Displaying publications 21 - 40 of 71 in total

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  1. About Ganoderma boninense in oil palm plantations of Sumatra and peninsular Malaysia: Ancient population expansion, extensive gene flow and large scale dispersion ability
    Mercière M, Boulord R, Carasco-Lacombe C, Klopp C, Lee YP, Tan JS, et al.
    Fungal Biol, 2017 Jun-Jul;121(6-7):529-540.
    PMID: 28606348 DOI: 10.1016/j.funbio.2017.01.001
    Wood rot fungi form one of the main classes of phytopathogenic fungus. The group includes many species, but has remained poorly studied. Many species belonging to the Ganoderma genus are well known for causing decay in a wide range of tree species around the world. Ganoderma boninense, causal agent of oil palm basal stem rot, is responsible for considerable yield losses in Southeast Asian oil palm plantations. In a large-scale sampling operation, 357 sporophores were collected from oil palm plantations spread over peninsular Malaysia and Sumatra and genotyped using 11 SSR markers. The genotyping of these samples made it possible to investigate the population structure and demographic history of G. boninense across the oldest known area of interaction between oil palm and G. boninense. Results show that G. boninense possesses a high degree of genetic diversity and no detectable genetic structure at the scale of Sumatra and peninsular Malaysia. The fact that few duplicate genotypes were found in several studies including this one supports the hypothesis of spore dispersal in the spread of G. boninense. Meanwhile, spatial autocorrelation analysis shows that G. boninense is able to disperse across both short and long distances. These results bring new insight into mechanisms by which G. boninense spreads in oil palm plantations. Finally, the use of approximate Bayesian computation (ABC) modelling indicates that G. boninense has undergone a demographic expansion in the past, probably before the oil palm was introduced into Southeast Asia.
  2. Fulltext Microtiter miniature shaken bioreactor system as a scale-down model for process development of production of therapeutic alpha-interferon2b by recombinant Escherichia coli
    Tan JS, Abbasiliasi S, Kadkhodaei S, Tam YJ, Tang TK, Lee YY, et al.
    BMC Microbiol, 2018 01 04;18(1):3.
    PMID: 29439680 DOI: 10.1186/s12866-017-1145-9
    BACKGROUND: Demand for high-throughput bioprocessing has dramatically increased especially in the biopharmaceutical industry because the technologies are of vital importance to process optimization and media development. This can be efficiently boosted by using microtiter plate (MTP) cultivation setup embedded into an automated liquid-handling system. The objective of this study was to establish an automated microscale method for upstream and downstream bioprocessing of α-IFN2b production by recombinant Escherichia coli. The extraction performance of α-IFN2b by osmotic shock using two different systems, automated microscale platform and manual extraction in MTP was compared.

    RESULTS: The amount of α-IFN2b extracted using automated microscale platform (49.2 μg/L) was comparable to manual osmotic shock method (48.8 μg/L), but the standard deviation was 2 times lower as compared to manual osmotic shock method. Fermentation parameters in MTP involving inoculum size, agitation speed, working volume and induction profiling revealed that the fermentation conditions for the highest production of α-IFN2b (85.5 μg/L) was attained at inoculum size of 8%, working volume of 40% and agitation speed of 1000 rpm with induction at 4 h after the inoculation.

    CONCLUSION: Although the findings at MTP scale did not show perfect scalable results as compared to shake flask culture, but microscale technique development would serve as a convenient and low-cost solution in process optimization for recombinant protein.

  3. 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.
  4. Direct recovery of Bacillus subtilis xylanase from fermentation broth with an alcohol/salt aqueous biphasic system
    Ng HS, Chai CXY, Chow YH, Loh WLC, Yim HS, Tan JS, et al.
    J Biosci Bioeng, 2018 May;125(5):585-589.
    PMID: 29339003 DOI: 10.1016/j.jbiosc.2017.12.010
    Xylanase enzyme degrades linear polysaccharide β-1,4 xylan and the hemicellulose of the plant cell wall. There is a growing demand in finding a cost-effective alternative for industrial scale production of xylanase with high purity for pharmaceutical applications. In this study, an alcohol/salt aqueous biphasic system (ABS) was adopted to recover xylanase from the Bacillus subtilis fermentation broth. The effects of several ABS parameters such as types and concentrations of alcohols and salts (i.e., sulphate, phosphate, and citrate), amount of crude loading and pH of the system on the recovery of xylanase were investigated. Partition coefficient of xylanase (KE), selectivity (S) and yield (YT) of xylanase in top phase of the ABS were measured. Highest KE (6.58 ± 0.05) and selectivity (4.84 ± 0.33) were recorded in an ABS of pH 8 composed of 26% (w/w) 1-propanol, 18% (w/w) ammonium sulphate. High YT of 71.88% ± 0.15 and a purification fold (PFT) of 5.74 ± 0.33 were recorded with this optimum recovery of xylanase using alcohol/salt ABS. The purity of xylanase recovered was then qualitatively verified with sodium dodecyl sulphate (SDS) gel electrophoresis. The SDS profile revealed the purified xylanase was successfully obtained in the top phase of the one-step 1-propanol/sulphate ABS with a distinct single band.
  5. Extractive purification of recombinant thermostable lipase from fermentation broth of Escherichia coli using an aqueous polyethylene glycol impregnated resin system
    Tan JS, Abbasiliasi S, Ariff AB, Ng HS, Bakar MHA, Chow YH
    3 Biotech, 2018 Jun;8(6):288.
    PMID: 29938157 DOI: 10.1007/s13205-018-1295-y
    This study aimed at recovery of thermostable lipase from Escherichia coli BL21 using porous glass beads grafted with polyethylene glycol (PEG) in aqueous impregnated resins system (AIRS). The influencing parameters such as concentration and pH of extraction solution, concentration of NaCl, size of the beads, and pH of the desorption solution on the partition behaviour of lipase were evaluated. Smaller adsorbent (4 mm) had a 65.5% of recovery yield with approximately two-fold higher purification factor compared to that obtained with the larger adsorbent. Recombinant lipase was purified successfully using AIRS with a purification factor of 7.6 and yield of 78.4% under optimum conditions of 18% (w/w) PEG 4000, 10% (w/w) of potassium citrate at pH 9 with 3% (w/w) of NaCl. Optimum desorption was obtained with 4.0 mm of porous glass beads at pH 9.
  6. 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.
  7. Fulltext Stability of Bacteriocin-Like Inhibitory Substance (BLIS) Produced by Pediococcus acidilactici kp10 at Different Extreme Conditions
    Md Sidek NL, Halim M, Tan JS, Abbasiliasi S, Mustafa S, Ariff AB
    Biomed Res Int, 2018;2018:5973484.
    PMID: 30363649 DOI: 10.1155/2018/5973484
    Nowadays, bacteriocin industry has substantially grown replacing the role of chemical preservatives in enhancing shelf-life and safety of food. The progress in bacteriocin study has been supported by the emerging of consumer demand on the applications of natural food preservatives. Since food is a complex ecosystem, the characteristics of bacteriocin determine the effectiveness of their incorporation into the food products. Among four commercial media (M17 broth, MRS broth, tryptic soy broth, and nutrient broth) tested, the highest growth of Pediococcus acidilactici kp10 and bacteriocin-like-inhibitory substance (BLIS) production were obtained in the cultivation with M17. BLIS production was found to be a growth associated process where the production was increased concomitantly with the growth of producing strain, P. acidilactici kp10. The antimicrobial property of BLIS against three indicator microorganisms (Listeria monocytogenes, Escherichia coli, and Staphylococcus aureus) remained stable upon heating at 100°C but not detectable at 121°C. The BLIS activity was also observed to be stable and active at a wide pH range (pH 2 to pH 7). The BLIS activity remained constant at -20°C and -80°C for 1 month of storage. However, the activity dropped after 3 and 6 months of storage at 4°C, -20°C, and -80°C with more than 80% reduction. The ability of bacteriocin from P. acidilactici kp10 to inhibit food-borne pathogens while remaining stable and active at extreme pH and temperature is of potential interest for future applications in food preservatives.
  8. The protective mechanisms of polydatin in cerebral ischemia
    Tang KS, Tan JS
    Eur J Pharmacol, 2019 Jan 05;842:133-138.
    PMID: 30385347 DOI: 10.1016/j.ejphar.2018.10.039
    The prevalence of stroke is high in both developing and developed nations. It causes a heavy social and financial burden to the sufferers and their caregivers. Thrombolytic therapy is the only pharmacological treatment available for stroke. However, thrombolytic agents do not provide substantial improvement on long term motor and cognitive disabilities. Thus, there is a need to explore for new compounds that can halt or reverse the deterioration of neurons in the stroke patients' brain. Polydatin, a precursor of resveratrol, is a natural stilbene commonly found in food. This review article describes how different parameters were altered with ischemic injury and polydatin treatment, why it is important and how it could be beneficial or useful in future studies. Our review of polydatin provides convincing evidence regarding the potential of polydatin to be developed into preventive or therapeutic products for ischemic stroke. Nevertheless, additional studies are necessary in order to properly elucidate the biological mechanisms of polydatin, especially its molecular mechanisms of protection and target proteins, in cerebral ischemia.
  9. Influence of amino acids and vitamins on the growth of gdhA derivative Pasteurella multocida B:2 for use as an animal vaccine
    Oslan SNH, Tan JS, Saad MZ, Halim M, Mohamed MS, Ariff AB
    Bioprocess Biosyst Eng, 2019 Mar;42(3):355-365.
    PMID: 30483888 DOI: 10.1007/s00449-018-2040-y
    Pasteurella multocida serotype B:2 is the causative agent of haemorrhagic septicaemia, a fatal disease in cattle and buffaloes. For use as a vaccine in the treatment of HS disease, an efficient cultivation of attenuated gdhA derivative P. multocida B:2 (mutant) for mass production of viable cells is required. In this study, the role of amino acids and vitamins on the growth of this particular bacterium was investigated. Initially, three basal media (Brain-heart infusion, Terrific broth, and defined medium YDB) were assessed in terms of growth performance of P. multocida B:2. YDB medium was selected and redesigned to take into account the effects of amino acids (glutamic acid, cysteine, glycine, methionine, lysine, tyrosine, and histidine) and vitamins (vitamin B1, nicotinic acid, riboflavin, pyridoxine, pantothenic acid, and biotin). High viable cell number was largely affected by the availability of micronutrient components and macronutrients. Histidine was essential for the growth whereby a traceable amount (20 mM) was found to greatly enhance the growth of gdhA derivative P. multocida B:2 mutant (6.6 × 109 cfu/mL) by about 19 times as compared to control culture (3.5 × 108 cfu/mL). In addition, amongst the vitamins added, riboflavin exhibited the highest impact on the viability of gdhA derivative P. multocida B:2 mutant (5.3 × 109 cfu/mL). Though the combined histidine and riboflavin in the culture eventually did not promote the stacking impact on cell growth and cell viability, nonetheless, they were still essential and important in either growth medium or production medium.
  10. Mucoadhesive chitosan-coated nanostructured lipid carriers for oral delivery of amphotericin B
    Ling Tan JS, Roberts CJ, Billa N
    Pharm Dev Technol, 2019 Apr;24(4):504-512.
    PMID: 30132723 DOI: 10.1080/10837450.2018.1515225
    This study describes the properties of an amphotericin B-containing mucoadhesive nanostructured lipid carrier (NLC), with the intent to maximize uptake within the gastrointestinal tract. We have reported previously that lipid nanoparticles can significantly improve the oral bioavailability of amphotericin B (AmpB). On the other hand, the aggregation state of AmpB within the NLC has been ascribed to some of the side effects resulting from IV administration. In the undissolved state, AmpB (UAmpB) exhibited the safer monomeric conformation in contrast to AmpB in the dissolved state (DAmpB), which was aggregated. Chitosan-coated NLC (ChiAmpB NLC) presented a slightly slower AmpB release profile as compared to the uncoated formulation, achieving 26.1% release in 5 hours. Furthermore, the ChiAmpB NLC formulation appeared to prevent the expulsion of AmpB upon exposure to simulated gastrointestinal pH media, whereby up to 63.9% of AmpB was retained in the NLC compared to 56.1% in the uncoated formulation. The ChiAmpB NLC demonstrated mucoadhesive properties in pH 5.8 and 6.8. Thus, the ChiAmpB NLC formulation is well-primed for pharmacokinetic studies to investigate whether delayed gastrointestinal transit may be exploited to improve the systemic bioavailability of AmpB, whilst simultaneously addressing the side-effect concerns of AmpB.
  11. 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.
  12. Comprehensive studies on optimization of cellulase and xylanase production by a local indigenous fungus strain via solid state fermentation using oil palm frond as substrate
    Tai WY, Tan JS, Lim V, Lee CK
    Biotechnol Prog, 2019 05;35(3):e2781.
    PMID: 30701709 DOI: 10.1002/btpr.2781
    The high cost of cellulases remains the most significant barrier to the economical production of bio-ethanol from lignocellulosic biomass. The goal of this study was to optimize cellulases and xylanase production by a local indigenous fungus strain (Aspergillus niger DWA8) using agricultural waste (oil palm frond [OPF]) as substrate. The enzyme production profile before optimization indicated that the highest carboxymethyl cellulose (CMCase), filter paper (FPase), and xylanase activities of 1.06 U/g, 2.55 U/g, and 2.93 U/g were obtained on day 5, day 4, and day 5 of fermentation, respectively. Response surface methodology was used to study the effects of several key process parameters in order to optimize cellulase production. Of the five physical and two chemical factors tested, only moisture content of 75% (w/w) and substrate amount of 2.5 g had statistically significant effect on enzymes production. Under optimized conditions of 2.5 g of substrate, 75% (w/w) moisture content, initial medium of pH 4.5, 1 × 106 spores/mL of inoculum, and incubation at ambient temperature (±30°C) without additional carbon and nitrogen, the highest CMCase, FPase, and xylanase activities obtained were 2.38 U/g, 2.47 U/g, and 5.23 U/g, respectively. Thus, the optimization process increased CMCase and xylanase production by 124.5 and 78.5%, respectively. Moreover, A. niger DWA8 produced reasonably good cellulase and xylanase titers using OPF as the substrate when compared with previous researcher finding. The enzymes produced by this process could be further use to hydrolyze biomass to generate reducing sugars, which are the feedstock for bioethanol production.
  13. 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.
  14. Transcriptomic data of mature oil palm basal trunk tissue infected with Ganoderma boninense
    Othman NQ, Sulaiman S, Lee YP, Tan JS
    Data Brief, 2019 Aug;25:104288.
    PMID: 31453289 DOI: 10.1016/j.dib.2019.104288
    To date, Ganoderma boninense is known to be the causal agent of basal stem rot (BSR) disease in oil palm (Elaeis guineensis). This disease causes rotting in the roots, basal and upper stem of oil palm. Infection causes progressive destruction of the basal tissues at the oil palm trunk and internal dry rotting, particularly at the intersection between the bole and trunk. Molecular responses of oil palm during infection are not well study although this information is crucial to strategize effective measures to control or eliminate BSR. Here we report three sets of transcriptome data from samples of near-rot section of basal stem tissue of oil palm tree infected with G. boninense (IPIT), healthy section of basal stem tissue of the same G. boninense infected palm (IPHT) and the healthy section of basal stem tissue of the healthy palm (HPHT). The raw reads were deposited into NCBI database and can be accessed via BioProject accession number PRJNA530030.
  15. Partition efficiency of cytochrome c with alcohol/salt aqueous biphasic flotation system
    Ng HS, Ng TC, Kee PE, Tan JS, Yim HS, Lan JC
    J Biosci Bioeng, 2020 Feb;129(2):237-241.
    PMID: 31629635 DOI: 10.1016/j.jbiosc.2019.08.013
    Aqueous biphasic flotation (ABF) integrates aqueous biphasic system (ABS) and solvent sublation for recovery of target biomolecules. The feasibility of the alcohol/salt ABF for exclusive partition of cytochrome c to one specific phase of the system was investigated. Aliphatic alcohols of different carbon chain length (ethanol, 1-propanol and 2-propanol) and salts (sulfate, phosphate and citrate) were used for the phase formation. The effects of phase composition, concentration of sample loading, pH, flotation time and flow rate of the system on the partition efficiency of cytochrome c were determined. Cytochrome c was exclusively partitioned to the alcohol-rich top phase of the ABF of 18% (w/w) ethanol and 26% (w/w) ammonium sulfate with pH 6 and 20% (w/w) of sample loading. Highest partition coefficient (K) of 6.85 ± 0.21 and yield (YT) of 99.40% ± 0.02 were obtained with optimum flotation rate of 10 mL/min and flow rate of 10 min.
  16. Isolation and characterization of Enterococcus faecium DSM 20477 with ability to secrete antimicrobial substance for the inhibition of oral pathogen Streptococcus mutans UKMCC 1019
    Ng ZJ, Zarin MA, Lee CK, Phapugrangkul P, Tan JS
    Arch Oral Biol, 2020 Feb;110:104617.
    PMID: 31794906 DOI: 10.1016/j.archoralbio.2019.104617
    Streptococcus mutans and Candida albicans are the main oral pathogens which contribute to dental caries that affects all ages of human being.

    OBJECTIVES: This study focuses on the potential of crude cell free supernatant (CCFS) from lactic acid bacteria (LAB) to inhibit of the growth of S. mutans UKMCC 1019.

    DESIGN: A total of 61 CCFS from LAB strains were screened for their inhibitory ability against S. mutans UKMCC 1019 by broth microdilution method. The selected LAB with highest antimicrobial activity was identified and its CCFS was characterized for pH stability, temperature tolerance, enzyme sensitivity, metabolism of carbohydrates, enzymatic activities and antimicrobial activity against S. mutans UKMCC 1019 and C. albicans UKMCC 3001 by well diffusion assay. The effect of CCFS on cell structure of S. mutans UKMCC 1019 was observed under transmission electron microscopy (TEM).

    RESULTS: The CCFS from isolate CC2 from Kimchi showed the highest inhibition against S. mutans UKMCC 1019, which was 76.46 % or 4406.08 mm2/mL and it was identified to be most closely related to Enterococcus faecium DSM 20477 based on 16 s rRNA sequencing. The CCFS of E. faecium DSM 20477 had high tolerance to acidic and alkaline environment as well as high temperature. It also shows high antifungal activities against C. albicans UKMCC 3001 with 2362.56 mm2/mL. Under TEM, the cell walls and the cytoplasm membrane of S. mutans UKMCC 1019 were disrupted by the antimicrobial substance, causing cell lysis.

    CONCLUSIONS: Hence, the CCFS from E. faecium DSM 20477 is a potential bacteriocin in future for the treatment of dental caries.

  17. Fulltext Draft genome assembly dataset of the Basidiomycete pathogenic fungus, Ganoderma boninense
    Sulaiman S, Othman NQ, Tan JS, Lee YP
    Data Brief, 2020 Apr;29:105167.
    PMID: 32025548 DOI: 10.1016/j.dib.2020.105167
    Ganoderma boninense is a soil-borne Basidiomycete pathogenic fungus that eminent as the key causal of devastating disease in oil palm, named basal stem rot. Being a threat to sustainable palm oil production, it is essential to comprehend the fundamental view of this fungus. However, there is gap of information due to its limited number of genome sequence that is available for this pathogenic fungus. This implies the hitches in performing biological research to unravel the mechanism underlying the pathogen attack in oil palm. Therefore, here we report a dataset of draft genome of G. boninense that was sequenced using Illumina Hiseq 2000. The raw reads were deposited into NCBI database (SRX7136614 and SRX7136615) and can be accessed via Bioproject accession number PRJNA503786.
  18. Efficiency of Ionic Liquids-Based Aqueous Two-phase Electrophoresis for Partition of Cytochrome c
    Kee PE, Lan JC, Yim HS, Tan JS, Chow YH, Ng HS
    Appl Biochem Biotechnol, 2020 May;191(1):376-386.
    PMID: 31907777 DOI: 10.1007/s12010-019-03202-y
    Cytochrome c is a small water-soluble protein that is abundantly found in the mitochondrial intermembrane space of microorganism, plants and mammalians. Ionic liquids (ILs)-based aqueous two-phase electrophoresis system (ATPES) was introduced in this study to investigate the partition efficiency of cytochrome c to facilitate subsequent development of two-phase electrophoresis for the separation of cytochrome c from microbial fermentation. The 1-Hexyl-3-methylimidazolium bromide, (C6mim)Br and potassium citrate salt were selected as the phase-forming components. Effects of phase composition; position of electrodes; pH and addition of neutral salt on the partition efficiency of cytochrome c in the ATPES were evaluated. Highest partition coefficient (K = 179.12 ± 0.82) and yield of cytochrome c in top phase (YT = 99.63% ± 0.00) were recorded with IL/salt ATPES composed of 30% (w/w) (C6mim)Br and 20% (w/w) potassium citrate salt of pH 7 and 3.0% (w/w) NaCl addition with anode at the bottom phase and cathode at the top phase. The SDS-PAGE profile revealed that cytochrome c with a molecular weight of 12 kDa was preferably partitioned to the IL-rich top phase. Present findings suggested that the single-step ATPES is a potential separation approach for the recovery of cytochrome c from microbial fermentation. Graphical Abstract.
  19. Fulltext Incidental hepatic tuberculosis during planned resection of locally advanced ampullary carcinoma: a case report
    Hoe VC, Khairuddin A, Tan JS, Sharif MS, Azizan N, Hayati F
    BMC Surg, 2020 Jun 30;20(1):145.
    PMID: 32605613 DOI: 10.1186/s12893-020-00806-8
    BACKGROUND: Tuberculosis (TB) is classified according to the site of disease as pulmonary or extrapulmonary. Extrapulmonary TB is less common than its counterpart in which it can be found anywhere in the body including the liver. Similar to ampullary carcinoma, TB liver can manifest with jaundice and deranged liver function tests, particularly in the obstructed biliary systems.

    CASE PRESENTATION: A 43-year-old gentleman with locally advanced ampullary carcinoma was noticed to have multiple suspicious liver nodules intraoperatively during curative ampulla resection. The surgery was then abandoned after a biopsy. The histology was consistent with chronic granulomatous inflammation. He was then subjected to a Whipple pancreaticoduodenectomy procedure after initiation of anti-tubercular treatment. He recovered well with no evidence of tumour recurrence and worsening TB.

    CONCLUSIONS: A high index of suspicion and quick decision making can help to diagnose a possible extrapulmonary TB masquerading as a malignant disease in a patient with curative intention of ampullary carcinoma.

  20. 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.
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