Upgrading of the surface characteristics could enhance the bulk properties of naturally abundant fiber-forming materials for better performance or create new value-added products. Laccase can induce cross-linkage and covalent coupling of low molecular weight compounds onto lignocellulosic surfaces. For this purpose the 38-kDa laccase from Trametes hirsuta was purified and characterized. The best conditions for laccase-induced coating of flax fibers were determined. This evaluation was based on the obtained coloration and color depth. A screening was carried out with different phenols for their potential as monomers for enzyme-catalyzed polymerization resulting in a coating with antibacterial performance. While all the methoxyphenols showed different coloration with weak fastness properties, bacterial growth of Bacillus subtilis and Staphylococcus aureus was reduced significantly using ferulic acid and hydroquinone. Using laccase-induced coupling and polymerization, multi-functionality of the lignocellulosic surface, such as coloration and antimicrobial performance, was achieved, which depended on the nature of the applied phenolic monomer.

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Contaminating microorganisms such as Actinomycetes, Alicyclobacillus, and Chlostridium can generate off-flavors in apple juices. Such bacterial metabolites represent, besides phenol types such as guaiacol and 2,6-dibromophenol, a broad range of other chemicals, for example, geosmin, 2-methylisoborneol, or alpha-terpineol. A laccase from Trametes hirsuta was purified, immobilized, and applied for the selective elimination of off-flavor substances in apple juice caused by microbial contamination. The evaluation using GC-MS showed that enzymatic treatment could reduce the amount of guaiacol and 2,6-dibromophenol in apple juice significantly by 99 and 52%, respectively. Upon addition of mediators, the degradation could be increased and the spectrum of substrates extented. Furthermore, commercial apple juices spiked with off-flavors were treated in a continuous-flow reactor and tested by sensory evaluation.

A novel bioremediation technology has been developed. This technology involves the incorporation of a newly isolated Pseudomonas putida GG04 and Bacillus sp. SF into an explosive formulation to enhance biodegradation of TNT residues and explosives which fail to detonate due to technical problems. The incorporation of these microorganisms into the explosive did not affect the quality of the explosive in terms of detonation velocity while complete degradation of TNT moieties upon transfer in liquid media was observed after 4 days. The incorporated microorganisms sequentially reduced TNT leading to the formation of hydroxylamnidnitrotoluenes (HADNT), 4-amino-2,6- dinitrotoluenes; 2-amino-4,6-dinitrotoluenes, different azoxy compounds; 2,6-diaminonitrotoluenes and 2,4- diaminonitrotoluenes. Aminodinitrotoluenes (AMDNT) and diamninonitrotoluenes (DAMNT) constituted the predominant metabolites which steadily increased achieving 41μM and 63 μM in P. putida GG04 cultures and, 73 μM and 109 μM in Bacillus SF cultures, respectively. Although both microorganisms use NAD(P)H dependent enzymes to transform TNT, P. putida GG04 has a preference for NADPH. The accumulation of AMDNT and DAMNT was effectively prevented in the presence of guaiacol and catechol. A 89 % reduction of AMDNT and a 80 % of DAMNT was achieved in P. putida GG04 cultures, while in Bacillus sp. SF, 91 % and 70 % reduction was achieved. This demonstrates that biodegradation of TNT in the presence of humic material is effective in immobilizing TNT metabolites. Addition of acetonitrile (1:4) to TNT and to its biodegradation products with sequential freezing of the samples at –20 °C was effective in concentrating and enhancing detection signals to identify TNT contaminates sites.