[Degradation of lignin-carbohydrate substrate by soil fungi--producers of laccase and cellobiose dehydrogenase].
The growth of nonsporulating mycelial fungi INBI 2-26(+), producer of laccase; INBI 2-26(-), producer of cellobiose dehydrogenase; and their mixed culture on lignin-carbohydrate substrates under conditions of submerged fermentation were studied. The degrees of degradation of lignin, cellulose, and hemicellulose of cut straw over 23 days amounted to 29.8, 51.4, and 72% for the laccase producer; 15.8, 33.9, and 59.1% for the cellobiose dehydrogenase producer; and 15.8, 39.4, and 64.5% for the mixed culture, respectively. The laccase activity in the medium when strain 2-26(+) was cultivated individually reached its maximum on day 28; the activity of cellobiose dehydrogenase of strain 2-26(-), on days 14 to 28. A method for determining cellobiose dehydrogenase activity in the presence of laccase was developed. In the mixed culture, both enzymes were formed; however, the level of laccase synthesis was 1.5-fold lower compared to that of strain 2-26(+), while synthesis of cellobiose dehydrogenase was similar to that of the corresponding producer. Cellobiose dehydrogenase failed to boost the action of laccase while degrading the lignin of straw.
Vasil'chenko
L G
LG
Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 119071 Russia.
Karapetian
K N
KN
Iachkova
S N
SN
ernova
E S
ES
Rabinovich
M L
ML
D002237:Carbohydrate Dehydrogenases / Q000096:biosynthesis*; D005658:Fungi / Q000201:enzymology / Q000378:metabolism*; D006868:Hydrolysis; D042845:Laccase / Q000096:biosynthesis*; D008031:Lignin / Q000378:metabolism*; D012988:Soil Microbiology; D013379:Substrate Specificity
D008031:Lignin; D002237:Carbohydrate Dehydrogenases; C019859:cellobiose-quinone oxidoreductase; D042845:Laccase