PVC, polypropilene and glass bottles properly cleaned and sanitized were rinsed with mineral water from a spring located in Lindóia, São Paulo State. Immediately after the bottling of the water, total hetherotrophic microorganisms were counted in Plate Count Agar and R2A agar. The evolution of the contamination was followed trough periodical examination. The changes of the population of Pseudomonas aeruginosa was studied by inoculation of the bottles with a suspension of P. aeruginosa ATCC 10145 in order to get a contamination of approximately 10² UFC/ml. The population of the bacteria was periodically evaluated during the storage time employing Pseudomonas P agar for counting. It was observed increasing of the population of hetherotrophic microorganisms during the firt 30 days of storage followed by lowering in an irregular manner. Then, the population remained approximately constant up to 6 months of observation. P. aeruginosa counts increased by during the 2 first weeks of storage followed by slight decrease until reaching levels similar to the initial counts. There were not differences when comparing the three types packaging material.
Pseudomonas aeruginosa; mineral water
