Assessment of toxicity of a biosurfactant from Candida sphaerica UCP 0995 cultivated with industrial residues in a bioreactor

• Published in: Electronic Journal of Biotechnology 2014-07, Vol.16 (4)
• Main Authors: de Souza Sobrinho, Humberto Bezerra, de Luna, Juliana Moura, Rufino, Raquel Diniz, Porto, Ana Lúcia Figueiredo, Sarubbo, Leonie Asfora
• Format: Article
• Language: English
• Subjects: bioreactor; biosurfactant; Candida sphaerica; industrial residues; toxicity
• ISSN: 0717-3458; 0717-3458

Background: The aim of the present study was to propose a low-cost method for the production of a biosurfactant by the yeast Candida sphaerica and assess its toxicity and phytotoxicity. The medium was formulated with distilled water supplemented with residue from a soy oil refinery (5%) and corn steep liquor (2.5%) as substrates. These two products were the sources of carbon and nitrogen as well as mineral elements to encourage the growth of the microorganism and production of a biosurfactant. Results: The isolated biosurfactant yield was 6.364 g/l. The biosurfactant exhibited an excellent ability to reduce surface tension (26 mN/m) and demonstrated no toxicity against seeds of Brassica oleracea , Chicoria intybus and Solanum gilo or the micro crustacean Artemia salina employed as a bioindicator. The biosurfactant exhibited no antimicrobial activity against the fungi and bacteria tested. Conclusions: The promising results obtained in this study indicate the feasibility of producing biosurfactants from powerful non-toxic organic residues and their application in the bioremediation of contaminated soil and water.