Sistem za bioremedijaciju voda zagađenih fenolom upotrebom sočivice (Lemna minor L.) i bakterija njene rizosfere
System for bioremediation of phenol-polluted waters based on the application of the common duckweed (Lemna minor L.) and the bacteria of its rhizosphere
Abstract:
In this dissertation, the possibility of phenol removal by the common duckweed (Lemna minor L.) and by the bacteria of its rhizosphere, was investigated. Six bacterial strains, selected according to their ability of growth on the minimal nutrient medium with phenol, high phenol-resistance, sensitivity to typical antibiotics, biofilm formation, positive effect on the multiplication rates of the plants and bacteria-plant interactions on the root surface were: Lelliottia sp. 11, Klebsiella oxytoca 14, Serratia marcescens 27, Hafnia alvei 37, H. paralvei 43, and S. nematodiphila 51. Duckweed inoculated with any of the aforementioned strains were more efficient in phenol removal than the surface-sterilized duckweed or the bacterial suspensions. The most efficient bacterial strain/duckweed system is the one based on H. paralvei 43 and plants. This bacterial strain also modulates the antioxidant response of the plant, indicated by the non-enzymatic (total AsA, soluble proteins, MDA and H2O2) and the enzymatic parameters. The zymogram detection of GPX in the plants showed 5 phenol-induced GPX isoforms, whereas the bacteria alone induced 4 different GPX isoforms. Bacteria showed a tendency to lower the intensity of GPX expression in plants. K. oxytoca 14 is an endophyte which induced a rapid multiplication of the duckweed. Six phenolic compounds were identified in the nutrient medium used to co-culture K. oxytoca 14 and the duckweed: lutheolin 6,8-di-C-hexoside, p-hidroxybenzoic acid, caffeic acid, apigenin 6-C-(2"-pentosyl) hexoside and p-coumaric acid. The results of this dissertation show that the selected bacteria /duckweed systems present an efficient solution for the bioremediation of the phenol-polluted wastewaters.
Keywords:
Bacteria; Duckweed; Bioremediation; PhenolSource:
University of Belgrade, Faculty of Biology, 2020, 1-88Funding / projects:
- Ministry of Science, Technological Development and Innovation of the Republic of Serbia, institutional funding - 200007 (University of Belgrade, Institute for Biological Research 'Siniša Stanković') (RS-MESTD-inst-2020-200007)