**4. Conclusions**

In this study, the feasibility of bioremediation strategies for ACE removal in mangrove sediments were tested. All of the treatments, addition of ACE-degrading bacterial strains, MC and electron acceptors (NaNO3, Na2SO4 or NaHCO3) can enhance the ACE biodegradation in mangrove sediments. Addition of NaNO3 exhibited the best effects for ACE biodegradation in mangrove sediments. Different treatments result in different bacterial communities and exhibited different ACE-degrading effectiveness. Sixteen microbial genera identified may be major microbes involved in anaerobic ACE degradation in mangrove sediments with electron acceptor addition. These results provide useful solutions for removal of ACE in mangrove sediments.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2071-1050/12/13/5410/s1. Figure S1: Mangrove sediment sampling sites Bali (25◦0948 N 121◦2504 E) and Guandu (25◦0721 N 121◦2740 E) in northern Taiwan.

**Author Contributions:** Data curation, C.-W.Y.; formal analysis, Y.-E.C.; funding acquisition, B.-V.C.; investigation, C.-W.Y.; methodology, Y.-E.C.; project administration, B.-V.C.; visualization, C.-W.Y.; writing—original draft, C.-W.Y. and B.-V.C.; writin—review & editing, C.-W.Y. and B.-V.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by the Ministry of Science and Technology, Republic of China, Taiwan (grant no. MOST 107-2313-B-031-002).

**Conflicts of Interest:** The authors declare that they have no conflicts of interest.
