constituents of hemicellulose (Jana et al. 2021). The backbone of mannans consists of β-1,4-linked mannose residues with variable degrees of side substitutions (Soni et al. 2016). Hardwoods and grasses are composed of xylans, while softwoods, fruits and seeds are mainly constituted of mannans (Singh et al. 2018). Locust bean gum (LBG) from Ceratonia siliqua (or carob gum), used as a substrate for β-mannanase production in this study, is a mannan material that consists of a β-1,4-linkage mannose backbone with galactose monomers randomly linked by α-1,6 bonds (Mamo 2019). This natural polymer is obtained from the carob tree's seed endosperm, which is widely abundant since ancient times in the Mediterranean region including the region of North Africa (Barak and Mudgil 2014;Brassesco et al. 2021;Erkan et al. 2021). Due to its accessibility and affordability, it has been employed as a source of pure mannans in numerous studies Hadjer Djelid