Assessing the Effect of Antibiotics on Lactuca sativa Cultivated in Soil Amended with Organic Residues

Abstract

The global increase in the use of antibiotics has resulted in the contamination of different ecosystems such as soil and water, which can have severe implications for crop productivity. This study investigates the effect of antibiotics, ampicillin and ofloxacin, on Lactuca sativa grown in antibiotic-contaminated soil (control, 5 and 10 mg kg-1) and treated with three organic amendments: compost, rice husk and vermicompost. In the germination test, compost as well as rice husk significantly reduced the inhibitory effect of antibiotics on root elongation by 51% and 75% respectively. In the pot experiment, enhanced plant biomass was observed with the use of rice husk. Furthermore, a synergistic effect between antibiotics and compost as well as vermicompost was observed in shoot and root length in the germination test. A similar effect was observed on the rubisco large subunit and soluble protein content of plants cultivated in rice husk and vermicompost. On the contrary, an antagonistic effect of the rice husk and antibiotics at 5 mg kg-1 was observed on the chlorophyll content. This study concludes that the effect of antibiotics on different plant traits vary, depending on the antibiotic concentration as well as type of amendment used to alleviate the antibiotic stress. Keywords: Lactuca sativa, antibiotic stress, biochemical plant traits, ampicillin, organic amendments, plant nutrients.