Bioconversion of low-cost brewery waste to biosurfactant: An improvement of surfactin production by culture medium optimization

Author(s)

Nazareth, Talita Correa ; Zanutto, Conrado Planas ; Maass, Danielle ; Ulson de Souza, Antonio Augusto ; Guelli Ulson de Souza, Selene Maria de Arruda

• Document type: Journal article
• Source: Biochemical Engineering Journal; v. 172, p. 10-pg., 2021-05-19.

Abstract

Trub is the second-largest residue from brewing industry (250 thousand tons/year) and, due to the presence of high amounts of carbon and nitrogen, it is a potential source of reducing sugars and nitrogen for biological processes. Therefore, this work aimed to enhance surfactin production by Bacillus subtilis using Trub as a carbon source. The effect of nitrogen sources on biosurfactant production was investigated by a full factorial design (2(2)). Yeast extract and its interaction with peptone presented a statistically significant effect on the response variable of surface tension (ST). ST was described by a linear regression model (R-2 = 0.93). The effect of metals supplementation on the culture medium was also investigated, where the volumetric productivity increased from 2.98 to 7.43 mg L-1 h(-1) for the medium without (M-I) and with metals (M-II), respectively. After 28 h, 210.11 mg L-1 was obtained in the batch culture with M-II medium, being higher than the maximum surfactin concentration achieved after 52 h (121.80 mg L-1) for M-I medium. The biosurfactant production in bioreactor was successfully performed since a concentrated extract was obtained in the foam collected, reaching the maximum of 1118.20 mg L-1 of surfactin. (AU)

• FAPESP's process: 19/07659-4 - Valorization of metals present in metal-rich wastes by biomining process - BIOMETALVALUE
• Grantee: Danielle Maass
• Support Opportunities: Regular Research Grants