Displaying publications 1 - 20 of 51 in total

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  1. Zaman SA, Sarbini SR
    Crit Rev Biotechnol, 2016 Jun;36(3):578-84.
    PMID: 25582732 DOI: 10.3109/07388551.2014.993590
    Resistant starch is defined as the total amount of starch and the products of starch degradation that resists digestion in the small intestine. Starches that were able to resist the digestion will arrive at the colon where they will be fermented by the gut microbiota, producing a variety of products which include short chain fatty acids that can provide a range of physiological benefits. There are several factors that could affect the resistant starch content of a carbohydrate which includes the starch granule morphology, the amylose-amylopectin ratio and its association with other food component. One of the current interests on resistant starch is their potential to be used as a prebiotic, which is a non-digestible food ingredient that benefits the host by stimulating the growth or activity of one or a limited number of beneficial bacteria in the colon. A resistant starch must fulfill three criterions to be classified as a prebiotic; resistance to the upper gastrointestinal environment, fermentation by the intestinal microbiota and selective stimulation of the growth and/or activity of the beneficial bacteria. The market of prebiotic is expected to reach USD 198 million in 2014 led by the export of oligosaccharides. Realizing this, novel carbohydrates such as resistant starch from various starch sources can contribute to the advancement of the prebiotic industry.
    Matched MeSH terms: Oligosaccharides
  2. Yusof Nurhayati, Abdul Manaf Ali
    MyJurnal
    Many researchers have focused chitosan as a source of potential bioactive material during the past few decades. However, chitosan has several drawbacks to be utilised in biological applications, including poor solubility under physiological conditions. Therefore, a new interest has recently emerged on partially hydrolysed chitosan, chitosan oligosaccharides (COS). In this study, degradation of chitosan was performed by Cellulase from Trichoderma reesei® 1.5L and Response Surface Methodology (RSM) were employed to optimize the hydrolysis temperature, pH, enzyme concentration and substrate concentration. Optimization of cellulase T. reesei® using central composite design (CCD) was to obtain optimum parameters and all the factors showed significant effects (p˂0.05). The maximum response, Celluclast® activity (1.268 U) was obtained by assaying the process at 49.79oC, pH 4.5, 3% (v/w) of enzyme concentration and 25% (w/v) concentration of chitosan for 24 hours.
    Matched MeSH terms: Oligosaccharides
  3. Yip YS, Manas NHA, Jaafar NR, Rahman RA, Puspaningsih NNT, Illias RM
    Int J Biol Macromol, 2023 Jul 01;242(Pt 1):124675.
    PMID: 37127056 DOI: 10.1016/j.ijbiomac.2023.124675
    Maltooligosaccharides (MOS) are functional oligosaccharides that can be synthesized through enzymatic cascade reaction between cyclodextrin glucanotransferase (CGTase) and maltogenic amylase (Mag1) from Bacillus lehensis G1. To address the problems of low operational stability and non-reusability of free enzymes, both enzymes were co-immobilized as combined cross-linked enzyme aggregates (Combi-CLEAs-CM) with incorporation of bovine serum albumin (BSA) and Tween 80 (Combi-CLEAs-CM-add). Combi-CLEAs-CM and Combi-CLEAs-CM-add showed activity recoveries of 54.12 % and 69.44 %, respectively after optimization. Combi-CLEAs-CM-add showed higher thermal stability at higher temperatures (40 °C) with longer half-life (46.20 min) as compared to those of free enzymes (36.67 min) and Combi-CLEAs-CM (41.51 min). Both combi-CLEAs also exhibited higher pH stability over pH 5 to pH 9, and displayed excellent reusability with >50 % of initial activity retained after four cycles. The reduction in Km value of about 22.80 % and 1.76-fold increase in starch hydrolysis in comparison to Combi-CLEAs-CM attested the improvement of enzyme-substrate interaction by Tween 80 and pores formation by BSA in Combi-CLEAs-CM-add. The improved product specificity of Combi-CLEAs-CM-add also produced the highest yield of MOS (492 mg/g) after 3 h. Therefore, Combi-CLEAs-CM-add with ease of preparation, excellent reusability and high operational stability is believed to be highly efficacious biocatalyst for MOS production.
    Matched MeSH terms: Oligosaccharides
  4. Yeo SK, Liong MT
    Int J Food Sci Nutr, 2010 Mar;61(2):161-81.
    PMID: 20085504 DOI: 10.3109/09637480903348122
    Lactobacillus sp. FTDC 2113, L. acidophilus FTDC 8033, L. acidophilus ATCC 4356, L. casei ATCC 393, Bifidobacterium FTDC 8943 and B. longum FTDC 8643 were incorporated into soymilk supplemented with fructooligosaccharides (FOS), inulin, mannitol, maltodextrin and pectin. The objective of the present study was to evaluate the effects of prebiotics on the bioactivity of probiotic-fermented soymilk. Proteolytic activity was increased in the presence of FOS, while the supplementation of inulin and pectin increased the angiotensin I-converting enzyme inhibitory activity accompanied by lower IC(50) values. The beta-glucosidase activity was also enhanced in the presence of pectin. This led to higher bioconversion of glucosides to aglycones by probiotics, especially genistin and malonyl genistin to genistein. Results from this study indicated that the supplementation of prebiotics enhanced the in-vitro antihypertensive effect and production of bioactive aglycones in probiotic-fermented soymilk. Therefore, this soymilk could potentially be used as a dietary therapy to reduce the risks of hypertension and hormone-dependent diseases such as breast cancer, prostate cancer and osteoporosis.
    Matched MeSH terms: Oligosaccharides
  5. Sukri SSM, Mimi Sakinah AM
    Appl Biochem Biotechnol, 2018 Jan;184(1):278-290.
    PMID: 28676961 DOI: 10.1007/s12010-017-2542-0
    The present study explores the utilisation of a new raw material from lignocellulose biomass, Meranti wood sawdust (MWS) for high commercial value xylooligosaccharides (XOS) production using immobilised xylanase. The xylanase was immobilised by a combination of entrapment and covalent binding techniques. The hemicellulosic xylan from MWS was extracted using a standard chlorite delignification method. The production of total and derivatives of XOS from the degradation of the hemicellulosic xylan of MWS were compared to the production from the commercial xylan from Beechwood. The utilisation of the extracted xylan from MWS yielded 0.36 mg/mL of total XOS after 60 h of hydrolysis. During the hydrolysis reaction, the immobilised xylanase released a lower degree of polymerisation (DP) of XOS, mainly X2 and X3, which were the major products of xylan degradation by xylanase enzymes. The production of XOS with a lower DP from MWS demonstrated the biotechnological potential of the MWS in the future. The XOS production retained about 70% of its initial XOS production during the second cycle. This is also the first report on the utilisation of MWS wastes in enzymatic hydrolysis using immobilised xylanase for XOS production.
    Matched MeSH terms: Oligosaccharides/chemical synthesis*
  6. Shuhaimi M, Kabeir BM, Yazid AM, Nazrul Somchit M
    J Appl Microbiol, 2009 Jan;106(1):191-8.
    PMID: 19054238 DOI: 10.1111/j.1365-2672.2008.03991.x
    This study demonstrated the optimum growth of Bifidobacterium pseudocatenulatum G4 with prebiotics via statistical model.
    Matched MeSH terms: Oligosaccharides/metabolism
  7. Shamsudin N, Tan AL, Wimmer FL, Young DJ, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Sep 1;71(Pt 9):1026-31.
    PMID: 26396840 DOI: 10.1107/S2056989015014280
    The asymmetric unit of the title compound, 2[Zn(C32H16N8)(C7H9N)]·3C7H9N, comprises two independent complex mol-ecules and three benzyl-amine solvent mol-ecules. Each complex mol-ecule features a penta-coordinated Zn(2+) ion within a square-pyramidal geometry, whereby the N5 donor set is defined by four atoms of the phthalocyaninate dianion (PC) and an N-bound benzyl-amine mol-ecule; it is the relative orientations of the latter that differentiate between the independent complex mol-ecules. The uncoordinated benzyl-amine mol-ecules display different conformations in the structure, with syn-Car-Car-Cm-N (ar = aromatic, m = methyl-ene) torsion angles spanning the range -28.7 (10) to 35.1 (14)°. In the crystal, N-H⋯N and N-H⋯π inter-actions lead to supra-molecular layers in the ab plane. The layers have a zigzag topology, have the coordinating and non-coordinating benzyl-amine mol-ecules directed to the inside, and present the essentially flat PC resides to the outside. This arrangement enables adjacent layers to associate via π-π inter-actions [inter-centroid distance between pyrrolyl and fused-benzene rings = 3.593 (2) Å] so that a three-dimensional architecture is formed.
    Matched MeSH terms: Oligosaccharides
  8. Sarbini SR, Kolida S, Deaville ER, Gibson GR, Rastall RA
    Br J Nutr, 2014 Oct 28;112(8):1303-14.
    PMID: 25196744 DOI: 10.1017/S0007114514002177
    The energy-salvaging capacity of the gut microbiota from dietary ingredients has been proposed as a contributing factor for the development of obesity. This knowledge generated interest in the use of non-digestible dietary ingredients such as prebiotics to manipulate host energy homeostasis. In the present study, the in vitro response of obese human faecal microbiota to novel oligosaccharides was investigated. Dextrans of various molecular weights and degrees of branching were fermented with the faecal microbiota of healthy obese adults in pH-controlled batch cultures. Changes in bacterial populations were monitored using fluorescent in situ hybridisation and SCFA concentrations were analysed by HPLC. The rate of gas production and total volume of gas produced were also determined. In general, the novel dextrans and inulin increased the counts of bifidobacteria. Some of the dextrans were able to alter the composition of the obese human microbiota by increasing the counts of Bacteroides-Prevotella and decreasing those of Faecalibacterium prausnitzii and Ruminococcus bromii/R. flavefaciens. Considerable increases in SCFA concentrations were observed in response to all substrates. Gas production rates were similar during the fermentation of all dextrans, but significantly lower than those during the fermentation of inulin. Lower total gas production and shorter time to attain maximal gas production were observed during the fermentation of the linear 1 kDa dextran than during the fermentation of the other dextrans. The efficacy of bifidobacteria to ferment dextrans relied on the molecular weight and not on the degree of branching. In conclusion, there are no differences in the profiles between the obese and lean human faecal fermentations of dextrans.
    Matched MeSH terms: Oligosaccharides/metabolism*; Oligosaccharides/therapeutic use; Oligosaccharides/chemistry
  9. Sarbini SR, Kolida S, Gibson GR, Rastall RA
    Br J Nutr, 2013 Jun;109(11):1980-9.
    PMID: 23116939 DOI: 10.1017/S0007114512004205
    The fermentation selectivity of a commercial source of a-gluco-oligosaccharides (BioEcolians; Solabia) was investigated in vitro. Fermentation by faecal bacteria from four lean and four obese healthy adults was determined in anaerobic, pH-controlled faecal batch cultures. Inulin was used as a positive prebiotic control. Samples were obtained at 0, 10, 24 and 36 h for bacterial enumeration by fluorescent in situ hybridisation and SCFA analyses. Gas production during fermentation was investigated in non-pH-controlled batch cultures. a-Gluco-oligosaccharides significantly increased the Bifidobacterium sp. population compared with the control. Other bacterial groups enumerated were unaffected with the exception of an increase in the Bacteroides–Prevotella group and a decrease in Faecalibacterium prausnitzii on both a-gluco-oligosaccharides and inulin compared with baseline. An increase in acetate and propionate was seen on both substrates. The fermentation of a-gluco-oligosaccharides produced less total gas at a more gradual rate of production than inulin. Generally, substrates fermented with the obese microbiota produced similar results to the lean fermentation regarding bacteriology and metabolic activity. No significant difference at baseline (0 h) was detected between the lean and obese individuals in any of the faecal bacterial groups studied.
    Matched MeSH terms: Oligosaccharides/metabolism*; Oligosaccharides/chemistry
  10. Sabiha-Hanim S, Noor MA, Rosma A
    Bioresour Technol, 2011 Jan;102(2):1234-9.
    PMID: 20797853 DOI: 10.1016/j.biortech.2010.08.017
    Oil palm (Elaeis guineensis Jacq.) is one of the most important commercial crops for the production of palm oil, which generates 10.88 tons of oil palm fronds per hectare of plantation as a by-product. In this study, oil palm frond fibres were subjected to an autohydrolysis treatment using an autoclave, operated at 121 °C for 20-80 min, to facilitate the separation of hemicelluloses. The hemicellulose-rich solution (autohydrolysate) was subjected to further hydrolysis with 4-16 U of mixed Trichoderma viride endo-(1,4)-β-xylanases (EC 3.2.1.8) per 100 mg of autohydrolysate. Autoclaving of palm fronds at 121°C for 60 min (a severity factor of 2.40) recovered 75% of the solid residue, containing 57.9% cellulose and 18% Klason lignin, and an autohydrolysate containing 14.94% hemicellulose, with a fractionation efficiency of 49.20%. Subsequent enzymatic hydrolysis of the autohydrolysate with 8 U of endoxylanase at 40 °C for 24 h produced a solution containing 17.5% xylooligosaccharides and 25.6% xylose. The results clearly indicate the potential utilization of oil palm frond, an abundantly available lignocellulosic biomass for the production of xylose and xylooligosaccharides which can serve as functional food ingredients.
    Matched MeSH terms: Oligosaccharides/biosynthesis*
  11. Rezaei S, Faseleh Jahromi M, Liang JB, Zulkifli I, Farjam AS, Laudadio V, et al.
    Poult Sci, 2015 Oct;94(10):2414-20.
    PMID: 26240398 DOI: 10.3382/ps/pev216
    This study examined the prebiotic effects of oligosaccharides extract from palm kernel expeller (OligoPKE) on growth performance, cecal microbiota and immune response of broiler chickens. A total of ninety 1-day-old broiler chicks (Cobb-500) were randomly allocated to three treatment groups of six pens (replicates) with five birds per pen. Dietary treatments were: (i) basal diet as control, (ii) basal diet plus 0.5% OligoPKE, and (iii) basal diet plus 1% OligoPKE. Birds growth traits (ADG, ADFI and G:F) were measured during the starter (1-21 day), finisher (22-35 day) and the entire experimental periods. Blood and cecal digesta samples were collected from chickens at 21 and 35 days of age (DOA). Microbial quantification of the digesta samples, white blood cells including heterophil, lymphocyte, monocyte, eosinophil, basophil counts and immunoglobulin (IgA and IgM) were also determined. OligoPKE had no effect on ADG and ADFI throughout the study period, but chickens fed OligoPKE supplemented diet had better (P < 0.05) G:F during finisher and overall rearing periods. Supplementing OligoPKE did not significantly alter the birds' microbiota of the cecal digesta. At 21 DOA, blood IgA concentration increased significantly when birds fed 1% OligoPKE in diet recorded compared to the control treatment. Similar observations were also recorded in birds at 35 DOA. Hematological data showed that heterophil and basophil counts of chickens fed OligoPKE supplement were lower than those in control group at 21 DOA. Our findings suggested that OligoPKE improved immune responses in broiler chickens, especially at younger age when the immune system is not still fully developed.
    Matched MeSH terms: Oligosaccharides/administration & dosage; Oligosaccharides/pharmacology*
  12. Phang, Y.L., Chan, H.K.
    MyJurnal
    A study was done on the feasibility of inulin, a fructooligosaccharides with the health benefits of prebiotic, as partial sugar replacer in “kaya” by investigating the effects of different substitution levels (0%; control, 10%, 30% and 50%) on the sensory properties. The samples were investigated by 10 descriptive panelists for colour, sweetness, smoothness, firmness, adhesiveness and spreadability attributes before further evaluated by 100 consumers for acceptance levels. Consistent with the descriptive panel, the evaluation by the consumers showed formulated samples at 10% and 30% were comparable to the commercial “kaya” being no significant difference (p>0.05) found in acceptability scores. 50% substitution received lower acceptability scores and was significantly different (p
    Matched MeSH terms: Oligosaccharides
  13. Nawawi NN, Hashim Z, Rahman RA, Murad AMA, Bakar FDA, Illias RM
    Int J Biol Macromol, 2020 May 01;150:80-89.
    PMID: 32035147 DOI: 10.1016/j.ijbiomac.2020.02.032
    Maltooligosaccharides (MOSs) are emerging oligosaccharides in food-based applications and can be synthesized through the enzymatic synthesis of maltogenic amylase from Bacillus lehensis G1 (Mag1). However, the lack of enzyme stability makes this approach unrealistic for industrial applications. The formation of cross-linked enzyme aggregates (CLEAs) is a promising tool for improving enzyme stability, and the substrate accessibility problem of CLEA formation was overcome by the addition of porous agents to generate porous CLEAs (p-CLEAs). However, p-CLEAs exhibited high enzyme leaching and low solvent tolerance. To address these problems, p-CLEAs of Mag1 (Mag1-p-CLEAs) were entrapped in calcium alginate beads (CA). Mag1-p-CLEAs-CA prepared with 2.5% (w/v) sodium alginate and 0.6% (w/v) calcium chloride yielded 53.16% (17.0 U/mg) activity and showed a lower deactivation rate and longer half-life than those of entrapped free Mag1 (Mag1-CA) and entrapped non-porous Mag1-CLEAs (Mag1-CLEAs-CA). Moreover, Mag1-p-CLEAs-CA exhibited low enzyme leaching and high tolerance in various solvents compared to Mag1-p-CLEAs. A kinetic study revealed that Mag1-p-CLEAs-CA exhibited relatively high affinity towards beta-cyclodextrin (β-CD) (Km = 0.62 mM). MOSs (300 mg/g) were synthesized by Mag1-p-CLEAs-CA at 50 °C. Finally, the reusability of Mag1-p-CLEAs-CA makes them as a potential biocatalyst for the continuous synthesis of MOSs.
    Matched MeSH terms: Oligosaccharides/biosynthesis*; Oligosaccharides/chemistry
  14. Nawawi KNM, Belov M, Goulding C
    Eur J Nutr, 2020 Aug;59(5):2237-2248.
    PMID: 31520160 DOI: 10.1007/s00394-019-02074-6
    INTRODUCTION: There is growing evidence that a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) improves symptoms in irritable bowel syndrome (IBS) patients. We aimed to retrospectively investigate the effects of this diet in Irish IBS cohort over a 12-month follow-up period, including after re-introduction of the high FODMAP foods.

    METHODS: All the tertiary referrals seen by an FODMAP-trained dietician were reviewed (2013-2016). Patients were evaluated for IBS symptoms by a questionnaire (four-point Likert scale). Subsequently, advice regarding the low FODMAP diet was given. Symptoms' response was assessed at 3-, 6-, and 12-month follow-up, by use of the same questionnaire. Re-introduction of high FODMAP foods was aimed to commence at the subsequent follow-up.

    RESULTS: A total of 164 patients were identified. Thirty-seven patients were excluded due to failure to attend for follow-up. Hundred and twenty-seven patients (77% patients, of which 85% were female) completed the initial 3-month follow-up. Forty-five percent (74/164) and twenty-five percent (41/164) of the patients had continued follow-up at 6 and 12 months, respectively. Of the 127 patients who returned for follow-up, their commonest baseline symptoms were lethargy (92%), bloating (91%), flatulence (91%), and abdominal pain (89%). All symptoms were significantly improved at the initial follow-up (p 

    Matched MeSH terms: Oligosaccharides
  15. Narisetty V, Parhi P, Mohan B, Hakkim Hazeena S, Naresh Kumar A, Gullón B, et al.
    Bioresour Technol, 2022 Feb;346:126590.
    PMID: 34953996 DOI: 10.1016/j.biortech.2021.126590
    Lignocellulosic wastes have the ability to be transformed into oligosaccharides and other value-added products. The synthesis of oligosaccharides from renewable sources bestow to growing bioeconomies. Oligosaccharides are synthesized chemically or biologically from agricultural residues. These oligosaccharides are functional food supplements that have a positive impact on humans and livestock. Non-digestible oligosaccharides, refered as prebiotics are beneficial for the colonic microbiota inhabiting the f the digestive system. These microbiota plays a crucial role in stimulating the host immune system and other physiological responses. The commonly known prebiotics, galactooligosaccharides (GOS), xylooligosaccharides (XOS), fructooligosaccharides (FOS), mannanooligosaccharides (MOS), and isomaltooligosaccharides (IOS) are synthesized either through enzymatic or whole cell-mediated approaches using natural or agricultural waste substrates. This review focusses on recent advancements in biological processes, for the synthesis of oligosaccharides using renewable resources (lignocellulosic substrates) for sustainable circular bioeconomy. The work also addresses the limitations associated with the processes and commercialization of the products.
    Matched MeSH terms: Oligosaccharides*
  16. Munir MB, Hashim R, Abdul Manaf MS, Nor SA
    Trop Life Sci Res, 2016 Aug;27(2):111-25.
    PMID: 27688855 MyJurnal DOI: 10.21315/tlsr2016.27.2.9
    This study used a two-phase feeding trial to determine the influence of selected dietary prebiotics and probiotics on growth performance, feed utilisation, and morphological changes in snakehead (Channa striata) fingerlings as well as the duration of these effects over a post-experimental period without supplementation. Triplicate groups of fish (22.46 ±0.17 g) were raised on six different treatment diets: three prebiotics (0.2% β-glucan, 1% galacto-oligosaccharides [GOS], 0.5% mannan-oligosaccharides [MOS]), two probiotics (1% live yeast [Saccharomyces cerevisiae] and 0.01% Lactobacillus acidophilus [LBA] powder) and a control (unsupplemented) diet; there were three replicates for each treatment. All diets contained 40% crude protein and 12% crude lipid. Fish were fed to satiation three times daily. No mortalities were recorded during Phase 1; however, 14% mortality was documented in the control and prebiotic-amended fish during Phase 2. At the end of Phase 1, growth performance and feed utilisation were significantly higher (p<0.05) in the LBA-treated fish, followed by live yeast treatment, compared with all other diets tested. The performance of fish on the three prebiotic diets were not significantly different from one another but was significantly higher than the control diet. During Phase 2 (the post-feeding phase), fish growth continued until the 6th week for the probiotic-based diets but levelled off after four weeks for the fish fed the prebiotic diets. The feed conversion ratio (FCR) was higher in all treatments during the post-feeding period. The hepatosomatic index (HSI) did not differ significantly among the tested diets. The visceral somatic index (VSI) and intraperitoneal fat (IPF) were highest in the LBA-based diet and the control diet, respectively. The body indices were significantly different (p<0.05) between Phases 1 and 2. This study demonstrates that probiotic-based diets have a more positive influence on the growth, feed utilisation, and survival of C. striata fingerlings compared with supplementation with prebiotics.
    Matched MeSH terms: Oligosaccharides
  17. Muniandy N, Love DN, Mukkur TK
    Comp Immunol Microbiol Infect Dis, 1998 Oct;21(4):257-79.
    PMID: 9775357
    Purified lipopolysaccharide (LPS) of Pasteurella multocida type 6:B, while toxic at higher doses, was protective at lower dose levels against experimentally-induced pasteurellosis in mice. However, the observed protection was abrogated if such LPS was digested with proteinase K prior to use in immunisation. The O-antigen polysaccharide side-chain (OS) of LPS did not appear to contribute to the observed protection as judged by the fact that immunisation of mice with purified OS or OS-protein conjugates, all of which were nontoxic, failed to confer protection against challenge with homologous virulent organisms. This was despite generation of significant levels of OS-specific antibodies, predominantly either of the IgM or IgG isotypes, in immunised mice.
    Matched MeSH terms: Oligosaccharides/immunology
  18. Mookiah S, Sieo CC, Ramasamy K, Abdullah N, Ho YW
    J Sci Food Agric, 2014 Jan 30;94(2):341-8.
    PMID: 24037967 DOI: 10.1002/jsfa.6365
    In view of a worldwide attempt to restrict or ban the use of antibiotics as growth promoters in animal production, probiotics, prebiotics and combinations of both, as synbiotics, have been suggested as potential alternatives. In this study, the effects of a prebiotic (isomalto-oligosaccharides, IMO), a multi-strain probiotic (consisting of 11 Lactobacillus strains), and a combination of these dietary additives as a synbiotic on the performance, caecal bacterial populations and concentrations of caecal volatile fatty acids and non-volatile fatty acids of broiler chickens were evaluated.
    Matched MeSH terms: Oligosaccharides/pharmacology*
  19. Misson M, Dai S, Jin B, Chen BH, Zhang H
    J Biotechnol, 2016 Mar 20;222:56-64.
    PMID: 26876609 DOI: 10.1016/j.jbiotec.2016.02.014
    The nanoenvironment of nanobiocatalysts, such as local hydrophobicity, pH and charge density, plays a significant role in optimizing the enzymatic selectivity and specificity. In this study, Kluyveromyces lactis β-galactosidase (Gal) was assembled onto polystyrene nanofibers (PSNFs) to form PSNF-Gal nanobiocatalysts. We proposed that local hydrophobicity on the nanofiber surface could expel water molecules so that the transgalactosylation would be preferable over hydrolysis during the bioconversion of lactose, thus improve the galacto-oligosaccharides (GOS) yield. PSNFs were fabricated by electro-spinning and the operational parameters were optimized to obtain the nanofibers with uniform size and ordered alignment. The resulting nanofibers were functionalized for enzyme immobilization through a chemical oxidation method. The functionalized PSNF improved the enzyme adsorption capacity up to 3100mg/g nanofiber as well as enhanced the enzyme stability with 80% of its original activity. Importantly, the functionalized PSNF-Gal significantly improved the GOS yield and the production rate was up to 110g/l/h in comparison with 37g/l/h by free β-galactosidase. Our research findings demonstrate that the localized nanoenvironment of the PSNF-Gal nanobiocatalysts favour transgalactosylation over hydrolysis in lactose bioconversion.
    Matched MeSH terms: Oligosaccharides
  20. Misson M, Du X, Jin B, Zhang H
    Enzyme Microb Technol, 2016 Mar;84:68-77.
    PMID: 26827776 DOI: 10.1016/j.enzmictec.2015.12.008
    Functional nanomaterials have been pursued to assemble nanobiocatalysts since they can provide unique hierarchical nanostructures and localized nanoenvironments for enhancing enzyme specificity, stability and selectivity. Functionalized dendrimer-like hierarchically porous silica nanoparticles (HPSNs) was fabricated for assembling β-galactosidase nanobiocatalysts for bioconversion of lactose to galacto-oligosaccharides (GOS). The nanocarrier was functionalized with amino (NH2) and carboxyl (COOH) groups to facilitate enzyme binding, benchmarking with non-functionalized HPSNs. Successful conjugation of the functional groups was confirmed by FTIR, TGA and zeta potential analysis. HPSNs-NH2 showed 1.8-fold and 1.1-fold higher β-galactosidase adsorption than HPSNs-COOH and HPSNs carriers, respectively, with the highest enzyme adsorption capacity of 328mg/g nanocarrier at an initial enzyme concentration of 8mg/ml. The HPSNs-NH2 and β-galactosidase assembly (HPSNs-NH2-Gal) demonstrated to maintain the highest activity at all tested enzyme concentrations and exhibited activity up to 10 continuous cycles. Importantly, HPSNs-NH2-Gal was simply recycled through centrifugation, overcoming the challenging problems of separating the nanocarrier from the reaction medium. HPSNs-NH2-Gal had distinguished catalytic reaction profiles by favoring transgalactosylation, enhancing GOS production of up to 122g/l in comparison with 56g/l by free β-galactosidase. Furthermore, it generated up to 46g/l GOS at a lower initial lactose concentration while the free counterpart had negligible GOS production as hydrolysis was overwhelmingly dominant in the reaction system. Our research findings show the amino-functionalized HPSNs can selectively promote the enzyme activity of β-galactosidase for transgalactosylation, which is beneficial for GOS production.
    Matched MeSH terms: Oligosaccharides/biosynthesis
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