Biochar and metal-tolerant bacteria in alleviating ZnO nanoparticles toxicity in barley

Vishnu D Rajput; Natalya Chernikova; Tatiana Minkina; Andrey Gorovtsov; Alexey Fedorenko; Saglara Mandzhieva; Tatiana Bauer; Victoria Tsitsuashvili; Vladimir Beschetnikov; Ming Hung Wong

doi:10.1016/j.envres.2023.115243

Biochar and metal-tolerant bacteria in alleviating ZnO nanoparticles toxicity in barley

Environ Res. 2023 Mar 1:220:115243. doi: 10.1016/j.envres.2023.115243. Epub 2023 Jan 9.

Affiliations

¹ Academy of Biology and Biotechnology, Southern Federal University, 344090, Rostov-on-Don, Russia. Electronic address: rvishnu@sfedu.ru.
² Academy of Biology and Biotechnology, Southern Federal University, 344090, Rostov-on-Don, Russia.
³ Southern Scientific Center of the Russian Academy of Sciences, Russia.
⁴ Academy of Biology and Biotechnology, Southern Federal University, 344090, Rostov-on-Don, Russia; Consortium on Health, Environment, Education, and Research (CHEER), And Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, Hong Kong, 999077, China.

PMID: 36632881
DOI: 10.1016/j.envres.2023.115243

Abstract

The constant use of zinc oxide nanoparticles (ZnO NPs) in agriculture could increase their concentration in soil, and cause a threat to sustainable crop production. The present study was designed to determine the role of spore-forming and metal-tolerant bacteria, and biochar in alleviating the toxic effects of a high dose of ZnO NPs (2000 mg kg^-1) spiked to the soil (Haplic Chernozem) on barley (Hordeum sativum L). The mobile compounds of Zn in soil and their accumulation in H. sativum tissues were increased significantly. The addition of biochar (2.5% of total soil) and bacteria (10¹⁰ CFU kg^-1) separately and in combination showed a favorable impact on H. sativum growth in ZnO NPs polluted soil. The application of bacteria (separately) to the contaminated soil reduced the mobility of Zn compounds by 7%, due to loosely bound Zn compounds, whereas only biochar inputs lowered Zn mobile compounds mobility by 33%, even the combined application of biochar and bacteria also suppressed the soil Zn mobile compounds. Individual application of biochar and bacteria reduced the Zn plant uptake, i.e., underground parts (roots) by 44% and 20%, and in the above-ground parts of H. sativum plants by 39% and 13%, respectively, compared to ZnO NPs polluted soil treatments. Biochar, both separately and in combination with bacteria improved the root length by 48 and 85%, and plant height by 53 and 40%, respectively, compared to the polluted control. The root length and plant height decreased by 52 and 40% in ZnO NPs spiked soil compared clean soil treatments. Anatomical results showed an improvement in the structural organization of cellular-sub-cellular tissues of root and leaf. The changes in ultrastructural organization of assimilation tissue cells were noted all treatments due to the toxic effects of ZnO NPs compared with control treatment. The results indicate that metal-tolerant bacteria and biochar could be effective as a soil amendment to reduce metal toxicity, enhance crop growth, and improve soil health.

Keywords: Carbon; Chernozem; Chlorenchyma cells; Crop growth; Microorganisms; Soil health.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacteria / metabolism
Hordeum* / metabolism
Metal Nanoparticles* / toxicity
Metals / metabolism
Plant Roots / metabolism
Plant Roots / microbiology
Soil / chemistry
Soil Pollutants* / analysis
Zinc Oxide* / chemistry
Zinc Oxide* / toxicity

Substances

Zinc Oxide
biochar
Metals
Soil
Soil Pollutants