Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis (Jan 2008)

Antibacterial effects of commercially available phosphates on selected microorganisms

  • Leona Buňková,
  • Pavel Pleva,
  • František Buňka,
  • Pavel Valášek,
  • Stanislav Kráčmar

DOI
https://doi.org/10.11118/actaun200856050019
Journal volume & issue
Vol. 56, no. 5
pp. 19 – 24

Abstract

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In the food industry, phosphates, polyphosphates and their salts are used, for example, as emul­si­fying agents in the production of processed cheese. The inhibitory effects of three commercially avai­la­ble phosphates and polyphosphates differing in their chain length (690, S9 and HBS) were tested on a set of 15 gram-positive or gram-negative CCM (Czech Collection of Microorganisms) strains and on 12 bacterial strains isolated from processed cheeses. Five different concentrations of each phosphate were chosen (0.1, 0.2, 0.3, 0.4 and 0.5% w/v) in order to observe the inhibitory effects of the phosphate salts on the growth of the microorganisms tested. Sensitivity of the individual bacterial strains to phosphates was observed of a liquid cultivation medium which was supplemented with applied salts. Subsequently, the growth in cells was determined by measuring optical density at a wavelength of 600 nm. According to the results, 690 and S9 phosphates, containing mainly orthophosphates, diphosphates (pyrophosphates) and short-chain polyphosphates, do not have a significant inhibitory effect on the growth of the tested bacteria. Significant inhibitory effects were observed only in HBS salt (a mixture of long-chain polyphosphates), which showed antibacterial effects on all gram-positive bacteria tested (both the CCM strains and those isolated from processed cheeses). The antibacterial effect of phosphates on gram-positive microorganisms is growing with the increasing length of the polyphosphate chain. This study has not proved a significant effect of the phosphates tested on the growth of gram-negative bacteria used.

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