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  1. Jamulidin, S.N.K., Manogaran. M., Yakasai, M.H., Rahman, M.F.A., Shukor, M.Y.
    MyJurnal
    In this study, a novel glyphosate-degrading shows the ability to reduce molybdenum to
    molybdenum blue. The enzyme from this bacterium was partially purified and partially
    characterized to ascertain whether the Mo-reducing enzyme from this bacterium shows better or
    lower efficiency in reducing molybdenum compared to other Mo-reducing bacterium that only
    exhibits a single biotransformation activity. The enzyme was partially purified using ammonium
    sulphate fractionation. The Vmax for the electron donating substrate or NADH was at 1.905 nmole
    Mo blue/min while the Km was 6.146 mM. The regression coefficient was 0.98. Comparative
    assessment with the previously characterized Mo-reducing enzyme from various bacteria showed
    that the Mo-reducing enzyme from Burkholderia vietnamiensis strain AQ5-12 showed a lower
    enzyme activity.
  2. Yadzir, Z.H.M., Gafar, A.A., Rahman, M.F., Yakasai, M.H., Abdullah, M.A., Shamaan, N.A., et al.
    MyJurnal
    Contamination of organic xenobiotic pollutants and heavy metals in a contaminated site allows
    the use of multiple bacterial degraders or bacteria with the ability to detoxify numerous toxicants
    at the same time. A previously isolated SDS- degrading bacterium, Acinetobacter baumannii
    strain Serdang 1 was shown to reduce molybdenum to molybdenum-blue. The bacterium works
    optimally at pH 6.5, the temperature range between 25 and 34°C with glucose serves as the best
    electron donor for molybdate reduction. This bacterium required additional concentration of
    phosphate at 5.0 mM and molybdate between 15 and 25 mM. The absorption spectrum of the
    molybdenum blue obtained is similar to the molybdenum blue from other earlier reported
    molybdate reducing bacteria, as it resembles a reduced phosphomolybdate closely. Ag(i), As(v),
    Pb(ii) and Cu(ii) inhibited molybdenum reduction by 57.3, 36.8, 27.7 and 10.9%, respectively, at
    1 p.p.m. Acrylamide was efficiently shown to support molybdenum reduction at a lower
    efficiency than glucose. Phenol, acrylamide and propionamide could support the growth of this
    bacterium independently of molybdenum reduction. This bacterium capability to detoxify several
    toxicants is an important tool for bioremediation in the tropical region.
  3. Abo-Shakeer, L.K.A., Yakasai, M.H., Rahman, M.F., Syed, M.A., Bakar, N.A., Othman, A.R.
    MyJurnal
    Molybdenum is an emerging pollutant. Bioremediation of this heavy metal is possible by the
    mediation of Mo-reducing bacteria. These bacteria contain the Mo-reducing enzymes that can
    conver toxic soluble molybdenum into molybdenum blue; a less soluble and less toxic form of the
    metal. To date only the enzyme has been purified from only one bacterium. The aim of this study is
    to purify the Mo-reducing enzyme from a previously isolated Mo-reducing bacterium Bacillus
    pumilus strain Lbna using ammonium sulphate fractionation followed by ion exchange and then
    gel filtration. Two clear bands were obtained after the gel filtration step with molecular weights
    of 70 and 100 kDa. This indicates that further additional purification methods need to be used
    to get a purified fraction. Hence, additional steps of chromatography such as hydroxyapatite or
    chromatofocusing techniques can be applied in the future.
  4. Yakasai, M.H., Rahman, M.F., Khayat, M.E., Shukor, M.Y., Shamaan, N.A., Rahim, M.B.H.A.
    MyJurnal
    The presence of both heavy metals and organic xenobiotic pollutants in a contaminated site
    justifies the application of either a multitude of microbial degraders or microorganisms having
    the capacity to detoxify a number of pollutants at the same time. Molybdenum is an essential
    heavy metal that is toxic to ruminants at a high level. Ruminants such as cow and goats
    experience severe hypocuprosis leading to scouring and death at a concentration as low as
    several parts per million. In this study, a molybdenum-reducing bacterium with amide-degrading
    capacity has been isolated from contaminated soils. The bacterium, using glucose as the best
    electron donor reduces molybdenum in the form of sodium molybdate to molybdenum blue. The
    maximal pH reduction occurs between 6.0 and 6.3, and the bacterium showed an excellent
    reduction in temperatures between 25 and 40 oC. The reduction was maximal at molybdate
    concentrations of between 15 and 25 mM. Molybdenum reduction incidentally was inhibited by
    several toxic heavy metals. Other carbon sources including toxic xenobiotics such as amides
    were screened for their ability to support molybdate reduction. Of all the amides, only
    acrylamide can support molybdenum reduction. The other amides; such as acetamide and
    propionamide can support growth. Analysis using phylogenetic analysis resulted in a tentative
    identification of the bacterium as Pseudomonas sp. strain 135. This bacterium is essential in
    remediating sites contaminated with molybdenum, especially in agricultural soil co-contaminated
    with acrylamide, a known soil stabilizer.
  5. Chee, H.S., Motharasan Manogaran, Yakasai, M.H., Rahman, M.F.A., Nur Adeela Yasid, Zarizal Suhaili, et al.
    MyJurnal
    The issue of heavy metal contamination and toxic xenobiotics has become a rapid global
    concern. This has ensured that the bioremediation of these toxicants, which are being carried out
    using novel microbes. A bacterium with the ability to reduce molybdenum has been isolated
    from contaminated soils and identified as Serratia marcescens strain DR.Y10. The bacterium
    reduced molybdenum (sodium molybdate) to molybdenum blue (Mo-blue) optimally at pHs of
    between 6.0 and 6.5 and temperatures between 30°C and 37°C. Glucose was the best electron
    donor for supporting molybdate reduction followed by sucrose, adonitol, mannose, maltose,
    mannitol glycerol, salicin, myo-inositol, sorbitol and trehalose in descending order. Other
    requirements include a phosphate concentration of 5 mM and a molybdate concentration of
    between 10 and 30 mM. The absorption spectrum of the Mo-blue produced was similar to the
    previously isolated Mo-reducing bacterium and closely resembles a reduced phosphomolybdate.
    Molybdenum reduction was inhibited by Hg (ii), Ag (i), Cu (ii), and Cr (vi) at 78.9, 69.2, 59.5
    and 40.1%, respectively. We also screen for the ability of the bacterium to use various organic
    xenobiotics such as phenol, acrylamide, nicotinamide, acetamide, iodoacetamide, propionamide,
    acetamide, sodium dodecyl sulfate (SDS) and diesel as electron donor sources for aiding
    reduction. The bacterium was also able to grow using amides such as acrylamide, propionamide
    and acetamide without molybdenum reduction. The unique ability of the bacterium to detoxify
    many toxicants is much in demand, making this bacterium a vital means of bioremediation.
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