Plant cell walls (lignocellulose) are the largest source of a renewable, terrestrial carbon reservoir on Earth (Doi & Kosugi, 2004;Ochoa-Villarreal & Aispuro-Hernández, 2012). The efficient and complete bioconversion of lignocellulose to component sugars is currently a major biotechnological goal toward the affordable production of renewable fuels and chemicals (Liu et al., 2019;Malherbe & Cloete, 2002). Consequently, uncovering microbial mechanisms to breakdown lignocellulose is an active area of research (Guo et al., 2018;Prasad et al., 2019;Rosnow et al., 2016). One challenge to overcoming the recalcitrance of lignocellulose is the complexity and crystallinity of the polysaccharide matrix (Gilbert, 2010).Hemicelluloses are a major polysaccharide component of lignocellulose, which can be further classified based on sugar composition and glycosidic linkage. For example, plant mannans are abundant in fruit trees, seeds, and softwoods, and may be found as a linear polymer of mannose or as heteropolymers (Moreira & Filho, 2008). Specifically, glucomannan, galactomannan, and galactoglucomannan are comprised of β-(1,4)-linked mannose that may also contain glucose residues and/or α-(1,6)-linked galactose substitutions (Malgas et al., 2015;Melton et al., 2009) (Figure S1). The cell walls of yeast and some bacterial species also contain linear and glucomannans, but with greater linkage variety through α-(1,2)-, α-(1,3)-, and/or
