Isolation and characterisation of a molybdenum-reducing and Metanil Yellow dye-decolourising Bacillus sp. strain neni-10 in soils from West Sumatera, Indonesia

• Main Authors: Mansur, Rusnam, Gusmanizar, Neni, Roslan, Muhamad Akhmal Hakim, Ahmad, Siti Aqlima, Shukor, Mohd Yunus
• Format: Article
• Language: English
• Published: Penerbit Universiti Sains Malaysia 2017
• Online Access: http://psasir.upm.edu.my/id/eprint/62225/1/Isolation%20and%20characterisation%20of%20a%20molybdenum-reducing%20and%20Metanil%20Yellow%20dye-decolourising%20Bacillus%20sp.%20strain%20neni-10%20in%20soils%20from%20West%20Sumatera%2C%20Indonesia.pdf; http://psasir.upm.edu.my/id/eprint/62225/; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5300016/

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.