Biochemical characterization of the novel endo -β-mannanase At Man5-2 from Arabidopsis thaliana

Abstract

Plant mannanases are enzymes that carry out fundamentally important functions in cell wall metabolism during plant growth and development by digesting manno-polysaccharides. In this work, the Arabidopsis mannanase 5-2 (AtMan5-2) from a previously uncharacterized subclade of glycoside hydrolase family 5 subfamily 7 (GH5_7) has been heterologously produced in Pichia pastoris. Purified recombinant AtMan5-2 is a glycosylated protein with an apparent molecular mass of 50kDa, a pH optimum of 5.5-6.0 and a temperature optimum of 25°C. The enzyme exhibits high substrate affinity and catalytic efficiency on mannan substrates with main chains containing both glucose and mannose units such as konjac glucomannan and spruce galactoglucomannan. Product analysis of manno-oligosaccharide hydrolysis shows that AtMan5-2 requires at least six substrate-binding subsites. No transglycosylation activity for the recombinant enzyme was detected in the present study. Our results demonstrate diversification of catalytic function among members in the Arabidopsis GH5_7 subfamily.

Characterization of mannanase-producing bacteria from sago hump

“…The same optimum pH has been reported by Titapoka et al [46]; Mabrouk and Ahwany [28]; Mou et al [33]; Kim et al [24]; Chandra et al [9] and Zhang et al [39]. Meanwhile, Lu et al [27]; Yoo et al [52]; Yang et al [51] and Wang et al [50] reported different optimum pH at 11, 4, 5.5 and 5.…”

“…Mannolytic bacteria have been isolated from variety of sources including oil waste [46]; activated sludge [8]; decayed konjac [54] and soil [33]. Currently, some microbes have been identified for having mannolytic activity such as Weissella viridescens LB37 [3], Gloeophyllum trabeum CBS900.73 [49], Neosartorya fischeri P1 [51], Arabidopsis thaliana [50], Bacillus nealsonii [10], Bacillus subtilis Bs5 [21], Bacillus subtilis NM-39 [30], Bacillus sp KKO1 [18], Thermotoga neopalitana 5068 [15]. Groups of fungi also exhibits mannolytic activity such as Streptomyces, Aspergillus and Trichoderma [52,27,10,14].…”

Recent advances in biotransformation, extraction and green production of D-mannose

“…In plants, these enzymes enhance plant metabolism mainly by degrading the mannan present in the cell wall ( Moreira, 2008 ). Currently, mannanase has been isolated from plants, animals, and microorganisms ( Jana et al, 2018 ; Kim et al, 2013 ; Wang et al, 2015b ). At present, most commercial β-mannanase are produced by microorganisms.…”

Applications of Microbial β-Mannanases

“…Mannanases have been isolated from plants, animals and microorganisms (Kim et al, 2013;Wang et al, 2015;Jana et al, 2018). Most of the commercial β-mannanases have been produced from microbes due to their higher stability, production within limited time and space, cost effectiveness and ease of genetic manipulation (Table 1).…”