A meta-analysis on the responses of soil microbial biomass and community structure to antibiotics

The overuse of antibiotics over the last few decades is of serious concern worldwide, and may lead to profound alterations in the biomass and structure of soil microbial communities, thus posing threats to soil ecosystems. However, on a global scale, the effects of antibiotics on soil microbial biomass and community structure remain elusive. Here, by performing 66 paired observations, we conducted one of the first global meta-analysis to evaluate the effects of various antibiotics on soil microbial communities and to explore the underlying mechanisms. Our results showed that antibiotics suppressed soil microbial biomass (indicated by PLFA) by 17 %, bacterial biomass by 17 %, and fungal biomass by 10 %. The ratio of bacteria to fungi biomass was decreased for all antibiotic types. The negative effects of antibiotics on soil microbial community and bacteria biomass attenuated with time. Additionally, the response of bacteria biomass to antibiotics, which is regulated by mean annual temperature and precipitation through soil pH and soil total nitrogen, diminished with latitude. Collectively, this study illustrates the global patterns and drivers of antibiotic-induced negative influences on microbial communities in soils, and can help identify global hotspots facing the negative effects of increasing anthropogenic usage of antibiotics.