چکیده مقاله
The imperative for sustainable bioprocessing of lignocellulosic wastes has catalyzed the exploration of marine derived enzymes for prebiotic synthesis, addressing both environmental remediation and functional food demands Rice straw, an abundant agro residue over 800 million tons annually , encapsulates hemicellulosic polysaccharides amenable to enzymatic hydrolysis into xylooligosaccharides XOS , potent prebiotics fostering Bifidobacterium proliferation and gut barrier integrity This study engineers a bifunctional recombinant xylanase XynC/R, fused from Psychromonas ingrahamii XynC cold active endo 1,4 ß xylanase and Rhodothermus marinus XynR thermostable reducing end xylose releasing exo oligoxylanase , expressed in Pichia pastoris for hyperglycosylated stability The chimeric enzyme, with a k_cat/K_m of 850 s¹ mM 1 at 45°C, catalyzes stoichiometric conversion of rice straw xylan to XOS DP 2 6 in a continuous stirred tank reactor CSTR scaled to 50 L Pretreatment of milled straw 1 2 mm via dilute acid 0 5% H2SO4, 121°C, 30 min solubilized 78% hemicellulose, yielding 42 g/L xylan feed Stoichiometric modeling revealed 1:0 85 molar equivalence of XynC endo cleavage to XynR exo trimming, producing 68% XOS yield X2:X3:X4:X5:X6 = 12:28:32:18:10% at 5 U/mL enzyme, 2 h residence time, pH 5 5 Reactor dynamics sustained 92% conversion over 720 h, with XOS flux 28 g/L h and minimal xylose byproduct 3 2% Prebiotic efficacy: XOS stimulated Bifidobacterium longum growth 3 2 fold OD600 2 1 vs 0 65 glucose , SCFAs 45 mM butyrate vs 18 mM inulin , and 52% pathogen inhibition E coli K12 In vitro colonic fermentation human fecal slurry elevated acetate/propionate/butyrate ratios to 58:22:20, enhancing tight junction ZO 1 expression 2 8 fold in Caco 2 monolayers Industrial viability: Enzyme half life >1,200 h at 45°C, recyclable via Ni NTA affinity 95% recovery post 10 cycles Cost projections: 1 8/kg XOS versus 12/kg commercial, leveraging zero waste straw valorization Challenges lignin fouling 18% flux decline mitigated by periodic NaOH washes restoring 88% performance This platform redefines prebiotic biosynthesis: Marine XynC/R's psychro thermo duality enables ambient processing, slashing energy 40% versus steam explosion Broader impacts encompass biorefinery integration, where XOS co products fortify animal feeds, curbing antibiotic reliance 30% Future iterations may incorporate CRISPR tuned Pichia for 5 fold titer escalation, propelling circular bioeconomy paradigms
کلیدواژهها
نویسندگان
Vahideh Mehrabi
PhD in Food Science and Technology, Department of Food Science and Technology, Faculty of Food Technology, Islamic Azad University, Science and Research Branch, Tehran, Iran
Morteza Jamshid Eini
PhD in Food Technology, Islamic Azad University, North Tehran Branch, Tehran, Iran
Behzad Beizaei
PhD student in Food Technology, Islamic Azad University, Tehran Azad Medical Sciences Branch, Tehran, Iran
Fataneh Jalili Yousef Nejad
Doctor of Veterinary Medicine D V M / Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran
شیوه ارجاع
Mehrabi, Vahideh and Jamshid Eini, Morteza and Beizaei, Behzad and Jalili Yousef Nejad, Fataneh,1404,Synthesis of Unique Prebiotics via Recombinant Enzyme Catalyst XynC/R Derived from Marine Microorganisms,The first national conference environment, smart agriculture, food security,Varamin
ارائهشده در
مجموعه مقالات اولین همایش ملی محیط زیست، کشاورزی هوشمند، امنیت غذایی28 آبان 1404 · ورامین