High lead-tolerant mutant Bacillus tropicus AT31-1 from rhizosphere soil of Pu-erh and its remediation mechanism

Qiang Li; Wenxia Yuan; Xiujuan Deng; Yaping Chen; Limei Li; Lijiao Chen; Raoqiong Che; Wei Huang; Yamin Wu; Chun Wang; Zejun Wang; Miao Zhou; Zongpei Fan; Baijuan Wang

doi:10.1016/j.biortech.2024.131751

High lead-tolerant mutant Bacillus tropicus AT31-1 from rhizosphere soil of Pu-erh and its remediation mechanism

Bioresour Technol. 2025 Jan:416:131751. doi: 10.1016/j.biortech.2024.131751. Epub 2024 Nov 7.

Authors

Qiang Li¹, Wenxia Yuan², Xiujuan Deng³, Yaping Chen², Limei Li³, Lijiao Chen³, Raoqiong Che³, Wei Huang³, Yamin Wu³, Chun Wang⁴, Zejun Wang³, Miao Zhou³, Zongpei Fan³, Baijuan Wang⁵

Affiliations

¹ Key Laboratory of Intelligent Organic Tea Garden Construction in Universities of Yunnan Province, Yunnan Organic Tea Industry Intelligent Engineering Research Center, Yunnan Agricultural University, Kunming 650201, China; School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan 610106, China.
² Key Laboratory of Intelligent Organic Tea Garden Construction in Universities of Yunnan Province, Yunnan Organic Tea Industry Intelligent Engineering Research Center, Yunnan Agricultural University, Kunming 650201, China.
³ Key Laboratory of Intelligent Organic Tea Garden Construction in Universities of Yunnan Province, Yunnan Organic Tea Industry Intelligent Engineering Research Center, Yunnan Agricultural University, Kunming 650201, China; College of Tea Science, Yunnan Agricultural University, Kunming 650201, China.
⁴ Key Laboratory of Intelligent Organic Tea Garden Construction in Universities of Yunnan Province, Yunnan Organic Tea Industry Intelligent Engineering Research Center, Yunnan Agricultural University, Kunming 650201, China; College of Mechanical and Electrical Engineering, Yunnan Agricultural University, Kunming 650201, China.
⁵ Key Laboratory of Intelligent Organic Tea Garden Construction in Universities of Yunnan Province, Yunnan Organic Tea Industry Intelligent Engineering Research Center, Yunnan Agricultural University, Kunming 650201, China; College of Tea Science, Yunnan Agricultural University, Kunming 650201, China. Electronic address: wangbaijuan123@126.com.

PMID: 39521187
DOI: 10.1016/j.biortech.2024.131751

Abstract

In this study, we successfully generated the mutant strain Bacillus tropicus AT31-1 from AT31 through atmospheric room-temperature plasma mutagenesis. This mutant strain AT31-1 demonstrated an impressive 48.6 % removal efficiency in 400 mg/L lead medium. Comparative genomic analysis showed that the mutant strain AT31-1 had three mutation sites, which affect the efflux RND transporter permease subunit, the response regulator transcription factor, and a gene with unknown function. The transcriptional analysis showed a notable upregulation in the expression of 283 genes in AT31-1 as lead concentrations increased from 0 to 200 mg/L and then to 400 mg/L, which include zinc-transporting ATPase, ferrous iron transport protein B, NADH dehydrogenase, and others. The Gene ontology function of the peptide metabolic process, along with the KEGG pathway of carbon metabolism were identified as closely linked to the extreme lead tolerance of AT31-1. This study presents novel insights into the lead tolerance mechanisms of bacteria.

Keywords: Bioremediation; Genetic mechanism; Heavy metals; Soil treatment.

MeSH terms

Bacillus* / genetics
Bacterial Proteins / genetics
Bacterial Proteins / metabolism
Biodegradation, Environmental
Gene Expression Regulation, Bacterial / drug effects
Lead* / metabolism
Mutation* / genetics
Rhizosphere*
Soil Microbiology
Soil Pollutants / metabolism

Substances

Lead
Soil Pollutants
Bacterial Proteins