Vol.:(0123456789) 1 3 International Journal of Environmental Science and Technology https://doi.org/10.1007/s13762-019-02400-9 ORIGINAL PAPER Fate of ibuprofen under optimized batch biodegradation experiments using Micrococcus yunnanensis isolated from pharmaceutical sludge K. Sharma 1  · G. Kaushik 1  · N. Thotakura 2  · K. Raza 2  · N. Sharma 3  · S. Nimesh 3 Received: 23 January 2019 / Revised: 2 May 2019 / Accepted: 8 May 2019 © Islamic Azad University (IAU) 2019 Abstract Ibuprofen, a frequently prescribed nonsteroidal anti-inflammatory drug, is a common environmental pollutant, and its increasing concentration in the environment leads to serious impacts. This concern has demanded a holistic scientific approach for the removal of pharmaceuticals and their by-products from the environment. Microbial degradation is an eco- friendly technique known to degrade complex molecules to simpler forms. The present study focuses on isolating the most potential bacterial strain from pharmaceutical industry site and investigates the biodegradation of ibuprofen. Among six isolated strains, one isolate KGP04 was identified as Micrococcus yunnanensis (GenBank: MG 493238), which exhibited the highest potential to degrade (~ 41.57%) ibuprofen before optimization. Taguchi-based L8 orthogonal array was used to optimize process parameters which improved the degradation rate by 83.50%. Drug concentration was reduced by 90.37% at optimum conditions (carbon 0.15%, nitrogen 0.1%, pH 7, inoculum size 2% (w/v), rpm 150, 12 h, 25 °C), as revealed by high-performance liquid chromatography. Q-time of flight mass spectrometry demonstrated the ibuprofen degradation path- way followed by the strain resulting in various transformative products. Further, the effect of ibuprofen on human embryonic kidney 293 cells was also analyzed through the Alamar Blue assay, which exhibited lower toxicity on the cells treated with the degraded samples. These results indicate that the strain is a capable candidate for the degradation of pharmaceuticals and optimized conditions can be employed to remove the nonsteroidal anti-inflammatory drugs and similar agents in a greener and economic manner from the pharmaceutical effluents. Keywords Bacteria · Biodegradation · Cytotoxicity · High-performance liquid chromatography · Ibuprofen · Mass spectroscopy · Taguchi approach Introduction Nowadays, occurrence of emerging contaminants has raised a worldwide concern due to their detrimental effects on the aquatic and terrestrial environment. Generally, emerging contaminants include pharmaceutical active compounds, surfactants, illicit drugs and endocrine disruptors (Iovino et al. 2015; Lechuga et al. 2016; Cosenza et al. 2018). These compounds reach the environment via various pathways including manufacturing units, wastewater treatment plants and other direct and indirect sources (Moreno-González et al. 2014; Rodriguez-Mozaz et al. 2015; Hanamoto et al. 2018). They affect human health and ecosystem by entering into food chain or through direct consumption (Collado et al. 2012). Pharmaceuticals remain persistent in the environment for a longer period and exhibit both chronic and sub-chronic effects on living beings, which are predominantly undesir- able in nature (Santos et al. 2010). Primarily, the occurrence Editorial responsibility: M. Abbaspour. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s13762-019-02400-9) contains supplementary material, which is available to authorized users. * G. Kaushik garima4rinku@gmail.com 1 Department of Environmental Science, School of Earth sciences, Central University of Rajasthan, Bandarsindri, Distt., Ajmer, Rajasthan 305817, India 2 Department of Pharmacy, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, Bandarsindri, Distt., Ajmer, Rajasthan 305817, India 3 Department of Biotechnology, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Distt., Ajmer, Rajasthan 305817, India