MyMedR

Displaying publications 41 - 47 of 47 in total

Abstract:

Sort:

Extractive bioconversion of cyclodextrins by Bacillus cereus cyclodextrin glycosyltransferase in aqueous two-phase system

Ng HS, Ooi CW, Mokhtar MN, Show PL, Ariff A, Tan JS, et al.

Bioresour Technol, 2013 Aug;142:723-6.
PMID: 23806510 DOI: 10.1016/j.biortech.2013.05.087

An extractive bioconversion with Bacillus cereus cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) in aqueous two-phase system (ATPS) was investigated for the synthesis and recovery of cyclodextrins (CDs). Optimum condition for the extractive bioconversion of CDs was achieved in ATPS consisted of 7.7% (w/w) polyethylene glycol (PEG) 20,000 and 10.3% (w/w) dextran T500 with volume ratio (VR) of 4.0. Enzymatic conversion of starch occurred mainly in dextran-rich bottom phase whereas the product, CDs was transferred to top phase and a higher partition coefficient of CDs was achieved. Repetitive batch of CDs synthesis was employed by replenishment of the top phase components and addition of starch every 8h. An average total CDs concentration of 13.7 mg/mL, (4.77 mg/mLα-CD, 5.02 mg/mLβ-CD and 3.91 mg/mLγ-CD) was recovered in the top phase of PEG 20,000/dextran T500 ATPS. This study showed the effectiveness of ATPS application in extractive bioconversion of CDs synthesis with B. cereus CGTase.
Fulltext Production and Status of Bacterial Cellulose in Biomedical Engineering

Moniri M, Boroumand Moghaddam A, Azizi S, Abdul Rahim R, Bin Ariff A, Zuhainis Saad W, et al.

Nanomaterials (Basel), 2017 Sep 04;7(9).
PMID: 32962322 DOI: 10.3390/nano7090257

Bacterial cellulose (BC) is a highly pure and crystalline material generated by aerobic bacteria, which has received significant interest due to its unique physiochemical characteristics in comparison with plant cellulose. BC, alone or in combination with different components (e.g., biopolymers and nanoparticles), can be used for a wide range of applications, such as medical products, electrical instruments, and food ingredients. In recent years, biomedical devices have gained important attention due to the increase in medical engineering products for wound care, regeneration of organs, diagnosis of diseases, and drug transportation. Bacterial cellulose has potential applications across several medical sectors and permits the development of innovative materials. This paper reviews the progress of related research, including overall information about bacterial cellulose, production by microorganisms, mechanisms as well as BC cultivation and its nanocomposites. The latest use of BC in the biomedical field is thoroughly discussed with its applications in both a pure and composite form. This paper concludes the further investigations of BC in the future that are required to make it marketable in vital biomaterials.
Defatted coconut residue crude polysaccharides as potential prebiotics: study of their effects on proliferation and acidifying activity of probiotics in vitro

Mohd Nor N'N, Abbasiliasi S, Marikkar MN, Ariff A, Amid M, Lamasudin DU, et al.

J Food Sci Technol, 2017 Jan;54(1):164-173.
PMID: 28242914 DOI: 10.1007/s13197-016-2448-9

This paper reports on the extraction, partial characterization and the potential application of crude polysaccharides from defatted coconut residue as a prebiotic. The coconut residue was defatted and extracted to obtain the crude polysaccharides and its physicochemical properties were determined. The crude polysaccharides were assessed for monosaccharide composition, total carbohydrate content, reducing sugar concentration and protein content determination. The functional group and structural elucidation of crude polysaccharides was also done using Fourier transform infrared spectra analysis. The product was then subjected to artificial human gastric juice treatment to determine digestibility. Finally, an in vitro proliferation and acid production by two probiotic bacteria namely Lactobacillus casei Shirota and Lactobacillus bulgaricus were included in this study. It was found that the defatted coconut residue contained ash (0.54%), moisture (55.42%), protein (1.69%), crude fat (17.26%) and carbohydrate (25.73%). The percentage of crude polysaccharides extracted was 0.73 ± 0.04. The two fractions of monosaccharides obtained were glucose and fructose. Total carbohydrate content of DCR was 13.35% (w/v). The quantitative value of the reducing sugars obtained was 20.71%. Protein content in the crude polysaccharides was 0.009% and the peaks which indicated the presence of protein were observed at around 1640 cm(-1) (amide I) and 1530 cm(-1) (amide II). DCR crude polysaccharides were highly resistant (88%) to hydrolysis when subjected to artificial human gastric juice. The product was found to markedly stimulate two tested probiotics to proliferate and produce organic acids. All the above findings are supportive of the fact that polysaccharides extracted from DCR, an industrial waste, have a vast potential to be exploited as novel prebiotics.
Fulltext Extractive Bioconversion of Gamma-Cyclodextrin and Recycling of Cyclodextrin Glycosyltransferase in Liquid Biphasic System Using Thermo-Separating Polymer

Lin YK, Show PL, Yap YJ, Ariff A, Annuar MSBM, Lai OM, et al.

Front Chem, 2018;6:448.
PMID: 30345267 DOI: 10.3389/fchem.2018.00448

An extractive bioconversion conducted on soluble starch with cyclodextrin glycosyltransferase (CGTase) enzyme in ethylene oxide-propylene oxide (EOPO)/potassium phosphates liquid biphasic system (LBS) to extract gamma-cyclodextrin (γ-CD) was examined. A range of EOPO (with potassium phosphates) molecular weights was screen to investigate the effect of the latter on the partioning efficency of CGTase and γ-CD. The results show that the optimal top phase γ-CD yield (74.4%) was reached in 35.0% (w/w) EOPO 970 and 10.0% (w/w) potassium phosphate with 2.0% (w/w) sodium chloride. A theoretical explanation for the effect of NaCl on γ-CD was also presented. After a 2 h bioconversion process, a total of 0.87 mg/mL concentration of γ-CD was produced in the EOPO/ phosphates LBS top phase. After the extraction of top phase from LBS, four continuous repetitive batches were successfully conducted with relative CGTase activity of 1.00, 0.86, 0.45, and 0.40 respectively.
Fulltext Ficus deltoidea suppresses endothelial activation, inflammation, monocytes adhesion and oxidative stress via NF-κB and eNOS pathways in stimulated human coronary artery endothelial cells

Mohd Ariff A, Abu Bakar NA, Abd Muid S, Omar E, Ismail NH, Ali AM, et al.

BMC Complement Med Ther, 2020 Feb 17;20(1):56.
PMID: 32066426 DOI: 10.1186/s12906-020-2844-6

BACKGROUND: Ficus deltoidea (FD) has been shown to have antidiabetic, anti-inflammatory, antinociceptive and antioxidant properties. However, its effects on key events in the pathogenesis of atherosclerosis are unknown.
AIM: To investigate the endothelial activation, inflammation, monocyte-endothelial cell binding and oxidative stress effects of four FD varieties.
METHODS: Human coronary artery endothelial cells (HCAEC) were incubated with different concentrations of aqueous ethanolic extracts of FD var. trengganuensis (FDT), var. kunstleri (FDK), var. deltoidea (FDD) and var. intermedia (FDI), together with LPS. Protein and gene expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), endothelial-leukocyte adhesion molecule-1 (E-selectin), interleukin-6 (IL-6), Nuclear factor-κB (NF-κB) p50 and p65 and endothelial nitric oxide synthase (eNOS) were measured using ELISA and QuantiGene plex, respectively. Adhesion of monocyte to HCAEC and formation of reactive oxygen species (ROS) were detected by Rose Bengal staining and 2'-7'-dichlorofluorescein diacetate (DCFH-DA) assay.
RESULTS: FDK exhibited the highest inhibition of biomarkers in relation to endothelial activation and inflammation, second in reducing monocyte binding (17.3%) compared to other varieties. FDK (25.6%) was also the most potent at decreasing ROS production.
CONCLUSION: FD has anti-atherogenic effects, possibly mediated by NF-κB and eNOS pathways; with FDK being the most potent variety. It is potentially beneficial in mitigating atherogenesis.
Interfacial partitioning behaviour of bovine serum albumin in polymer-salt aqueous two-phase system

Chow YH, Yap YJ, Anuar MS, Tejo BA, Ariff A, Show PL, et al.

J Chromatogr B Analyt Technol Biomed Life Sci, 2013 Sep 1;934:71-8.
PMID: 23911538 DOI: 10.1016/j.jchromb.2013.06.034

A relationship is proposed for the interfacial partitioning of protein in poly(ethylene glycol) (PEG)-phosphate aqueous two-phase system (ATPS). The relationship relates the natural logarithm of interfacial partition coefficient, ln G to the PEG concentration difference between the top and bottom phases, Δ[PEG], with the equation ln G=AΔ[PEG]+B. Results showed that this relationship provides good fits to the partition of bovine serum albumin (BSA) in ATPS which is comprised of phosphate and PEG of four different molecular weight 1450g/mol, 2000g/mol, 3350g/mol and 4000g/mol, with the tie-line length (TLL) in the range of 44-60% (w/w) at pH 7.0. The decrease of A values with the increase of PEG molecular weight indicates that the correlation between ln G and Δ[PEG] decreases with the increase in PEG molecular weight and the presence of protein-polymer hydrophobic interaction. When temperature was increased, a non-linear relationship of ln G inversely proportional to temperature was observed. The amount of proteins adsorbed at the interface increased proportionally with the amount of BSA loaded whereas the partition coefficient, K remained relatively constant. The relationship proposed could be applied to elucidate interfacial partitioning behaviour of other biomolecules in polymer-salt ATPS.
Fulltext The Discovery of New Antilisterial Proteins From Paenibacillus polymyxa Kp10 via Genome Mining and Mass Spectrometry

Mokhtar NFK, Hashim AM, Hanish I, Zulkarnain A, Raja Nhari RMH, Abdul Sani AA, et al.

Front Microbiol, 2020;11:960.
PMID: 32714281 DOI: 10.3389/fmicb.2020.00960

The inhibitory properties of novel antimicrobial proteins against food-borne pathogens such as Listeria monocytogenes offer extensive benefits to the food and medical industries. In this study, we have identified antimicrobial proteins from a milk curd-derived bacterial isolate that exhibits antilisterial activity using genome mining and mass spectrometry analysis. The analysis of the draft genome sequence identified the isolate as Paenibacillus polymyxa Kp10, and predicted the presence of antimicrobial paenibacillin, paenilan, paeninodin, sactipeptides, thiazole-oxazole modified microcin, and histone-like DNA binding protein HU encoded in its genome. Interestingly, nanoLC-MS/MS analysis identified two histone-like DNA binding proteins HU as predicted in silico earlier, exhibiting antilisterial activity. Additionally, translation initiation factor IF-1 and 50S ribosomal protein L29 were also discovered by the mass spectrometry in the active fractions. The antilisterial activity of the four proteins was verified through heterologous protein expression and antimicrobial activity assay in vitro. This study has identified structural regulatory proteins from Paenibacillus possessing antilisterial activity with potential future application in the food and medical industries.