Journal of Environmental Biology

Low toxicity and high surface activity of sophorolipids from Starmerella bombicola in aquatic species:

A preliminary study

Paper received: 27.03.2018??????? ?? ??????Revised received: 12.11.2018??????? ????????? ????Re-revised received: 18.12.2018?????????? ????????????????? Accepted: 29.01.2019

Authors Info

W. Kumano, K. Namakoshi,

M. Araki, Y. Oda, A. Ueda

and Y. Hirata*     

Biochemical Laboratory,???????????? Saraya Co. Ltd.,????????????????????????????? Osaka- 582-0028, Japan

*Corresponding Author Email :

hirata@saraya.com

Abstract

Aim: This study was carried out to evaluate aquatic toxicity and surface activity of sophorolipids extracted from yeast Starmerella bombicola.    

Methodology: The half maximal effective concentration (EC₅₀) values of sophorolipids were determined in three aquatic species, and the surface activity of sophorolipids in aqueous solutions was examined at EC₅₀ concentration.?? ?

Results: The EC₅₀ of sophorolipid surfactant >473 mg l^-1 was found in alga Pseudokirchneriella subcapitata, a median lethal concentration (LC₅₀) of 64.8 mg l^-1 in fish Oryzias latipes, whereas a high EC₅₀ of 48.2 mg l^-1 was noted in crustacean Daphnia magna, respectively. Sophorolipids effectively reduced the aquatic surface tension to 39 mN m^-1 in O. latipes and to 41 mN m^-1 in D. magna.?? ?

Interpretation: These results show that sophorolipids from S. bombicola are a promising biosurfactant with an ideal balance of low aquatic toxicity and high surface activity.

Key words: Aquatic toxicity, Biosurfactant, Sophorolipid, Surfactant

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