Orientadores: Sérgio Marangoni, Saulo Luis da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-10-31T14:37:34Z (GMT). No. of bitstreams: 1 GasparJunior_PascoalJose_D.pdf: 6862970 bytes, checksum: 60c120eb2e9159656d5c493ee05eca1a (MD5) Previous issue date: 2014 / Resumo: A triagem de fungos produtores de holocelulases é uma estratégia para a obtenção de enzimas capazes de hidrolisar o material lignocelulósico da biomassa vegetal, contribuindo para aumentar a viabilidade da produção de etanol celulósico Este trabalho avaliou o potencial enzimático dos fungos Penicillium corylophilum e Penicillium simplicissimum com relação às enzimas (endoglicanase, exoglicanase, ?-glicosidase, FPase, xilanase, pectinase e mananase) sobre substratos lignocelulósicos e comerciais como fonte de carbono. Além disso, avaliou-se também a influência da adição de diferentes fontes orgânicas e inorgânicas de nitrogênio sobre a atividade enzimática. Os fungos foram cultivados em triplicata em meio líquido suplementar com 1% de substrato lignocelulósico como fonte de carbono, em pH 7,0. A inoculação foi feita por suspensão de esporos (108 esporos/mL). O cultivo foi feito sob agitação a 120 rpm, a 28°C e os filtrados resultantes em 12, 24, 72 e 120 horas foram utilizados como fontes enzimáticas pelo método do DNS (ácido-3,5- dinitrosalicílico) em triplicata. De todas as atividades enzimáticas analisadas nas fontes lignocelulósicas, a atividade de xilanase do P. simplicissimum sobre a linhaça foi a mais expressiva (3,87 e 3,97 UI/ml), cultivados em 72 e 120 horas, respectivamente, e selecionada para os testes de purificação proteica. A atividade xilanásica específica aumentou consideravelmente após os passos cromatográficos de gel filtração e troca iônica (CTI), sendo inicialmente 3x10-3 atv/ µg de proteína no liofilizado e 19,2 atv/ µg de proteína na fração proveniente da CTI. Nos testes de pH, observou-se que a atividade de xilanase foi maior em pH=4,0 e temperatura de 50°C. Com relação à adição de substratos comerciais, a celulose microcristalina e a xilana apresentaram os resultados mais expressivos da indução da produção de xilanase, sendo que a concentração de 0,5% de xilana mostrou a melhor atividade enzimática em ambos os fungos estudados. A xilose apresentou uma concentração indutora mínima de 0,04% que foi suficiente para aumentar a atividade de xilanase do P. simplicissimum. Com relação à suplementação de fontes de nitrogênio no meio de cultivo para a produção de holocelulases, a adição de (NH4)2SO4 e caseína é uma alternativa importante para a potencialização das atividades de pectinase e de endoglicanase respectivamente pois foram fontes de nitrogênio que proporcionaram um aumento da atividade enzimática em ambos os fungos estudados como também nas duas fontes de carbono testadas. As frações contendo xilanases após cromatografia de gel filtração seguida de fase reversa, após análises por espectrometria de massas apresentam relação massa/carga de 18831,26 Da. A utilização do resíduo lignocelulósico da linhaça, como fonte de carbono para o cultivo submerso do Penicillium simplicissimum é uma opção ecologicamente correta, exequível e de baixo custo para a produção de xilanases. Diversas aplicações biotecnológicas como a utilização na ração animal, na indústria do papel e no etanol de segunda geração, dentre outros, possibilitam um acréscimo substancial do valor agregado desse substrato, permitindo uma ampliação da utilização da linhaça, além do aproveitamento do óleo, sem aumentar a área plantada / Abstract: Screening for producing fungi holocelulases is a strategy for obtaining enzymes that hydrolyze the lignocellulosic material from plant biomass, helping to increase the viability of cellulosic ethanol production This study evaluated the enzymatic potential of Penicillium simplicissimum and Penicillium corylophilum regarding enzymes (endoglicanase, exoglicanase, ?-glucosidase, FPase, xylanase, pectinase and mannanase) for commercial and lignocellulosic substrates as a carbon source. Furthermore, it was also evaluated the influence of the addition of different organic and inorganic nitrogen sources on enzyme activity. The fungus was grown in triplicate in a liquid medium supplement with 1% lignocellulosic substrate as carbon source, pH 7.0. The inoculation was done by the spore suspension (108 spores/ml). The cultivation was done with stirring at 120 rpm at 28 °C and the resulting filtered in 12, 24, 72 and 120 hours were used as enzyme sources for DNS (acid-3,5- dinitrosalicilic) method in triplicates. All enzymatic activities analyzed in lignocellulosic sources, the xylanase activity of P. simplicissimum about flaxseed was greater (3.87 and 3.97 IU/ml), grown at 72 and 120 h of cultivation, respectively, and selected for testing for protein purification. The specific xylanase activity increased considerably after the chromatographic steps of gel filtration and ion exchange (CTI), initially 3x10-3 atv/ mg of protein in lyophilized and 19.2 atv/ mg of protein in the fraction from the CTI. In pH testing, it was noted that the xylanase activity was higher at pH 4.0 and 50 °C. With respect to the addition of commercial substrates, microcrystalline cellulose and xylan showed the most significant results of induction of xylanase production, and the concentration of 0.5% xylan showed the best enzyme activity in both fungi studied. The xylose showed a minimal inducing concentration of 0.04% which was sufficient to increase the activity of xylanase from P. simplicissimum. With respect to supplemental nitrogen sources in the culture medium for the production of holocelulases, the addition of (NH4)2SO4 and casein can be an important tool for the enhancement of pectinase and endoglicanase activities respectively as alternative nitrogen sources that were provided an increase in enzyme activity in both fungi studied as well as the two carbon sources tested. The use of lignocellulosic residue of flaxseed as a source of carbon for submerged cultivation of Penicillium simplicissimum is an environmentally friendly, feasible and cost effective for the production of xylanases option. The fractions containing xylanases after gel filtration chromatography followed by reverse fase after analysis by mass spectrometry are related mass/charge of 18831 26 Da. The use of lignocellulosic waste of flaxseed as a source of carbon for submerged cultivation of Penicillium simplicissimum is an environmentally friendly, feasible and cost effective for the production of xylanases option. Various biotechnological applications such as use in animal feed, in the paper industry and in second generation ethanol, among others, allow a substantial increase in the value of this substrate, allowing an expansion of the use of flaxseed, plus the use of oil, without increasing acreage / Doutorado / Bioquimica / Doutor em Biologia Funcional e Molecular

Demand for lithium (Li) and cobalt (Co) is on the rise, due in part to their increased use in rechargeable Li-ion batteries (RLIB). Current recycling processes that utilize chemical leaching efficiently recover in Li and Co from the cathode material in spent batteries; however, these processes are costly and emit hazardous waste into the environment. Therefore, a more sustainable process for recycling Li and Co is needed, and bioleaching may provide a solution. Fungal bioleaching has been shown in previous studies to effectively mobilize metals (Pb, Al, Mn, Cu, and Zn) from mine tailings, electronic scrap, and spent batteries with organic acids. However, little is known regarding fungal tolerance to Li and Co, and if the concentrations of organic acids excreted by fungi can effectively leach Li and Co from the cathode material. In order to address these questions, experiments were first conducted to test the Li and Co leaching efficiency with organic acids at concentrations similar to what has been previously reported in fungal cultures. The remaining experiments were performed with three fungal species: Aspergillus niger, Penicillium chrysogenum, and Penicillium simplicissimum. First, fungal biomass production, pH and organic acid excretion were examined when the fungi were grown in Czapek dox broth (CDB) or Sabouraud dextrose broth (SDB). Second, fungal biomass production and pH were examined when the fungi were grown in the presence of Li or Co. This determines tolerance of the fungi to the metals, and if fungal processes were inhibited by the metals. Third, bioleaching was performed with cathode material from RLIB in batch cultures to test the ability of organic acids excreted by A. niger to mobilize Li and Co. Three bioleaching strategies, one-step, two-step, and spent-medium leaching techniques were used to mobilize Li and Co from the cathode in RLIB. Low concentrations of organic acids similar to what is excreted by fungi have not been tested to leach Li and Co from the cathode in RLIB. Results from chemical leaching with low concentrations of organic acids in this study indicate that organic acid leaching efficiency can be increased by utilizing higher concentrations (above 50 mM) of citric or oxalic acid to mobilize Li or Co from the cathode in RLIB. Furthermore, 100 mM of citric acid or 100 mM of oxalic acid mobilized more Co or Li than mixtures of organic acids. Notably the addition of hydrogen peroxide to mixed concentrations of organic acids significantly improved mobilization of Li and Co under abiotic conditions. Different growth media may alter biomass production and potentially organic acid excretion by the three fungal species. Analysis of biomass production by A. niger and P. simplicissimum showed that differences in media composition between CDB and SDB did not affect collected biomass for each species. However, CDB cultures with P. chrysogenum had significantly less biomass than SDB cultures after 10 days of growth. Differences in growth by P. chrysogenum between CDB and SDB may be attributed to preferred nutrients and/or low pH present in SDB cultures. Biomass production by the three fungi increased up to day 10 in CDB or SDB. This result indicated that nutrients in CDB or SDB were not limiting toward fungal growth. Cultures with A. niger had the highest concentrations of organic acids (50 mM of oxalic acid), followed by cultures with P. simplicissimum (30 mM oxalic acid), and P. chrysogenum (less than 5 mM oxalic acid). Organic acids excreted by all three fungal species were detected in cultures in CDB, while only A. niger and P. chrysogenum excreted organic acids in SDB cultures. Metals such a Li or Co present in the cathode of RLIB may be toxic to fungal processes when exposed to high metal concentrations. Metal tolerance experiments indicate that biomass production by the three fungi was significantly inhibited by 100 mg/L Co compared to controls, which contained no metal. Li at a concentration of 1000 mg/L inhibited biomass production by A. niger and P. simplicissimum. However, biomass production by P. chrysogenum was not significantly inhibited by 1000 mg/L Li. I found that P. simplicissimum was the most susceptible to toxic effects of Li and Co among the three fungi. In A. niger cultures amended with 100 mg/L Li or Co, pH at day 5 was similar to control cultures of A. niger without metals (pH 3.0 – 3.4), whereas pH was significantly higher in cultures with 1000 mg/L of Li or Co (pH 7.1 – 7.3). Cultures of A. niger were exposed to the cathode material from RLIB to test the leaching efficiency of excreted organic acids after mobilizing Li and Co. In bioleaching experiments with A. niger, organic acids excreted in the presence of cathode material from RLIB were quantified at concentrations under 50 mM. At the end of bioleaching experiments with A. niger, 40 mM tartaric acid was detected and was the highest produced organic acid in bioleaching cultures. However, with conditions set in this study, organic acids excreted by A. niger mobilized only ̴7% of Co and 20% of Li when using spent medium with cathode material from RLIB. According to findings in chemical leaching experiments, concentrations of organic acids higher than 50 mM will be required in fungal cultures to increase mobilization of Li or Co from the cathode material in RLIB. Modifying growth media to include higher concentrations of sucrose will potentially increase organic acid excretion as demonstrated in previous publications. Future studies should focus on how to maximize organic acid excretion by fungi when exposed to metals found in the cathode of RLIB.

La présente étude vise d'une part, à fournir et définir les paramètres de base nécessaires au développement de la lixiviation fongique des métaux et d'autre part, à améliorer sa rentabilité économique par l'utilisation d'une source de substrat économique. Pour ce faire, différents essais en flacons ont été réalisés en laboratoire. En premier lieu, ces essais ont permis de mettre au point une procédure de lixiviation, notamment le choix d'une méthode de lixiviation adaptée à la lixiviation de deux résidus miniers d'origines différentes. En second lieu, le perméat de lactosérum a été sélectionné parmi 7 résidus agroalimentaires comme une nouvelle source de substrat pour remplacer le sucrose habituellement utilisé au laboratoire lors des essais de lixiviation fongique. Par la suite, l'influence de divers paramètres de production des acides organiques (qui sont les agents de lixiviation) et de lixiviation des métaux sur la solubilisation de 6 métaux lourds (Cu, Fe, Mn, Ni, Pb et Zn) a été évaluée. L'influence de la distribution géochimique des métaux a été étudiée en particulier. Les résultats obtenus montrent que la lixiviation fongique offre la possibilité de récupérer à des concentrations commercialement attractives les métaux lourds retenus dans les importantes quantités de résidus miniers rejetés par l'industrie minière. Elle se révèle ainsi comme une biotechnologie prometteuse qui s'intègre au développement durable non seulement en préservant l'environnement et la santé publique des conséquences néfastes de la présence des métaux lourds, mais aussi en permettant la valorisation de ces derniers comme une source secondaire de matières premières, ainsi que celle du perméat de lactosérum comme une source de substrat pour la biosynthèse des acides organiques.