Usage of microbial combination degradation technology for the remediation of uranium contaminated ryegrass

Luhuai Jing; Xianghui Zhang; Imran Ali; Xiaoming Chen; Li Wang; Hao Chen; Mengwei Han; Ran Shang; Yuewen Wu

doi:10.1016/j.envint.2020.106051

Usage of microbial combination degradation technology for the remediation of uranium contaminated ryegrass

Environ Int. 2020 Nov:144:106051. doi: 10.1016/j.envint.2020.106051. Epub 2020 Sep 1.

Authors

Luhuai Jing¹, Xianghui Zhang¹, Imran Ali², Xiaoming Chen³, Li Wang⁴, Hao Chen⁵, Mengwei Han⁶, Ran Shang⁷, Yuewen Wu⁸

Affiliations

¹ School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
² School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 621010, China; Institute of Biochemistry, University of Balochistan, Quetta 87300, Pakistan. Electronic address: imranalisheik@yahoo.com.
³ School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 621010, China. Electronic address: cxmxkd@163.com.
⁴ College of Life Science and Technology, Southwest Minzu University, Chengdu 610041, China.
⁵ Sichuan Institute of Atomic Energy, Chengdu 610061, China.
⁶ State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
⁷ State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. Electronic address: shangran@139.com.
⁸ Xinjiang Center for Disease Control and Prevention, Xinjiang 830002, China.

PMID: 32889480
DOI: 10.1016/j.envint.2020.106051

Abstract

Post phytoremediation accumulation of heavy metals in plants is causing an environmental issue worldwide. In this study, we investigated the ability of eight different kinds of microorganisms to degrade and release heavy metals from heavy metal enriched ryegrass, including 5 species of bacteria (Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus-I, Bacillus pumilus-II and Bacillus cereus) and 3 of fungi (Phanerochaete chrysosporium, Trichoderma ressei and Pterula sp. strain QD-1), by growing them under uranium stress and assessing their ability to degrade biomass. After 30 days, the degradation ability of fungi was found better than that of bacteria, while the metal leaching ability of bacteria was found better. The highest degradation rate (upto 60%) was obtained by using P. chrysosporium, Pterula sp. strain QD-1 exhibited the best leaching rate for uranium (upto 77%). The overall degradation rate of lignin and cellulose and hemicellulose was found lower (40% and 60%, respectively). According to the antagonistic characteristics of microbes, we combined different dominant species, in which under optimal conditions the T2 combination (P. chrysosporium, T. reesei, and Pterula sp. strain QD-1 and B. subtilis) was able to degrade 80% of the ryegrass, 51% of lignin, 74% of cellulose and hemicellulose, releasing 78% of U, 90% of Pb and the releasing rate of other heavy metals was more than 95%. FTIR analysis showed the least degradation of lignin, while SEM-EDX analysis of the degradation residues displayed the microstructure of ryegrass being greatly damaged. Only a small amount of U was found in the residues of the researched combinations. This study provides efficient Microbial Combined Degradation Technology for heavy metal enriched biomass, which can effectively deal with heavy metal enriched plants, and provide a basis for the recovery and utilization of heavy metals, avoiding secondary pollution in the environment caused by this type of biomass.

Keywords: Heavy metal enriched plants; Microbial degradation; Phytoremediation; Ryegrass; Uranium.

Publication types

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

MeSH terms

Biodegradation, Environmental
Lolium*
Metals, Heavy* / analysis
Soil
Soil Pollutants* / analysis
Technology
Uranium*

Substances

Metals, Heavy
Soil
Soil Pollutants
Uranium