However, as with hydrothermal pretreatment, higher enzyme loadings and higher pretreatment severity increased sugar yields for dilute acid pretreatments under both hydrolysis regimens.
Diminution of substrate particles has previously been shown to increase sugar yield during enzymatic hydrolysis of lignocellulosic residues by increasing the surface available to enzymes and reducing the crystallinity of the sample [ 14].
Ultrasonic pretreatment significantly improves cellulose hydrolysis increasing sugar yields, but current system designs have limitations related to efficiency and scalability.
In addition, recent studies have found that deacetylation not only significantly improves the downstream fermentability of the sugar hydrolysates but also increases sugar yields in pretreatment and enzymatic hydrolysis [ 6, 8].
First stage is carried out at low severity for hydrolyzing the hemicellulose while second stage is carried out at high severity for depolymerization of cellulose and increase sugar yield.
The genetic manipulation of xylan and pectin biosynthetic genes is a potential means to develop Populus plants with reduced xylan and pectin content and biomass that yields increased sugar release for biofuel production.
Here, for the first time, we designed a sequential, combinatorial lignocellulose pretreatment procedure (SCLPP) for microbial biofuel fermentation to reduce generation of microbial growth inhibitors and furthermore increase sugar yields.
The increased carbohydrate yields in the solid substrates potentially can result in increased monomeric sugar recovery through enzymatic saccharification, beneficial to increasing overall sugar yield.
Down-regulation of the COMT gene in switchgrass decreased the lignin content, reduced the S/G ratio, increased sugar release, and improved the bioconversion yield after dilute acid pretreatment for yeast-based SSF on the switchgrass lines T1-2, 3, and 12 and CBP with C. thermocellum on switchgrass line T1-3 [ 12].
Sonication of corn starch slurry for 40 s increased the sugar yield by 5 6 times as compared to control (Montalbo et al. 2010).
