Production of free-melanin pullulan by Aureobasidium pullulans in fermentation processes assisted by led light

• Grant number: 15/26698-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2016
• End date: May 31, 2017
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Júlio César dos Santos
• Grantee: Camila Ayres Orsi
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

Exopolysaccharides (EPS) are biopolymers obtained from microbial sources that can form gels and viscous solutions in aqueous medium. The EPS is an alternative to synthetic polymers, with application in a wide range of pH and temperature. These polysaccharides have a number of industrial applications, such as in the production of biodegradable films. Among the various available EPS, pullulan, a homopolysaccharide produced mainly by the fungus Aureobasidium pullulans, stands out. The polymeric films produced from the pullulan have excellent physico-chemical and mechanical properties, but do not exhibit properties such as antimicrobial activity. However, certain natural antimicrobial compounds can be incorporated in the matrix, ensuring antimicrobial activity to the film. Lignin, for instance, can be obtained after pre-treatment of lignocellulosic material and, according to several studies, has potential as antimicrobial and antioxidant and, thus, the study of alternatives to use this material in applications of economic importance is interesting. The production of pullulan, however, shows technological inconvenience due to the presence of the pigment melanin (dark pigment) produced by the fungus during cultivation. The removal of melanin by adsorption with activated charcoal or by use of combinations of solvents/salts, increases the cost of pullulan production. Thus, research work to improve strains of Aureobasidium pullulans or about processes that limit the synthesis of melanin are essential. In this context, inhibition of the synthesis of melanin during pullulan production by a wild type strain of Aureobasidium pullulans cultured under LED light of different wavelengths is proposed. The cultivation will be carried out in semi-synthetic medium and in medium based in sugarcane bagasse cellulosic hydrolysate. Hydrolysate will be obtained by enzymatic hydrolysis of cellulose after a pre-treatment of material. The project will contribute to increase the knowledge about LED light effect on microbial cultures to biopolymers production. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

HILARES, RULY TERAN; ORSI, CAMILA AYRES; AHMED, MUHAMMAD AJAZ; MARCELINO, PAULO FRANCO; MENEGATTI, CARLOS RENATO; DA SILVA, SILVIO SILVERIO; DOS SANTOS, JULIO CESAR. Low-melanin containing pullulan production from sugarcane bagasse hydrolysate by Aureobasidium pullulans in fermentations assisted by light-emitting diode. Bioresource Technology, v. 230, p. 76-81, APR 2017. (15/26698-0)