Screening of fungi with potential for producing fructooligosaccharides with enhanced bioactivity

Fructooligosaccharides (FOS) are present in plants and fruits at low concentrations and with varying individual relative proportions. So, for the industrial application, fructooligosaccharides extraction from natural sources may not be economically viable. Recently, several works have been published within the field of research usually aiming to establish the best experimental conditions to maximizing fructooligosaccharides yields/synthesis. However, although it is known that these compounds may have a great health impact, it is also reported that beneficial health effects may depend on the relative fructoligosaccharisdes composition, seeming that nystose-rich diet is preferable compared to a kestose-rich preparation, exhibiting a higher anti-hydroxyl radical activity. So, in this work, a screening study was firstly carried out aiming to evaluate the bioactive activity of the fermentation broths obtained using different fungi (A. aculeatus, A. japonicus, P. corylophilum, P. spinulosum and P. thomii) with reported potential for producing fructooligosaccharides. Based on the screening antioxidant results (DPPH free radical scavenging activity and iron chelating activity), A. aculeatus was selected as the fungi with the highest antioxidant potential. After, batch fermentations were carried out aiming to establish, based on an experimental design, the initial sucrose concentration (from 88 to 265 g/L) and fermentation temperature (from 22 to 32ºC), which enhance the broths bioactivities. Among the two evaluated experimental conditions, the initial sucrose concentration significantly influenced biomass growth (a maximum value of 16± 1.5 g was achieved) although it did not significantly affect the maximum FOS yield obtained, which varied between 51 to 59 g of FOS/g of initial sucrose. Finally, the preliminary results obtained did not allowed establishing straightforward correlation betwwen antioxidant activities of the fermentation broths and the individual or total FOS concentrations.Fruto-oligossacáridos (FOS) podem ser encontrados em plantas e frutos, embora em concentrações reduzidas e com diferentes proporções relativas de cada FOS individual. Assim, de um ponto de vista industrial, a extração de fruto-oligossacáridosa partir de fontes naturais pode não ser economicamente viável. Recentemente, vários trabalhos foram publicados com o objetivo de estabelecer as melhores condições experimentais para maximizar os rendimentos / síntese de fruto-oligossacáridos. No entanto, embora se saiba que estes compostos podem ter um grande impacto na saúde, também tem sido reportado que os efeitos benéficos para a saúde podem depender da composição relativa de fruto-oligossacáridos. Aparentemente, uma dieta rica em nistose é preferível em comparação com uma preparação rica em questose, exibindo uma maior atividade antioxidante. Assim, neste trabalho, realizou-se um estudo inicial para avaliar a bioatividade de meios fermentativos obtidos usando diferentes fungos (A. aculeatus, A. japonicus, P. corylophilum, P. spinulosum e P. thomii), os quais são conhecidos produtores de FOS. Com base nos resultados preliminares da actividade antioxidante de (atividade de eliminação de radicais livres DPPH e atividade quelante de ferro), o fugo A. aculeatus foi selecionado como sendo aquele que apresentava maior poder antioxidante. Posteriormente, foram realizadas fermentações com o objetivo de estabelecer, com base num desenho experimental, a concentração inicial de sacarose (de 88 a 265 g / L) e a temperatura de fermentação (de 22 a 32ºC), que maximizava o poder antiooxidante dos meios fermentativos. De entre as duas condições experimentais avaliadas, verificou-se que a concentração inicial de sacarose influenciou significativamente o crescimento da biomassa (valor máximo de 16 ± 2 g), embora não tenha afetado significativamente o rendimento de FOS obtido, que variou entre 51 a 59 g de FOS/g de sacarose inicial. Finalmente, os resultados preliminares obtidos não permitiram estabelecer uma correlação direta entre as atividades antioxidantes dos caldos de fermentação e as concentrações de FOS individuais ou totais

Monitoring fructooligossacharides production using Aspergillus aculeatus by HPLC ELSD

Fructooligosaccharides (FOS) are present in plants and fruits at low concentrations, thus their extraction from natural sources may not be economically viable for a large scale industrial application. Therefore, FOS production by fermentation using fungi can be an alternative. In this work, FOS were produced using Aspergillus aculeatus at different sucrose initial concentrations (88 to 265 g/L) and at temperatures from 22 to 32ºC. FOS production was monitored by HPLC-ELSD, allowing to confirm that the initial sucrose concentration significantly influenced biomass growth (a maximum value of 16 ± 2 g was achieved) although it did not significantly affect the maximum FOS yield (amount of FOS produced per initial sucrose) obtained, which varied from 51 to 59 g/g) obtained, which varied from 51 to 59 g/g. Finally, the preliminary results enabled verifying that depending on the fermentation conditions, slightly different FOS production profiles were obtained (Figure 1), revealing differences in the individual FOS concentrations (i.e., 1-kestose, nystose and fructofuranosylnystose), which could be of interest since it has been reported that the beneficial health effects of FOS may depend on the relative FOS composition.This work was also financially supported by Project POCI-01–0145-FEDER-006984–Associate Laboratory LSRE-LCM, UID/AGR/00690/2013 –CIMO and UID/BIO/04469/2013 funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia, Portugal.info:eu-repo/semantics/publishedVersio

Antioxidant and chealting activities of fermentation broths containing fructooligossacharides

Fructooligossacharides are present in plants and fruits at low concentrations and with varying individual relative proportions. So, for industrial application, fructooligossacharides extraction from natural sources may not be economically viable. Recently, several works have been published within this field of research usually aiming to establish the best experimental conditions to maximizing fructooligossacharides yield/synthesis [1-3]. However, although it is known that these compounds may have a great health impact, it is also reported that beneficial health effects may depend on the relative fructooligossacharides composition, seeming that nystose-rich diet is preferable compared to a kestoserich preparation, exhibiting a higher anti-hydroxyl radical activity [4,5]. So, in this work it is reported the results regarding a screening study concerning the bioactivity activity of the fermentation broth extracts obtained using fungi with potential for producing fructooligossacharides. The potential use of five fungi (i.e., A. aculeatus, A. japonicus, A. opinicosulum, P. thoumii and P. cornyphipum) was evaluated. Batch fermentation were carried out during 96 hours, at constant temperature (27 ºC) and agitation (100 rpm), being the initial sucrose concentration fixed at 30 g/L. Samples were taken at 24-h intervals and the radical scavenging activity as well as the iron binding ability of chelators, of the different broth extracts, were determined using the DPPH and ferrozine. The overall results obtained showed that although the extracts possessed relatively low bioactive activity; it was possible to set some preliminary insights that allowed selecting the most promissory(s) mold(s), which could enable achieving, in a near future, a final fructooligossacharides formulation with the greatest antioxidant capacity.This work was financially supported by Project POCI-01-0145-FEDER-006984 – Associate Laboratory LSRE-LCM funded by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia.info:eu-repo/semantics/publishedVersio

Monitoring fructooligossacharides production using Aspergillus aculeatus by HPLC-ELSD

Fructooligosaccharides (FOS) are present in plants and fruits at low concentrations, thus their extraction from natural sources may not be economically viable for a large scale industrial application. Therefore, FOS production by fermentation using fungi can be an alternative. In this work, FOS were produced using Aspergillus aculeatus at different sucrose initial concentrations (88 to 265 g/L) and at temperatures from 22 to 32ºC. FOS production was monitored by HPLC-ELSD, allowing to confirm that the initial sucrose concentration significantly influenced biomass growth (a maximum value of 16 ± 2 g was achieved) although it did not significantly affect the maximum FOS yield (amount of FOS produced per initial sucrose) obtained, which varied from 51 to 59 g/g) obtained, which varied from 51 to 59 g/g. Finally, the preliminary results enabled verifying that depending on the fermentation conditions, slightly different FOS production profiles were obtained (Figure 1), revealing differences in the individual FOS concentrations (i.e., 1-kestose, nystose and fructofuranosylnystose), which could be of interest since it has been reported that the beneficial health effects of FOS may depend on the relative FOS composition.This work was also financially supported by Project POCI-01–0145-FEDER-006984–Associate Laboratory LSRE-LCM, UID/AGR/00690/2013 – CIMO and UID/BIO/04469/2013 funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia, Portugal.info:eu-repo/semantics/publishedVersio