Biomass Converting Enzymes as Industrial Biocatalysts for Fuels and Chemicals: Recent Developments

Abstract

Abstract:The economic utilization of abundant lignocellulosic biomass as a feedstock for the production of fuel and chemicals would represent a profound shift in industrial carbon utilization, allowing sustainable resources to substitute for, and compete with, petroleum based products. In order to exploit biomass as a source material for production of renewable compounds, it must first be broken down into constituent compounds, such as sugars, that can be more easily converted in chemical and biological processes. Lignocellulose is, unfortunately, a heterogeneous and recalcitrant material which is highly resistant to depolymerization. Many microorganisms have evolved repertoires of enzyme activities which act in tandem to decompose the various components of lignocellulosic biomass. In this review, we discuss recent advances in the understanding of these enzymes, with particular regard to those activities deemed likely to be applicable in commercialized biomass utilization processes.

High-throughput Screening of Carbohydrate-degrading Enzymes Using Novel Insoluble Chromogenic Substrate Assay Kits

“…, while other methods are available for exoacting enzymes 11,12 . The limitation of this assay kit lies in the detection of endo-enzyme activity, as CPH as well as the ICB substrates are not degradable by exo-enzymes most likely due to steric hindrance arising from the dye and crosslinker molecules 8 .…”

Phylogeny, classification and metagenomic bioprospecting of microbial acetyl xylan esterases

“…The most prominent potential application of AcXEs is specifically in the saccharification of acetylated hemicellulose extracted from plant biomass under non-alkaline conditions [148][149][150]. The potential role of AcXEs in enhanced lignocellulosic biomass degradation processes has been extensively reviewed [3,5,6,9,19,[151][152][153][154][155]. While alkaline and certain non-alkaline pretreatment methods in current use remove most acetyl groups from lignocellulosic biomass, they each have their drawbacks based on factors such as type of lignocellulosic feedstock, temperature requirements, intensity of pre-treatment, detoxification requirements and economic viability [154][155][156].…”

“…The importance of AcXEs in lignocellulose degradation [9] supports the need for continuous bioprospecting for novel AcXEs with improved functional properties [10] using both culturedependent and genomic bioprospecting approaches. Although, several AcXEs have been identified, the discovery and characterization of new AcXEs of microbial origin with improved catalytic activities via functional metagenomics will result in the availability of a huge reservoir of xylan deacetylases for maximising xylan hydrolysis given different processing conditions [11].…”

Applications of Microbial Enzymes in Food Industry

“…These differ in their substrate specificities and the GH10 is more active on substituted xylan. Similar to cellulases, they may also contain CBMs (102). Exoxylanases randomly cleave the xylan backbone from inside, releasing long chain xylooligomers on which the β-xylosidases act.…”