Recovery of Phenolic Acid and Enzyme Production from Corn Silage Biologically Treated by Trametes versicolor

Abstract

Corn silage is used as high-energy forage for dairy cows and more recently for biogas production in a process of anaerobic co-digestion with cow manure. In this work, fresh corn silage after the harvest was used as a substrate in solid-state fermentations with T. versicolor with the aim of phenolic acid recovery and enzyme (laccase and manganese peroxidase) production. During 20 days of fermentation, 10.4-, 3.4-, 3.0-, and 1.8-fold increments in extraction yield of syringic acid, vanillic acid, p-hydroxybenzoic acid, and caffeic acid, respectively, were reached when compared to biologically untreated corn silage. Maximal laccase activity was gained on the 4th day of fermentation (V.A. = 180.2 U/dm), and manganese peroxidase activity was obtained after the 3rd day of fermentation (V.A. = 30.1 U/dm). The addition of copper(II) sulfate as inducer during solid state fermentation resulted in 8.5- and 7-fold enhancement of laccase and manganese peroxidase activities, respectively. Furthermore, the influence of pH and temperature on enzyme activities was investigated. Maximal activity of laccase was obtained at T = 50 °C and pH = 3.0, while manganese peroxidase is active at temperature range T = 45-70 °C with the maximal activity at pH = 4.5.

Biovalorization of brewers’ spent grain for the production of laccase and polyphenols

“…BSG was a better substrate than corn silage for laccase production, since a higher activity of laccase was achieved. When corn silage was used, laccase activities of 180 U/L (in jars without addition of inducers) or 260 U/L (in a tray bioreactor, without addition of inducers) were measured (20,21). These results suggest that BSG from malt was supplemented with 60% barley, could be a promising substrate for laccase production during solid-state fermentation with T. versicolor.…”

“…In order to be used in biofuel production, different pretreatment methods need to be applied to break down the linkage between polysaccharides and lignin so as to make cellulose and hemicellulose more accessible to hydrolysis. Biological pretreatments, such as implementation of white‐rot fungi, can offer significant benefits over chemical and physical methods . During these pretreatments, various enzymes, some of them industrially important, such as laccase, are formed.…”

“…The white‐rot fungus Trametes versicolor is one of the most studied fungi for laccase production. In order to produce laccase, T. versicolor can be cultivated in submerged cultivation or in solid‐state cultivation . Solid‐state fermentation is an old technology that has recently been used for the biological treatment of lignocellulose in the production of value‐added products and for biological pretreatment in biofuel production.…”

Proximate analysis of cold‐press oil cakes after biological treatment with Trametes versicolor and Humicola grisea

“…T. versicolor is known to be a good producer of lignolytic enzymes such as laccase [27] and was chosen for this study due to our previous experience with its solid-state cultivation on corn silage [28,29] and brewery spent grains [30]. The study aims to identify the possible pathways for the utilization of hull-less pumpkin, flax, and hemp oil cakes, before and after biological treatment.…”

“…The study aims to identify the possible pathways for the utilization of hull-less pumpkin, flax, and hemp oil cakes, before and after biological treatment. T. versicolor is known to be a good producer of lignolytic enzymes such as laccase [27] and was chosen for this study due to our previous experience with its solid-state cultivation on corn silage [28,29] and brewery spent grains [30]. On the other hand, there is scarce literature data on the use of H. grisea in solid-state fermentation.…”