string: …isolates, Pseudomonas and Rhodococcus are well-known biosurfactant producers (Syldatk et al. 1985; Desai and Banat 1997; Husain et al. 1997; Coelho et al.
  2003; Maier 2003), but such capability was rarely reported for cold-adapted isolates (Yakimov et al. 1999; Pini et al. 2007; Cai et al. 2014).