title: Recovery and purification of oligosaccharides from copra meal by recombinant endo-β-mannanase and deciphering molecular mechanism involved and its role as potent therapeutic agent.
abstract: Production of manno-oligosaccharides (MOSs) from pretreated and defatted copra meal (dFCO) hydrolysis was achieved by endo-mannanase. Structural characterization of dFCO by FT-IR and NMR exhibited resemblance with galactomannan. The time-dependent hydrolysis of dFCO by recombinant endo-β-(1 → 4)-mannanase of Clostridium thermocellum by TLC and HPAEC displayed the release of mannose and MOSs mannobiose and mannotriose. Purified MOSs yielded 40 % mannobiose and 18 % mannotriose confirmed by mass spectroscopy which showed mannobiose (m/z = 365) and mannotriose (m/z = 527). The homology based structural analysis of catalytic endo-mannanase (CtManT) showed the catalytic core composed of Glu181 and Glu300 acting as acid/base and Glu288 as a nucleophile during galactomannan hydrolysis. Sub-site mapping of CtManT exhibited two aglycone and four glycone sites at cleavage sites existing on either side of β-(1 → 4)-linkage of galactomannan. Isolated MOSs displayed potential prebiotic characteristics and supported higher growth of probiotic Lactobacillus acidophilus and Bifidobacterium infantis than with standard inulin. Moreover, MOSs displayed over 97 % tolerance to simulated gastric juice, intestinal fluid, and α-amylase proving its potential as a stable prebiotic over inulin. In vitro cytotoxicity assay of MOSs (500 µg/mL) on human epithelial colorectal adenocarcinoma cell line (HT-29) demonstrated 60 % decreased viability of cells after 48 h displaying anti-tumorigenic property.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, 781 039, Assam, India, arabinda@iitg.ernet.in.
authors.forename: Arabinda
authors.initials: A
authors.lastname: Ghosh
authors.forename: Anil Kumar
authors.initials: AK
authors.lastname: Verma
authors.forename: Jaganmohan Rao
authors.initials: JR
authors.lastname: Tingirikari
authors.forename: Rishikesh
authors.initials: R
authors.lastname: Shukla
authors.forename: Arun
authors.initials: A
authors.lastname: Goyal
mesh_terms: D001644:Bifidobacterium / Q000187:drug effects / Q000254:growth & development; D003001:Cloning, Molecular; D048013:Acetivibrio thermocellus / Q000187:drug effects; D005690:Galactose / Q000031:analogs & derivatives; D006801:Humans; D006868:Hydrolysis; D007779:Lactobacillus acidophilus / Q000187:drug effects / Q000254:growth & development; D008351:Mannans / Q000737:chemistry / Q000302:isolation & purification*; D008358:Mannose / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics; D017550:Spectroscopy, Fourier Transform Infrared; D044902:beta-Mannosidase / Q000737:chemistry* / Q000235:genetics
chemical_list: D008351:Mannans; D009844:Oligosaccharides; D011994:Recombinant Proteins; C012990:galactomannan; D044902:beta-Mannosidase; D008358:Mannose; D005690:Galactose