| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1107-1 | ||||
Resumo:Production of bio-pigments, particularly carotenoids, from non-food raw materials such as lignocellulosic biomass and different organic residues from the agroindustry, has the potential to strengthen the biorefineries. This work aimed to support the development of a new process for carotenoid production by Rhodotorula glutinis CCT-2186 growing on lignocellulosic biomass in the fermentation step. The primary idea behind this proposal is that it could lead to a sustainable way to produce these high-value-added compounds, with the potential to reduce production costs. Firstly, for the pretreatment of sugarcane bagasse, different total solids (TS) concentrations were chosen (10, 15, and 20 %TS) for the lignin removal and carbohydrate retention in the biomass. Each pretreated sample was taken to enzymatic hydrolysis, comparing the influence on the concentration of total solids (5 and 10%) with an enzymatic loading of 10 FPU/g of dry biomass. Likewise, the sugarcane bagasse hydrolysate obtained was taken to fermentation to evaluate its potential in carotenoid production by yeast. Alkaline pretreatment led to a maximum delignification of 81.97%, and retained 92.34 and 61.36 % of cellulose and hemicellulose, respectively, when 20% of total solids was used in the pretreatment step. The recovered biomass showed a maximum saccharification yield of 90.77% from cellulose and 78.07% from hemicellulose, after 72 h of enzymatic hydrolysis. Subsequently, fermentation tests were performed to evaluate carotenoid production in a synthetic medium, from different concentrations of glucose and xylose as carbon sources, concomitantly the supplementation of peptone, rice bran (RB), and soybean meal (SM) as nitrogen sources. Finally, sugarcane bagasse hydrolysate (SCBH) was evaluated as a carbon source for carotenoid production, supplemented only with peptone (4 g/L). The results showed the highest maximum production of β-carotene using an initial concentration of 10 g/L of total reducing sugars in a culture medium. The maximum recovery of β-carotene in a synthetic medium was 128.43 mg/L using glucose (10 g/L) after 72 h of fermentation. Fermentation supplemented with SM and RB showed that the concentration of 2.5 g/L of total protein of each hydrolysate leads to a higher production of carotenoids, reaching 129.34 and 110.96 mg/L of β-carotene, respectively. On the other hand, SCBH supplementing with peptone (4 g/L) presented a concentration of β-carotene of 118.56 mg/L after 72 h of fermentation. Thus, it is evident that the lignocellulosic hydrolysates used in this work (SCBH, RB, and SM) represent a potential source of nutrients for β-carotene production by the yeast R. glutinis CCT-2186. Palavras-chave: Sugarcane bagasse, Pretreatment, Enzymatic hydrolysis, β-carotene, Rhodotorula glutinis Agência de fomento:Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq (no. de processo: 309214/2021-1) | |||||