Expression of pRSETA manb-1601 construct in Hi-Control Escherichia coli BL21 (DE3) cells improved recombinant endo-mannanase (ManB-1601) production by 2.73-fold (1821 +/- 100 U/ml). A low-cost, agro-industrial residue supplemented industrial medium for enhanced and economical production of ManB-1601 was developed in two mutual phases. Phase-I revealed the potential of various pre-(induction time: 5 h, induction mode: lactose 0.5 mM) and post-induction [peptone supplementation: 0.94% (w/v), glycerol 0.123% (v/v)] parameters for enhanced production of ManB-1601 and resulted in 4.61-fold (8406 +/- 400 U/ml) and 2.53-fold (3.30 g/l) higher ManB-1601 and biomass production, respectively. Under phase-II, economization of phase-I medium was carried out by reducing/replacing costly ingredients with solubilized-defatted flax seed meal (S-DFSM), which resulted in 3.25-fold (5926 U/ml) higher ManB-1601 production. Industrial potential of ManB-1601 was shown in oil extraction from copra as enzyme treatment led to cracks, peeling, fracturing and smoothening of copra, which facilitated higher (18.75%) oil yield. (C) 2016 Elsevier Ltd. All rights reserved.