Displaying publications 61 - 80 of 382 in total

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  1. Wan Safwani WK, Makpol S, Sathapan S, Chua KH
    PMID: 22221649 DOI: 10.1186/1477-5751-11-3
    Adipose tissue is a source of multipotent adult stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic cells and adipogenic cells. Several reports have shown adipose-derived stem cells (ASCs) have the ability to undergo cardiomyogenesis. Studies have shown 5-azacytidine can successfully drive stem cells such as bone marrow derived stem cells to differentiate into cardiomyogenic cells. Therefore, in this study, we investigated the effect 5-azacytidine on the cardiogenic ability of ASCs.
    Matched MeSH terms: Culture Media/pharmacology
  2. Chua KB, Chua IL, Chua IE, Chong KH, Chua KH
    Malays J Pathol, 2005 Dec;27(2):99-105.
    PMID: 17191392
    A mycological medium was developed for primary isolation and culture of lipophilic yeasts. It was initially based on published information of nutrients and trace components that would promote the growth of these yeasts. It was subsequently modified and adjusted to specifically promote the growth of lipophilic yeasts and simultaneously avoid the luxurious growth of other fungi and bacteria. With this medium, the conventional bacteriological procedures such as microbial streaking for pure culture and anti-microbial sensitivity testing could be carried out for these lipophilic yeasts.
    Matched MeSH terms: Culture Media/chemistry*
  3. Al-Masawa ME, Wan Kamarul Zaman WS, Chua KH
    Sci Rep, 2020 12 09;10(1):21583.
    PMID: 33299022 DOI: 10.1038/s41598-020-78395-y
    The scarcity of chondrocytes is a major challenge for cartilage tissue engineering. Monolayer expansion is necessary to amplify the limited number of chondrocytes needed for clinical application. Growth factors are often added to improve monolayer culture conditions, promoting proliferation, and enhancing chondrogenesis. Limited knowledge on the biosafety of the cell products manipulated with growth factors in culture has driven this study to evaluate the impact of growth factor cocktail supplements in chondrocyte culture medium on chondrocyte genetic stability and tumorigenicity. The growth factors were basic fibroblast growth factor (b-FGF), transforming growth factor β2 (TGF β2), insulin-like growth factor 1 (IGF-1), insulin-transferrin-selenium (ITS), and platelet-derived growth factor (PD-GF). Nasal septal chondrocytes cultured in growth factor cocktail exhibited a significantly high proliferative capacity. Comet assay revealed no significant DNA damage. Flow cytometry showed chondrocytes were mostly at G0-G1 phase, exhibiting normal cell cycle profile with no aneuploidy. We observed a decreased tumour suppressor genes' expression (p53, p21, pRB) and no TP53 mutations or tumour formation after 6 months of implantation in nude mice. Our data suggest growth factor cocktail has a low risk of inducing genotoxic and tumorigenic effects on chondrocytes up to passage 6 with 16.6 population doublings. This preclinical tumorigenicity and genetic instability evaluation is crucial for further clinical works.
    Matched MeSH terms: Culture Media/pharmacology*
  4. Mai-Ngam K, Chumningan P
    Med J Malaysia, 2004 May;59 Suppl B:137-8.
    PMID: 15468856
    Matched MeSH terms: Culture Media
  5. Wu YS, Looi CY, Subramaniam KS, Masamune A, Chung I
    Oncotarget, 2016 Jun 14;7(24):36719-36732.
    PMID: 27167341 DOI: 10.18632/oncotarget.9165
    Pancreatic stellate cells (PSC), a prominent stromal cell, contribute to the progression of pancreatic ductal adenocarcinoma (PDAC). We aim to investigate the mechanisms by which PSC promote cell proliferation in PDAC cell lines, BxPC-3 and AsPC-1. PSC-conditioned media (PSC-CM) induced proliferation of these cells in a dose- and time-dependent manner. Nrf2 protein was upregulated and subsequently, its transcriptional activity was increased with greater DNA binding activity and transcription of target genes. Downregulation of Nrf2 led to suppression of PSC-CM activity in BxPC-3, but not in AsPC-1 cells. However, overexpression of Nrf2 alone resulted in increased cell proliferation in both cell lines, and treatment with PSC-CM further enhanced this effect. Activation of Nrf2 pathway resulted in upregulation of metabolic genes involved in pentose phosphate pathway, glutaminolysis and glutathione biosynthesis. Downregulation and inhibition of glucose-6-phosphate-dehydrogenase with siRNA and chemical approaches reduced PSC-mediated cell proliferation. Among the cytokines present in PSC-CM, stromal-derived factor-1 alpha (SDF-1α) and interleukin-6 (IL-6) activated Nrf2 pathway to induce cell proliferation in both cells, as shown with neutralization antibodies, recombinant proteins and signaling inhibitors. Taken together, SDF-1α and IL-6 secreted from PSC induced PDAC cell proliferation via Nrf2-activated metabolic reprogramming and ROS detoxification.
    Matched MeSH terms: Culture Media, Conditioned/pharmacology
  6. Abdul Khalil K, Mustafa S, Mohammad R, Bin Ariff A, Shaari Y, Abdul Manap Y, et al.
    Biomed Res Int, 2014;2014:787989.
    PMID: 24527457 DOI: 10.1155/2014/787989
    This study was undertaken to optimize skim milk and yeast extract concentration as a cultivation medium for optimal Bifidobacteria pseudocatenulatum G4 (G4) biomass and β -galactosidase production as well as lactose and free amino nitrogen (FAN) balance after cultivation period. Optimization process in this study involved four steps: screening for significant factors using 2(3) full factorial design, steepest ascent, optimization using FCCD-RSM, and verification. From screening steps, skim milk and yeast extract showed significant influence on the biomass production and, based on the steepest ascent step, middle points of skim milk (6% wt/vol) and yeast extract (1.89% wt/vol) were obtained. A polynomial regression model in FCCD-RSM revealed that both factors were found significant and the strongest influence was given by skim milk concentration. Optimum concentrations of skim milk and yeast extract for maximum biomass G4 and β -galactosidase production meanwhile low in lactose and FAN balance after cultivation period were 5.89% (wt/vol) and 2.31% (wt/vol), respectively. The validation experiments showed that the predicted and experimental values are not significantly different, indicating that the FCCD-RSM model developed is sufficient to describe the cultivation process of G4 using skim-milk-based medium with the addition of yeast extract.
    Matched MeSH terms: Culture Media/metabolism; Culture Media/chemistry*
  7. Fui LW, Lok MPW, Govindasamy V, Yong TK, Lek TK, Das AK
    J Tissue Eng Regen Med, 2019 12;13(12):2218-2233.
    PMID: 31648415 DOI: 10.1002/term.2966
    Mesenchymal stem cells (MSCs) transplantation seems to be a promising new therapy for diabetic wound healing (DWH), and currently, arrays of MSCs from various sources ranging from umbilical, adipose to dental sources are available as a treatment modality for this disease. However, it now appears that only a fraction of transplanted cells actually assimilate and survive in host tissues suggesting that the major mechanism by which stem cells participate in tissue repair are most likely related to their secretome level. These include a wide range of growth factors, cytokines, and chemokines, which can be found from the conditioned medium (CM) used to culture the cells. Basic studies and preclinical work confirm that the therapeutic effect of CMs are comparable with the application of stem cells. This review describes in detail the wound healing process in diabetes and the cellular and biological factors that influence the process. Subsequently, through a comprehensive literature search of studies related to wound healing in diabetics, we aim to provide an overview of scientific merits of using MSCs-CM in the treatment of diabetic wound as well as the significant caveats, which restricts its potential use in clinical set-ups. To our best knowledge, this is one of the first review papers that collect the importance of stem cells as an alternative treatment to the DWH. We anticipate that the success of this treatment will have a significant clinical impact on diabetic wounds.
    Matched MeSH terms: Culture Media, Conditioned/metabolism; Culture Media, Conditioned/pharmacology
  8. Far FE, Al-Obaidi MMJ, Desa MNM
    J Mycol Med, 2018 Sep;28(3):486-491.
    PMID: 29753721 DOI: 10.1016/j.mycmed.2018.04.007
    BACKGROUND: Malassezia furfur is lipodependent yeast like fungus that causes superficial mycoses such as pityriasis versicolor and dandruff. Nevertheless, there are no standard reference methods to perform susceptibility test of Malassezia species yet.

    AIMS: Therefore, in this study, we evaluated the optimized culture medium for growth of this lipophilic yeast using modified leeming-Notman agar and colorimetric resazurin microtiter assay to assess antimycotic activity of fluconazole against M. furfur.

    RESULTS: The result showed that these assays were more adjustable for M. furfur with reliable and reproducible MIC end-point, by confirming antimycotic activity of fluconazole with MIC of 2μg/ml.

    CONCLUSION: We conclude that this method is considered as the rapid and effective susceptibility testing of M. furfur with fluconazole antifungal activity.

    Matched MeSH terms: Culture Media/chemistry
  9. Venugopal C, K S, Rai KS, Pinnelli VB, Kutty BM, Dhanushkodi A
    Curr Gene Ther, 2018;18(5):307-323.
    PMID: 30209999 DOI: 10.2174/1566523218666180913152615
    INTRODUCTION: Mesenchymal Stem Cell (MSC) therapy in recent years has gained significant attention. Though the functional outcomes following MSC therapy for neurodegenerative diseases are convincing, various mechanisms for the functional recovery are being debated. Nevertheless, recent studies convincingly demonstrated that recovery following MSC therapy could be reiterated with MSC secretome per se thereby shifting the dogma from cell therapy to cell "based" therapy. In addition to various functional proteins, stem cell secretome also includes extracellular membrane vesicles like exosomes. Exosomes which are of "Nano" size have attracted significant interest as they can pass through the bloodbrain barrier far easily than macro size cells or growth factors. Exosomes act as a cargo between cells to bring about significant alterations in target cells. As the importance of exosomes is getting unveil, it is imperial to carry out a comprehensive study to evaluate the neuroprotective potential of exosomes as compared to conventional co-culture or total condition medium treatments.

    OBJECTIVE: Thus, the present study is designed to compare the neuroprotective potential of MSC derived exosomes with MSC-condition medium or neuron-MSC-co-culture system against kainic acid induced excitotoxicity in in vitro condition. The study also aims at comparing the neuroprotective efficacy of exosomes/condition medium/co-culture of two MSC viz., neural crest derived human Dental Pulp Stem Cells (hDPSC) and human Bone-Marrow Mesenchymal Stem Cells (hBM-MSC) to identify the appropriate MSC source for treating neurodegenerative diseases.

    RESULT: Our results demonstrated that neuroprotective efficacy of MSC-exosomes is as efficient as MSC-condition medium or neuron-MSC co-culture system and treating degenerating hippocampal neurons with all three MSC based approaches could up-regulate host's endogenous growth factor expressions and prevent apoptosis by activating cell survival PI3K-B-cell lymphoma-2 (Bcl-2) pathway.

    CONCLUSION: Thus, the current study highlights the possibilities of treating neurodegenerative diseases with "Nano" size exosomes as opposed to transplanting billions of stem cells which inherit several disadvantages.

    Matched MeSH terms: Culture Media, Conditioned/pharmacology
  10. Senthilkumar S, Venugopal C, Parveen S, K S, Rai KS, Kutty BM, et al.
    Neurotoxicology, 2020 12;81:89-100.
    PMID: 32905802 DOI: 10.1016/j.neuro.2020.08.006
    Stem cell therapy provides a ray of hope for treating neurodegenerative diseases (ND). Bone marrow mesenchymal stem cells (BM-MSC) were extensively investigated for their role in neuroregeneration. However, drawbacks like painful bone marrow extraction, less proliferation and poor CNS engraftment following systemic injections of BM-MSC prompt us to search for alternate/appropriate source of MSC for treating ND. In this context, dental pulp stem cells (DPSC) could be an alternative to BM-MSC as it possess both mesenchymal and neural characteristic features due to its origin from ectoderm, ease of isolation, higher proliferation index and better neuroprotection. A study on the migration potential of DPSC compared to BM-MSC in a neurodegenerative condition is warranted. Given the neural crest origin, we hypothesize that DPSC possess better migration towards neurodegenerative milieu as compared to BM-MSC. In this prospect, we investigated the migration potential of DPSC in an in vitro neurodegenerative condition. Towards this, transwell, Matrigel and chorioallantoic membrane (CAM) migration assays were carried-out by seeding hippocampal neurons in the lower chamber and treated with 300 μM kainic acid (KA) for 6 h to induce neurodegeneration. Subsequently, the upper chamber of transwell was loaded with DPSC/BM-MSC and their migration potential was assessed following 24 h of incubation. Our results revealed that the migration potential of DPSC/BM-MSC was comparable in non-degenerative condition. However, following injury the migration potential of DPSC towards the degenerating site was significantly higher as compared to BM-MSC. Furthermore, upon exposure of naïve DPSC/BM-MSCs to culture medium derived from neurodegenerative milieu resulted in significant upregulation of homing factors like SDF-1alpha, CXCR-4, VCAM-1, VLA-4, CD44, MMP-2 suggesting that the superior migration potential of DPSC might be due to prompt expression of homing factors in DPSC compared to BM-MSCs.
    Matched MeSH terms: Culture Media, Conditioned/metabolism
  11. Liu G, Tiang MF, Ma S, Wei Z, Liang X, Sajab MS, et al.
    PeerJ, 2024;12:e16995.
    PMID: 38426145 DOI: 10.7717/peerj.16995
    BACKGROUND: Hermetia illucens (HI), commonly known as the black soldier fly, has been recognized for its prowess in resource utilization and environmental protection because of its ability to transform organic waste into animal feed for livestock, poultry, and aquaculture. However, the potential of the black soldier fly's high protein content for more than cheap feedstock is still largely unexplored.

    METHODS: This study innovatively explores the potential of H. illucens larvae (HIL) protein as a peptone substitute for microbial culture media. Four commercial proteases (alkaline protease, trypsin, trypsase, and papain) were explored to hydrolyze the defatted HIL, and the experimental conditions were optimized via response surface methodology experimental design. The hydrolysate of the defatted HIL was subsequently vacuum freeze-dried and deployed as a growth medium for three bacterial strains (Staphylococcus aureus, Bacillus subtilis, and Escherichia coli) to determine the growth kinetics between the HIL peptone and commercial peptone.

    RESULTS: The optimal conditions were 1.70% w/w complex enzyme (alkaline protease: trypsin at 1:1 ratio) at pH 7.0 and 54 °C for a duration of 4 h. Under these conditions, the hydrolysis of defatted HIL yielded 19.25% ±0.49%. A growth kinetic analysis showed no significant difference in growth parameters (μmax, Xmax, and λ) between the HIL peptone and commercial peptone, demonstrating that the HIL hydrolysate could serve as an effective, low-cost alternative to commercial peptone. This study introduces an innovative approach to HIL protein resource utilization, broadening its application beyond its current use in animal feed.

    Matched MeSH terms: Culture Media
  12. Ibrahim WN, Muizzuddin Bin Mohd Rosli L, Doolaanea AA
    Int J Nanomedicine, 2020;15:8059-8074.
    PMID: 33116518 DOI: 10.2147/IJN.S269340
    Introduction: Thymoquinone (TQ) is the main active compound extracted from Nigella sativa a traditional herb with wide therapeutic applications and recognizable anticancer properties. This study aimed to formulate and characterize TQ-nanoparticles using PLGA as a biocompatible coating material (TQ-PLGA NPs) with the evaluation of its therapeutic properties in human melanoma cancer cells.

    Methods: The TQ-PLGA NPs were prepared and characterized for size, zeta potential, encapsulation efficiency, and release profile.

    Results: The particle size was 147.2 nm, with 22.1 positive zeta potential and 96.8% encapsulation efficiency. The NPs released 45.6% of the encapsulated TQ within 3 h followed by characteristic sustained release over 7 days with a total of 69.7% cumulative release. TQ-PLGA NPs were taken up effectively by the cells in a time-dependent manner up to 24 h. Higher cell toxicity was determined within the first 24 h in melanoma cells due to the rapid release of TQ from the NPs and its low stability in the cell culture media.

    Conclusion: TQ-PLGA NPs is a potential anticancer agent taking advantage of the sustained release and tailored size that allows accumulation in the cancer tissue by the enhanced permeability and retention effect. However, stability problems of the active ingredient were address in this study and requires further investigation.

    Matched MeSH terms: Culture Media
  13. Wang Y, Lee SM, Dykes GA
    Biofouling, 2013;29(3):307-18.
    PMID: 23528127 DOI: 10.1080/08927014.2013.774377
    Tea can inhibit the attachment of Streptococcus mutans to surfaces and subsequent biofilm formation. Five commercial tea extracts were screened for their ability to inhibit attachment and biofilm formation by two strains of S. mutans on glass and hydroxyapatite surfaces. The mechanisms of these effects were investigated using scanning electron microscopy (SEM) and phytochemical screening. The results indicated that extracts of oolong tea most effectively inhibited attachment and extracts of pu-erh tea most effectively inhibited biofilm formation. SEM images showed that the S. mutans cells treated with extracts of oolong tea, or grown in medium containing extracts of pu-erh tea, were coated with tea components and were larger with more rounded shapes. The coatings on the cells consisted of flavonoids, tannins and indolic compounds. The ratio of tannins to simple phenolics in each of the coating samples was ∼3:1. This study suggests potential mechanisms by which tea components may inhibit the attachment and subsequent biofilm formation of S. mutans on tooth surfaces, such as modification of cell surface properties and blocking of the activity of proteins and the structures used by the bacteria to interact with surfaces.
    Matched MeSH terms: Culture Media/chemistry
  14. Teh AH, Lee SM, Dykes GA
    Curr Microbiol, 2016 Dec;73(6):859-866.
    PMID: 27623781
    Campylobacter jejuni is one of the most common causes of bacterial gastrointestinal food-borne infection worldwide. It has been suggested that biofilm formation may play a role in survival of these bacteria in the environment. In this study, the influence of prior modes of growth (planktonic or sessile), temperatures (37 and 42 °C), and nutrient conditions (nutrient broth and Mueller-Hinton broth) on biofilm formation by eight C. jejuni strains with different antibiotic resistance profiles was examined. The ability of these strains to form biofilm on different abiotic surfaces (stainless steel, glass, and polystyrene) as well as factors potentially associated with biofilm formation (bacterial surface hydrophobicity, auto-aggregation, and initial attachment) was also determined. The results showed that cells grown as sessile culture generally have a greater ability to form biofilm (P media, while growth at different temperatures affects biofilm formation in a strain-dependent manner. The strains were able to attach and form biofilms on different abiotic surfaces, but none of them demonstrated strong, complex, or structured biofilm formation. There were no clear trends between the bacterial surface hydrophobicity, auto-aggregation, attachment, and biofilm formation by the strains. This finding suggests that environmental factors did affect biofilm formation by C. jejuni, and they are more likely to persist in the environment in the form of mixed-species rather than monospecies biofilms.
    Matched MeSH terms: Culture Media/metabolism*; Culture Media/chemistry
  15. Teh AHT, Lee SM, Dykes GA
    Food Microbiol, 2017 Feb;61:120-125.
    PMID: 27697161 DOI: 10.1016/j.fm.2016.09.008
    Campylobacter jejuni survival in aerobic environments has been suggested to be mediated by biofilm formation. Biofilm formation by eight C. jejuni strains under both aerobic and microaerobic conditions in different broths (Mueller-Hinton (MH), Bolton and Brucella) was quantified. The dissolved oxygen (DO) content of the broths under both incubation atmospheres was determined. Biofilm formation for all strains was highest in MH broth under both incubation atmospheres. Four strains had lower biofilm formation in MH under aerobic as compared to microaerobic incubation, while biofilm formation by the other four strains did not differ under the 2 atm. Two strains had higher biofilm formation under aerobic as compared to microaerobic atmospheres in Bolton broth. Biofilm formation by all other strains in Bolton, and all strains in Brucella broth, did not differ under the 2 atm. Under aerobic incubation DO levels in MH > Brucella > Bolton broth. Under microaerobic conditions levels in MH = Brucella > Bolton broth. Levels of DO in MH and Brucella broth were lower under microaerobic conditions but those of Bolton did not differ under the 2 atm. Experimental conditions and especially the DO of broth media confound previous conclusions drawn about aerobic biofilm formation by C. jejuni.
    Matched MeSH terms: Culture Media/chemistry*
  16. Alsaheb RA, Zjeh KZ, Malek RA, Abdullah JK, El Baz A, El Deeb N, et al.
    Recent Pat Food Nutr Agric, 2020;11(3):211-218.
    PMID: 32178622 DOI: 10.2174/2212798411666200316153148
    BACKGROUND: For many years, Ganoderma was highly considered as biofactory for the production of different types of bioactive metabolites. Of these bioactive compounds, polysaccharides gained much attention based on their high biotherapeutic properties. Therefore, special attention has been paid during the last years for the production of mushrooms bioactive compounds in a closed cultivation system to shorten the cultivation time and increase the product yield.

    OBJECTIVES: This work focuses on the development of a simple cultivation strategy for exopolysaccharides (EPS) production using Ganoderma lucidum and submerged cultivation system.

    METHODS: At first, the best medium supporting EPS production was chosen experimentally from the current published data. Second, like many EPS production processes, carbon and nitrogen concentrations were optimized to support the highest production of polysaccharides in the shake flask level. Furthermore, the process was scaled up in 16-L stirred tank bioreactor.

    RESULTS: The results clearly demonstrated that the best cultivation strategy was cultivation under controlled pH conditions (pH 5.5). Under this condition, the maximal volumetric and specific yield of EPS production were, 5.0 g/L and 0.42 g/g, respectively.

    CONCLUSION: The current results clearly demonstrate the high potential use of submerged cultivation system as an alternative to conventional solid-state fermentation for EPS production by G. lucidum. Furthermore, the optimization of both carbon and nitrogen sources concentration and scaling up of the process showed a significant increase in both volumetric and specific EPS production.

    Matched MeSH terms: Culture Media
  17. Elsayed EA, Farid MA, El-Enshasy HA
    BMC Biotechnol, 2019 07 16;19(1):46.
    PMID: 31311527 DOI: 10.1186/s12896-019-0546-2
    BACKGROUND: Natamycin is an antifungal polyene macrolide antibiotic with wide applications in health and food industries. Currently, it is the only antifungal food additive with the GRAS status (Generally Regarded as Safe).

    RESULTS: Natamycin production was investigated under the effect of different initial glucose concentrations. Maximal antibiotic production (1.58 ± 0.032 g/L) was achieved at 20 g/L glucose. Under glucose limitation, natamycin production was retarded and the produced antibiotic was degraded. Higher glucose concentrations resulted in carbon catabolite repression. Secondly, intermittent feeding of glucose improved natamycin production due to overcoming glucose catabolite regulation, and moreover it was superior to glucose-beef mixture feeding, which overcomes catabolite regulation, but increased cell growth on the expense of natamycin production. Finally, the process was optimized in 7.5 L stirred tank bioreactor under batch and fed-batch conditions. Continuous glucose feeding for 30 h increased volumetric natamycin production by about 1.6- and 1.72-folds in than the batch cultivation in bioreactor and shake-flasks, respectively.

    CONCLUSIONS: Glucose is a crucial substrate that significantly affects the production of natamycin, and its slow feeding is recommended to alleviate the effects of carbon catabolite regulation as well as to prevent product degradation under carbon source limitation. Cultivation in bioreactor under glucose feeding increased maximal volumetric enzyme production by about 72% from the initial starting conditions.

    Matched MeSH terms: Culture Media/metabolism; Culture Media/chemistry
  18. Sayyed RZ, Wani SJ, Alarfaj AA, Syed A, El-Enshasy HA
    PLoS One, 2020;15(1):e0220095.
    PMID: 31910206 DOI: 10.1371/journal.pone.0220095
    There are numerous reports on poly-β-hydroxybutyrate (PHB) depolymerases produced by various microorganisms isolated from various habitats, however, reports on PHB depolymerase production by an isolate from plastic rich sites scares. Although PHB has attracted commercial significance, the inefficient production and recovery methods, inefficient purification of PHB depolymerase and lack of ample knowledge on PHB degradation by PHB depolymerase have hampered its large scale commercialization. Therefore, to ensure the biodegradability of biopolymers, it becomes imperative to study the purification of the biodegrading enzyme system. We report the production, purification, and characterization of extracellular PHB depolymerase from Stenotrophomonas sp. RZS7 isolated from a dumping yard rich in plastic waste. The isolate produced extracellular PHB depolymerase in the mineral salt medium (MSM) at 30°C during 4 days of incubation under shaking. The enzyme was purified by three methods namely ammonium salt precipitation, column chromatography, and solvent purification. Among these purification methods, the enzyme was best purified by column chromatography on the Octyl-Sepharose CL-4B column giving optimum yield (0.7993 Umg-1mL-1). The molecular weight of purified PHB depolymerase was 40 kDa. Studies on the assessment of biodegradation of PHB in liquid culture medium and under natural soil conditions confirmed PHB biodegradation potential of Stenotrophomonas sp. RZS7. The results obtained in Fourier-Transform Infrared (FTIR) analysis, High-Performance Liquid Chromatography (HPLC) study and Gas Chromatography Mass-Spectrometry (GC-MS) analysis confirmed the biodegradation of PHB in liquid medium by Stenotrophomonas sp. RZS7. Changes in surface morphology of PHB film in soil burial as observed in Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the biodegradation of PHB under natural soil environment. The isolate was capable of degrading PHB and it resulted in 87.74% biodegradation. A higher rate of degradation under the natural soil condition is the result of the activity of soil microbes that complemented the biodegradation of PHB by Stenotrophomonas sp. RZS7.
    Matched MeSH terms: Culture Media/chemistry
  19. Alalayah WM, Kalil MS, Kadhum AA, Jahim J, Zaharim A, Alauj NM, et al.
    Pak J Biol Sci, 2010 Jul 15;13(14):674-82.
    PMID: 21848059
    Box-Wilson design (BWD) model was applied to determine the optimum values of influencing parameters in anaerobic fermentation to produce hydrogen using Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564). The main focus of the study was to find the optimal relationship between the hydrogen yield and three variables including initial substrate concentration, initial medium pH and reaction temperature. Microbial growth kinetic parameters for hydrogen production under anaerobic conditions were determined using the Monod model with incorporation of a substrate inhibition term. The values of micro(max) (maximum specific growth rate) and K, (saturation constant) were 0.398 h(-1) and 5.509 g L(-1), respectively, using glucose as the substrate. The experimental substrate and biomass-concentration profiles were in good agreement with those obtained by the kinetic-model predictions. By varying the conditions of the initial substrate concentration (1-40 g L(-1)), reaction temperature (25-40 degrees C) and initial medium pH (4-8), the model predicted a maximum hydrogen yield of 3.24 mol H2 (mol glucose)(-1). The experimental data collected utilising this design was successfully fitted to a second-order polynomial model. An optimum operating condition of 10 g L(-1) initial substrate concentration, 37 degrees C reaction temperature and 6.0 +/- 0.2 initial medium pH gave 80% of the predicted maximum yield of hydrogen where as the experimental yield obtained in this study was 77.75% exhibiting a close accuracy between estimated and experimental values. This is the first report to predict bio-hydrogen yield by applying Box-Wilson Design in anaerobic fermentation while optimizing the effects of environmental factors prevailing there by investigating the effects of environmental factors.
    Matched MeSH terms: Culture Media/chemistry
  20. Khoo BY, Miswan N, Balaram P, Nadarajan K, Elstner E
    Int J Mol Sci, 2012;13(5):5607-27.
    PMID: 22754319 DOI: 10.3390/ijms13055607
    In the present study, we aimed to preincubate MCF-10A cells with pioglitazone and/or serum-rich growth media and to determine adhesive and non-adhesive interactions of the preincubated MCF-10A cells with BT-474 cells. For this purpose, the MCF-10A cells were preincubated with pioglitazone and/or serum-rich growth media, at appropriate concentrations, for 1 week. The MCF-10A cells preincubated with pioglitazone and/or serum-rich growth media were then co-cultured adhesively and non-adhesively with BT-474 cells for another week. Co-culture of BT-474 cells with the preincubated MCF-10A cells, both adhesively and non-adhesively, reduced the growth of the cancer cells. The inhibitory effect of the preincubated MCF-10A cells against the growth of BT-474 cells was likely produced by increasing levels of soluble factors secreted by the preincubated MCF-10A cells into the conditioned medium, as immunoassayed by ELISA. However, only an elevated level of a soluble factor distinguished the conditioned medium collected from the MCF-10A cells preincubated with pioglitazone and serum-rich growth medium than that with pioglitazone alone. This finding was further confirmed by the induction of the soluble factor transcript expression in the preincubated MCF-10A cells, as determined using real-time PCR, for the above phenomenon. Furthermore, modification of the MCF-10A cells through preincubation did not change the morphology of the cells, indicating that the preincubated cells may potentially be injected into mammary fat pads to reduce cancer growth in patients or to be used for others cell-mediated therapy.
    Matched MeSH terms: Culture Media, Conditioned/metabolism; Culture Media, Conditioned/pharmacology*
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