Evaluating the occurrence frequency of horizontal gene transfer induced by different degrees of heavy metal stress. (1st January 2023)

• Record Type: Journal Article
• Authors: Chen, Xiaomeng; Du, Zhuang; Song, Xiaoyang; Wang, Liqin; Wei, Zimin; Jia, Liming; Zhao, Ran
• Is Part Of: Journal of cleaner production. Volume 382(2023)
• Publication Date: 2023-01-01
• Subjects: Heavy metal pollution -- Composting -- Horizontal gene transfer -- Microbial community -- Impact pathway; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.135371
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Horizontal gene transfer of heavy metal resistance genes and antibiotic resistance genes in bacteria frequently occurred during composting. However, the relevancy between heavy metal pollution with different degrees and the occurrence of horizontal gene transfer during composting was unclear. Therefore, this study aimed to clarify the underlying relationship. The changes of resistance gene abundance and network analysis results showed that heavy metal pollution induced high level of resistance gene abundance in microorganisms and promoted the occurrence of horizontal gene transfer. Furthermore, regression fitting models indicated that the relevancy between resistance genes abundance and horizontal gene transfer under high pollution (HP: R = 0.90) was weakener than that under low pollution (LP: R = 0.95) and medium pollution (MP: R = 0.97). Ultimately, structural equation models further verified that the abundance of resistance genes was mainly caused by horizontal gene transfer during LP (coefficients: 0.997) and MP (coefficients: 0.993) composting. However, the high level of resistance gene abundance was caused by host bacteria (coefficients: 0.775) and horizontal gene transfer (coefficients: 0.701) during HP composting. The serious heavy metal pollution had selection pressure on host bacteria to induce them to develop resistance during HP composting, rather than only through horizontal gene transfer. Therefore, mild heavy metal pollution was more liable to cause horizontal gene transfer and increase the spread risk of resistance genes during composting. This study helped to better understand the risks caused by heavy metal pollution by evaluating the frequency of horizontal gene transfer at different pollution levels during composting. Graphical abstract: Image 1 Highlights: Heavy metal pollution induced a high level of resistance gene abundance. Horizontal gene transfer contributed more to gene abundance under mild pollution. Heavy metals induced selection pressure on host bacteria under serious pollution. The gene abundance was caused by host bacteria abundance under serious pollution. Mild metal pollution was more likely to cause spread risk of resistance genes.