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Silicate-based microporous materials like zeolites are nano enabled particles and used for various applications including pharmaceutical formulations. This study reports on the chemo-enzymatic functionalization of chitosan-zeolite particles (CTS-zeolites) with caffeic acid (CA) and glucose oxidase (GOX) to impart combined antioxidant and antimicrobial properties. CA was grafted on the chitosan moieties by using laccase generating stable particles (zeta potential -36.7 mV) of high antioxidant activity (44% DPPH inhibition). GOX was immobilized both on CTS-zeolites and on CA modified CTS-zeolites and creating a hydrogen peroxide generation system continuously and in-situ producing this oxidative and antimicrobial agent. The system prevented bacterial growth of E. coli and S. aureus over 24 h whereby a steady-state concentration of around 60 μM hydrogen peroxide in the culture medium was observed. CA and GOX functionalized CTS-zeolite particles additionally showed combinatorial antioxidant and antimicrobial properties providing a powerful bioactive system for medical applications. These particles proved their suitability for incorporation in bioactive formulations which could be used, inter alia, for topical wound treatments., (© 2018 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

Mixed fermentative/hydrolytic bacteria were enriched on lignocellulose substrates in minimal medium under semi-anaerobic mesophilic conditions in the presence or absence of natural zeolite as growth supporter to ultimately bioaugment non-adapted sludge and thereby enhance the overall anaerobic digestion (AD) of recalcitrant plant material. Desired enzyme activities, i.e. xylanases and cellulase were monitored during subsequent cultivation cycles. Furthermore, enriched microbial communities were characterized by 16S rRNA-based 454-Pyrosequencing, revealing Firmicutes, Bacteriodetes, Proteobacteria and Spirochaetes to be the predominant bacterial groups in cultures derived from anaerobic sludge and raw crop material, i.e. maple green cut and wheat straw as well. Enriched populations relevant for biopolymer hydrolysis were then compared in biological methane potential tests to demonstrate positive effects on the biogasification of renewable plant substrate material. A significant impact on methane productivity was observed with adapted mixed cultures when used in combination with clinoptilolite to augment and supplement non-adapted bioreactor sludge., (Copyright © 2016. Published by Elsevier Ltd.)