Colonization of oil palm empty fruit bunches by basidiomycetes from the Brazilian cerrado: deconstruction of biomass

Abstract

The sustainable use of residual lignocellulosic biomass is an opportunity to help to overcome the global need to reduce the emission of pollutants as well as depletion of fossil fuel resources and increasing energy demands. This study aimed to establish a deconstruction process of oil palm empty fruit bunches (EFBs), employing hydrothermal and biological pretreatments. Initially, the yields of cellulose, hemicellulose, lignin, extractives and ashes resulting from the autohydrolysis of raw EFBs were measured. The biological pretreatment of the raw EFBs followed using eight basidiomycetes strains. Finally, an enzymatic hydrolysis comparison between basidiomycetes and commercial enzymes evaluated glucose and xylose yields, the synergism degree and the reduction of phenolic substances. Autohydrolysis pretreatment presented the best sugar yields after hydrolysis. However, biological pretreatment provides enzymes and other advantages. The combination of enzymatic extracts of basidiomycetes with Celluclast and Novozyme‐188 Sigma® gave the best glucose yield with Flavodon flavus BRM‐055676 (14.78%). Synergism degree analyses showed an increase of 47% in glucose release by the cocktail of Fomes fasciatus BRM‐055675 with commercial enzymes. The deconstruction of EFBs by biological pretreatment presented a 2.96 ratio loss of lignin/loss of cellulose with F. flavus BRM‐055676. Finally, combinations of enzymatic extracts from basidiomycetes and ascomycetes, mainly F. fasciatus BRM‐055675, provided the reduction of phenolic substances. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

The use of xylose from elephant grass liquor and coproduction of organic acids by wild‐type bacteria isolated from food waste

“…The lignocellulosic raw material has three main components in the cell wall: cellulose, hemicellulose, and lignin 17 . The bond between them forms a recalcitrant structure, giving the cells a resistant, dense, and stable wall, requiring the use of biological, chemical, and/or physical mechanisms to break down the lignocellulosic complex and gain access to the polysaccharides for the subsequent release of fermentable sugars 18,19 . Pennisetum purpureum Schumach, popularly known as elephant grass (EG), is an angiosperm plant species that has accelerated growth and the ability to fix CO 2 easily, and also functions as an important raw material for the production of renewable inputs, such as bioethanol, biogas, bio‐oil, and charcoal 20 .…”

“…17 The bond between them forms a recalcitrant structure, giving the cells a resistant, dense, and stable wall, requiring the use of biological, chemical, and/or physical mechanisms to break down the lignocellulosic complex and gain access to the polysaccharides for the subsequent release of fermentable sugars. 18,19 Pennisetum purpureum Schumach, popularly known as elephant grass (EG), is an angiosperm plant species that has accelerated growth and the ability to fix CO 2 easily, and also functions as an important raw material for the production of renewable inputs, such as bioethanol, biogas, bio-oil, and charcoal. 20 There are several studies that have used pretreated P. purpureum as a carbon source for subsequent industrial processes, especially with regard to the production of second-generation ethanol, as in Menegol et al, 21 Montipó et al 22 and Scholl et al 23 Considering that current studies generally use genetically modified organisms (GMOs) to degrade pentoses, the present work sought to isolate bacteria potentially capable of metabolizing xylose, to inoculate them into the pretreated EG liquor with the aim of producing AA and LA.…”