An intensified degradation of phenanthrene with macroporous alginate–lignin beads immobilized Phanerochaete chrysosporium
Macroporous Ca-alginate (MCA) beads and macroporous Ca-alginate–lignin (MCAL) beads were prepared to immobilize Phanerochaete chrysosporium for the degradation of phenanthrene. The diameters of MCA and MCAL beads were 3.8 ± 0.2 and 4.1 ± 0.4 mm, respectively, while the diameters of macropores within them were determined to be 10–40 μm. Compared with conventional Ca-alginate (CA) beads, MCA beads prepared with 5% CaCO3 granules of 15 μm as porogenic diluent yielded a 1.5-fold increase in the diffusivity of glucose, an index of mass transfer performance. This difference was magnified to 2.2-fold when CA and MCA beads were applied to the cultivation of P. chrysosporium pre-cultivated for 2 days. Moreover, the net increase in the biomass of P. chrysosporium immobilized in MCAL beads was 1.1-, 1.7- and 3.4-fold than that immobilized in MCA beads, CA beads and in free form, respectively, within 8-day cultivation. The presence of lignin in MCAL beads led to a 28.7-fold increase in the phenanthrene adsorption capacity compared with that by MCA beads. The degradation of phenanthrene was also increased from 28.2% (MCA) to 42.3% (MCAL) after 4-day degradation. The enhanced growth and degradation indicated a high potential of MCAL-immobilized P. chrysosporium as an effective microbial model for an intensified biodegradation of phenanthrene.
Journal: Biochemical Engineering Journal - Volume 41, Issue 3, 1 October 2008, Pages 251–257