| Congresso Brasileiro de Microbiologia 2023 | Resumo: 863-1 | ||||
Resumo:Lignin has long been considered a significant obstacle in biorefinery processes aiming to derive sustainable and viable bioproducts from lignocellulosic biomass. Its recalcitrance has spurred the search for more efficient and cost-effective treatments to modify and valorize this polymer, elevating its importance at an industrial level. In this context, the emergence of lytic polysaccharide monooxygenases (LPMOs), enzymes capable of breaking down glycosidic bonds through oxidation, has revolutionized our understanding of enzymatic degradation of polysaccharides, especially cellulose. LPMOs are predominantly found in filamentous fungi, such as ascomycetes and basidiomycetes, which are known for their ability to degrade plant biomass. Numerous genes encode different families of LPMOs within their genomes, with the AA9 family being the focus of this work. The objective of this study revolves around the recombinant production of LPMOs from these fungi, intending to apply them to modify lignin. To achieve our goals, the genes encoding the enzymes TtLPMO9C and TvAA9B from Thermothielavioides terrestris and Trametes versicolor, respectively, underwent analysis for amplification, cloning, and transformation into Aspergillus nidulans A773. The resulting transformants were employed to express the target proteins, which were subsequently purified using chromatography techniques. Following the purification, the two LPMOs underwent biochemical characterization, including examinations of their pH and optimal temperature range, as well as their thermostability, to gain deeper insights into the operational conditions of both LPMOs. Subsequently, their activity was analyzed through testing on 2,6-DMP and PASC, revealing their regioselectivity at C1, C4, and C1/C4 in cellulose. Furthermore, preliminary tests were performed to observe their impact on in natura pine biomass. These tests demonstrated the LPMOs’ capacity to modify the structure of plant biomass, as confirmed through Fluorescence Optical Microscopy. These findings underscore the significant potential of LPMOs in lignin modification. Palavras-chave: Protein expression, filamentous fungi, LPMO, Lignin Agência de fomento:CAPES, FAPESP, CNPq | |||||