 10 hours of fermentation had values close to 50% and maintained the emulsion stability above 24 hours. The results obtained for emulsifying activity showed that the higher the biosurfactant concentration and the longer the fermentation time the higher the emulsifying activity value. Reductions of the surface tension for the biosurfactants produced from the hydrolysates of all the substrates were observed. From this, the biosurfactant obtained using the pineapple stem hydrolyzate reduced the surface tension to 30 mNm-1. The critical micellar concentration was also lower with the biosurfactant produced by the pineapple stem hydrolyzate, but all the substrates maintained low values indicating that the biosurfactants produced were effective. The emulsification index was assayed in assays mimicking a French type dressing. The formulation containing 6 ml of biosurfactant stabilized the mixture better. The analysis at 15-day times showed that with this formulation there is a stabilization of the sauce, with little variation in the 120 days analyzed.
Biosurfactants are groups of chemical compounds produced by bacteria, fungi and yeasts through the biodegradation of renewable raw materials. Such compounds have amphipathic properties, acting as hydrocarbon emulsifiers. They are polymers that form micelles that accumulate at the interface between liquids of different degrees of polarity. The use of biosurfactants has become a rather interesting alternative to synthetic surfactants because they generate less environmental impact due to their biodegradability, structural diversity and low toxicity. Pineapple is a tropical fruit very consumed in Brazil, mainly the juice and the fruit "in natura", thus generating a great amount of residues like the pell and the stem of pineapple. The present work had as objective the production of biosurfactant by means of the fermentation of the hydrolyzed residues of the processing of the pineapple (Ananas comosus), by Candida tropicalis. The hydrolysis was performed using different concentrations of sulfuric acid submitted to different autoclaving times. Analyzes of sugars, phenolic compounds and biosurfactants production were carried out. The results indicated that the best sulfuric acid concentration for the hydrolysis was 2.5% H2SO4 with a heating time of 15 minutes. Detoxification decreased the amount of phenolic compounds. The best form of biosurfactant production was determined by fermentation for 12 hours and using the hydrolysates of pineapple peel, pineapple stem and glucose at 5% concentration as the carbon source. From these results the biosurfactant production capacity was tested using the hydrolyzate of the peel and the stem of pineapple and glucose. The biosurfactants produced after 2h, 4h, 6h and 8h in all substrates maintained an emulsification index of less than 50%, while the biosurfactants produced after 10 hours of fermentation had values close to 50% and maintained the emulsion stability above 24 hours. The results obtained for emulsifying activity showed that the higher the biosurfactant concentration and the longer the fermentation time the higher the emulsifying activity value. Reductions of the surface tension for the biosurfactants produced from the hydrolysates of all the substrates were observed. From this, the biosurfactant obtained using the pineapple stem hydrolyzate reduced the surface tension to 30 mNm-1. The critical micellar concentration was also lower with the biosurfactant produced by the pineapple stem hydrolyzate, but all the substrates maintained low values indicating that the biosurfactants produced were effective. The emulsification index was assayed in assays mimicking a French type dressing. The formulation containing 6 ml of biosurfactant stabilized the mixture better. The analysis at 15-day times showed that with this formulation there is a stabilization of the sauce, with little variation in the 120 days analyzed.
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Palavras-chave
Biossurfactante, Fermentação, Abacaxi, Biosurfactant, Fermentation, Pineapple