Expression of manganese peroxidase by Lentinula edodes and Lentinula boryana in solid state and submerged system fermentation

Abstract

The production of ethanol from lignocellulosic biomass is referred as a second generation biofuel, whose processing is one of the most promising technologies under development. There are few available studies on the use of enzymes produced by fungi as active for the biodegradation of lignocellulosic biomass. However, the manganese peroxidase (MnP) enzyme presents high potential to degrade lignin and the basidiomycetes are the major producers of this oxidase. Thus, this study aimed at evaluating the ability of fungi Lentinula edodes and Lentinula boryana to produce this enzyme when cultivated in submerged fermentation system (SS) and also in solid-state fermentation system (SSF) containing Eucalyptus benthamii sawdust with or without corn cob meal. In the SS the greatest MnP expression occurred on the 25 th day, being of 70 UI.L . Therefore, the results indicated that the studied fungi express the enzyme of interest and that its production is enhanced when cultivated in solid system.

Influence of nitrogen sources on the enzymatic activity and grown by Lentinula edodes in biomass Eucalyptus benthamii

“…These results were similar to Ohga (1999) and Hermann et al (2013), who found near pH 4.6 during growth of L. edodes in sawdust. Studies have shown that L. edodes obtained higher mycelial growth at low pH (Furlan et al, 1997).…”

“…The humidity results were similar to the ones carried by Hermann et al (2013), using the fungus L. edodes cultivated biomass of E. benthamii. The amount of water is limited to solid substrates which are critical in the formation of a water film on the surface, facilitating dissolution and transfer of nutrients and oxygen.…”

“…Other studies have shown that the best fungal biomass and enzymes were obtained from sawdust with a high level of nitrogen, supplemented with 20% soybean (Silva et al, 2005). Hermann et al (2013) obtained maximum activity for L. edodes (110 UI.L -1 ), in 10 days of cultivation. In contrast, in studies Dias et al (2010), the peak production of MnP was on the 23 rd day of incubation, and lower values (0.83 UI.L -1 ) to those obtained in this study.…”

“…The substrates were supplemented with different nitrogen sources of ammonium sulfate, potassium nitrate and soybean flour cooked, and the proportion of nitrogen of 1% was calculated for each treatment ( Table 1). The amount of water used was 50 mL, using methods described by Hermann et al (2013). Each substrate was autoclaved at 121 °C, 1 atm for 15 minutes, and after they were inoculated with 1/6 of the Petri plate of Lentinula edodes in PDA.…”

“…Analysis were performed using humidity (%), pH, water activity (a w ) (Hermann et al, 2013) and analysis of microbial growth (ASTM, 1990).…”