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Fulltext Optical tomography: real time image reconstruction for various flow regimes in gravity flow conveyor

Abdul Rahim, R., Pang, J.F., Chan, K.S., Leong, L.C., Fazalul Rahiman, M.H.

ASM Science Journal, 2007;1(1):27-36.
MyJurnal

In this study, real-time imaging was monitored for flowing solid particles when various baffles were created to block certain areas of the pipe. The generated flow regimes were full-flow, three-quarter-flow, half-flow and quarter-flow. A vertical pneumatic conveyor was designed to hold a 85 mm inner diameter pipeline. The four projection optical tomography systems used, applied the parallel beam projection approach and use infrared light sources so that the sensor was free of noise from the surrounding visible light source. The two orthogonal and two rectilinear projections were axial, but ideally they should have been in the same layer. The sensor readings could be related to the varying light intensity effects of the dropping particles and were used to provide cross-sectional distribution information for the conveyor. By using computer programming, the information was reconstructed to produce coloured images and concentration was obtained by reference to a colour code. The results obtained from this study showed how imaged flow followed the artificial flow regime. This study could benefit industrial production lines in maintaining the desired flow rates.
Fulltext Small scale imaging using ultrasonic tomography

Zakaria, Z., Fazalul Rahiman, M.H., Abdul Rahim, R., Megat Ali, M.S.A., Baharuddin, M.Y., Jahidin, A.H.

Journal of Nuclear and Related Technologies, 2009;2009(1):266-281.
MyJurnal

Ultrasound technology progressed through the 1960’s from simple A-mode and B-mode scans to today’s M-mode and Doppler two dimensional (2-D) and even three dimensional (3-D) systems. Modern ultrasound imaging has its roots in sonar technology after it was first described by Lord John Rayleigh over 100 years ago on the interaction of acoustic waves with media. Tomography technique was developed as a diagnostic tool in the medical area since the early of 1970’s. This research initially focused on how to retrieve a cross sectional images from living or non-living things. After a decade, the application of tomography systems span into the industrial area. However, the long exposure time of medical radiation-based method cannot tolerate the dynamic changes in industrial process two phase liquid/gas flow system.. An alternative system such as a process tomography system, can give information on the nature of the flow regime characteristic. The overall aim of this paper is to investigate the use of a small scale ultrasonic tomography method based on ultrasonic transmission mode tomography for online monitoring of liquid/gas flow in pipe/vessel system through ultrasonic transceivers application. This non-invasive technique applied sixteen transceivers as the sensing elements to cover the pipe/vessel cross section. The paper also details the transceivers selection criteria, hardware setup, the electronic measurement circuit and also the image reconstruction algorithm applied. The system was found capable of visualizing the internal characteristics and provides the concentration profile for the corresponding liquid and gas phases.
Fulltext The effect of flaxseed extract on skin elasticity of the healing wound in rabbits.

Abdul Jabbar O, Kashmoola MA, Mustafa Al-Ahmad BE, Mokhtar KI, Muhammad N, Abdul Rahim R, et al.

IIUM Medical Journal Malaysia, 2019;18(1):5-12.
MyJurnal

Management of disturbed wounds, large skin defects and the areas where skin tension precludes wound closure is of high clinical importance. Healing in wounds occurs through epithelization and contraction processes (second-intentions healing) that may result in certain undesirable complications including keloid and formation of a fragile epithelial layer.Materials and methods: 27 white New Zealand rabbit included in this study divided into 3 groups; one group of 9 rabbits received Flaxseed gel topically for three time intervals (1, 7, and 14 days); a second group received Fucidin cream as positive control, while a third group has not received any treatment as negative control, Skin elasticity measurements were performed using the DermaLab system. Results: Throughout the study, skin elasticity was significantly greater in Flaxseed group than in others. Flaxseed decrease elasticity value from (3.46 ± 2.05). Hence, Young's modulus of skin elasticity in flaxseed group was (2.46 ± 1.02) after 14 days (p = 0.003), while no significant differences were evident in both Fucidin group (1.16 ± 0.77) and non-treated group (1.86 ± 1.40) (p = 0.019), accordingly flaxseed extract more reproducible than other groups demonstrating comparable efficacy in skin elasticity and distensibility.Conclusions: This study showed the therapeutic effect of flaxseed on biologic tissue. Elasticity evaluation demonstrated increased density and firmness in the network of collagen fibers in the dermis and subcutis during wound healing process promise in generating therapeutic gel to be used in wound healing process.
Fulltext Neural network and principal component regression in non-destructive soluble solids content assessment: a comparison

Chia KS, Abdul Rahim H, Abdul Rahim R

J Zhejiang Univ Sci B, 2012 Feb;13(2):145-51.
PMID: 22302428 DOI: 10.1631/jzus.B11c0150

Visible and near infrared spectroscopy is a non-destructive, green, and rapid technology that can be utilized to estimate the components of interest without conditioning it, as compared with classical analytical methods. The objective of this paper is to compare the performance of artificial neural network (ANN) (a nonlinear model) and principal component regression (PCR) (a linear model) based on visible and shortwave near infrared (VIS-SWNIR) (400-1000 nm) spectra in the non-destructive soluble solids content measurement of an apple. First, we used multiplicative scattering correction to pre-process the spectral data. Second, PCR was applied to estimate the optimal number of input variables. Third, the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models. The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN. Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR.
Hydrogel beads bio-nanocomposite based on Kappa-Carrageenan and green synthesized silver nanoparticles for biomedical applications

Azizi S, Mohamad R, Abdul Rahim R, Mohammadinejad R, Bin Ariff A

Int J Biol Macromol, 2017 Nov;104(Pt A):423-431.
PMID: 28591593 DOI: 10.1016/j.ijbiomac.2017.06.010

This paper describes the fabrication and characterization of bio-nanocomposite hydrogel beads based on Kappa-Carrageenan (κ-Carrageenan) and bio-synthesized silver nanoparticles (Ag-NPs). The silver nanoparticles were prepared in aqueous Citrullus colocynthis seed extract as both reducing and capping agent. Cross-linked κ-Carrageenan/Ag-NPs hydrogel beads were prepared using potassium chloride as the cross-linker. The hydrogel beads were characterized using XRD and FESEM. Moreover, swelling property of the hydrogel beads was investigated. The Ag release profile of the hydrogels was obtained by fitting the experimental data to power law equation. The direct visualization of the green synthesized Ag-NPs using TEM shows particle size in the range of 23±2nm. The bio-nanocomposite hydrogels showed lesser swelling behavior in comparison with pure κ-Carrageenan hydrogel. Regardless the slow Ag release, κ-Carrageenan/Ag-NPs presented good antibacterial activities against Staphylococcus aureus, Methicilin Resistant Staphylococcus aurous, Peseudomonas aeruginosa and Escherichia coli with maximum zones of inhibition 11±2mm. Cytotoxicity study showed that the bio-nanocomposite hydrogels with non-toxic effect of concentration below 1000μg/mL have great pharmacological potential and a suitable level of safety for use in the biological systems.
Determination and Quantification of the Vinblastine Content in Purple, Red, and White Catharanthus Roseus Leaves Using RP-HPLC Method

Abdul Rahim R, Ahmad NH, Al Azzam KM, Mat I

Adv Pharm Bull, 2018 Mar;8(1):157-161.
PMID: 29670851 DOI: 10.15171/apb.2018.019

Purpose:
To determine and quantify vinblastine in different varieties of Catharanthus roseus using reversed-phase HPLC method.
Methods:
The liquid chromatographic separation was performed using a reversed phase C18, Microsorb - MV column (250 mm x 4.6 mm, 5 µm) at room temperature and eluted with a mobile phase containing methanol - phosphate buffer (5 mM, pH 6.0) - acetonitrile with different proportion gradient elution at a flow rate of 2.0 mL min-1 and detection at 254 nm.
Results:
The HPLC method was utilized for the quantification of vinblastine in purple, red and white varieties of Catharanthus roseus leaves. The separation was achieved in less than 8 min. The peak confirmation was done based on the retention times and UV spectra of the reference substance. The method was validated with respect to linearity, precision, recovery, limit of detection and quantification. Results showed that the purple variety gives 1.2 and 1.5 times more vinblastine concentration compared to the white and pink varieties, respectively.
Conclusion:
The obtained results from different varieties are thus useful for the purpose of vinblastine production from Catharanthus roseus plant.
Fulltext Engineering integrative vectors based on phage site-specific recombination mechanism for Lactococcus lactis

Koko I, Song AA, Masarudin MJ, Abdul Rahim R

BMC Biotechnol, 2019 11 27;19(1):82.
PMID: 31775775 DOI: 10.1186/s12896-019-0575-x

BACKGROUND: Site-specific integration system allows foreign DNA to be integrated into the specific site of the host genome, enabling stable expression of heterologous protein. In this study, integrative vectors for secretion and surface display of proteins were constructed based on a lactococcal phage TP901-1 integrating system.
RESULTS: The constructed integration system comprises of a lactococcal promoter (PnisA or P170), phage attachment site (attP) from bacteriophage TP901-1, a signal peptide (USP45 or SPK1) for translocation of the target protein, and a PrtP344 anchor domain in the case of the integrative vectors for surface display. There were eight successfully constructed integrative vectors with each having a different combination of promoter and signal peptide; pS1, pS2, pS3 and pS4 for secretion, and pSD1, pSD2, pSD3 and pSD4 for surface display of desired protein. The integration of the vectors into the host genome was assisted by a helper vector harbouring the integrase gene. A nuclease gene was used as a reporter and was successfully integrated into the L. lactis genome and Nuc was secreted or displayed as expected. The signal peptide SPK1 was observed to be superior to USP45-LEISSTCDA fusion in the secretion of Nuc. As for the surface display integrative vector, all systems developed were comparable with the exception of the combination of P170 promoter with USP45 signal peptide which gave very low signals in whole cell ELISA.
CONCLUSION: The engineered synthetic integrative vectors have the potential to be used for secretion or surface display of heterologous protein production in lactococcal expression system for research or industrial purposes, especially in live vaccine delivery.
Fulltext Effects of lysine and methionine in a low crude protein diet on the growth performance and gene expression of immunity genes in broilers

Lee CY, Song AA, Loh TC, Abdul Rahim R

Poult Sci, 2020 Jun;99(6):2916-2925.
PMID: 32475425 DOI: 10.1016/j.psj.2020.03.013

Globally, the poultry industry is 1 of the most advanced livestock industries. Feed contributes to the biggest proportion (65-70%) of the production cost. Most feed ingredients in Malaysia are imported, which contributes to the high food bill annually, and alternative feed formulation may help decrease the cost of poultry feed. Feed formulation are improved to efficiently meet the dietary requirements of the broilers and 1 of the ways is by reducing the level of crude protein in the diet while supplementing essential amino acids. In this study, the effects of methionine and lysine, which are the 2 most limiting amino acids in the chicken diet, were supplemented in a low crude protein diet, and its effects on the growth and expression of immunity genes such as MUC2, SLC, GAL6, and LEAP-2 were studied. A total of 300 Cobb500 broilers were tested with 10 different dietary treatments. Experimental treatment diets consist of high, standard, and low levels of methionine and lysine in the diet with reduced crude protein. The control group consists of diet with standard levels of lysine, methionine, and crude protein as recommended for Cobb500 broilers. Ribonucleic acid was extracted from the jejunum, spleen, and liver for gene expression analysis which was performed with real-time polymerase chain reaction using SYBR Green chemistry. Results of the growth performance at 6 wk showed improved feed conversion ratio when lysine was increased by 0.2% in a low crude protein diet at 1.96 ± 0.11. Gene expression of MUC2 gene in the jejunum showed a significant increase across all experimental diets with the treatment with higher lysine in low crude protein diet with the highest increase of 3.8 times as compared with the control diet. The other genes expressed in the spleen and liver were mostly downregulated. It was concluded that supplementation of high lysine with standard methionine in a low crude protein diet performed better in terms of lowest feed conversion ratio and high upregulation of MUC2 gene.
Lensed optical fiber sensors for on-line measurement of flow

Ibrahim S, Green RG, Dutton K, Abdul Rahim R

ISA Trans, 2002 Jan;41(1):13-8.
PMID: 12014798

This paper describes a system using lensed optical fiber sensors that are arranged in the form of two orthogonal projections. The sensors are placed around a process vessel for upstream and downstream measurements. The purpose of the system is for on-line monitoring of particles and droplets being conveyed by a fluid. The lenses were constructed using a custom heating fixture. The fixture enables the lenses to be constructed with similar radii resulting in identical characteristics with minimum differences in transmitted intensity and emission angle. By collimating radiation from two halogen bulbs, radiation can be obtained by the sensors with radiation intensity related to the nature of the media. Each sensor interrogates a finite section of the measurement section. Each sensor provides a view. Parallel sensors provide a projection. Signal processing is carried out on the measured data in the time and frequency domains to investigate the latent information present in the flow signals.
Fulltext Outcomes of Prostate Artery Embolisation in Patients with Severe Symptoms of Benign Prostate Hyperplasia

Abdul Rahim R, Eng Hong G, Nik Ismail NA, Zakaria R

Malays J Med Sci, 2021 Dec;28(6):55-63.
PMID: 35002490 DOI: 10.21315/mjms2021.28.6.6

Background: Benign prostatic hyperplasia (BPH) is associated with severe lower urinary tract symptoms (LUTS). The severity of LUTS is assessed by the International Prostate Symptoms Score (IPSS). Prostate artery embolisation (PAE) is a newly available method for combating LUTS. This study aims to assess the outcomes of PAE in reducing LUTS and prostate volume in patients with BPH.
Methods: Patients diagnosed with BPH with severe LUTS who had undergone PAE were included. Their IPSS score was ≥ 20 despite medical therapy. PAE was performed via the unilateral femoral artery using various types of embolic material. Bilateral or unilateral embolisation of the prostate artery was considered a technical success. The severity of LUTS pre- and post-PAE were assessed using IPSS while prostate volume pre- and post-PAE were assessed by ultrasound and magnetic resonance imaging (MRI).
Results: Ninety percent of patients had technical success and one required transurethral resection of the prostate (TURP). The mean IPSS reduction at the final follow-up was 12.9 (P < 0.028). The mean reduction of prostate volume at the last follow-up by ultrasound was 114.99 mL (P < 0.028) and by MRI was 29.17 mL (P < 0.028).
Conclusion: PAE is safe and effective in reducing severe LUTS and prostate gland volume in BPH patients.
Fulltext Molecular characterization of a recombinant manganese superoxide dismutase from Lactococcus lactis M4

Tan BH, Chor Leow T, Foo HL, Abdul Rahim R

Biomed Res Int, 2014;2014:469298.
PMID: 24592392 DOI: 10.1155/2014/469298

A superoxide dismutase (SOD) gene of Lactococcus lactis M4 was cloned and expressed in a prokaryotic system. Sequence analysis revealed an open reading frame of 621 bp which codes for 206 amino acid residues. Expression of sodA under T7 promoter exhibited a specific activity of 4967 U/mg when induced with 1 mM of isopropyl-β-D-thiogalactopyranoside. The recombinant SOD was purified to homogeneity by immobilised metal affinity chromatography and Superose 12 gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot analyses of the recombinant SOD detected a molecular mass of approximately 27 kDa. However, the SOD was in dimer form as revealed by gel filtration chromatography. The purified recombinant enzyme had a pI of 4.5 and exhibited maximal activity at 25°C and pH 7.2. It was stable up to 45°C. The insensitivity of this lactococcal SOD to cyanide and hydrogen peroxide established that it was a MnSOD. Although it has 98% homology to SOD of L. lactis IL1403, this is the first elucidated structure of lactococcal SOD revealing active sites containing the catalytic manganese coordinated by four ligands (H-27, H-82, D-168, and H-172).
Fulltext Purification and Characterization of a Thermostable Lipase from Geobacillus thermodenitrificans IBRL-nra

Balan A, Ibrahim D, Abdul Rahim R, Ahmad Rashid FA

Enzyme Res, 2012;2012:987523.
PMID: 23198138 DOI: 10.1155/2012/987523

Thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was purified and characterized. The production of thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was carried out in a shake-flask system at 65°C in cultivation medium containing; glucose 1.0% (w/v); yeast extract 1.25% (w/v); NaCl 0.45% (w/v) olive oil 0.1% (v/v) with agitation of 200 rpm for 24 hours. The extracted extracellular crude thermostable lipase was purified to homogeneity by using ultrafiltration, Heparin-affinity chromatography, and Sephadex G-100 gel-filtration chromatography by 34 times with a final yield of 9%. The molecular weight of the purified enzyme was estimated to be 30 kDa after SDS-PAGE analysis. The optimal temperature for thermostable lipase was 65°C and it retained its initial activity for 3 hours. Thermostable lipase activity was highest at pH 7.0 and stable for 16 hours at this pH at 65°C. Thermostable lipase showed elevated activity when pretreated with BaCl(2), CaCl(2), and KCl with 112%, 108%, and 106%, respectively. Lipase hydrolyzed tripalmitin (C16) and olive oil with optimal activity (100%) compared to other substrates.
Global Transcriptome Analysis of Gracilaria changii (Rhodophyta) in Response to Agarolytic Enzyme and Bacterium

Lim EL, Siow RS, Abdul Rahim R, Ho CL

Mar Biotechnol (NY), 2016 Apr;18(2):189-200.
PMID: 26631182 DOI: 10.1007/s10126-015-9680-6

Many bacterial epiphytes of agar-producing seaweeds secrete agarase that degrade algal cell wall matrix into oligoagars which elicit defense-related responses in the hosts. The molecular defense responses of red seaweeds are largely unknown. In this study, we surveyed the defense-related transcripts of an agarophyte, Gracilaria changii, treated with β-agarase through next generation sequencing (NGS). We also compared the defense responses of seaweed elicited by agarase with those elicited by an agarolytic bacterium isolated from seaweed, by profiling the expression of defense-related genes using quantitative reverse transcription real-time PCR (qRT-PCR). NGS detected a total of 391 differentially expressed genes (DEGs) with a higher abundance (>2-fold change with a p value <0.001) in the agarase-treated transcriptome compared to that of the non-treated G. changii. Among these DEGs were genes related to signaling, bromoperoxidation, heme peroxidation, production of aromatic amino acids, chorismate, and jasmonic acid. On the other hand, the genes encoding a superoxide-generating NADPH oxidase and related to photosynthesis were downregulated. The expression of these DEGs was further corroborated by qRT-PCR results which showed more than 90 % accuracy. A comprehensive analysis of their gene expression profiles between 1 and 24 h post treatments (hpt) revealed that most of the genes analyzed were consistently upregulated or downregulated by both agarase and agarolytic bacterial treatments, indicating that the defense responses induced by both treatments are highly similar except for genes encoding vanadium bromoperoxidase and animal heme peroxidase. Our study has provided the first glimpse of the molecular defense responses of G. changii to agarase and agarolytic bacterial treatments.
Fulltext Eco-Friendly Formulated Zinc Oxide Nanoparticles: Induction of Cell Cycle Arrest and Apoptosis in the MCF-7 Cancer Cell Line

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

Genes (Basel), 2017 Oct 20;8(10).
PMID: 29053567 DOI: 10.3390/genes8100281

Green products have strong potential in the discovery and development of unique drugs. Zinc oxide nanoparticles (ZnO NPs) have been observed to have powerful cytotoxicity against cells that cause breast cancer. The present study aims to examine the cell cycle profile, status of cell death, and pathways of apoptosis in breast cancer cells (MCF-7) treated with biosynthesized ZnO NPs. The anti-proliferative activity of ZnO NPs was determined using MTT assay. Cell cycle analysis and the mode of cell death were evaluated using a flow cytometry instrument. Quantitative real-time-PCR (qRT-PCR) was employed to investigate the expression of apoptosis in MCF-7 cells. ZnO NPs were cytotoxic to the MCF-7 cells in a dose-dependent manner. The 50% growth inhibition concentration (IC50) of ZnO NPs at 24 h was 121 µg/mL. Cell cycle analysis revealed that ZnO NPs induced sub-G₁ phase (apoptosis), with values of 1.87% at 0 μg/mL (control), 71.49% at IC25, 98.91% at IC50, and 99.44% at IC75. Annexin V/propidium iodide (PI) flow cytometry analysis confirmed that ZnO NPs induce apoptosis in MCF-7 cells. The pro-apoptotic genes p53, p21, Bax, and JNK were upregulated, whereas anti-apoptotic genes Bcl-2, AKT1, and ERK1/2 were downregulated in a dose-dependent manner. The arrest and apoptosis of MCF-7 cells were induced by ZnO NPs through several signalling pathways.
Fulltext A Review of the Biomedical Applications of Zerumbone and the Techniques for Its Extraction from Ginger Rhizomes

Kalantari K, Moniri M, Boroumand Moghaddam A, Abdul Rahim R, Bin Ariff A, Izadiyan Z, et al.

Molecules, 2017 Sep 30;22(10).
PMID: 28974019 DOI: 10.3390/molecules22101645

Zerumbone (ZER) is a phytochemical isolated from the subtropical Zingiberaceae family and as a natural compound it has different biomedical properties such as antioxidant, anti-inflammatory anti-proliferative activity. ZER also has effects on angiogenesis and acts as an antitumor drug in the treatment of cancer, showing selective toxicity toward various cancer cell lines. Several techniques also have been established for extraction of ZER from the rhizomes of ginger. This review paper is an overview of recent research about different extraction methods and their efficiencies, in vivo and vitro investigations of ZER and also its prominent chemopreventive properties and treatment mechanisms. Most of the studies mentioned in this review paper may be useful use as a knowledge summary to explain ZER extraction and anticancer activities, which will show a way for the development of strategies in the treatment of malignancies using ZER.
Fulltext Molecular study of wound healing after using biosynthesized BNC/Fe3O4 nanocomposites assisted with a bioinformatics approach

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

Int J Nanomedicine, 2018;13:2955-2971.
PMID: 29861630 DOI: 10.2147/IJN.S159637

Background: Molecular investigation of wound healing has allowed better understanding about interaction of genes and pathways involved in healing progression.
Objectives: The aim of this study was to prepare magnetic/bacterial nanocellulose (Fe3O4/BNC) nanocomposite films as ecofriendly wound dressing in order to evaluate their physical, cytotoxicity and antimicrobial properties. The molecular study was carried out to evaluate expression of genes involved in healing of wounds after treatment with BNC/Fe3O4 films.
Study design materials and methods: Magnetic nanoparticles were biosynthesized by using Aloe vera extract in new isolated bacterial nanocellulose (BNC) RM1. The nanocomposites were characterized using X-ray diffraction, Fourier transform infrared, and field emission scanning electron microscopy. Moreover, swelling property and metal ions release profile of the nanocomposites were investigated. The ability of nanocomposites to promote wound healing of human dermal fibroblast cells in vitro was examined. Bioinformatics databases were used to identify genes with important healing effect. Key genes which interfered with healing were studied by quantitative real time PCR.
Results: Spherical magnetic nanoparticles (15-30 nm) were formed and immobilized within the structure of BNC. The BNC/Fe3O4 was nontoxic (IC50>500 μg/mL) with excellent wound healing efficiency after 48 hours. The nanocomposites showed good antibacterial activity ranging from 6±0.2 to 13.40±0.10 mm against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. The effective genes for the wound healing process were TGF-B1, MMP2, MMP9, Wnt4, CTNNB1, hsa-miR-29b, and hsa-miR-29c with time dependent manner. BNC/Fe3O4 has an effect on microRNA by reducing its expression and therefore causing an increase in the gene expression of other genes, which consequently resulted in wound healing.
Conclusion: This eco-friendly nanocomposite with excellent healing properties can be used as an effective wound dressing for treatment of cutaneous wounds.
Fulltext Proof of concept in utilizing in-trans surface display system of Lactobacillus plantarum as mucosal tuberculosis vaccine via oral administration in mice

Mustafa AD, Kalyanasundram J, Sabidi S, Song AA, Abdullah M, Abdul Rahim R, et al.

BMC Biotechnol, 2018 10 11;18(1):63.
PMID: 30309359 DOI: 10.1186/s12896-018-0461-y

BACKGROUND: Tuberculosis is one of the most common and deadliest infectious diseases worldwide affecting almost a third of the world's population. Although this disease is being prevented and controlled by the Bacille Calmette Guérin (BCG) vaccine, the protective efficacy is highly variable and substandard (0-80%) in adults. Therefore, novel and effective tuberculosis vaccine that can overcome the limitations from BCG vaccine need to be developed.
RESULTS: A novel approach of utilizing an in-trans protein surface display system of Lactobacillus plantarum carrying and displaying combination of Mycobacterium tuberculosis subunit epitope antigens (Ag85B, CFP-10, ESAT-6, Rv0475 and Rv2031c) fused with LysM anchor motif designated as ACERL was constructed, cloned and expressed in Esherichia coli Rossetta expression host. Subsequently the binding capability of ACERL to the cell wall of L. plantarum was examined via the immunofluorescence microscopy and whole cell ELISA where successful attachment and consistent stability of cell wall binding up to 4 days was determined. The immunization of the developed vaccine of L. plantarum surface displaying ACERL (Lp ACERL) via the oral route was studied in mice for its immunogenicity effects. Lp ACERL immunization was able to invoke significant immune responses that favor the Th1 type cytokine response of IFN-γ, IL-12 and IL-2 as indicated by the outcome from the cytokine profiling of spleen, lung, gastrointestinal tract (GIT), and the re-stimulation of the splenocytes from the immunized mice. Co-administration of an adjuvant consisting of Lactococcus lactis secreting mouse IL-12 (LcIL-12) with Lp ACERL was also investigated. It was shown that the addition of LcIL-12 was able to further generate significant Th1 type cytokines immune responses, similar or better than that of Lp ACERL alone which can be observed from the cytokine profiling of the immunized mice's spleen, lung and GIT.
CONCLUSIONS: This study represents a proof of concept in the development of L. plantarum as a carrier for a non-genetically modified organism (GMO) tuberculosis vaccine, which may be the strategy in the future for tuberculosis vaccine development.
Fulltext In vitro molecular study of wound healing using biosynthesized bacteria nanocellulose/silver nanocomposite assisted by bioinformatics databases

Moniri M, Boroumand Moghaddam A, Azizi S, Abdul Rahim R, Zuhainis SW, Navaderi M, et al.

Int J Nanomedicine, 2018;13:5097-5112.
PMID: 30254435 DOI: 10.2147/IJN.S164573

Background: In recent years, bacterial nanocellulose (BNC) based nanocomposites have been developed to promote healing property and antibacterial activity of BNC wound dressing. Molecular study can help to better understanding about interaction of genes and pathways involved in healing progression.
Objectives: The aim of this study was to prepare bacterial nanocellulose/silver (BNC/Ag) nanocomposite films as ecofriendly wound dressing in order to assess their physical, cytotoxicity and antimicrobial properties. The in vitro molecular study was performed to evaluate expression of genes involved in healing of wounds after treatment with BNC/Ag biofilms.
Study design materials and methods: Silver nanoparticles were formed by using Citrullus colocynthis extract within new isolated bacterial nanocellulose (BNC) RM1. The nanocomposites were characterized using X-ray diffraction, Fourier transform infrared, and field emission scanning electron microscopy. Besides, swelling property and Ag release profile of the nanocomposites were studied. The ability of nanocomposites to promote wound healing of human dermal fibroblast cells in vitro was studied. Bioinformatics databases were used to identify genes with important healing effect. Key genes which interfered with healing were studied by quantitative real time PCR.
Results: Spherical silver nanoparticles with particle size ranging from 20 to 50 nm were synthesized and impregnated within the structure of BNC. The resulting nanocomposites showed significant antibacterial activities with inhibition zones ranging from 7±0.25 to 16.24±0.09 mm against skin pathogenic bacteria. Moreover, it was compatible with human fibroblast cells (HDF) and could promote in vitro wound healing after 48h. Based on bioinformatics databases, the genes of TGF-β1, MMP2, MMP9, CTNNB1, Wnt4, hsa-miR-29b-3p and hsa-miR-29c-3p played important role in wound healing. The nanocomposites had an effect in expression of the genes in healing. Thus, the BNC/Ag nanocomposite can be used to heal wound in a short period and simple manner.
Conclusion: This eco-friendly nanocomposite with excellent antibacterial activities and healing property confirming its utility as potential wound dressings.
Enhanced secretion of cyclodextrin glucanotransferase (CGTase) by Lactococcus lactis using heterologous signal peptides and optimization of cultivation conditions

Mahmud H, Ismail A, Abdul Rahim R, Low KO, Md Illias R

J Biotechnol, 2019 Apr 20;296:22-31.
PMID: 30878516 DOI: 10.1016/j.jbiotec.2019.02.013

In previous studies of Lactococcus lactis, the levels of proteins secreted using heterologous signal peptides were observed to be lower than those obtained using the signal peptide from Usp45, the major secreted lactococcal protein. In this study, G1 (the native signal peptide of CGTase) and the signal peptide M5 (mutant of the G1 signal peptide) were introduced into L. lactis to investigate the effect of signal peptides on lactococcal protein secretion to improve secretion efficiency. The effectiveness of these signal peptides were compared to the Usp45 signal peptide. The highest secretion levels were obtained using the G1 signal peptide. Sequence analysis of signal peptide amino acids revealed that a basic N-terminal signal peptide is not absolutely required for efficient protein export in L. lactis. Moreover, the introduction of a helix-breaking residue in the H-region of the M5 signal peptide caused a reduction in the signal peptide hydrophobicity and decreased protein secretion. In addition, the optimization of cultivation conditions for recombinant G1-CGTase production via response surface methodology (RSM) showed that CGTase activity increased approximately 2.92-fold from 5.01 to 16.89 U/ml compared to the unoptimized conditions.
Fulltext Extracellular Proteolytic Activity and Amino Acid Production by Lactic Acid Bacteria Isolated from Malaysian Foods

Toe CJ, Foo HL, Loh TC, Mohamad R, Abdul Rahim R, Idrus Z

Int J Mol Sci, 2019 Apr 10;20(7).
PMID: 30974873 DOI: 10.3390/ijms20071777

Amino acids (AAs) are vital elements for growth, reproduction, and maintenance of organisms. Current technology uses genetically engineered microorganisms for AAs production, which has urged the search for a safer food-grade AA producer strain. The extracellular proteolytic activities of lactic acid bacteria (LAB) can be a vital tool to hydrolyze extracellular protein molecules into free AAs, thereby exhibiting great potential for functional AA production. In this study, eight LAB isolated from Malaysian foods were determined for their extracellular proteolytic activities and their capability of producing AAs. All studied LAB exhibited versatile extracellular proteolytic activities from acidic to alkaline pH conditions. In comparison, Pediococcus pentosaceus UP-2 exhibited the highest ability to produce 15 AAs extracellularly, including aspartate, lysine, methionine, threonine, isoleucine, glutamate, proline, alanine, valine, leucine, tryptophan, tyrosine, serine, glycine, and cystine, followed by Pediococcus pentosaceus UL-2, Pediococcus acidilactici UB-6, and Pediococcus acidilactici UP-1 with 11 to 12 different AAs production detected extracellularly. Pediococcus pentosaceus UL-6 demonstrated the highest increment of proline production at 24 h of incubation. However, Pediococcusacidilactici UL-3 and Lactobacillus plantarum I-UL4 exhibited the greatest requirement for AA. The results of this study showed that different LAB possess different extracellular proteolytic activities and potentials as extracellular AA producers.

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