Displaying publications 1 - 20 of 71 in total

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  1. Primary recovery of a bacteriocin-like inhibitory substance derived from Pediococcus acidilactici Kp10 by an aqueous two-phase system
    Abbasiliasi S, Tan JS, Ibrahim TA, Kadkhodaei S, Ng HS, Vakhshiteh F, et al.
    Food Chem, 2014 May 15;151:93-100.
    PMID: 24423507 DOI: 10.1016/j.foodchem.2013.11.019
    A polymer-salt aqueous two-phase system (ATPS) consisting of polyethylene-glycol (PEG) with sodium citrate was developed for direct recovery of a bacteriocin-like inhibitory substance (BLIS) from a culture of Pediococcus acidilactici Kp10. The influences of phase composition, tie-line length (TLL), volume ratio (VR), crude sample loading, pH and sodium chloride (NaCl) on the partition behaviour of BLIS was investigated. Under optimum conditions of ATPS, the purification of BLIS was achieved at 26.5% PEG (8000)/11% sodium citrate with a TLL of 46.38% (w/w), VR of 1.8, and 1.8% crude load at pH 7 without the presence of NaCl. BLIS from P. acidilactici Kp10 was successfully purified by the ATPS up to 8.43-fold with a yield of 81.18%. Given that the operation of ATPS is simple, environmentally friendly and cost-effective, as it requires only salts and PEG, it may have potential for industrial applications in the recovery of BLIS from fermentation broth.
  2. Fulltext Isolation of Pediococcus acidilactici Kp10 with ability to secrete bacteriocin-like inhibitory substance from milk products for applications in food industry
    Abbasiliasi S, Tan JS, Ibrahim TA, Ramanan RN, Vakhshiteh F, Mustafa S, et al.
    BMC Microbiol, 2012;12:260.
    PMID: 23153191 DOI: 10.1186/1471-2180-12-260
    Lactic acid bacteria (LAB) can be isolated from traditional milk products. LAB that secrete substances that inhibit pathogenic bacteria and are resistant to acid, bile, and pepsin but not vancomycin may have potential in food applications.
  3. Fulltext In vitro assessment of Pediococcus acidilactici Kp10 for its potential use in the food industry
    Abbasiliasi S, Tan JS, Bashokouh F, Ibrahim TAT, Mustafa S, Vakhshiteh F, et al.
    BMC Microbiol, 2017 May 23;17(1):121.
    PMID: 28535747 DOI: 10.1186/s12866-017-1000-z
    BACKGROUND: Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro.

    RESULTS: P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities.

    CONCLUSION: The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

  4. Fulltext Kinetic modeling of bacteriocin-like inhibitory substance secretion by Pediococcus acidilactici Kp10 and its stability in food manufacturing conditions
    Abbasiliasi S, Tan JS, Ibrahim TAT, Ramanan RN, Kadkhodaei S, Mustafa S, et al.
    J Food Sci Technol, 2018 Apr;55(4):1270-1284.
    PMID: 29606741 DOI: 10.1007/s13197-018-3037-x
    This paper deliberates the modelling and validation of bacteriocin-like inhibitory substance (BLIS) secretion by Pediococcus acidilactici Kp10 at different agitation speeds in a stirred tank bioreactor. A range of models namely the re-parameterised logistic, Luedeking-Piret and maintenance energy were assessed to predict the culture performance of the said bacterium. Growth of P. acidilactici Kp10 was enhanced with increased agitation speed up to 600 rpm while BLIS secretion was maximum at 400 rpm but decreased at higher agitation speed. Growth of P. acidilactici aptly subscribed to the re-parameterised logistic model while BLIS secretion and lactose consumption fitted well with the Luedeking-Piret model. The models revealed a relationship between growth of the bacterium and BLIS secretion. Bacterial growth and BLIS secretion were largely affected by the agitation speed of the stirred tank bioreactor which regulated the oxygen transfer to the culture. BLIS secretion by P. acidilactici Kp10 was however enhanced in oxygen-limited culture. The study also assessed BLIS from the perspective of its stability when subjected to factors such as temperature, pH and detergents. Results showed that BLIS produced by this strain was not affected by heat (at 25-100 °C for 20 min and at 121 °C for 15 min), surfactant (Tween 40, 60 and 80 and urea), detergents (up to 1% SDS), organic solvents (50% each of acetone, methanol and ethanol) and stable in a wide range of pH (2-10). The above information are pertinent with reference to commercial applications of this bacterial product in food manufacturing which invariably involve various sterilization processes and subjected to a wide pH range.
  5. Fulltext Recovery of a Bacteriocin-Like Inhibitory Substance from Lactobacillus bulgaricus FTDC 1211 Using Polyethylene-Glycol Impregnated Amberlite XAD-4 Resins System
    Abdul Aziz NFH, Abbasiliasi S, Ng ZJ, Abu Zarin M, Oslan SN, Tan JS, et al.
    Molecules, 2020 Nov 16;25(22).
    PMID: 33207534 DOI: 10.3390/molecules25225332
    Lactobacillus bulgaricus is a LAB strain which is capable of producing bacteriocin substances to inhibit Staphylococcus aureus. The aim of this study was to purify a bacteriocin-like inhibitory substance (BLIS) produced by L. bulgaricus FTDC 1211 using an aqueous impregnated resins system consisting of polyethylene-glycol (PEG) impregnated on Amberlite XAD4. Important parameters influencing on purification of BLIS, such as the molecular weight and concentration of PEG, the concentration and pH of sodium citrate and the concentration of sodium chloride, were optimized using a response surface methodology. Under optimum conditions of 11% (w/w) of PEG 4000 impregnated Amberlite XAD4 resins and 2% (w/w) of sodium citrate at pH 6, the maximum purification factor (3.26) and recovery yield (82.69% ± 0.06) were obtained. These results demonstrate that AIRS could be used as an alternate purification system in the primary recovery step.
  6. Fulltext Extraction behaviors of aqueous PEG impregnated resin system in terms of impregnation stability and recovery via protein impregnated resin interactions on bovine serum albumin
    Abdul Aziz NFH, Abbasiliasi S, Abu Zarin M, Ng HS, Lan C, Tan JS
    PeerJ, 2021;9:e11920.
    PMID: 34963820 DOI: 10.7717/peerj.11920
    Background: Current advances in biotechnology have been looked at as alternative approaches towards the limited product recovery due to time- and cost-consuming drawbacks on the conventional purification methods. This study aimed to purify bovine serum albumin (BSA) as an exemplary target product using an aqueous impregnated resin system (AIRS). This method implies the concept of hydrophobicity of polymer that impregnated into the resins and driven by electrostatic attractions and hydrophilicity of aqueous salt solution to extract the target product.

    Methods: The extraction behaviors of impregnation in terms of stability and adsorption kinetics via protein-aqueous polymer impregnated resin were studied. Impregnation stability was determined by the leaching factor of polyethylene glycol (PEG). The major factors such as PEG molecular weights and concentration, pH of aqueous salt solution, extraction methods (sonication and agitation) and types of adsorbent material and concentration of aqueous salt phase influencing on partitioning of biomolecule were also investigated.

    Results: For impregnation stability, the leaching factor for Amberlite XAD4 did not exceed 1%. The scanning electron microscopy (SEM) image analysis of Amberlite XAD4 attributes the structural changes with impregnation of resins. For adsorption kinetics, Freundlich adsorption isotherm with the highest R2 value (0.95) gives an indication of favorable adsorption process. Performance of AIRS impregnated with 40% (w/w) of PEG 2000 was found better than aqueous-two phase system (ATPS) by yielding the highest recovery of BSA (53.72%). The outcomes of this study propound the scope for the application of AIRS in purification of biomolecules.

  7. Celastrol attenuates mitochondrial dysfunction and inflammation in palmitate-mediated insulin resistance in C3A hepatocytes
    Abu Bakar MH, Sarmidi MR, Tan JS, Mohamad Rosdi MN
    Eur J Pharmacol, 2017 Mar 15;799:73-83.
    PMID: 28161417 DOI: 10.1016/j.ejphar.2017.01.043
    Accumulating evidence indicates that mitochondrial dysfunction-induced inflammation is among the convergence points for the greatest hallmarks of hepatic insulin resistance. Celastrol, an anti-inflammatory compound from the root of Tripterygium Wilfordii has been reported to mitigate insulin resistance and inflammation in animal disease models. Nevertheless, the specific mechanistic actions of celastrol in modulating such improvements at the cellular level remain obscure. The present study sought to explore the mechanistic roles of celastrol upon insulin resistance induced by palmitate in C3A human hepatocytes. The hepatocytes exposed to palmitate (0.75mM) for 48h exhibited reduced both basal and insulin-stimulated glucose uptake, mitochondrial dysfunction, leading to increased mitochondrial oxidative stress with diminished fatty acid oxidation. Elevated expressions of nuclear factor-kappa B p65 (NF-κB p65), c-Jun NH(2)-terminal kinase (JNK) signaling pathways and the amplified release of pro-inflammatory cytokines including IL-8, IL-6, TNF-α and CRP were observed following palmitate treatment. Consistently, palmitate reduced and augmented phosphorylated Tyrosine-612 and Serine-307 of insulin receptor substrate-1 (IRS-1) proteins, respectively in hepatocytes. However, celastrol at the optimum concentration of 30nM was able to reverse these deleterious occasions and protected the cells from mitochondrial dysfunction and insulin resistance. Importantly, we presented evidence for the first time that celastrol efficiently prevented palmitate-induced insulin resistance in hepatocytes at least, via improved mitochondrial functions and insulin signaling pathways. In summary, the present investigation underlines a conceivable mechanism to elucidate the cytoprotective potential of celastrol in attenuating mitochondrial dysfunction and inflammation against the development of hepatic insulin resistance.
  8. Improvement of mitochondrial function by celastrol in palmitate-treated C2C12 myotubes via activation of PI3K-Akt signaling pathway
    Abu Bakar MH, Tan JS
    Biomed Pharmacother, 2017 Sep;93:903-912.
    PMID: 28715871 DOI: 10.1016/j.biopha.2017.07.021
    Compelling evidences posited that high level of saturated fatty acid gives rise to mitochondrial dysfunction and inflammation in the development of insulin resistance in skeletal muscle. Celastrol is a pentacyclic triterpenoid derived from the root extracts of Tripterygium wilfordii that possesses potent anti-inflammatory properties in a number of animal models with metabolic diseases. However, the cellular mechanistic action of celastrol in alleviating obesity-induced insulin resistance in skeletal muscle remains largely unknown. Therefore, the present investigation evaluated the attributive properties of celastrol at different concentrations (10, 20, 30 and 40nM) on insulin resistance in C2C12 myotubes evoked by palmitate. We demonstrated that celastrol improved mitochondrial functions through significant enhancement of intracellular ATP content, mitochondrial membrane potential, citrate synthase activity and decrease of mitochondrial superoxide productions. Meanwhile, augmented mitochondrial DNA (mtDNA) content with suppressed DNA oxidative damage were observed following celastrol treatment. Celastrol significantly enhanced fatty acid oxidation rate and increased the level of tricarboxylic acid (TCA) cycle intermediates in palmitate-treated cells. Further analysis revealed that the improvement of glucose uptake activity in palmitate-loaded myotubes was partly mediated by celastrol via activation of PI3K-Akt insulin signaling pathway. Collectively, these findings provided evidence for the first time that the protection from palmitate-mediated insulin resistance in C2C12 myotubes by celastrol is likely associated with the improvement of mitochondrial functions-related metabolic activities.
  9. Celastrol attenuates inflammatory responses in adipose tissues and improves skeletal muscle mitochondrial functions in high fat diet-induced obese rats via upregulation of AMPK/SIRT1 signaling pathways
    Abu Bakar MH, Shariff KA, Tan JS, Lee LK
    Eur J Pharmacol, 2020 Sep 15;883:173371.
    PMID: 32712089 DOI: 10.1016/j.ejphar.2020.173371
    Accumulating evidence indicates that adipose tissue inflammation and mitochondrial dysfunction in skeletal muscle are inextricably linked to obesity and insulin resistance. Celastrol, a bioactive compound derived from the root of Tripterygium wilfordii exhibits a number of attributive properties to attenuate metabolic dysfunction in various cellular and animal disease models. However, the underlying therapeutic mechanisms of celastrol in the obesogenic environment in vivo remain elusive. Therefore, the current study investigated the metabolic effects of celastrol on insulin sensitivity, inflammatory response in adipose tissue and mitochondrial functions in skeletal muscle of the high fat diet (HFD)-induced obese rats. Our study revealed that celastrol supplementation at 3 mg/kg/day for 8 weeks significantly reduced the final body weight and enhanced insulin sensitivity of the HFD-fed rats. Celastrol noticeably improved insulin-stimulated glucose uptake activity and increased expression of plasma membrane GLUT4 protein in skeletal muscle. Moreover, celastrol-treated HFD-fed rats showed attenuated inflammatory responses via decreased NF-κB activity and diminished mRNA expression responsible for classically activated macrophage (M1) polarization in adipose tissues. Significant improvement of muscle mitochondrial functions and enhanced antioxidant defense machinery via restoration of mitochondrial complexes I + III linked activity were effectively exhibited by celastrol treatment. Mechanistically, celastrol stimulated mitochondrial biogenesis attributed by upregulation of the adenosine monophosphate-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) signaling pathways. Together, these results further demonstrate heretofore the conceivable therapeutic mechanisms of celastrol in vivo against HFD-induced obesity mediated through attenuation of inflammatory response in adipose tissue and enhanced mitochondrial functions in skeletal muscle.
  10. Withaferin A Protects Against High-Fat Diet-Induced Obesity Via Attenuation of Oxidative Stress, Inflammation, and Insulin Resistance
    Abu Bakar MH, Azmi MN, Shariff KA, Tan JS
    Appl Biochem Biotechnol, 2019 May;188(1):241-259.
    PMID: 30417321 DOI: 10.1007/s12010-018-2920-2
    Withaferin A (WA), a bioactive constituent derived from Withania somnifera plant, has been shown to exhibit many qualifying properties in attenuating several metabolic diseases. The current investigation sought to elucidate the protective mechanisms of WA (1.25 mg/kg/day) on pre-existing obese mice mediated by high-fat diet (HFD) for 12 weeks. Following dietary administration of WA, significant metabolic improvements in hepatic insulin sensitivity, adipocytokines with enhanced glucose tolerance were observed. The hepatic oxidative functions of obese mice treated with WA were improved via augmented antioxidant enzyme activities. The levels of serum pro-inflammatory cytokines and hepatic mRNA expressions of toll-like receptor (TLR4), nuclear factor κB (NF-κB), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand-receptor, and cyclooxygenase 2 (COX2) in HFD-induced obese mice were reduced. Mechanistically, WA increased hepatic mRNA expression of peroxisome proliferator-activated receptors (PPARs), cluster of differentiation 36 (CD36), fatty acid synthase (FAS), carnitine palmitoyltransferase 1 (CPT1), glucokinase (GCK), phosphofructokinase (PFK), and phosphoenolpyruvate carboxykinase (PCK1) that were associated with enhanced lipid and glucose metabolism. Taken together, these results indicate that WA exhibits protective effects against HFD-induced obesity through attenuation of hepatic inflammation, oxidative stress, and insulin resistance in mice.
  11. Fulltext Investigation of potential anti-urolithiatic activity from different types of Musa pseudo-stem extracts in inhibition of calcium oxalate crystallization
    Abu Zarin M, Tan JS, Murugan P, Ahmad R
    BMC Complement Med Ther, 2020 Oct 19;20(1):317.
    PMID: 33076892 DOI: 10.1186/s12906-020-03113-0
    BACKGROUND: The banana or scientifically referred to as Musa sp., is one of the most popular fruits all over the world. Almost all parts of a banana tree, including the fruits, stem juice, and flowers are commonly used as traditional medicine for treating diarrhoea (unripe), menorrhagia, diabetes, dysentery, and antiulcerogenic, hypoglycemic, antilithic, hypolipidemic conditions, plus antioxidant actions, inflammation, pains and even snakebites. The study carried out was to evaluate in vitro anti-urolithiatic activity from different types of Musa pseudo-stems.

    METHODS: Observing anti-urolithiathic activity via in vitro nucleation and aggregation assay using a spectrophotometer followed by microscopic observation. A total of 12 methanolic extracts were tested to determine the potential extracts in anti-urolithiasis activities. Cystone was used as a positive control.

    RESULTS: The results manifested an inhibition of nucleation activity (0.11 ± 2.32% to 55.39 ± 1.01%) and an aggregation activity (4.34 ± 0.68% to 58.78 ± 1.81%) at 360 min of incubation time. The highest inhibition percentage in nucleation assay was obtained by the Musa acuminate x balbiciana Colla cv "Awak Legor" methanolic pseudo-stem extract (2D) which was 55.39 ± 1.01%at 60 min of incubation time compared to the cystone at 30.87 ± 0.74%. On the other hand,the Musa acuminate x balbiciana Colla cv "Awak Legor" methanolic bagasse extract (3D) had the highest inhibition percentage in the aggregation assay incubated at 360 min which was obtained at 58.78 ± 1.8%; 5.53% higher than the cystone (53.25%).The microscopic image showed a great reduction in the calcium oxalate (CaOx) crystals formation and the size of crystals in 2D and 3D extracts, respectively, as compared to negative control.

    CONCLUSIONS: The results obtained from this study suggest that the extracts are potential sources of alternative medicine for kidney stones disease.

  12. Fulltext Clinicopathological Features of Telbivudine-Associated Myopathy
    Ambang T, Tan JS, Ong S, Wong KT, Goh KJ
    PLoS One, 2016;11(9):e0162760.
    PMID: 27611456 DOI: 10.1371/journal.pone.0162760
    Telbivudine, a thymidine nucleoside analog, is a common therapeutic option for chronic hepatitis B infection. While raised serum creatine kinase is common, myopathy associated with telbivudine is rare. Reports on its myopathological features are few and immunohistochemical analyses of inflammatory cell infiltrates have not been previously described. We describe the clinical, myopathological and immunohistochemical features of four patients who developed myopathy after telbivudine therapy for chronic hepatitis B infection. All four patients presented with progressive proximal muscle weakness, elevation of serum creatine kinase and myopathic changes on electromyography. Muscle biopsies showed myofiber degeneration/necrosis, regeneration, and fibers with cytoplasmic bodies and cytochrome c oxidase deficiency. There was minimal inflammation associated with strong sarcolemmal overexpression of class I major histocompatibility complex (MHC class I). Upon withdrawal of telbivudine, muscle weakness improved in all patients and eventually completely resolved in three. In our series, telbivudine-associated myopathy is characterized by necrotizing myopathy which improved on drug withdrawal. Although the occasional loss of cytochrome c oxidase is consistent with mitochondrial toxicity, the overexpression of MHC class I in all patients could suggest an underlying immune-mediated mechanism which may warrant further investigation.
  13. Optimization of an induction strategy for improving interferon-alpha2b production in the periplasm of Escherichia coli using response surface methodology
    Azaman SN, Ramakrishnan NR, Tan JS, Rahim RA, Abdullah MP, Ariff AB
    Biotechnol Appl Biochem, 2010 Aug;56(4):141-50.
    PMID: 20604747 DOI: 10.1042/BA20100104
    Induction strategies for the periplasmic production of recombinant human IFN-alpha2b (interferon-alpha2b) by recombinant Escherichia coli Rosetta-gami 2(DE3) were optimized in shake-flask cultures using response surface methodology based on the central composite design. The factors included in the present study were induction point, which related to the attenuance of the cell culture, IPTG (isopropyl beta-D-thiogalactoside) concentration and induction temperature. Second-order polynomial models were used to correlate the abovementioned factors to soluble periplasmic IFN-alpha2b formation and percentage of soluble IFN-alpha2b translocated to the periplasmic space of E. coli. The models were found to be significant and subsequently validated. The proposed induction strategies consisted of induction at an attenuance of 4 (measured as D600), IPTG concentration of 0.05 mM and temperature of 25 degrees C. The optimized induction strategy reduced inclusion-body formation as evidenced by electron microscopy and yielded 323.8 ng/ml of IFN-alpha2b in the periplasmic space with translocation of 74% of the total soluble product. In comparison with the non-optimized condition, soluble periplasmic production and the percentage of soluble IFN-alpha2b translocated to the periplasmic space obtained in optimized induction strategies were increased by approx. 20-fold and 1.4-fold respectively.
  14. Purification of β-mannanase derived from Bacillus subtilis ATCC 11774 using ionic liquid as adjuvant in aqueous two-phase system
    Aziz NFHA, Abbasiliasi S, Ng HS, Phapugrangkul P, Bakar MHA, Tam YJ, et al.
    J Chromatogr B Analyt Technol Biomed Life Sci, 2017 Jun 15;1055-1056:104-112.
    PMID: 28458127 DOI: 10.1016/j.jchromb.2017.04.029
    The partitioning of β-mannanase derived from Bacillus subtilis ATCC 11774 in aqueous two-phase system (ATPS) was studied. The ATPS containing different molecular weight of polyethylene glycol (PEG) and types of salt were employed in this study. The PEG/salt composition for the partitioning of β-mannanase was optimized using response surface methodology. The study demonstrated that ATPS consists of 25% (w/w) of PEG 6000 and 12.52% (w/w) of potassium citrate is the optimum composition for the purification of β-mannanase with a purification fold (PF) of 2.28 and partition coefficient (K) of 1.14. The study on influences of pH and crude loading showed that ATPS with pH 8.0 and 1.5% (w/w) of crude loading gave highest PF of 3.1. To enhance the partitioning of β-mannanase, four ionic liquids namely 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4), 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF4), 1-butyl-3-methylimidazolium bromide ([Bmim]Br), 1-ethyl-3-methylimidazolium bromide ([Emim]Br) was added into the system as an adjuvant. The highest recovery yield (89.65%) was obtained with addition of 3% (w/w) of [Bmim]BF4. The SDS-PAGE analysis revealed that the β-mannanase was successfully recovered in the top phase of ATPS with the molecular size of 36.7kDa. Therefore, ATPS demonstrated a simple and efficient approach for recovery and purification of β-mannanase from fermentation broth in one single-step strategy.
  15. Fulltext Optimization of cultivation conditions for monoclonal IgM antibody production by M1A2 hybridoma using artificial neural network
    Bashokouh F, Abbasiliasi S, Tan JS
    Cytotechnology, 2019 Jul 16;71(4):849-860.
    PMID: 31312930 DOI: 10.1007/s10616-019-00330-5
    Monoclonal antibody (McAb) has been established as one of the most successful therapeutic strategies for the treatment of cancer. M1A2 (McAb) as a new monoclonal antibody was designed to recognize heat shock protein (HSP60), but its optimum production condition has not been studied. In this study, the cell culture conditions for both Roswell Park Memorial Institute Medium (RPMI 1640) and Dulbecco's Modified Eagle Medium (DMEM) were optimized using artificial neural network (ANN) analysis to obtain maximum production of IgM McAb by hybridoma M1A2 cells. By using a central composite design, an experimental matrix with cultivation parameters of incubation time, temperature and fetal bovine serum (FBS) concentration on IgM McAb production was designed. The results was analysed by ANN network with different learning algorithms. From the analysis, batch back propagation (BBP) trained ANN composed of eight hidden nodes using a hyperbolic tangent sigmoid transfer function was capable to provide the highest McAb production for both RPMI and DMEM media. Under optimum conditions of 12.5% of FBS, at 33 °C after 3(1/2) days of incubation, maximum McAb production (1132.69 μg/ml) in DMEM was achieved. With PRMI 1640 medium, maximum McAb production (1105.12 μg/ml) was achieved at optimum conditions of 11% of FBS, at 33 °C after 4 days of incubation. The results of this study will provide information for optimum culture conditions of M1A2 McAb production in both DMEM and RPMI 1640 media and also give some clues for the other hybridoma excreting antibodies in the development of in vitro cell culture.
  16. Fulltext Evaluation of the effect of soluble polysaccharides of palm kernel cake as a potential prebiotic on the growth of probiotics
    Bello B, Mustafa S, Tan JS, Ibrahim TAT, Tam YJ, Ariff AB, et al.
    3 Biotech, 2018 Aug;8(8):346.
    PMID: 30073131 DOI: 10.1007/s13205-018-1362-4
    This paper deliberates the extraction, characterization and examination of potential application of soluble polysaccharides of palm kernel cake (PKC) as a prebiotic. The PKC was defatted and crude polysaccharide was obtained through water, citric acid or NaOH extraction. The physiochemical properties of the extracted polysaccharides viz. total carbohydrates, protein content, solubility rate, monosaccharides composition, structural information and thermal properties were also determined. The extracted soluble polysaccharides were further subjected to a digestibility test using artificial human gastric juice. Finally, their prebiotic potential on two probiotics, namely Lactobacillus plantarum ATCC 8014 and Lb. rhamnosus ATCC 53103 were evaluated in vitro. It was observed that PKC contained ash (5.2%), moisture (7.4%), carbohydrates (65.8%), protein (16.5%) and fat (5.1%). There were significant differences (P  95%). Protein content in SCPW, SCPCA and SCPN are 0.72, 0.40 and 0.58, respectively, and the peaks which indicated the presence of protein were observed at approximately 1640 cm-1 (amide I). FTIR spectroscopy revealed that the polysaccharides extracts were linked to β and α-glycosidic bonds and thermal analysis using differential scanning calorimeter (DSC) showed the main degradation temperature of SP is about 121 to 125 °C. The SP were found to be highly resistance (> 96%) to hydrolysis when subjected to artificial human gastric juice. The prebiotics potentials of the polysaccharides on probiotics in vitro demonstrated an increase in proliferation of Lb. plantarum ATCC 8014 and Lb. rhamnosus ATCC 53103 with decrease in the pH of the medium and producing organic acids.All the above findings strongly indicated that polysaccharides extracted from PKC, an industrial waste, have a potential to be exploited as novel prebiotics.
  17. Fulltext Enhancement of Biomass and Calcium Carbonate Biomineralization of Chlorellavulgaris through Plackett-Burman Screening and Box-Behnken Optimization Approach
    Chin ZW, Arumugam K, Ashari SE, Faizal Wong FW, Tan JS, Ariff AB, et al.
    Molecules, 2020 Jul 28;25(15).
    PMID: 32731437 DOI: 10.3390/molecules25153416
    The biosynthesis of calcium carbonate (CaCO3) minerals through a metabolic process known as microbially induced calcium carbonate precipitation (MICP) between diverse microorganisms, and organic/inorganic compounds within their immediate microenvironment, gives rise to a cementitious biomaterial that may emerge as a promissory alternative to conventional cement. Among photosynthetic microalgae, Chlorella vulgaris has been identified as one of the species capable of undergoing such activity in nature. In this study, response surface technique was employed to ascertain the optimum condition for the enhancement of biomass and CaCO3 precipitation of C. vulgaris when cultured in Blue-Green (BG)-11 aquaculture medium. Preliminary screening via Plackett-Burman Design showed that sodium nitrate (NaNO3), sodium acetate, and urea have a significant effect on both target responses (p < 0.05). Further refinement was conducted using Box-Behnken Design based on these three factors. The highest production of 1.517 g/L C. vulgaris biomass and 1.143 g/L of CaCO3 precipitates was achieved with a final recipe comprising of 8.74 mM of NaNO3, 61.40 mM of sodium acetate and 0.143 g/L of urea, respectively. Moreover, polymorphism analyses on the collected minerals through morphological examination via scanning electron microscopy and crystallographic elucidation by X-ray diffraction indicated to predominantly calcite crystalline structure.
  18. Enhancing food preservation with postbiotic metabolites γ-aminobutyric acid (GABA) and bacteriocin-like inhibitory substances (BLIS) produced by Lactobacillus brevis C23 co-cultures in plant-based medium
    Chuah WW, Tan JS, Hazwani Oslan SN, Bothi Raja P
    Prep Biochem Biotechnol, 2024 Apr;54(4):514-525.
    PMID: 37694843 DOI: 10.1080/10826068.2023.2252047
    Lactic acid bacteria (LAB) can produce γ-aminobutyric acid (GABA) with antioxidant properties and sedative effects when it binds to the GABA receptor in the human brain. LAB can also produce bacteriocin-like inhibitory substances (BLIS) with antimicrobial capabilities during carbohydrate fermentation. GABA and BLIS are natural compounds with potential health benefits and food preservation properties. Lactobacillus brevis C23 was co-cultured with three different LABs as inducers, which produced the highest GABA content and BLIS activity. They were cultured in various plant-based media to obtain an edible and better-tasting final product over commercially available media like MRS broth. A coconut-based medium with additives was optimized using response surface methodology (RSM) to increase GABA and BLIS production. The optimized medium for maximum GABA production (3.22 ± 0.01 mg/mL) and BLIS activity (84.40 ± 0.44%) was a 5.5% coconut medium containing 0.23% glucose, 1.44% Tween 20, 0.48% L-glutamic acid, and 0.02% pyridoxine. Due to the presence of GABA, the cell-free supernatant (CFS) as a postbiotic showed higher antioxidant activity than other food preservatives like nisin and potassium sorbate. Finally, microbiological tests on food samples showed that the postbiotic was more effective than other preservatives at combating the growth of LAB, molds and coliform bacteria, making it a possible food preservative.
  19. Optimization of conditions for the single step IMAC purification of miraculin from Synsepalum dulcificum
    He Z, Tan JS, Lai OM, Ariff AB
    Food Chem, 2015 Aug 15;181:19-24.
    PMID: 25794715 DOI: 10.1016/j.foodchem.2014.11.166
    In this study, the methods for extraction and purification of miraculin from Synsepalum dulcificum were investigated. For extraction, the effect of different extraction buffers (phosphate buffer saline, Tris-HCl and NaCl) on the extraction efficiency of total protein was evaluated. Immobilized metal ion affinity chromatography (IMAC) with nickel-NTA was used for the purification of the extracted protein, where the influence of binding buffer pH, crude extract pH and imidazole concentration in elution buffer upon the purification performance was explored. The total amount of protein extracted from miracle fruit was found to be 4 times higher using 0.5M NaCl as compared to Tris-HCl and phosphate buffer saline. On the other hand, the use of Tris-HCl as binding buffer gave higher purification performance than sodium phosphate and citrate-phosphate buffers in IMAC system. The optimum purification condition of miraculin using IMAC was achieved with crude extract at pH 7, Tris-HCl binding buffer at pH 7 and the use of 300 mM imidazole as elution buffer, which gave the overall yield of 80.3% and purity of 97.5%. IMAC with nickel-NTA was successfully used as a single step process for the purification of miraculin from crude extract of S. dulcificum.
  20. Pullulanase: role in starch hydrolysis and potential industrial applications
    Hii SL, Tan JS, Ling TC, Ariff AB
    Enzyme Res, 2012;2012:921362.
    PMID: 22991654
    The use of pullulanase (EC 3.2.1.41) has recently been the subject of increased applications in starch-based industries especially those aimed for glucose production. Pullulanase, an important debranching enzyme, has been widely utilised to hydrolyse the α-1,6 glucosidic linkages in starch, amylopectin, pullulan, and related oligosaccharides, which enables a complete and efficient conversion of the branched polysaccharides into small fermentable sugars during saccharification process. The industrial manufacturing of glucose involves two successive enzymatic steps: liquefaction, carried out after gelatinisation by the action of α-amylase; saccharification, which results in further transformation of maltodextrins into glucose. During saccharification process, pullulanase has been used to increase the final glucose concentration with reduced amount of glucoamylase. Therefore, the reversion reaction that involves resynthesis of saccharides from glucose molecules is prevented. To date, five groups of pullulanase enzymes have been reported, that is, (i) pullulanase type I, (ii) amylopullulanase, (iii) neopullulanase, (iv) isopullulanase, and (v) pullulan hydrolase type III. The current paper extensively reviews each category of pullulanase, properties of pullulanase, merits of applying pullulanase during starch bioprocessing, current genetic engineering works related to pullulanase genes, and possible industrial applications of pullulanase.
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