Bacterial growth prevention in liquid bicarbonate concentrate

We describe an original Liquid Bicarbonate Concentrate (LBC) production and distribution unit, now functioning for five years. To prevent bacterial growth several measures were taken: LBC osmolarity as high as possible, fast concentrate turnover, UV irradiation of the tank and continuous circulation of LBC. Although, six and ten months elapsed before the first two positive cultures appeared after implementation of the new distribution circuit, subsequently, the interval between positive cultures became much shorter so that disinfection of the LBC unit is now required every 3 weeks. Changing the disinfecting agent from hypochlorite to peracetic acid did not succeed in increasing this interval. Our experience draws special the attention to the problem of bacterial growth in an on-line LBC production and distribution unit and defines the potential methods to control it. Continuous vigilance remains mandatory.