INTRODUCTION

Heavy metals and arsenic, getting into the environment, cause its pollution, negatively affect human health. Volatile organic compounds (VOCs) synthesized by bacteria are able to modulate the growth and metabolism of pro- and eukaryotes, function as signals for distance communication between organisms, and influence the action of various stress agents.

MATERIAL AND METHODS

The effect of sulfur-containing dimethyl disulfide (DMDS) and ketones (2-undecanone, 2-nonanone, 2-heptanone, 2-pentanone and 2-propanone) on the expression from promoters of copA, zntA and arsR genes (PcopA, PzntA and ParsR) responding to stresses caused by the action of heavy metal ions and arsenic was studied. lux-Biosensors containing inducible promoters of the listed genes and the lux-operon as reporter were used. The degree of expression from the corresponding promoters was determined by the intensity of bioluminescence.

RESULTS

The action of 2-undecanone, 2-nonanone, 2-heptanone, and DMDS led to decreased expression of lux-operon, which is controlled by PcopA and ParsR. Pretreatment of biosensors with these VOCs caused a decrease in the induction of expression with PzntA and ParsR under the action of ZnSO₄ and NaAsO₂, respectively; in the presence of CuSO₄, this effect was expressed only for 2-undecanone. Under the action of 2-pentanone there was an increase in expression of the lux-reporter from PcopA and PzntA. Pretreatment with 2-pentanone led to an increase of the expression of the lux-reporter from PzntA by 80%, compared with the action of ZnSO₄ without 2-pentanone.

CONCLUSION

The effect of VOCs on the expression from promoters of genes that respond to stresses caused by copper, zinc, and arsenic is multidirectional and depends on the structure of VOCs.