Enhanced sulfamethoxazole degradation in soil by immobilized sulfamethoxazole-degrading microbes on bagasse

Shengbing Hu,Minghua Li,Yaoyi Ke,Wenlong Li,Huimin Hu,Yuechun Zhao

doi:10.1039/c7ra10150c

Abstract

The presence of sulfamethoxazole (SMX) in the environment is becoming a serious problem because of its toxicity and high risk to human health and microbial activity.

Highlights

The morphology of the two isolates under microscope is shown in Fig. 2.45 Biochemical characterization tests of the T2 bacterium are presented in Table 1, which showed that T2 was catalase-positive, motile, indole-negative, facultatively anaerobic or anaerobic, methyl red-negative and starch hydrolysis-positive
Within 30 d of the incubation period, the concentrations of SMX in soil declined rapidly in the rst 15 d under all experimental conditions, this decline slowed a er this period. This could be due to the decrease in nutrients and microelements and the accumulation of toxic intermediates, which would cause a reduction in the activity of the cells and enzymes
The optimal temperature and pH for the degradation of SMX by the bacterial strain T2 immobilized on bagasse were determined to be 28 C and 3.5, respectively

Summary

Introduction

Due to the characteristics of SMX, approximately 15–25% is incompletely metabolized and excreted into the surrounding environment from the human or animal body a er ingestion.[7,8,9,10] The wide use of SMX raises particular concerns for human health because its presence in the environment may harm human health and lead to antibiotic resistance,[11,12,13] as well as being a serious threat to soil and water ecosystems. In. China, SMX is released from four major sources: industry, hospitals, farms, and households; some SMX is released into water and soil without pre-treatment.[6,14] The degradation of SMX in soil, has become a major environmental concern. Different physicochemical techniques have been tested to remove SMX from polluted soil or water including oxidation,[15,16,17] adsorption,[18,19,20,21] photodegradation[22]

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Results

Conclusion