Displaying publications 81 - 100 of 216 in total

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  1. Zulkeflee Z, Aris AZ, Shamsuddin ZH, Yusoff MK
    ScientificWorldJournal, 2012;2012:495659.
    PMID: 22997497
    A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological characteristics identified as Bacillus spp. UPMB13 was found to be a potential bioflocculant-producing bacterium. The effect of cation dependency, pH tolerance and dosage requirement on flocculating ability of the strain was determined by flocculation assay with kaolin as the suspended particle. The flocculating activity was measured as optical density and by flocs formation. A synergistic effect was observed with the addition of monovalent and divalent cations, namely, Na⁺, Ca²⁺, and Mg²⁺, while Fe²⁺ and Al³⁺ produced inhibiting effects on flocculating activity. Divalent cations were conclusively demonstrated as the best cation source to enhance flocculation. The bioflocculant works in a wide pH range, from 4.0 to 8.0 with significantly different performances (P < 0.05), respectively. It best performs at pH 5.0 and pH 6.0 with flocculating performance of above 90%. A much lower or higher pH would inhibit flocculation. Low dosage requirements were needed for both the cation and bioflocculant, with only an input of 50 mL/L for 0.1% (w/v) CaCl₂ and 5 mL/L for culture broth, respectively. These results are comparable to other bioflocculants produced by various microorganisms with higher dosage requirements.
    Matched MeSH terms: Batch Cell Culture Techniques/methods; Batch Cell Culture Techniques/standards*
  2. Lam MK, Lee KT
    Biotechnol Adv, 2012 May-Jun;30(3):673-90.
    PMID: 22166620 DOI: 10.1016/j.biotechadv.2011.11.008
    Culturing of microalgae as an alternative feedstock for biofuel production has received a lot of attention in recent years due to their fast growth rate and ability to accumulate high quantity of lipid and carbohydrate inside their cells for biodiesel and bioethanol production, respectively. In addition, this superior feedstock offers several environmental benefits, such as effective land utilization, CO(2) sequestration, self-purification if coupled with wastewater treatment and does not trigger food versus fuel feud. Despite having all these 'theoretical' advantages, review on problems and issues related to energy balance in microalgae biofuel are not clearly addressed until now. Base on the maturity of current technology, the true potential of microalgae biofuel towards energy security and its feasibility for commercialization are still questionable. Thus, this review is aimed to depict the practical problems that are facing the microalgae biofuel industry, covering upstream to downstream activities by accessing the latest research reports and critical data analysis. Apart from that, several interlink solutions to the problems will be suggested with the purpose to bring current microalgae biofuel research into a new dimension and consequently, to revolutionize the entire microalgae biofuel industry towards long-term sustainability.
    Matched MeSH terms: Cell Culture Techniques
  3. Muntari B, Amid A, Mel M, Jami MS, Salleh HM
    AMB Express, 2012;2:12.
    PMID: 22336426 DOI: 10.1186/2191-0855-2-12
    Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period). The optimized conditions by response surface methodology using face centered central composite design were 0.2% (w/v) L-arabinose, 8 hr and 25°C. The analysis of variance coupled with larger value of R2 (0.989) showed that the quadratic model used for the prediction was highly significant (p < 0.05). Under the optimized conditions, the model produced bromelain activity of 9.2 U/mg while validation experiments gave bromelain activity of 9.6 ± 0.02 U/mg at 0.15% (w/v) L-arabinose, 8 hr and 27°C. This study had innovatively developed cultivation conditions for better production of recombinant bromelain in shake flask culture.
    Matched MeSH terms: Batch Cell Culture Techniques
  4. Yamin, S., Shuhaimi, M., Arbakariya, A., Khalilah, A. K., Anas, O., Yazid, A. M., et al.
    MyJurnal
    The use of component from Ganoderma lucidum as prebiotic source is interesting as the G. lucidum itself was known for more than a decade in the traditional Chinese medicine. In this work, Ganoderma lucidum crude polysaccharides (GLCP) and Polysaccharide-fraction number 2 (PF-2) were used as carbon sources in the fermentation with Bifidobacterium sp. The results showed the potential of prebiotic effect of the G. lucidum extract in batch-culture fermentation based on increment in the growth of bacteria used (0.4 – 1.5 log10 CFU/mL) after 18h fermentation. Fermentation was further done using faecal materials as bacterial inocula and bacterial growth changes were examined using real-time PCR. The results showed the ability of GLCP and PF-2 to support the growth of Bifidobacterium genus with 0.3 and 0.7 log10 cells/ml increased, respectively. Interestingly, Lactobacillus which is known as beneficial bacterial genus also showed growth increment with 0.7 and 1 log10 cells/ml increased. The competition for carbon sources thus inhibits the growth of potentially harmful genus, Salmonella (0.3 and 0.5 log10 cells/ml) in comparison to the control.
    Matched MeSH terms: Batch Cell Culture Techniques
  5. Lim MN, Hussin NH, Othman A, Umapathy T, Baharuddin P, Jamal R, et al.
    Mol Vis, 2012;18:1289-300.
    PMID: 22665977
    The presence of multipotent human limbal stromal cells resembling mesenchymal stromal cells (MSC) provides new insights to the characteristic of these cells and its therapeutic potential. However, little is known about the expression of stage-specific embryonic antigen 4 (SSEA-4) and the embryonic stem cell (ESC)-like properties of these cells. We studied the expression of SSEA-4 surface protein and the various ESC and MSC markers in the ex vivo cultured limbal stromal cells. The phenotypes and multipotent differentiation potential of these cells were also evaluated.
    Matched MeSH terms: Cell Culture Techniques
  6. Lim JW, Lim PE, Seng CE, Adnan R
    Bioresour Technol, 2013 Feb;129:485-94.
    PMID: 23266850 DOI: 10.1016/j.biortech.2012.11.111
    Moving bed sequencing batch reactors (MBSBRs) packed with 8% (v/v) of 8-, 27- and 64-mL polyurethane (PU) foam cubes, respectively, were investigated for simultaneous 4-chlorophenol (4-CP) and nitrogen removal at increasing 4-CP concentration. When the 4-CP concentration exceeded 300 mg L(-1), the MBSBR with 27-mL foam cubes was observed to outperform the other MBSBRs in removing 4-CP and nitrogen. The reasons were: (1) there were more biomass in inner layer of the 27-mL cubes, compared to that of the 8-mL cubes, which was more shielded from the inhibitory effect of 4-CP and (2) the 27-mL cubes were more mobile than the 64-mL cubes. Although increasing 4-CP concentration to 600 mg L(-1) resulted in incomplete removal of 4-CP in the MBSBRs, results of the batch reactor with 27-mL foam cubes showed that complete 4-CP removal within the REACT period could be achieved by increasing the packing volume to 20%.
    Matched MeSH terms: Batch Cell Culture Techniques/instrumentation*
  7. Rosman NH, Nor Anuar A, Othman I, Harun H, Sulong Abdul Razak MZ, Elias SH, et al.
    Bioresour Technol, 2013 Feb;129:620-3.
    PMID: 23317554 DOI: 10.1016/j.biortech.2012.12.113
    Aerobic granular sludge (AGS) was successfully cultivated at 27±1 °C and pH 7.0±1 during the treatment of rubber wastewater using a sequential batch reactor system mode with complete cycle time of 3 h. Results showed aerobic granular sludge had an excellent settling ability and exhibited exceptional performance in the organics and nutrients removal from rubber wastewater. Regular, dense and fast settling granule (average diameter, 1.5 mm; settling velocity, 33 m h(-1); and sludge volume index, 22.3 mL g(-1)) were developed in a single reactor. In addition, 96.5% COD removal efficiency was observed in the system at the end of the granulation period, while its ammonia and total nitrogen removal efficiencies were up to 94.7% and 89.4%, respectively. The study demonstrated the capabilities of AGS development in a single, high and slender column type-bioreactor for the treatment of rubber wastewater.
    Matched MeSH terms: Batch Cell Culture Techniques
  8. Ramasamy S, Abdul Wahab N, Zainal Abidin N, Manickam S
    Exp. Toxicol. Pathol., 2013 Mar;65(3):341-9.
    PMID: 22217449 DOI: 10.1016/j.etp.2011.11.005
    Species of Phyllanthus have traditionally been used for hundreds of years for treating many ailments including diabetes, anemia, bronchitis and hepatitis. The present study aims to investigate the cytotoxic and apoptotic effects of methanol (PWM), hexane (PWH) and ethyl acetate (PWE) extracts from the leaves of the endemic plant Phyllanthus watsonii Airy Shaw (Phyllanthaceae) on MCF-7 human breast cancer cells. We observed that the PWM, PWH and PWE extracts were cytotoxic and selectively inhibited the growth and proliferation of MCF-7 cells compared to untreated control in a dose dependent manner with an IC(50) of 12.7 ± 4.65, 7.9 ± 0.60 and 7.7 ± 0.29 μg/ml, respectively. However, the extracts were not toxic at these concentrations to normal human lung fibroblast MRC-5 cells. Cell death induced by PWM, PWH and PWE extracts were mainly due to apoptosis which was characterized by apoptotic morphological changes and a nuclear DNA fragmentation. Caspase-3 activation following P. watsonii extracts treatment was also evident for apoptotic cell death which was preceded by an S phase cell cycle perturbation. The results suggested that the cytotoxic activity of P. watsonii extracts was related to an early event of cell cycle perturbation and a later event of apoptosis. Hence, P. watsonii displays potential to be further exploited in the discovery and development of new anticancer agents.
    Matched MeSH terms: Cell Culture Techniques
  9. Ab-Rahim S, Selvaratnam L, Raghavendran HR, Kamarul T
    Mol Cell Biochem, 2013 Apr;376(1-2):11-20.
    PMID: 23238871 DOI: 10.1007/s11010-012-1543-0
    Tissue engineering approaches often require expansion of cell numbers in vitro to accelerate tissue regenerative processes. Although several studies have used this technique for therapeutic purposes, a major concern involving the use of isolated chondrocyte culture is the reduction of extracellular matrix (ECM) protein expressed due to the transfer of cells from the normal physiological milieu to the artificial 2D environment provided by the cell culture flasks. To overcome this issue, the use of alginate hydrogel beads as a substrate in chondrocyte cultures has been suggested. However, the resultant characteristics of cells embedded in this bead is elusive. To elucidate this, a study using chondrocytes isolated from rabbit knee articular cartilage expanded in vitro as monolayer and chondrocyte-alginate constructs was conducted. Immunohistochemical evaluation and ECM distribution was examined with or without transforming growth factor (TGF-β1) supplement to determine the ability of cells to express major chondrogenic proteins in these environments. Histological examination followed by transmission electron microscopy and scanning electron microscopy was performed to determine the morphology and the ultrastructural characteristics of these cells. Results demonstrated a significant increase in glycosaminoglycan/mg protein levels in chondrocyte cultures grown in alginate construct than in monolayer cultures. In addition, an abundance of ECM protein distribution surrounding chondrocytes cultured in alginate hydrogel was observed. In conclusion, the current study demonstrates that the use of alginate hydrogel beads in chondrocyte cultures with or without TGF-β1 supplement provided superior ECM expression than monolayer cultures.
    Matched MeSH terms: Cell Culture Techniques/methods*
  10. Chua KH, Raduan F, Wan Safwani WK, Manzor NF, Pingguan-Murphy B, Sathapan S
    Cell Prolif, 2013 Jun;46(3):300-11.
    PMID: 23672290 DOI: 10.1111/cpr.12029
    OBJECTIVES: This study investigated effects of reduced serum condition and vascular endothelial growth factor (VEGF) on angiogenic potential of adipose stromal cells (ASCs) in vitro.

    MATERIALS AND METHODS: Adipose stromal cells were cultured in three different types of medium: (i) F12/DMEM (FD) supplemented with 10% FBS from passage 0 (P0) to P6; (ii) FD supplemented with 2% FBS at P6; and (iii) FD supplemented with 2% FBS plus 50 ng/ml of VEGF at P6. Morphological changes and growth rate of ASCs were recorded. Changes in stemness, angiogenic and endogenic genes' expressions were analysed using Real-Time PCR.

    RESULTS: Adipose stromal cells changed from fibroblast-like shape when cultured in 10% FBS medium to polygonal when cultured in 2% FBS plus VEGF-supplemented medium. Their growth rate was lower in 2% FBS medium, but increased with addition of VEGF. Real-Time PCR showed that ASCs maintained most of their stemness and angiogenic genes' expression in 10% FBS at P1, P5 and P6, but this increased significantly in 2% FBS at P6. Endogenic genes expression such as PECAM-1, VE chaderin and VEGFR-2 decreased after serial passage in 10% FBS, but increased significantly at P6 in 2% FBS. Addition of VEGF did not cause any significant change in gene expression level.

    CONCLUSION: Adipose stromal cells had greater angiogenic potential when cultured in reduced serum conditions. VEGF did not enhance their angiogenic potential in 2% FBS-supplemented medium.

    Matched MeSH terms: Cell Culture Techniques
  11. Romli F, Alitheen NB, Hamid M, Ismail R, Abd Rahman NM
    J Cell Biochem, 2013 Jun;114(6):1230-7.
    PMID: 23239017 DOI: 10.1002/jcb.24477
    The first successful attempt to reprogram somatic cell into embryonic-like stem cell was achieved on 2006. Since then, it had sparked a race against time to bring this wonderful invention from bench to bedside but it is not easily achieved due to severe problems in term of epigenetic and genomic. With each problem arise, new technique and protocol will be constructed to try to overcome it. This review addresses the various techniques made available to create iPSC with problems hogging down the technique.
    Matched MeSH terms: Cell Culture Techniques
  12. Fatimah SS, Chua K, Tan GC, Azmi TI, Tan AE, Abdul Rahman H
    Cytotherapy, 2013 Aug;15(8):1030-41.
    PMID: 23830235 DOI: 10.1016/j.jcyt.2013.05.003
    The aim of the present study was to evaluate the effects of air-liquid interface on the differentiation potential of human amnion epithelial cells (HAECs) to skin-like substitute in organotypic culture.
    Matched MeSH terms: Cell Culture Techniques
  13. Cheah SX, Tay JW, Chan LK, Jaal Z
    Parasitol Res, 2013 Sep;112(9):3275-82.
    PMID: 23835922 DOI: 10.1007/s00436-013-3506-0
    This study focuses on the larvicidal, oviposition, and ovicidal effects of a crude extract of Artemisia annua against Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus. Dried cells of Artemisia annua from cell suspension cultures were extracted using hexane. The extract showed moderate larvicidal effects against mosquitoes. At 24-h post treatment, the LC50 values for Anopheles sinensis, Aedes aegypti, and Culex quinquefasciatus were recorded as 244.55, 276.14, and 374.99 ppm, respectively. The percentage mortality of larvae was directly proportional to the tested concentration. Anopheles sinensis was found to be the most susceptible species, whereas Culex quinquefasciatus was the most tolerant to the Artemisia annua extract. The results indicated that the Artemisia annua extract showed concentration-dependent oviposition deterrent activity and had a strong deterrent effect. At 500 ppm, the percentage effective repellency was more than 85% compared with the control group for all the species, with oviposition activity index values of -0.94, -0.95, and -0.78 for Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus, respectively. In the ovicidal assay, the percentage hatchability of eggs after treatment with 500 ppm of Artemisia annua extract was significantly lower than the control, with values of 48.84 ± 4.08, 38.42 ± 3.67, and 79.35 ± 2.09% for Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus, respectively. Artemisia annua was found to be more effective against Aedes aegypti and Anopheles sinensis compared with Culex quinquefasciatus. This study indicated that crude extract of A. annua could be a potential alternative for use in vector management programs.
    Matched MeSH terms: Cell Culture Techniques
  14. Alkaisi A, Ismail AR, Mutum SS, Ahmad ZA, Masudi S, Abd Razak NH
    J Oral Maxillofac Surg, 2013 Oct;71(10):1758.e1-13.
    PMID: 24040948 DOI: 10.1016/j.joms.2013.05.016
    The main aim of the present study was to evaluate the capacity of stem cells from human exfoliated deciduous teeth (SHED) to enhance mandibular distraction osteogenesis (DO) in rabbits.
    Matched MeSH terms: Cell Culture Techniques
  15. Reshak AH, Shahimin MM, Buang F
    Prog Biophys Mol Biol, 2013 Nov;113(2):295-8.
    PMID: 24080186 DOI: 10.1016/j.pbiomolbio.2013.09.001
    Mammalian adipose tissue derived stem cells (AT-SC) have a tremendous potential in regenerative medicine for tissue engineering and somatic nuclear transfer (SNT). The isolation methods of human and bovine adipose tissue derived stem cells are compared in this paper to determine the feasibility and optimum method of isolation. The optimum isolation method will reduce the processing time, efforts and money as isolation is the first crucial and important step in stem cells research. Human abdominal subcutaneous adipose tissue and bovine abdominal subcutaneous adipose tissue are digested in three collagenase type 1 concentration 0.075%, 0.3% and 0.6% agitated at 1 h and 2 h under 37 °C in 5% CO2 incubator. The cultures are then morphologically characterised. Human adipose tissue stem cells are found to be best isolated using abdominal subcutaneous depot, using 0.075% collagenase type 1 agitated at 1 h under 37 °C in CO2 incubator. While bovine adipose tissue derived stem cells are best isolated using abdominal subcutaneous depot, using 0.6% collagenase type 1 agitated at 2 h under 37 °C in CO2 incubator.
    Matched MeSH terms: Cell Culture Techniques/methods
  16. Shah SA, Sultan S, Hassan NB, Muhammad FK, Faridz MA, Hussain FB, et al.
    Steroids, 2013 Dec 20;78(14):1312-24.
    PMID: 24135562 DOI: 10.1016/j.steroids.2013.10.001
    Structural modification of steroids through whole-cell biocatalysis is an invaluable procedure for the production of active pharmaceutical ingredients (APIs) and key intermediates. Modifications could be carried out with regio- and stereospecificity at positions hardly available for chemical agents. Much attention has been focused recently on the biotransformation of 17α-ethynyl substituted steroidal drugs using fungi, bacteria and plant cell cultures in order to obtained novel biologically active compounds with diverse structure features. Present article includes studies on biotransformation on 17α-ethynyl substituted steroidal drugs using microorganisms and plant cell cultures. Various experimental and structural elucidation methods used in biotransformational processes are also highlighted.
    Matched MeSH terms: Cell Culture Techniques
  17. Alshelmani MI, Loh TC, Foo HL, Lau WH, Sazili AQ
    ScientificWorldJournal, 2013;2013:689235.
    PMID: 24319380 DOI: 10.1155/2013/689235
    Nine aerobic cellulolytic bacterial cultures were obtained from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). The objectives of this study were to characterize the cellulolytic bacteria and to determine the optimum moisture ratio required for solid state fermentation (SSF) of palm kernel cake (PKC). The bacteria cultures were grown on reconstituted nutrient broth, incubated at 30°C and agitated at 200 rpm. Carboxymethyl cellulase, xylanase, and mannanase activities were determined using different substrates and after SSF of PKC. The SSF was conducted for 4 and 7 days with inoculum size of 10% (v/w) on different PKC concentration-to-moisture ratios: 1 : 0.2, 1 : 0.3, 1 : 0.4, and 1 : 0.5. Results showed that Bacillus amyloliquefaciens 1067 DSMZ, Bacillus megaterium 9885 ATCC, Paenibacillus curdlanolyticus 10248 DSMZ, and Paenibacillus polymyxa 842 ATCC produced higher enzyme activities as compared to other bacterial cultures grown on different substrates. The cultures mentioned above also produced higher enzyme activities when they were incubated under SSF using PKC as a substrate in different PKC-to-moisture ratios after 4 days of incubation, indicating that these cellulolytic bacteria can be used to degrade and improve the nutrient quality of PKC.
    Matched MeSH terms: Cell Culture Techniques/methods
  18. Haque N, Rahman MT, Abu Kasim NH, Alabsi AM
    ScientificWorldJournal, 2013;2013:632972.
    PMID: 24068884 DOI: 10.1155/2013/632972
    Cell-based regenerative therapies, based on in vitro propagation of stem cells, offer tremendous hope to many individuals suffering from degenerative diseases that were previously deemed untreatable. Due to the self-renewal capacity, multilineage potential, and immunosuppressive property, mesenchymal stem cells (MSCs) are considered as an attractive source of stem cells for regenerative therapies. However, poor growth kinetics, early senescence, and genetic instability during in vitro expansion and poor engraftment after transplantation are considered to be among the major disadvantages of MSC-based regenerative therapies. A number of complex inter- and intracellular interactive signaling systems control growth, multiplication, and differentiation of MSCs in their niche. Common laboratory conditions for stem cell culture involve ambient O₂ concentration (20%) in contrast to their niche where they usually reside in 2-9% O₂. Notably, O₂ plays an important role in maintaining stem cell fate in terms of proliferation and differentiation, by regulating hypoxia-inducible factor-1 (HIF-1) mediated expression of different genes. This paper aims to describe and compare the role of normoxia (20% O₂) and hypoxia (2-9% O₂) on the biology of MSCs. Finally it is concluded that a hypoxic environment can greatly improve growth kinetics, genetic stability, and expression of chemokine receptors during in vitro expansion and eventually can increase efficiency of MSC-based regenerative therapies.
    Matched MeSH terms: Cell Culture Techniques
  19. Puvaneswary S, Balaji Raghavendran HR, Ibrahim NS, Murali MR, Merican AM, Kamarul T
    Int J Med Sci, 2013;10(12):1608-14.
    PMID: 24151432 DOI: 10.7150/ijms.6496
    The objective of this study was to compare the morphological and chemical composition of bone graft (BG) and coral graft (CG) as well as their osteogenic differentiation potential using rabbit mesenchymal stem cells (rMSCs) in vitro. SEM analysis of BG and CG revealed that the pores in these grafts were interconnected, and their micro-CT confirmed pore sizes in the range of 107-315 µm and 103-514 µm with a total porosity of 92% and 94%, respectively. EDS analysis indicated that the level of calcium in CG was relatively higher than that in BG. FTIR of BG and CG confirmed the presence of functional groups corresponding to carbonyl, aromatic, alkyl, and alkane groups. XRD results revealed that the phase content of the inorganic layer comprised highly crystalline form of calcium carbonate and carbon. Atomic force microscopy analysis showed CG had better surface roughness compared to BG. In addition, significantly higher levels of osteogenic differentiation markers, namely, alkaline phosphatase (ALP), Osteocalcin (OC) levels, and Osteonectin and Runx2, Integrin gene expression were detected in the CG cultures, when compared with those in the BG cultures. In conclusion, our results demonstrate that the osteogenic differentiation of rMSCs is relatively superior in coral graft than in bone graft culture system.
    Matched MeSH terms: Cell Culture Techniques*
  20. Mohamed MS, Tan JS, Mohamad R, Mokhtar MN, Ariff AB
    ScientificWorldJournal, 2013;2013:948940.
    PMID: 24109209 DOI: 10.1155/2013/948940
    Mixotrophic metabolism was evaluated as an option to augment the growth and lipid production of marine microalga Tetraselmis sp. FTC 209. In this study, a five-level three-factor central composite design (CCD) was implemented in order to enrich the W-30 algal growth medium. Response surface methodology (RSM) was employed to model the effect of three medium variables, that is, glucose (organic C source), NaNO3 (primary N source), and yeast extract (supplementary N, amino acids, and vitamins) on biomass concentration, X(max), and lipid yield, P(max)/X(max). RSM capability was also weighed against an artificial neural network (ANN) approach for predicting a composition that would result in maximum lipid productivity, Pr(lipid). A quadratic regression from RSM and a Levenberg-Marquardt trained ANN network composed of 10 hidden neurons eventually produced comparable results, albeit ANN formulation was observed to yield higher values of response outputs. Finalized glucose (24.05 g/L), NaNO3 (4.70 g/L), and yeast extract (0.93 g/L) concentration, affected an increase of X(max) to 12.38 g/L and lipid a accumulation of 195.77 mg/g dcw. This contributed to a lipid productivity of 173.11 mg/L per day in the course of two-week cultivation.
    Matched MeSH terms: Cell Culture Techniques
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