A new yeast strain isolated from the pharmaceutical wastewater was capable of utilizing cefdinir as a sole carbon source for their growth in mineral medium. The yeast was identified and named as Candida sp. SMN04 based on morphology and 18S-ITS-D1/D2/D3 rRNA sequence analysis. The interaction between factors pH (3.0-9.0), inoculum dosage (1-7{\%}), time (1-11 day) and cefdinir concentration (50-450 mg/L) was studied using a Box-Behnken design. The factors were studied as a result of their effect on cell dry weight (R1; g/L), extended spectrum $\beta$-lactamase (ESBL) assay (R2; mm), P450 activity (R3; U/mL) and degradation (R4; {\%}). Maximum values of R1, R2, R3 and R4 were obtained at central values of all the parameters. The isolated yeast strain efficiently degraded 84{\%} of 250 mg L-1 of cefdinir within 6 days with a half-life of 2.97 days and degradation rate constant of 0.2335 per day. Pseudo-first-order model efficiently described the process. Among the various enzymes tested, the order of activity at the end of Day 4 was noted to be: cytochrome P450 (1.76 ± 0.03) {\textgreater} NADPH reductase (1.51 ± 0.20) {\textgreater} manganese peroxidase and amylase (0.66 ± 0.15; 0.66 ± 0.70). Intermediates were successfully characterized by liquid chromatography-mass spectrometry. The opening of the $\beta$-lactam ring involving ESBL activity was considered as one of the major steps in the cefdinir degradation process. Fourier transform-infrared spectroscopy analysis showed the absence of spectral vibrations between 1766 and 1519 cm-1 confirming the complete removal of lactam ring during cefdinir degradation. The results of the present study are promising for the use of isolated yeast Candida sp. SMN04 as a potential bioremediation agent.

Nilanjana Mitra

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Vellore Campus

Das D

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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Potentiality of yeast Candida sp. SMN04 for degradation of cefdinir, a cephalosporin antibiotic: kinetics, enzyme analysis and biodegradation pathway

Environmental Technology

Antibiotics have been categorized as emerging pollutants due to their indiscriminate usage, continuous input and persistence in various environmental matrices even at lower concentrations. Cephalosporins are the broad-spectrum antibiotics of $\beta$-lactam family. Owing to its enormous production and consumption, it is reported as the second most prescribed antibiotic classes in Europe. The cephalosporin wastewater contains toxic organic compounds, inorganic salts and active pharmaceutical ingredients (API) which pose a potential threat to the organisms in the environment. Therefore, removal of cephalosporin antibiotics from the environment has become mandatory as it contributes to increase in the level of chemical oxygen demand (COD), causing toxicity of the effluent and production of cephalosporin-resistant microbes. So far, several processes have been reported for degradation/removal of cephalosporins from the environment. A number of individual studies have been published within the last decade covering the various aspects of antibiotics. However, a detailed compilation on cephalosporin antibiotics as an emerging environmental contaminant is still lacking. Hence, the present review intends to highlight the current ecological scenario with respect to distribution, toxicity, degradation, various remediation technologies and the regulatory aspects concerning cephalosporins. The latest successful technologies for cephalosporin degradation/removal discussed in this review will help researchers for a better understanding of the nature and persistence of cephalosporins in the environment along with the risks associated with their existence. The research thrust discussed in this review will also evoke new technologies to be attempted by the future researchers to develop sustainable options to remediate cephalosporin-contaminated environments.

Fulltext

3 Biotech

An overview of cephalosporin antibiotics as emerging contaminants: a serious environmental concern

The present study evaluates the effect of integrated nano-bio approach involving nanoscale magnesium oxide (n-MgO) and yeast Candida sp. SMN04 on cefdinir degradation in aqueous medium. The nanoparticle was chemically synthesized and characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), EDAX analysis and particle size analyser. Nano-bio integrated system was prepared using chemically synthesized n-MgO (10 mg mL−1), coated onto the surface of yeast cells without causing any lethal effects to the cell. Cefdinir (250 mg L−1) degradation was studied using individual and nano-bio integrated system both. Nano-bio integrated system was found to be more effective for cefdinir degradation compared to native yeast cell. The adherence of nanoparticles on the surface of the yeast cells increased the permeability of the cell membrane, thereby enhancing the entry of cefdinir into the cell. The kinetic data showed the half-life of cefdinir, which was 1.46 days for integrated system and 2.97 days for native yeast, which confirmed that the integrated approach reduced the half-life to less than half of the time taken by the yeast alone. This study signifies the potential efficacy of the nano-bio integrated approach to serve as an effective remedial tool for the treatment of pharmaceutical wastewater. {\textcopyright} 2015 American Institute of Chemical Engineers Environ Prog, 35: 706–714, 2016.

Environmental Progress & Sustainable Energy

Degradation of cefdinir byCandidaSp. SMN04 and MgO nanoparticles-An integrated (Nano-Bio) approach

Cefdinir being a semi-synthetic third generation cephalosporin antibiotic is considered as an emerging pollutant which demands removal from environment. Degradation of cefdinir by yeast Candida sp. SMN04 immobilized on various single and hybrid matrices was investigated using entrapment method. The biofilm forming ability of Candida sp. was evaluated by crystal violet staining assay and the formed biofilm was monitored by SEM and AFM analysis. The amount of exopolysaccharides (EPS) produced by Candida sp. was quantified and characterized by FTIR, HPLC and TGA analysis respectively. Cefdinir degradation from pharmaceutical wastewater was found to be 96.6{\%} and 92.2{\%} by PVA-alginate immobilized yeas tand yeast biofilm formed on gravels over a period of 48 h in batch mode. Effectiveness of the process was also tested involving continuous-flow column studies. This is the first successful attempt on cefdinir degradation using immobilized yeast cells and yeast biofilm on solid substrate.

Journal of Applied Pharmaceutical Science

Degradation of cefdinir from pharmaceutical wastewater using immobilized Candida sp. SMN04 and biofilm formed on gravels

Cefdinir, a semi-synthetic third generation cephalosporin antibiotic being considered as an emerging pollutant, demands removal from aquatic ecosystems. A yeast strain isolated from pharmaceutical wastewater which was identified as Ustilago sp. SMN03 by molecular techniques and was found to be capable of utilizing cefdinir as a sole carbon source. The isolate was found to degrade 81 {\%} of cefdinir within 6 days under optimized conditions viz. pH 6.0, temperature 30 °C, a shaking speed of 120 rpm, an inoculum dosage of 4 {\%} (w/v) and an initial cefdinir concentration of 200 mg L{\textless}sup{\textgreater}−1{\textless}/sup{\textgreater}. Kinetic studies revealed that cefdinir degradation followed the pseudo-first order model, a rate constant of 0.222 per day and a half-life period of 3.26 days. Using LC–MS analysis, six novel intermediates formed during the cefdinir degradation were identified and characterized. FT-IR analysis showed that the functional groups ranging from 1,766 to 1,519 cm{\textless}sup{\textgreater}−1{\textless}/sup{\textgreater}, characteristic for lactam ring were completely removed during the cefdinir degradation. The opening of the $\beta$-lactam ring was one of the major steps in the cefdinir degradation process. Based on the results from the present study, a possible pathway of cefdinir degradation by Ustilago sp. SMN03 was proposed. To the best of our knowledge, this is the first report on microbial degradation of cefdinir by yeast.

Journal	Environmental Technology
Publisher	Informa UK Limited
ISSN	0959-3330
Open Access	0