Stainless steel sponge: a novel carrier for the immobilisation of the white-rot fungus Trametes hirsuta for decolourization of textile dyes.
Alginate beads, polyurethane foam, nylon sponge and stainless steel sponge were tested as carrier materials for the white-rot fungus Trametes hirsuta for laccase production under submerged fermentation conditions. Stainless steel sponge was the best carrier material leading to the highest laccase activities of up to 800 U/l after 8 days of cultivation. These values are higher than those reported to date operating with inert supports and without inducer addition. In a 1-l bioreactor containing T. hirsuta immobilised on stainless steel sponge laccase activities of about 2200 U/l were obtained when the culture medium was supplemented with 1 mM copper sulphate. There were no operational problems with this system during culturing time. The textile dye Indigo Carmine was almost totally degraded in 3 days by T. hirsuta grown in this bioreactor, while Lanaset Marine was degraded in two successive batches, reaching in the first batch a decolourization percentage of about 82% in 15 h and in the second one by 71% in 28 h. Results obtained after inhibition of growth of T. hirsuta by antibiotics indicated that dye decolourization could not exclusively be attributed to laccase activity.
Rodríguez Couto
S
S
Department of Chemical Engineering, University of Vigo, Lagoas-Marcosende s/n, 36200, Spain. srcouto@uvigo.es
Sanromán
M A
MA
Hofer
D
D
Gübitz
G M
GM
D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D018914:Cells, Immobilized; D004396:Coloring Agents / Q000737:chemistry* / Q000378:metabolism; D042845:Laccase / Q000378:metabolism; D020072:Polyporales / Q000378:metabolism*; D013193:Stainless Steel; D013784:Textiles; D014865:Waste Disposal, Fluid / Q000379:methods*
D004396:Coloring Agents; D013193:Stainless Steel; D042845:Laccase