By-products from the biodiesel chain as a substrate to citric acid production by solid-state fermentation

Abstract

In this study, we propose the use of tung cake for the production of organic acids, with an emphasis on citric acid by solid-state fermentation. We evaluated the conditions of production and the by-products from the biodiesel chain as raw materials involved in this bioprocess. First, we standardized the conditions of solid-state fermentation in tung cake with and without residual fat and with different concentrations of glycerine using the fungus Aspergillus niger The solid-state fermentation process was monitored for 7 days considering the biomass growth and pH level. Citric acid production was determined by high-performance liquid chromatography. Fungal development was better in the crude tung cake, consisting of 20% glycerine. The highest citric acid yield was 350 g kg(-1) of biomass. Therefore, the solid-state fermentation of the tung cake with glycerine led to citric acid production using the Aspergillus niger fungus.

Solid-State Fermentation as a Novel Paradigm for Organic Waste Valorization: A Review

“…Apart from fruit wastes, citric acid can also be produced from agro-industrial wastes such as oil palm empty fruit bunches [142], sugarcane bagasse [143], cassava bagasse [144], and biodiesel by-products [145] through SSF. Yadegary et al [143] optimized citric acid production using sugarcane bagasse as a substrate by SSF using the Taguchi statistical method.…”

“…The bioconversion of biodiesel by-product (tung cake and glycerine) by A. niger under SSF for the production of citric acid has also been reported. The high yield of citric acid obtained (350 g·kg −1 ) provides a feasible way to manage the solid waste economically [145].…”

Aproveitamento da glicerina de biodiesel obtida a partir de óleo de fritura para o cultivo do fungo Aspergillus niger

“…Há relatos da utilização do meio de cultivo enriquecido com esse ácido, resultante da ação de A. niger sobre a glicerina de biodiesel em condições apropriadas, para o branqueamento de caulim (MUSIAL; CIBIS; RYMOWICZ, 2011). A glicerina de biodiesel também já foi utilizada como complemento ao meio sólido na produção de ácido cítrico por A. niger a partir de torta de tungue (SCHNEIDER et al, 2014). A redução do pH no presente estudo mostra que é possível obter ácidos a partir de glicerina de óleo de fritura sem prévia purificação.…”

Kinetics of Polycondensation of Citric Acid with Glycerol Based on a Genetic Algorithm

“…The problems related to the synthesis, known already in 1988, were not resolved, and PGCit was somewhat forgotten. However, there are a few mentions of the use of this material as an additive to blends or copolymers and the use of citric acid and glycerol as cross-linking agents . The synthesis of similar materials such as POC or PGS shows the high attractiveness of PGCit .…”