TY - JOUR
T1 - Role of organic acids in the manganese-independent biobleaching system of bjerkandera sp. Strain BOS55
AU - Moreira, María Teresa
AU - Feijoo, Gumersindo
AU - Mester, Tünde
AU - Mayorga, Pablo
AU - Sierra-Alvarez, Reyes
AU - Field, Jim A.
PY - 1998/7
Y1 - 1998/7
N2 - Bjerkandera sp. strain BOS55 is a white rot fungus that can bleach EDTA- extracted eucalyptus oxygen. delignified kraft pulp (OKP) without any requirement for manganese. Under manganese-free conditions, additions of simple physiological organic acids (e.g., glycolate, glyoxylate, oxalate, and others) at 1 to 5 mM stimulated brightness gains and pulp delignification two- to threefold compared to results for control cultures not receiving acids. The role of the organic acids in improving the manganese-independent biobleaching was shown not to be due to pH-buffering effects. Instead, the stimulation was attributed to enhanced production of manganese peroxidase (MnP) and lignin peroxidase (LIP) as well as increased physiological concentrations of veratryl alcohol and oxalate. These factors contributed to greatly improved production of superoxide anion radicals, which may have accounted for the more extensive biobleaching. Optimum biobleaching corresponded most to the production of MnP. These results suggest that MnP from Bjerkandera is purposefully produced in the absence of manganese and can possibly function independently of manganese in OKP delignification. LiP probably also contributed to OKP delignification when it was present.
AB - Bjerkandera sp. strain BOS55 is a white rot fungus that can bleach EDTA- extracted eucalyptus oxygen. delignified kraft pulp (OKP) without any requirement for manganese. Under manganese-free conditions, additions of simple physiological organic acids (e.g., glycolate, glyoxylate, oxalate, and others) at 1 to 5 mM stimulated brightness gains and pulp delignification two- to threefold compared to results for control cultures not receiving acids. The role of the organic acids in improving the manganese-independent biobleaching was shown not to be due to pH-buffering effects. Instead, the stimulation was attributed to enhanced production of manganese peroxidase (MnP) and lignin peroxidase (LIP) as well as increased physiological concentrations of veratryl alcohol and oxalate. These factors contributed to greatly improved production of superoxide anion radicals, which may have accounted for the more extensive biobleaching. Optimum biobleaching corresponded most to the production of MnP. These results suggest that MnP from Bjerkandera is purposefully produced in the absence of manganese and can possibly function independently of manganese in OKP delignification. LiP probably also contributed to OKP delignification when it was present.
UR - http://www.scopus.com/inward/record.url?scp=0031816162&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031816162&partnerID=8YFLogxK
U2 - 10.1128/aem.64.7.2409-2417.1998
DO - 10.1128/aem.64.7.2409-2417.1998
M3 - Article
AN - SCOPUS:0031816162
SN - 0099-2240
VL - 64
SP - 2409
EP - 2417
JO - Applied and environmental microbiology
JF - Applied and environmental microbiology
IS - 7
ER -