Author(s): MASAAKI MORIKAWA, HIROMI DAIDO, TOSHIFUMI TAKAO, SATORU MURATA, YASUTSUGU SHIMONISHI, TADAYUKI IMANAKA
A biosurfactant termed arthrofactin produced by Arthrobacter species strain MIS38 was purified and chemically characterized as 3-hydroxydecanoyl-D-leucyl-D-asparagyl-D-threonyl-D-leucyl-D-leucyl-D-seryl-L- leucyl-D-seryl-L-isoleucyl-L-isoleucyl-L-asparagyl lactone. Surface activity of arthrofactin was examined, with surfactin as a control. Critical micelle concentration values of arthrofactin and surfactin were around 1.0 X 10 - 5 M and 7.0 x 10- 5 M at 25°C, respectively. Arthrofactin was found to be five to seven times more effective than surfactin. The minimum surface tension value of arthrofactin was 24 mN/m at a concentration higher than the critical micelle concentration. According to the oil displacement assay, arthrofactin was a better oil remover than synthetic surfactants, such aas Triton X-100 and sodium dodecyl sulfate. Arthrofactin is one of the most effective lipopeptide biosurfactants.