Benzoic acid‐degrading bacteria from the intestinal tract of Macrotermes michaelseni Sjöstedt

AbstractThe intestinal tracts of termites host a wide variety of microbial symbionts, which have been implicated in degradative processes. In this study, a fungus‐cultivating termite, Macrotermes michaelseni was found to harbor 2.2 × 106 bacterial cells per ml of gut homogenates capable of degrading benzoic acid. Two benzoic acid degrading bacteria were isolated from the highest dilution of gut homogenates in oxic media with benzoic acid as the sole carbon source. Isolate CBC was related to Stenotrophomonas maltophila LMG 958T, Xanthomonas campestris DSM 3586T and Stenotrophomonas acidaminophila DSM 13117T with a sequence similarity of 98.3%, 94.7% and 94.2%, respectively. Isolate CBW was related to Enterobacter aerogenes JCM 1235T and Raoultella ornithinolytica ATCC 31898T with sequence similarity of 98.4% and 97.8%, respectively. In addition to growing on benzoic acid (up to 9 mM) aerobically, isolate CBW also degraded benzoic acid under anoxic conditions with nitrate as electron acceptor. Isolate CBC did not degrade bezoic acid with nitrate but could degraded resorcinol under oxic conditions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)