Adaptation of Rhizosphere Microbial Communities to Continuous Exposure to Multiple Residual Antibiotics in Vegetable Farms

Abstract

The constant application of manure-based fertilizers in vegetable farms leads to antibiotic residue accumulation in soils, which has become a major stressor affecting agroecosystem stability. The present study investigated the adaptation profiles of rhizosphere microbial communities in different vegetable farms to multiple residual antibiotics. Multiple antibiotics, including trimethoprim, sulfonamides, quinolones, tetracyclines, macrolides, lincomycins, and chloramphenicols, were detected in the vegetable farms; the dominant antibiotic (trimethoprim) had a maximum concentration of 36.7 ng/g. Quinolones and tetracyclines were the most prevalent antibiotics in the vegetable farms. The five most abundant phyla in soil samples were Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi and Firmicutes, while the five most abundant phyla in root samples were Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Myxococcota. Macrolides were significantly correlated with microbial community composition changes in soil samples, while sulfonamides were significantly correlated with microbial community composition changes in root samples. Soil properties (total carbon and nitrogen contents and pH) influenced the shifts in microbial communities in rhizosphere soils and roots. This study provides evidence that low residual antibiotic levels in vegetable farms can shift microbial community structures, potentially affecting agroecosystem stability. However, the degree to which the shift occurs could be regulated by environmental factors, such as soil nutrient conditions.

Influence of the Antibiotic Oxytetracycline on the Morphometric Characteristics and Endophytic Bacterial Community of Lettuce (Lactuca sativa L.)

“…It was found that the greatest diversity of the bacterial community was in the soil samples, and the least was in the samples of the leaves and roots of lettuce. The literature also describes a higher diversity of bacterial species in soil than in plants [32,59]. In contrast to the hydroponic experiment with lettuce, soil contamination with OTC did not lead to significant differences in the level of alpha diversity in the bacterial community between samples with different doses, which is probably due to the sorption of the antibiotic in the soil [60].…”

“…The effect of antibiotics on plants can also be indirect through a change in the number and diversity of the bacterial community of the rhizosphere, which is actively involved in the growth and development of plants. A change in the composition of the bacterial community of the rhizosphere and root endosphere was demonstrated in the presence of macrolides and sulfonamides [32].…”

“…As a result, the endophytic community of an adult plant consists of the species present in the seed and the species present in the substrate. A small proportion of the community is also occupied by accidentally penetrating species (for example, from the air through damage in plant cells) [32,35].…”

“…The results obtained are in line with those presented in the scientific literature. Indeed, antibiotics caused alterations in endospheric bacterial communities' structures [32,62,64], and those alterations were more pronounced in the root endosphere compared with the leaf endosphere [65,66].…”

Impacts of florfenicol on soil bacterial community structure and diversity by high throughput sequencing analysis

“…The structure of bacterial communities is intricately linked to the soil environment, and any alterations in the soil environment can lead to corresponding changes in the bacterial community structure (Zhang et al 2022). Antibiotics have a profound impact on microbial communities, primarily influencing community diversity, abundance, composition, and function (Qiu et al 2023). Extensive research has indicated that antibiotics can modulate microbial biomass and community structure by affecting microbial enzyme activity and metabolic capacity (Wang et al 2020).…”