Biochemical and molecular characterization of Klebsiella sp. isolated from environment polluted with perfluoroalkyl substances

Abstract

The development of chemical industry in the last century has contributed to an increase in food production, more effective disease control and improved living standards. Nevertheless, it left huge quantities of toxic substances in the environment. Persistent organic pollutants are chemicals that persist, accumulate throughout the food chain and have harmful effects on human health and the environment. Perfluoroalkyl substances such as perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride, are on the list of persistent organic pollutants. Several recent publications have shown that microorganisms isolated from environments polluted by perfluoroalkyl substances can reduce the level of these compounds. In this paper, bacterial strain isolated from such an environment, which demonstrated capability to reduce perfluoroalkyl substances in a preliminary study, was physiologically, biochemically and molecularly characterized. The microorganism is Gram-negative, nonmotile, oxidase negative and catalase positive. The microorganism can produce a variety of hydrolase enzymes. Fatty acid methyl ester profile was also determined. Molecular characterization confirmed that the bacterium belongs to Klebsiella sp. Microorganism was successfully characterized using different methods and in the future this strain will be used in a laboratory study to analyze the mechanisms of reduction of perfluoroalkyl substance concentration.

Razvoj hemijske industrije u prošlom veku doprineo je povećanoj proizvodnji hrane, efikasnijoj kontroli bolesti i poboljšanju životnog standarda. Ipak, usled industrijskog razvoja došlo je do nagomilavanja velikih količina toksičnih supstanci u životnoj sredini. Dugotrajni organski zagađivači su hemikalije koje se zadržavaju, akumuliraju u čitavom lancu ishrane i imaju štetan uticaj na ljudsko zdravlje i životnu sredinu. Perfluorovana jedinjenja, kao što su perfluoroktan sulfonska kiselina, njene soli i perfluoroktan sulfonil fluorid, nalaze se na listi dugotrajnih organskih zagađivača. Nekoliko skorašnjih publikacija je pokazalo da mikroorganizmi izolovani iz životne sredine zagađene perfluorovanim jedinjenjima mogu smanjiti nivo istih. U ovom radu je bakterijski soj izolovan iz takve životne sredine fiziološki, biohemijski i molekularno okarakterisan. U preliminarnim laboratorijskim testovima soj je pokazao sposobnost smanjenja količine perfluorovanih jedinjenja. Mikroorganizam je Gram-negativan, nepokretan, oksidaza negativan i pozitivan na katalazu, proizvodi različite hidrolazne enzime. Mikroorganizmu je određen i masno-kiselinski profil. Molekularna karakterizacija je potvrdila da izolovani soj pripada rodu Klebsiella. Mikroorganizam je uspešno okarakterisan različitim metodama i ubuduće će biti korišćen u detaljnoj laboratorijskoj studiji analize mehanizama smanjenja koncentracije perfluorovanih jedinjenja.