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Better understanding through direct observation of the mechanisms involved in chemical and enzymatic hydrolysis of biomass is of great importance, to implement a substitute for the common cellulose standards. We report the hydrolysis of biomass, using exclusively the parenchyma, to isolate cellulose nanoplatelets using a less harsh pretreatment. Then, we show direct evidence of the effect of endoglucanase on the structure of cellulose nanoplatelets, finding that amorphous cellulose is exclusively digested, loosening the cellulose nanofibrils in the process. The analysis of micrographs demonstrates that when cellulose nanoplatelets are deposited on a silicon wafer, its thickness can be qualitatively measured by the interference color detected using an optical microscope. This finding facilitates further studies of mechanisms involved in lignin removal and cellulose nanofibrils production by specific enzymatic digestion., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In this work, nanofilms of hyaluronan/chitosan (HA/CHI) assembled layer by layer were synthesized; their application as a potential antimicrobial material was demonstrated for the phytopathogen Xylella fastidiosa, a gram-negative bacterium, here used as a model. For the synthesis, the influence of pH and ionic strength of these natural polymer stem-solutions on final characteristics of the HA/CHI nanofilms was studied in detail. The antibacterial effect was evaluated using widefield fluorescence microscopy. These results were correlated with the chemical properties of the nanofilms, studied by FTIR and Raman spectroscopy, as well as with their morphology and surface properties characterized using SEM and AFM. The present findings can be extended to design and optimize HA/CHI nanofilms with enhanced antimicrobial behavior for other type of phytopathogenic gram-negative bacteria species, such as Xanthomonas citri, Xanthomas campestri and Ralstonia solanacearum., (Copyright © 2015 Elsevier Ltd. All rights reserved.)