Structural and functional properties of pectin and lignin–carbohydrate complexes de-esterases: a review

Abstract

Biological conversion of plant biomass into commercially valuable products is one of the highly studied subjects in the last two decades. Studies were continuously being conducted to understand and develop efficient enzymes for the breakdown and conversion of plant cell-wall components into valuable commercial products. Naturally, plant cell-wall components are differentially esterified to protect from the invading microorganisms. However, during the process of evolution, microorganisms have developed special set of enzymes to de-esterify the plant cell-wall components. Among the carbohydrate-active enzymes (CAZy), carbohydrate esterases stand first during the process of enzymatic conversion of plant biomass, as these enzymes de-esterify the plant biomass and make it accessible for the hydrolytic enzymes such as cellulases, hemicellulases, ligninolytic and pectinases. In this article, we have extensively discussed about the structural and functional properties of pectin methyl esterases, feruloyl, cinnamoyl and glucuronoyl esterases which are required for the de-esterification of pectin and lignin-carbohydrate complexes. Pectin esterases are classified among CE8, CE12, CE13 and CE15 carbohydrate esterase class of CAZy database. Whereas, lignin-carbohydrate complex de-esterifying enzymes are classified among CE1 (feruloyl esterase) and CE15 (glucuronoyl esterase) classes. Understanding the structural and functional abilities of pectin and lignin-carbohydrate esterases will significantly aid in developing efficient class of de-esterases for reducing the recalcitrant nature of plant biomass. These efficient de-esterases will have various applications including pretreatment of plant biomass, food, beverage, pulp and paper, textile, pharmaceutical and biofuel industries. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Anaerobic microbial methanol conversion in marine sediments

“…As much as 0.3% of all assimilated carbon was sequestered in methanol, and it was implied that the genus Prochlorococcus alone could produce 846–1693 Tg of methanol per year, worldwide (Neufeld et al ., 2008; Mincer and Aicher, 2016). Furthermore, phytoplankton mobilizes between 10% and 35% of their assimilated carbon into pectin, lignin and galactans, which are methoxylated polysaccharides (Sista Kameshwar and Qin, 2018). Thus, through demethoxylation of these carbohydrates by both aerobic microorganisms in the water column and oxic sediment and anaerobic microorganisms in the anoxic sediment, methanol is released (Schink and Zeikus, 1980, 1982; Sieburth and Keller, 1989; Sista Kameshwar and Qin, 2018).…”

Kinetic field dissipation and fate of endosulfan after application on Theobroma cacao farm in tropical Southwestern Nigeria

“…The moisture content of cocoa husk is about 14% (w/w) (Daud et al, 2013), this may have facilitated the hydrolysis of endosulfan in pod tissues to form the diol metabolite. Besides, the presence of some endogenous biological enzymes such as lignin peroxidases and pectin methyl esterase (Falade et al, 2016, Kameshwar andQin 2018) may have enhanced the rapid degradation of endosulfan observed on day 0 in pods (Wolejko et al, 2017). These other metabolites were not determined; endosulfan sulfate is reported to be the major metabolite of endosulfan -which also is an intermediary metabolite to the formation of other metabolites in plants and animals via the endosulfan diol route.…”

Investigation of antioxidant and anticancer activities of unsaturated oligo-galacturonic acids produced by pectinase of Streptomyces hydrogenans YAM1

“…Pectin, a polymeric diver’s matrix in the plant cell wall, consists of a core of α -1,4-linked D-galacturonic acid units with a various number of natural sugars such as rhamnose, arabinose, galactose, and less amount of fucose, aceric acid, apiose, xylose and glucuronic acid 7 .…”