Biosurfactant Production by Rhodococcus Erythropolis Sp. SB-1A Isolated from North Atlantic Ocean

Tong Cao, Baiyu Zhang, Bing Chen, Qinhong Cai, He Zhang, Zhiwen Zhu, Kedong Zhang

Biosurfactant production by Rhodococcus erythropolis SB-1A was studied based on Atlas oil agar medium in a batch reactor. The strain was isolated from a water sample collected from Northern Atlantic Ocean. Several parameters including carbon source (n-hexadecane, 0.5, 2, 3.5 and 5 v/v%), nitrogen source (NH4NO3,0.4, 0.7, 1 and 1.3 g/L), pH (5,6, 7 and 8) and salinity (NaCl, 13, 26, 39 and 52 g/L) were analyzed to optimize cultural and environmental conditions for biosurfactant production. Surface active properties of biosurfactants in the cell-free broth were monitored periodically. Results showed that the crude biosurfactants in the media cultivated under experimentally defined conditions reduced surface tension by 40 dynes/cm within 10 hours of cultivation. The research outputs demonstrated the possibility of using biosurfactants produced by Rhodococcus erythropolis SB-1A for remedying hydrocarbon contamination in North Atlantic Canada and beyond.