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Fungi in pressmud composting: diversity, genomics and biotechnological aspects / Fungos na compostagem da torta de filtro: diversidade, genômica e potencial biotecnológicoOliveira, Tássio Brito de [UNESP] 18 November 2016 (has links)
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Previous issue date: 2016-11-18 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A torta de filtro é gerada após o processo de filtração do caldo de cana (cerca de 26 a 40 kg por t de cana) e geralmente é utilizada como fertilizante nas lavouras sem qualquer tratamento prévio. A diversidade de fungos presentes na torta de filtro fresca e no processo de compostagem desse substrato foi acessada utilizando sequenciamento em larga escala. Além disso, fungos tolerantes ao calor foram isolados e avaliados quanto à capacidade de produzir enzimas de degradação da biomassa (celulase, xilanase, lacase e poligalacturonase). Considerando que esse grupo de fungos carece de uma revisão taxonômica atual, aproveitamos as recentes mudanças proporcionadas pelo Código de Nomenclatura para Algas, Fungos e Plantas para gerar uma revisão taxonômica do grupo. Uma gama de patógenos oportunistas foi encontrada entre os taxa mais abundantes na torta de filtro fresca, como Lomentospora prolificans (43,13%), Trichosporon sp. (10,07%), Candida tropicalis (7,91%) e Hormographiella aspergillata (8,19%). Isso indica que a torta de filtro pode ser uma potencial fonte de fungos patogênicos, apresentando riscos para a saúde humana se aplicado como fertilizante sem qualquer tratamento. No entanto, o processo de compostagem reduz efetivamente a carga desses fungos. Além disso, cria um ambiente interessante para fungos capazes de produzir enzimas com potencial aplicação biotecnológica, uma vez que todos os 110 isolados avaliados foram capazes de produzir, pelo menos, uma das enzimas avaliadas. Além disso, a análise comparativa de genes codificantes para peptidases presentes nos genomas de fungos termofílicos (encontrados em sistemas de compostagem) e mesofílicos mostrou que a termofilia levou à várias adaptações para a termoestablidade enzimática. / Pressmud is derived from sugarcane juice filtrate (around 26 to 40 kg per ton of sugarcane) and it is mainly used as fertilizer in crops without prior treatment. Here, the fungal diversity present in both fresh and composting pressmud was revealed by 454 pyrosequencing. In addition, heat-tolerant fungi were isolated and surveyed for their repertoire of biomass-degrading enzymes (cellulase, xylanase, laccase and polygalacturonase). The fact that the taxonomy of such organisms is still obscure, we revised their taxonomy in the light of the recent changes adopted in the Code of Nomenclature for Algae, Fungi and Plants. A wide range of opportunistic pathogens was found among the most abundant taxa in fresh pressmud, such as Lomentospora prolificans (43.13%), Trichosporon sp. (10.07%), Candida tropicalis (7.91%), and Hormographiella aspergillata (8.19%). This indicates that fresh pressmud may be a source of human pathogenic fungi, presenting a potential threat to human health if applied as fertilizer without treatment. Composting of the pressmud effectively reduces the load of such fungi. Furthermore, the composting system creates an interesting environment for fungi able to produce enzymes with biotechnological applications, since all the 110 isolates screened were able to produce at least one of the tested enzymes.Furthermore, comparative analysis of peptidases genes encoded by thermophilic (generally found in composting systems) and mesophilic fungi showed that thermophyly selected for thermostable enzymes. / FAPESP: 2012/14594-7 / FAPESP: 2015/25252-8
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Suivi physico-chimique, microbiologique et écotoxicologique du compostage de boues de STEP mélangées à des déchets de palmier : validation de nouveaux indices de maturité / physico-chemical microbiological and ecotoxicological monitoring during composting of sewage sludge-date palme waste : validation of new maturity indexEl Fels, Loubna 20 December 2014 (has links)
Le traitement de boues de station d'épuration (Boues activées de Marrakech) en mélange avec déchets verts (Palmier dattier) selon deux mélanges dont les proportions : A (1/3 Boues + 2/3 Déchets de palmier) et B (1/2 Boues + 1/2 Déchets de palmier), a été effectué par la filière du compostage, pendant six mois. Au cours du co-compostage, l’intense activité microbienne s’est traduite par une augmentation de température (autour 65 C°) au cours des premières semaines (phase thermophile) et un taux de décomposition final de l’ordre de 40%. Après six mois de co-compostage, le compost final est caractérisé par un rapport C/N voisin de 10, un rapport de NH4+/NO3- < 1, un pH autour de la neutralité signe de maturité des composts. L’analyse FTIR a montré une diminution de l'absorbance des bandes aliphatiques et l'augmentation de la structure de bandes d'absorbance aromatiques reflètent l'état d'avancement du processus d'humification. Le taux d’abattement des lipides totaux est de l’ordre de 43%. Les esters méthyliques d’acide gras (FAMEs) des Gram-positif (i,C15 :0) ont augmenté durant la phase thermophile. Les FAMEs d’origine non spécifique (C6 :0, C14 :0) ont connu une intense diminution, les FAMEs de bactéries non spécifiques représentent une grande teneur durant la phase thermophile. L’indice CPI a augmenté à la fin du co-compostage indiquant l’enrichissement du compost en FAMEs d’origine végétale. Les principaux composés ligneux identifiés, au cours du co-compostage, par Py-GC-MS, sont classés en deux groupes. Le premier est constitué de 7 composés dont la teneur diminue au cours du co-compostage, parmi lesquels : Toluène, 2,4-diméthylbenzène, éthylbenzène, Styrène, 1-éthyl-2-méthylbenzène, 4-méthylphénol et 2-méthylnaphthalène. Le deuxième groupe est constitué de 4 composés qui augmentent au cours du co-compostage : phénol, benzofuran, éthylméthoxyphénol et diméthoxyphénol. Les principaux stéroïdes identifiés sont les C27-C29 sterènes, stanols, 5β-cholesta-3-one, cholesta-3,5-diène et 2 thiostéranes. A l’exception des thiosteranes et quelques composés de C27-C29 cholestenes la concentration relative des stéroides diminue au cours du processus suit à leur attaque microbien. L’abattement total de la teneur des stéroïdes est corrélé positivement avec les indicateurs de maturité du compost (C/N et NH4+/NO3-) ce qui ouvre la voie à une éventuelle utilisation des stéroïdes comme indicateur de dépollution et de maturité de compost. 12 isolats d’actinomycètes ayant une activité antimicrobienne vis-à-vis d’un large spectre des germes pathogènes ont été isolés sur le milieu sélectif CTEA. Le degré d’hygiénisation est confirmé par la diminution de la concentration des coliformes fécaux et totaux, et l’abattement des œufs d’helminthes identifiés (Ascaris sp., Capillaria sp., et Trichuris sp.) vers la fin du co-compostage. La phytotoxicité, déterminée par l’effet des extraits hydrosolubles à différents stades de co-compostage sur la germination et la croissance des radicules (Navet, Cresson, Laitue, Luzerne), a diminué et l’indice de germination dépasse 100%, après six mois de co-compostage. La génotoxicité du chrome hexavalent (Cr(VI)) du substrat de co-compostage est corrélée positivement avec la fréquence des micronoyaux (MN). Après six mois de co-compostage le taux des MN diminue avec un taux d’abattement de 70,4% et 77,2% avec l’abattement de la concentration du Cr(VI) avec 58 et 58,6% respectivement pour le mélange A et B. Ceci ouvrira la voie d’utilisation de cet indice comme un indice de maturité des composts. La diminution de la phytotoxicité et la génotoxicté au cours du co-compostage confirme l’état de stabilisation et de la maturité des co-composts, ce qui pemettra l’épandage de ces composts en tant qu’amendement organique des sols sans risque de contamination du système sol-plante. / The co-composting of activated sludge and lignocellulose waste (palm tree waste) was monitored to study the behaviour of two mixtures, referred to as A (1/3 sludge + 2/3 palm waste) and B (1/2 sludge + 1/2 waste palm) for 6 months. The biotransformation was evaluated by physicochemical and spectroscopic analyses. The thermophilic phase is characterized by a rise in temperature, which peaked at 65°C. This is the result of intense microbial activities. The final composts exhibited a higher degree of decomposition than the controls as shown by a decomposition rate of about 40%, decrease of C/N ratio to around 10 and NH4 +/NO3 - ratio below 1. The decrease of aliphatic absorbance bands and the increase of aromatic absorbance bands follow the progress of the humification process. Total extractable lipid was decreased by 43%. The fatty acid methyl esters (FAMEs) from Gram-positive bacteria (i, C15: 0) increased during the thermophilic phase. FAMEs from non-spécific origin (C6 :0, C14 :0) exhibited a decrease toward the end of co-compostin, linear FAMEs from non-specific bacteria underwent a decrease during co-composting. The CPI index thus increased at the end of the composting process, indicating that the final product was proportionally richer in fatty acids of plant origin. Two lignin groups were distinguished by Py-GC-MS. Group 1 contained toluene, 2,4-dimethylbenzene, ethylbenzene, styrene, 1-ethyl-2-methylbenzene, 4-methylphenol and 2-methylnaphthalene; their relative proportions decreased during co-composting. A second group of 4 components showed concentrations that increased with co-composting time: phenol, benzofuran, ethylmethoxyphenol and dimethoxyphenol. The main steroids identified were C27-C29 sterenes and stanols, 5β-cholesta-3-one, cholesta-3,5-diene and 2 thiosteranes. Except for thiosteranes and some of the C27-C29 cholestenes, the relative concentrations decreased during co-composting due to microbial degradation. The changes in steroids during co-composting, was positively correlated with the physico-chemical parameters of mature compost, especially C/N and NH4 +/NO3 - ratios, opening the way for the use of steroids as indicators of pollution and compost maturity. On the selective CTEA medium, 12 active strains of isolated actinobacteria presented a suppressive action against various pathogens. This may justify that a biotic factor is also an important factor contributing to making co-composting substrates hygienic. The degree hygiene reached is confirmed by the reduction in the faecal and total coliforms, and by the abatement of identified helminth eggs (Ascaris sp., Capillaria sp., and Trichuris sp.) towards the end of the process. The phytotoxicity determined by the effect of aqueous extract, at various stages of the co-composting, performed by monitoring the number of germinated seeds and the rootlets growth of turnip, watercress, alfalfa, and lettuce was decreased, and the growth of radicals that have a germination index that exceeds 100% after six months of co-composting. Hexavalent chromium (Cr(VI)) genotoxicity showed a positive correlation with micronucleus (MN) frequency. After six months of co-composting, the MN rate decreased significantly by 70.4 and 77.2% with decreasing Cr(VI) concentration with 58 and 58.6%, for mixtures A and B respectively. That indicates their suitability for use as a maturity index. During co-composting the abatement rate of phytotoxicity and genotoxicity confirme the maturation and stabilization degree of co-composting end products which encourages their recycling in agriculture as a fertilizer for the soil without any contamination of the soil-plant system.
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