Microbiological analysis of drinking water from water vending machines


  • Mustapha Salisu Muhammad Universiti Teknologi Malaysia
  • Mohd Firdaus Abdul-Wahab Universiti Teknologi Malaysia
  • Mohammad Abdul Razis Saidin Universiti Teknologi Malaysia
  • Muhammad Hariz Asraf Universiti Teknologi Malaysia
  • Nik Ahmad Nizam Nik Malek Universiti Teknologi Malaysia




Bacterial isolation, drinking water, water vending machines, public health


Commercial water vending machines are gaining popularity nowadays among the general public, probably due to the ease of obtaining clean drinking water. However, improper maintenance of the machines can lead to bacterial contamination. Hence, this study aimed to investigate and determine the microbiological characteristics of drinking water from Water Vending Machines (WVM) by isolating and characterizing culturable bacteria in the water and nozzle swab samples. The samples were obtained from WVM at eight different locations around Johor Bahru, Johor, Malaysia. Several unique bacterial isolates were found, from both Gram-positive and Gram-negative groups. Polymerase chain reaction amplification and 16S rRNA sequence analysis suggested that these isolates are from Pseudomonas, Bacillus, and Stenotrophomonas genera. In situ water quality tests which include pH, conductivity, and total dissolved solids were also conducted. Two samples from the inlet source have pH and conductivity values slightly above the reference values stipulated in drinking water regulations. The findings presented here suggest the importance of regular service maintenance of the WVM to ensure that the water samples meet the standard stipulated by the authority.

Author Biographies

Mustapha Salisu Muhammad, Universiti Teknologi Malaysia

Department of Biosciences, Faculty of Science

Mohd Firdaus Abdul-Wahab, Universiti Teknologi Malaysia

Department of Biosciences, Faculty of Science

Mohammad Abdul Razis Saidin, Universiti Teknologi Malaysia

Advanced Membrane Technology Research Centre (AMTEC)

Muhammad Hariz Asraf, Universiti Teknologi Malaysia

Advanced Membrane Technology Research Centre (AMTEC)

Nik Ahmad Nizam Nik Malek, Universiti Teknologi Malaysia

Centre for Sustainable Nanomaterials (CSNano), Ibnu Sina Institute for Scientific and Industrial Research (ISI-SIR)


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