*Article* **Microbial Communities Associated with Acetaminophen Biodegradation from Mangrove Sediment**

#### **Chu-Wen Yang, Yi-En Chen and Bea-Ven Chang \***

Department of Microbiology, Soochow University, Taipei 11101, Taiwan; ycw6861@scu.edu.tw (C.-W.Y.); xx0521xx@gmail.com (Y.-E.C.)

**\*** Correspondence: bvchang@scu.edu.tw; Tel.: +886-228-819-471 (ext. 6859)

Received: 10 May 2020; Accepted: 2 July 2020; Published: 4 July 2020

**Abstract:** Acetaminophen (ACE) is a widely used medicine. Currently, concerns regarding its potential adverse e ffects on the environments are raised. The aim of this study was to evaluate ACE biodegradation in mangrove sediments under aerobic and anaerobic conditions. Three ACE biodegradation strategies in mangrove sediments were tested. The degradation half-lives (*<sup>t</sup>*1/2) of ACE in the sediments with spent mushroom compost under aerobic conditions ranged from 3.24 ± 0.16 to 6.25 ± 0.31 d. The degradation half-lives (*<sup>t</sup>*1/2) of ACE in sediments with isolated bacterial strains ranged from 2.54 ± 0.13 to 3.30 ± 0.17 d and from 2.62 ± 0.13 to 3.52 ± 0.17 d under aerobic and anaerobic conditions, respectively. The degradation half-lives (*<sup>t</sup>*1/2) of ACE in sediments amended with NaNO3, Na2SO4 and NaHCO3 under anaerobic conditions ranged from 1.16 ± 0.06 to 3.05 ± 0.15 d, 2.39 ± 0.12 to 3.84 ± 0.19 d and 2.79 ± 0.14 to 10.75 ± 0.53 d, respectively. The addition of the three electron acceptors enhanced ACE degradation in mangrove sediments, where NaNO3 yielded the best e ffects. Sixteen microbial genera were identified as the major members of microbial communities associated in anaerobic ACE degradation in mangrove sediments with addition of NaNO3 and Na2SO4. Three (*Arthrobacter*, *Enterobacter* and *Bacillus*) of the sixteen microbial genera were identified in the isolated ACE-degrading bacterial strains.

**Keywords:** acetaminophen; mangrove sediments; biodegradation; aerobic conditions; anaerobic conditions
