Thirteen deuteromycete ligninolytic fungal strains were grown in media containing polycyclic aromatic hydrocarbons (PAHs), for 6 and 10 days. The PAHs were added directly with the inocula or on the third day of cultivation. A selection of the best strains was carried out based on the levels of degradation of the PAHs and also on the ligninolytic activities produced by the fungi. The selected strains were cultivated for 3, 6, 9, 12 and 15 days in the PAHs-containing media. Degradation of PAHs, as measured by reversed-phase HPLC on a C18 column, varied with each strain as did the ligninolytic enzymes present in the culture supernatants. Highest degradation of naphthalene (69%) was produced by the strain 984, having Mn-peroxidase activity, followed by strain 870 (17%) showing lignin peroxidase and laccase activities. The greatest degradation of phenanthrene (12%) was observed with strain 870 containing Mn-peroxidase and laccase activities. When anthracene was used, the strain 710 produced a good level of degradation (65%).
SummaryPoly(methyloctylsiloxane) (PMOS), sorbed into the pores of HPLC silica particles by solvent evaporation, can function as a useful stationary phase for reversedphase chromatography. The present work addresses the question of how the PMOS is distributed in the pores. Measurements of the surface area (BET, N2) of a series of partially loaded samples (0-40 % PMOS, m/m) using a typical batch of HPLC silica (10 gm irregular particles with 6 nm pores) show that the specific surface area of the samples decreases linearly with the specific loading (mass of PMOS per gram of silica). This result is not consistent with a "film" model in which the PMOS is deposited uniformly on the pore walls, but is consistent with a model in which long segmented "plugs" of PMOS are deposited within the pore system.
Three different reversed-phase materials for high-performance liquid chromatography,
obtained by sorption of poly(methyloctylsiloxane) (PMOS) onto bare silica, titanized silica,
and zirconized silica pores, followed by immobilization with γ-radiation, were characterized
by means of solid-state NMR spectroscopy. The surface properties of these stationary phases
were investigated by 29Si CP/MAS and 13C CP/MAS NMR spectroscopy. γ-Radiation causes
the formation of new bonds, either between PMOS and the different supports or between
different siloxane chains, which leads, in either case, to a higher amount of polysiloxane
immobilized onto the silica support material.
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