Displaying publications 81 - 100 of 120 in total

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  1. Synovial sarcoma: a rare presentation of parapharyngeal mass
    Shaariyah MM, Mazita A, Masaany M, Razif MY, Isa MR, Asma A
    Chin J Cancer, 2010 Jun;29(6):631-3.
    PMID: 20507738
    Synovial sarcoma is a rare soft tissue sarcoma of the head and neck region involving the parapharyngeal space. The diagnosis of synovial sarcoma can be very challenging to the pathologists. We present a rare case of parapharyngeal synovial sarcoma in a young female patient who had a two-month history of left cervical intumescent mass at level II. The fine needle aspiration cytology of the mass was proved inconclusive. Transcervical excision of the mass was performed and the first case of parapharyngeal sarcoma was identified in our center by fluorescence in situ hybridization (FISH) technique. Repeat imaging revealed residual tumor. The patient successfully underwent a second excision of the residual tumor and received adjuvant radiotherapy.
  2. ProLysED: an integrated database and meta-server of bacterial protease systems
    Firdaus Raih M, Ahmad HA, Sharum MY, Azizi N, Mohamed R
    Appl. Bioinformatics, 2005;4(2):147-50.
    PMID: 16128617
    Bacterial proteases are an important group of enzymes that have very diverse biochemical and cellular functions. Proteases from prokaryotic sources also have a wide range of uses, either in medicine as pathogenic factors or in industry and therapeutics. ProLysED (Prokaryotic Lysis Enzymes Database), our meta-server integrated database of bacterial proteases, is a useful, albeit very niche, resource. The features include protease classification browsing and searching, organism-specific protease browsing, molecular information and visualisation of protease structures from the Protein Data Bank (PDB) as well as predicted protease structures.
  3. Fulltext Artificial Neural Networks (ANNs) and Response Surface Methodology (RSM) Approach for Modelling the Optimization of Chromium (VI) Reduction by Newly Isolated Acinetobacter radioresistens Strain NS-MIE from Agricultural Soil
    Ram Talib NS, Halmi MIE, Abd Ghani SS, Zaidan UH, Shukor MYA
    Biomed Res Int, 2019;2019:5785387.
    PMID: 31240217 DOI: 10.1155/2019/5785387
    Numerous technologies and approaches have been used in the past few decades to remove hexavalent chromium (Cr[VI]) in wastewater and the environment. However, these conventional technologies are not economical and efficient in removing Cr(VI) at a very low concentration (1-100 ppm). As an alternative, the utilization of bioremediation techniques which uses the potential of microorganisms could represent an effective technique for the detoxification of Cr(VI). In this study, we reported a newly isolated bacterium identified as Acinetobacter radioresistens sp. NS-MIE from Malaysian agricultural soil. The chromate reduction potential of strain NS-MIE was optimized using RSM and ANN techniques. The optimum condition predicted by RSM for the bacterium to reduce hexavalent chromium occurred at pH 6, 10 g/L ppm of nutrient broth (NB) concentration and 100 ppm of chromate concentration while the optimum condition predicted by ANN is at pH 6 and 10 g/L of NB concentration and of 60 ppm of chromate concentration with chromate reduction (%) of 75.13 % and 96.27 %, respectively. The analysis by the ANN model shows better prediction data with a higher R2 value of 0.9991 and smaller average absolute deviation (AAD) and root mean square error (RMSE) of 0.33 % and 0.302 %, respectively. Validation analysis showed the predicted values by RSM and ANN were close to the validation values, whereas the ANN showed the lowest deviation, 2.57%, compared to the RSM. This finding suggests that the ANN showed a better prediction and fitting ability compared to the RSM for the nonlinear regression analysis. Based on this study, A. radioresistens sp. NS-MIE exhibits strong potential characteristics as a candidate for the bioremediation of hexavalent chromium in the environment.
  4. Fulltext Effective production of keratinase by gellan gum-immobilised Alcaligenes sp. AQ05-001 using heavy metal-free and polluted feather wastes as substrates
    Yusuf I, Ahmad SA, Phang LY, Yasid NA, Shukor MY
    3 Biotech, 2019 Jan;9(1):32.
    PMID: 30622870 DOI: 10.1007/s13205-018-1555-x
    The ability of gellan gum-immobilised cells of the heavy metal-tolerant bacterium Alcaligenes sp. AQ05-001 to utilise both heavy metal-free and heavy metal-polluted feathers (HMPFs) as substrates to produce keratinase enzyme was studied. Optimisation of the media pH, incubation temperature and immobilisation parameters (bead size, bead number, gellan gum concentration) was determined for the best possible production of keratinase using the one-factor-at-a-time technique. The results showed that the immobilised cells could tolerate a broader range of heavy metal concentrations and produced higher keratinase activity at a gellan gum concentration of 0.8% (w/v), a bead size of 3 mm, bead number of 250, pH of 8 and temperature of 30 °C. The entrapped bacterium was used repeatedly for ten cycles to produce keratinase using feathers polluted with 25 ppm of Co, Cu and Ag as substrates without the need for desorption. However, its inability to tolerate/utilise feathers polluted with Hg, Pb, and Zn above 5 ppm, and Ag and Cd above 10 ppm resulted in a considerable decrease in keratinase production. Furthermore, the immobilised cells could retain approximately 95% of their keratinase production capacity when 5 ppm of Co, Cu, and Ag, and 10 ppm of As and Cd were used to pollute feathers. When the feathers containing a mixture of Ag, Co, and Cu at 25 ppm each and Hg, Ni, Pb, and Zn at 5 ppm each were used as substrates, the immobilised cells maintained their operational stability and biological activity (keratinase production) at the end of 3rd and 4th cycles, respectively. The study indicates that HMPF can be effectively utilised as a substrate by the immobilised-cell system of Alcaligenes sp. AQ05-001 for the semi-continuous production of keratinase enzyme.
  5. In vivo and in vitro effects on cholinesterase of blood of Oreochromis mossambicus by copper
    Basirun AA, Ahmad SA, Sabullah MK, Yasid NA, Daud HM, Khalid A, et al.
    3 Biotech, 2019 Feb;9(2):64.
    PMID: 30729088 DOI: 10.1007/s13205-019-1592-0
    The present study is aimed to evaluate the effects of sub-acute toxicity testing of copper sulphate (CuSO4), on behavioural, histological and biochemical changes of the Oreochromis mossambicus (black tilapia) blood tissues. The effects were assessed according to the previous results on sub-acute toxicity test after exposing fish to several concentrations (0.0, 2.5, 5.0, and 10.0 mg/L). The observations of scanning electron microscope, and transmission electron microscope studies revealed severe histopathological changes on the surface and the cellular changes in blood tissues, respectively. The morphological alterations in blood involved irregular structure of red blood cell and blood clot formation. CuSO4 affected the biochemical alteration of the blood cholinesterase also known as serum cholinesterase (ChE). Blood ChE inhibited up to 80% of activity when exposed to 10.0 mg/L CuSO4. The findings from this study can further improve the quality standards of aquaculture industry and the fundamental basis in selecting suitable strains among freshwater fish species to be used as bioindicator.
  6. Fulltext Improvement of Ficin-Based Inhibitive Enzyme Assay for Toxic Metals Using Response Surface Methodology and Its Application for Near Real-Time Monitoring of Mercury in Marine Waters
    Uba G, Manogaran M, Gunasekaran B, Halmi MIE, Shukor MYA
    Int J Environ Res Public Health, 2020 11 19;17(22).
    PMID: 33227985 DOI: 10.3390/ijerph17228585
    Potentially toxic metals pollution in the Straits of Malacca warrants the development of rapid, simple and sensitive assays. Enzyme-based assays are excellent preliminary screening tools with near real-time potential. The heavy-metal assay based on the protease ficin was optimized for mercury detection using response surface methodology. The inhibitive assay is based on ficin action on the substrate casein and residual casein is determined using the Coomassie dye-binding assay. Toxic metals strongly inhibit this hydrolysis. A central composite design (CCD) was utilized to optimize the detection of toxic metals. The results show a marked improvement for the concentration causing 50% inhibition (IC50) for mercury, silver and copper. Compared to one-factor-at-a-time (OFAT) optimization, RSM gave an improvement of IC50 (mg/L) from 0.060 (95% CI, 0.030-0.080) to 0.017 (95% CI, 0.016-0.019), from 0.098 (95% CI, 0.077-0.127) to 0.028 (95% CI, 0.022-0.037) and from 0.040 (95% CI, 0.035-0.045) to 0.023 (95% CI, 0.020-0.027), for mercury, silver and copper, respectively. A near-real time monitoring of mercury concentration in the Straits of Malacca at one location in Port Klang was carried out over a 4 h interval for a total of 24 h and validated by instrumental analysis, with the result revealing an absence of mercury pollution in the sampling site.
  7. Fulltext Comparison of Joint Effect of Acute and Chronic Toxicity for Combined Assessment of Heavy Metals on Photobacterium sp.NAA-MIE
    Adnan NA, Halmi MIE, Abd Gani SS, Zaidan UH, Abd Shukor MY
    Int J Environ Res Public Health, 2021 06 21;18(12).
    PMID: 34205553 DOI: 10.3390/ijerph18126644
    Predicting the crucial effect of single metal pollutants against the aquatic ecosystem has been highly debatable for decades. However, dealing with complex metal mixtures management in toxicological studies creates a challenge, as heavy metals may evoke greater toxicity on interactions with other constituents rather than individually low acting concentrations. Moreover, the toxicity mechanisms are different between short term and long term exposure of the metal toxicant. In this study, acute and chronic toxicity based on luminescence inhibition assay using newly isolated Photobacterium sp.NAA-MIE as the indicator are presented. Photobacterium sp.NAA-MIE was exposed to the mixture at a predetermined ratio of 1:1. TU (Toxicity Unit) and MTI (Mixture Toxic Index) approach presented the mixture toxicity of Hg2+ + Ag+, Hg2+ + Cu2+, Ag+ + Cu2+, Hg2+ + Ag+ + Cu2+, and Cd2+ + Cu2+ showed antagonistic effect over acute and chronic test. Binary mixture of Cu2+ + Zn2+ was observed to show additive effect at acute test and antagonistic effect at chronic test while mixture of Ni2+ + Zn2+ showing antagonistic effect during acute test and synergistic effect during chronic test. Thus, the strain is suitable and their use as bioassay to predict the risk assessment of heavy metal under acute toxicity without abandoning the advantage of chronic toxicity extrapolation.
  8. Fulltext Isolation and Characterisation of a Molybdenum-reducing and Metanil Yellow Dye-decolourising Bacillus sp. strain Neni-10 in Soils from West Sumatera, Indonesia
    Mansur R, Gusmanizar N, Roslan MA, Ahmad SA, Shukor MY
    Trop Life Sci Res, 2017 Jan;28(1):69-90.
    PMID: 28228917 MyJurnal DOI: 10.21315/tlsr2017.28.1.5
    A molybdenum reducing bacterium with the novel ability to decolorise the azo dye Metanil Yellow is reported. Optimal conditions for molybdenum reduction were pH 6.3 and at 34°C. Glucose was the best electron donor. Another requirement includes a narrow phosphate concentration between 2.5 and 7.5 mM. A time profile of Mo-blue production shows a lag period of approximately 12 hours, a maximum amount of Mo-blue produced at a molybdate concentration of 20 mM, and a peak production at 52 h of incubation. The heavy metals mercury, silver, copper and chromium inhibited reduction by 91.9, 82.7, 45.5 and 17.4%, respectively. A complete decolourisation of the dye Metanil Yellow at 100 and 150 mg/L occurred at day three and day six of incubations, respectively. Higher concentrations show partial degradation, with an approximately 20% decolourisation observed at 400 mg/L. The bacterium is partially identified based on biochemical analysis as Bacillus sp. strain Neni-10. The absorption spectrum of the Mo-blue suggested the compound is a reduced phosphomolybdate. The isolation of this bacterium, which shows heavy metal reduction and dye-decolorising ability, is sought after, particularly for bioremediation.
  9. Fulltext Mometasone furoate intranasal spray is effective in reducing symptoms and adenoid size in children and adolescents with adenoid hypertrophy
    Ghafar MHA, Mohamed H, Mohammad NMY, Mohammad ZW, Madiadipoera T, Wang Y, et al.
    Acta Otorrinolaringol Esp (Engl Ed), 2019 08 07;71(3):147-153.
    PMID: 31400807 DOI: 10.1016/j.otorri.2019.04.004
    INTRODUCTION: The use of mometasone furoate (MF) intranasal spray in treating adenoid hypertrophy (AH) has a variable outcome due the different methods of adenoid size evaluation. The aim of our study was to evaluate the effect of MF intranasal spray in children and adolescents with AH using a reliable and consistent endoscopic evaluation.

    MATERIAL AND METHOD: A prospective interventional study was conducted. Evaluation took place during the first visit (week 0) and second visit (week 12). Symptoms of nasal obstruction, rhinorrhoea, cough and snoring were assessed, and an overall total symptoms score was obtained. A rigid nasoendoscopic examination using a four-grading system of adenoid size from 1 to 4 was performed. Patients were treated with MF intranasal spray for 12 weeks. Patients' aged 7-11-years old used 1 spray in each nostril once daily, while patients aged 12-17 used two sprays in each nostril once daily. Reassessment was carried out during the second visit (week 12).

    RESULTS: A total of 74 patients was recruited. There were significant improvements from week 0 to week 12 in the symptoms' score for nose obstruction, rhinorrhoea, cough, snoring including the total nasal symptoms' score (p<0.001). AH significantly reduced in size from week 0 (2.89±.87) to week 12 (1.88±.83) (p<0.001).

    CONCLUSION: MF intranasal spray is effective in improving the symptoms attributed to AH as well as reducing the adenoid size. MF intranasal spray is advocated as a treatment option before adenoidectomy is considered.

  10. Fulltext Microbial Decolorization of Triazo Dye, Direct Blue 71: An Optimization Approach Using Response Surface Methodology (RSM) and Artificial Neural Network (ANN)
    Zin KM, Effendi Halmi MI, Abd Gani SS, Zaidan UH, Samsuri AW, Abd Shukor MY
    Biomed Res Int, 2020;2020:2734135.
    PMID: 32149095 DOI: 10.1155/2020/2734135
    The release of wastewater from textile dyeing industrial sectors is a huge concern with regard to pollution as the treatment of these waters is truly a challenging process. Hence, this study investigates the triazo bond Direct Blue 71 (DB71) dye decolorization and degradation dye by a mixed bacterial culture in the deficiency source of carbon and nitrogen. The metagenomics analysis found that the microbial community consists of a major bacterial group of Acinetobacter (30%), Comamonas (11%), Aeromonadaceae (10%), Pseudomonas (10%), Flavobacterium (8%), Porphyromonadaceae (6%), and Enterobacteriaceae (4%). The richest phylum includes Proteobacteria (78.61%), followed by Bacteroidetes (14.48%) and Firmicutes (3.08%). The decolorization process optimization was effectively done by using response surface methodology (RSM) and artificial neural network (ANN). The experimental variables of dye concentration, yeast extract, and pH show a significant effect on DB71 dye decolorization percentage. Over a comparative scale, the ANN model has higher prediction and accuracy in the fitness compared to the RSM model proven by approximated R2 and AAD values. The results acquired signify an efficient decolorization of DB71 dye by a mixed bacterial culture.
  11. Bioluminescent method for the rapid screening of toxic heayy metals in environmental samples using Photobacterium leiognathi strain AK-MIE
    Kassim A, Halmi MIE, Gani SSA, Zaidan UH, Othman R, Mahmud K, et al.
    Ecotoxicol Environ Saf, 2020 Jun 15;196:110527.
    PMID: 32278138 DOI: 10.1016/j.ecoenv.2020.110527
    Assessment of eco-toxicant using bioluminescent bacterial assay is a widely used and globally accepted method. In this work, a new luminescent bacterium was isolated from squid (Loligo duvauceli) and identified as Photobacterium leiognathi strain AK-MIE using 16S rRNA, phylogeny analysis. The predicted optimum conditions by RSM were 2.76% (w/v) NaCl, 2.28% (w/v) peptone, 0.34% (w/v) yeast extract, and pH 6.83 with 541,211.80 RLU of luminescent production whereas the predicted optimum conditions by ANN were 2.21% (w/v) NaCl, 2.27% (w/v) peptone, 0.39% (w/v) yeast extract, and pH 6.94 which produced 541,986.20 RLU. The validation analysis of both RSM and ANN show 0.60% and 0.69% deviation from the predicted results indicating that both models provided good quality predictions with ANN showing a superior data fitting capability for non-linear regression analysis. Toxicity tests show strain AK-MIE was sensitive to mercury (concentration causing 50% inhibition or IC50 of 0.00978 mgL-1), followed by cadmium (IC50 of 0.5288 mgL-1), copper IC50 of (0.8117 mgL-1), silver (IC50 of 1.109 mgL-1), and lead (IC50 of 10.71 mgL-1) which are more sensitive than previously isolated luminescent bacteria, suggesting that strain AK-MIE has the potential to be used in toxicity assessment of heavy metals in the environment. Based on the field trial results, several sediment samples from industrial areas in Bangi, Selangor managed to inhibit the bioluminescence of strain AK-MIE. Validation method carried out using ICP-MS proved the presence of several toxic heavy metal elements.
  12. Fulltext Hyperdiploid Multiple Myeloma with Novel Complex Structural Chromosome Abnormalities Associated with Poor Prognosis : A Rare Case Report
    Ankathil R, Foong E, Siti-Mariam I, Norhidayah R, Nazihah MY, Sangeetha V, et al.
    Int J Hematol Oncol Stem Cell Res, 2021 Jul 01;15(3):199-205.
    PMID: 35083001 DOI: 10.18502/ijhoscr.v15i3.6852
    Hyperdiploid multiple myeloma (MM) is associated with better prognosis and non-hyperdiploid subtype is associated with variable to adverse prognosis based on the nature of karyotype abnormality.  Rarely exceptions to this hyperdiploid and non-hyperdiploid divisions do exist in a minority. We report an adult male MM patient who showed hyperdiploid karyotype with few novel complex abnormalities and who showed poor clinical outcome. Conventional cytogenetic analysis carried out in 22 GTG banded metaphases showed 53,Y,der(X)t(X;22)(q27;q11.2),+3,+5,+6,+9,+11,+15,der(17)ins(17;1;3)(q11.2;?;?),der(17)ins(17;1;3)(q11.2;?;?),+19,-22,+mar karyotype pattern in 15 metaphases whereas 7 metaphases showed 46,XY karyotype  pattern.  Interphase FISH revealed biallelic del(13q14) and del(17p13) but no translocations involving the 14q32 region. Through Spectral karyotyping FISH, the origin of complex abnormalities involving der(17) chromosome,  translocation t(X;22), and marker chromosome could be clearly delineated. Although the present case showed hyperdiploid karyotype, he showed an adverse prognosis probably due to the co-existence of high risk and complex abnormalities and expired 5 months after initial diagnosis despite standard treatment given.
  13. Fulltext Batch growth kinetic studies of locally isolated cyanide-degrading Serratia marcescens strain AQ07
    Karamba KI, Ahmad SA, Zulkharnain A, Yasid NA, Ibrahim S, Shukor MY
    3 Biotech, 2018 Jan;8(1):11.
    PMID: 29259886 DOI: 10.1007/s13205-017-1025-x
    The evaluation of degradation and growth kinetics of Serratia marcescens strain AQ07 was carried out using three half-order models at all the initial concentrations of cyanide with the values of regression exceeding 0.97. The presence of varying cyanide concentrations reveals that the growth and degradation of bacteria were affected by the increase in cyanide concentration with a total halt at 700 ppm KCN after 72 h incubation. In this study, specific growth and degradation rates were found to trail the substrate inhibition kinetics. These two rates fitted well to the kinetic models of Teissier, Luong, Aiba and Heldane, while the performance of Monod model was found to be unsatisfactory. These models were used to clarify the substrate inhibition on the bacteria growth. The analyses of these models have shown that Luong model has fitted the experimental data with the highest coefficient of determination (R2) value of 0.9794 and 0.9582 with the lowest root mean square error (RMSE) value of 0.000204 and 0.001, respectively, for the specific rate of degradation and growth. It is the only model that illustrates the maximum substrate concentration (Sm) of 713.4 and empirical constant (n) of 1.516. Tessier and Aiba fitted the experimental data with a R2 value of 0.8002 and 0.7661 with low RMSE of 0.0006, respectively, for specific biodegradation rate, while having a R2 value of 0.9 and RMSE of 0.001, respectively, for specific growth rate. Haldane has the lowest R2 value of 0.67 and 0.78 for specific biodegradation and growth rate with RMSE of 0.0006 and 0.002, respectively. This indicates the level of the bacteria stability in varying concentrations of cyanide and the maximum cyanide concentration it can tolerate within a specific time period. The biokinetic constant predicted from this model demonstrates a good ability of the locally isolated bacteria in cyanide remediation in industrial effluents.
  14. Optimisation of culture composition for glyphosate degradation byBurkholderia vietnamiensisstrain AQ5-12
    Manogaran M, Shukor MY, Yasid NA, Khalil KA, Ahmad SA
    3 Biotech, 2018 Feb;8(2):108.
    PMID: 29430369 DOI: 10.1007/s13205-018-1123-4
    The herbicide glyphosate is often used to control weeds in agricultural lands. However, despite its ability to effectively kill weeds at low cost, health problems are still reported due to its toxicity level. The removal of glyphosate from the environment is usually done by microbiological process since chemical process of degradation is ineffective due to the presence of highly stable bonds. Therefore, finding glyphosate-degrading microorganisms in the soil of interest is crucial to remediate this glyphosate.Burkholderia vietnamiensisstrain AQ5-12 was found to have glyphosate-degrading ability. Optimisation of biodegradation condition was carried out utilising one factor at a time (OFAT) and response surface methodology (RSM). Five parameters including carbon and nitrogen source, pH, temperature and glyphosate concentration were optimised. Based on OFAT result, glyphosate degradation was observed to be optimum at fructose concentration of 6, 0.5 g/L ammonia sulphate, pH 6.5, temperature of 32 °C and glyphosate concentration at 100 ppm. Meanwhile, RSM resulted in a better degradation with 92.32% of 100 ppm glyphosate compared to OFAT. The bacterium was seen to tolerate up to 500 ppm glyphosate while increasing concentration results in reduced degradation and bacterial growth rate.
  15. Characterisation of the simultaneous molybdenum reduction and glyphosate degradation byBurkholderia vietnamiensisAQ5-12 andBurkholderiasp. AQ5-13
    Manogaran M, Ahmad SA, Yasid NA, Yakasai HM, Shukor MY
    3 Biotech, 2018 Feb;8(2):117.
    PMID: 29430378 DOI: 10.1007/s13205-018-1141-2
    In this novel study, we report on the use of two molybdenum-reducing bacteria with the ability to utilise the herbicide glyphosate as the phosphorus source. The bacteria reduced sodium molybdate to molybdenum blue (Mo-blue), a colloidal and insoluble product, which is less toxic. The characterisation of the molybdenum-reducing bacteria was carried out using resting cells immersed in low-phosphate molybdenum media. Two glyphosate-degrading bacteria, namelyBurkholderia vietnamiensisAQ5-12 andBurkholderiasp. AQ5-13, were able to use glyphosate as a phosphorous source to support molybdenum reduction to Mo-blue. The bacteria optimally reduced molybdenum between the pHs of 6.25 and 8. The optimum concentrations of molybdate for strainBurkholderia vietnamiensis strainAQ5-12 was observed to be between 40 and 60 mM, while forBurkholderiasp. AQ5-13, the optimum molybdate concentration occurred between 40 and 50 mM. Furthermore, 5 mM of phosphate was seen as the optimum concentration supporting molybdenum reduction for both bacteria. The optimum temperature aiding Mo-blue formation ranged from 30 to 40 °C forBurkholderia vietnamiensis strainAQ5-12, whereas forBurkholderiasp. AQ5-13, the range was from 35 to 40 °C. Glucose was the best electron donor for supporting molybdate reduction, followed by sucrose, fructose and galactose for both strains. Ammonium sulphate was the best nitrogen source in supporting molybdenum reduction. Interestingly, increasing the glyphosate concentrations beyond 100 and 300 ppm forBurkholderia vietnamiensis strainAQ5-12 andBurkholderiasp. AQ5-13, respectively, significantly inhibited molybdenum reduction. The ability of these bacteria to reduce molybdenum while degrading glyphosate is a useful process for the bioremediation of both toxicants.
  16. Fulltext Evaluation of conventional and response surface level optimisation of n-dodecane (n-C12) mineralisation by psychrotolerant strains isolated from pristine soil at Southern Victoria Island, Antarctica
    Habib S, Ahmad SA, Johari WLW, Shukor MYA, Alias SA, Khalil KA, et al.
    Microb Cell Fact, 2018 Mar 17;17(1):44.
    PMID: 29549881 DOI: 10.1186/s12934-018-0889-8
    BACKGROUND: Biodegradation of hydrocarbons in Antarctic soil has been reported to be achieved through the utilisation of indigenous cold-adapted microorganisms. Although numerous bacteria isolated from hydrocarbon-contaminated sites in Antarctica were able to demonstrate promising outcomes in utilising hydrocarbon components as their energy source, reports on the utilisation of hydrocarbons by strains isolated from pristine Antarctic soil are scarce. In the present work, two psychrotolerant strains isolated from Antarctic pristine soil with the competency to utilise diesel fuel as the sole carbon source were identified and optimised through conventional and response surface method.

    RESULTS: Two potent hydrocarbon-degraders (ADL15 and ADL36) were identified via partial 16S rRNA gene sequence analysis, and revealed to be closely related to the genus Pseudomonas and Rhodococcus sp., respectively. Factors affecting diesel degradation such as temperature, hydrocarbon concentration, pH and salt tolerance were studied. Although strain ADL36 was able to withstand a higher concentration of diesel than strain ADL15, both strains showed similar optimal condition for the cell's growth at pH 7.0 and 1.0% (w/v) NaCl at the conventional 'one-factor-at-a-time' level. Both strains were observed to be psychrotrophs with optimal temperatures of 20 °C. Qualitative and quantitative analysis were performed with a gas chromatograph equipped with a flame ionisation detector to measure the reduction of n-alkane components in diesel. In the pre-screening medium, strain ADL36 showed 83.75% of n-dodecane mineralisation while the reduction of n-dodecane by strain ADL15 was merely at 22.39%. The optimised condition for n-dodecane mineralisation predicted through response surface methodology enhanced the reduction of n-dodecane to 99.89 and 38.32% for strain ADL36 and strain ADL15, respectively.

    CONCLUSIONS: Strain ADL36 proves to be a better candidate for bioaugmentation operations on sites contaminated with aliphatic hydrocarbons especially in the Antarctic and other cold regions. The results obtained throughout strongly supports the use of RSM for medium optimisation.

  17. Toxic effects of copper on liver and cholinesterase of Clarias gariepinus
    Padrilah SN, Ahmad SA, Yasid NA, Sabullah MK, Daud HM, Khalid A, et al.
    Environ Sci Pollut Res Int, 2017 Oct;24(28):22510-22523.
    PMID: 28804856 DOI: 10.1007/s11356-017-9923-3
    The release of pollutants, especially heavy metals, into the aquatic environment is known to have detrimental effects on such an environment and on living organisms including humans when those pollutants are allowed to enter the food chain. The aim of this study is to analyse the damage to Clarias gariepinus' liver caused by exposure to different concentrations of copper. In the present study, samples of C. gariepinus were exposed to sub-lethal copper sulphate (CuSO4) concentrations (from 0.2 to 20.0 mg/L) for 96 h. Physiological and behavioural alterations were observed with respect to their swimming pattern, mucus secretion and skin colour. Mortality was also observed at high concentrations of copper. Histopathological alterations of the liver were analysed under light, transmission and scanning electron microscopies. The liver of the untreated group showed normal tissue structures, while histopathological abnormalities were observed in the treated fish under light and electron microscopes with increased copper concentrations. Histopathological abnormalities include necrosis, melanomacrophage, hepatic fibrosis and congested blood vessels. In addition, the enzyme activity of liver cholinesterase (ChE) was also found to be affected by copper sulphate, as 100% of cholinesterase activity was inhibited at 20.0 mg/L. Thus, liver enzyme activity and histopathological changes are proven to be alternative sources for biomarkers of metal toxicity.
  18. Fulltext Microbiological Reduction of Molybdenum to Molybdenum Blue as a Sustainable Remediation Tool for Molybdenum: A Comprehensive Review
    Yakasai HM, Rahman MF, Manogaran M, Yasid NA, Syed MA, Shamaan NA, et al.
    Int J Environ Res Public Health, 2021 May 27;18(11).
    PMID: 34071757 DOI: 10.3390/ijerph18115731
    Molybdenum (Mo) microbial bioreduction is a phenomenon that is beginning to be recognized globally as a tool for the remediation of molybdenum toxicity. Molybdenum toxicity continues to be demonstrated in many animal models of spermatogenesis and oogenesis, particularly those of ruminants. The phenomenon has been reported for more than 100 years without a clear understanding of the reduction mechanism, indicating a clear gap in the scientific knowledge. This knowledge is not just fundamentally important-it is specifically important in applications for bioremediation measures and the sustainable recovery of metal from industrial or mine effluent. To date, about 52 molybdenum-reducing bacteria have been isolated globally. An increasing number of reports have also been published regarding the assimilation of other xenobiotics. This phenomenon is likely to be observed in current and future events in which the remediation of xenobiotics requires microorganisms capable of degrading or transforming multi-xenobiotics. This review aimed to comprehensively catalogue all of the characterizations of molybdenum-reducing microorganisms to date and identify future opportunities and improvements.
  19. Fulltext Biodegradation of Petroleum Sludge by Methylobacterium sp. Strain ZASH
    Harumain ZAS, Mohamad MAN, Nordin NFH, Shukor MYA
    Trop Life Sci Res, 2023 Jun;34(2):197-222.
    PMID: 38144383 DOI: 10.21315/tlsr2023.34.2.10
    A bacterium was isolated from sludge-contaminated soil in a petroleum refinery and tested for its ability to degrade aliphatic hydrocarbon compounds present in petroleum sludge. The isolate was grown on minimal salt media agar supplemented with 1% (w/v) petroleum sludge. The isolate was tentatively identified as Methylobacterium s p. s t rain ZASH based on the partial 16s rDNA molecular phylogeny. The bacterium grew optimally between the temperatures of 30°C and 35°C, pH 7 and 7.5, 0.5% and 1.5% (v/v) Tween 80 as the surfactant, and between 1% and 2% (w/v) peptone as the nitrogen source. The constants derived from the Haldane equation were μmax = 0.039 hr-1, Ks = 0.385% (w/v) total petroleum hydrocarbons (TPH) or 3,850 mg/L TPH, and Ki =1.12% (w/v) TPH or 11,200 mg/L. The maximum biodegradation rate exhibited by this strain was 19 mg/L/hr at an initial TPH concentration of 10,000 mg/L. Gas chromatography analysis revealed that after 15 days the strain was able to degrade all aliphatic n-alkanes investigated with different efficiencies. Shorter n-alkanes were generally degraded more rapidly than longer n-alkanes with 90% removal for C-12 compared to only 30% removal for C-36. The addition of sawdust did not improve bacterial degradation of petroleum hydrocarbons, but it assisted in the removal of remaining undegraded hydrocarbons through adsorption.
  20. Fulltext Anti-HMG-CoA Reductase, Antioxidant, and Anti-Inflammatory Activities of Amaranthus viridis Leaf Extract as a Potential Treatment for Hypercholesterolemia
    Salvamani S, Gunasekaran B, Shukor MY, Shaharuddin NA, Sabullah MK, Ahmad SA
    Evid Based Complement Alternat Med, 2016;2016:8090841.
    PMID: 27051453 DOI: 10.1155/2016/8090841
    Inflammation and oxidative stress are believed to contribute to the pathology of several chronic diseases including hypercholesterolemia (elevated levels of cholesterol in blood) and atherosclerosis. HMG-CoA reductase inhibitors of plant origin are needed as synthetic drugs, such as statins, which are known to cause adverse effects on the liver and muscles. Amaranthus viridis (A. viridis) has been used from ancient times for its supposedly medically beneficial properties. In the current study, different parts of A. viridis (leaf, stem, and seed) were evaluated for potential anti-HMG-CoA reductase, antioxidant, and anti-inflammatory activities. The putative HMG-CoA reductase inhibitory activity of A. viridis extracts at different concentrations was determined spectrophotometrically by NADPH oxidation, using HMG-CoA as substrate. A. viridis leaf extract revealed the highest HMG-CoA reductase inhibitory effect at about 71%, with noncompetitive inhibition in Lineweaver-Burk plot analysis. The leaf extract showed good inhibition of hydroperoxides, 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), and ferric ion radicals in various concentrations. A. viridis leaf extract was proven to be an effective inhibitor of hyaluronidase, lipoxygenase, and xanthine oxidase enzymes. The experimental data suggest that A. viridis leaf extract is a source of potent antioxidant and anti-inflammatory agent and may modulate cholesterol metabolism by inhibition of HMG-CoA reductase.
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