Study on the fermentation effect of Rhodotorula glutinis utilizing tofu whey wastewater and the influence of Rhodotorula glutinis on laying hens

Abstract

BackgroundTofu whey wastewater (TWW) is the wastewater of tofu processing, which is rich in a variety of nutrients. Rhodotorula glutinis can make full use of TWW to ferment and reproduce yeast cells, produce carotenoids and other nutrients, improve the utilization value of TWW, and reduce environmental pollution and resource waste.MethodsIn this study, the nutrient composition changes of TWW treated by Rhodotorula glutinis were analyzed to reformulate TWW medium, and the optimal composition and proportion of TWW medium that can improve the biomass and carotenoids production of Rhodotorula glutinis were explored. Meanwhile, the Rhodotorula glutinis liquid obtained under these conditions was used to prepare biological feed for laying hens, and the effect of Rhodotorula glutinis growing on TWW as substrate on laying performance and egg quality of laying hens were verified.ResultsThe results showed that the zinc content of TWW after Rhodotorula glutinis fermentation increased by 62.30%, the phosphorus content decreased by 42.31%, and the contents of vitamin B1, B2 and B6 increased to varying degrees. The optimal fermentation conditions of Rhodotorula glutinis in the TWW medium were as follow: the initial pH was 6.40, the amount of soybean oil, glucose and zinc ions was 0.80 ml/L, 16.32 g/L, and 20.52 mg/L, respectively. Under this condition, the biomass of Rhodotorula glutinis reached 2.23 g/L, the carotenoids production was 832.86 μg/g, and the number of effective viable yeast count was 7.08 × 107 cfu/ml. In addition, the laying performance and egg quality of laying hens fed Rhodotorula glutinis biological feed were improved.DiscussionIn this study, we analyzed the composition changes of TWW, optimized the fermentation conditions of Rhodotorula glutinis in TWW medium, explored the influence of Rhodotorula glutinis utilizing TWW on laying layers, and provided a new idea for the efficient utilization of TWW.

Enhancing Selenium Accumulation in Rhodotorula mucilaginosa Strain 6S Using a Proteomic Approach for Aquafeed Development

“…The utilization of Rhodotorula yeasts, specifically R. mucilaginosa and R. glutinis , has exhibited significant promise in augmenting the nutritional composition of livestock feed by elevating the provision of vital minerals and vitamins. Through the fermentation of tofu whey wastewater, Rhodotorula species have been able to boost the zinc content by 62.3% and enhance the levels of essential vitamins B1, B2, and B6, which play a critical role in animal nutrition [ 78 ]. Overall, the diverse metabolic proficiencies and adaptability of Rhodotorula yeasts position them as a valuable asset for enhancing mineral provision and promoting the health and productivity of farm animals.…”

Effects of fermented tofu processing wastewater on growth performance and meat quality of Xianghuang broilers

“…This discarded TPW may pollute the environment due to its high chemical oxygen demand and biochemical oxygen demand (Chua, 2019). But there is still soluble protein, fat, sugar, vitamin and minerals remaining in the soybean residue juice (Chua, 2019; Xu et al, 2023), which can be used as a growth substrate for microorganisms and be treated as animal feed or plant fertiliser (Lu et al, 2022). Cyanobacteria Nostocmuscorum can grow well in TPW medium even if its concentration reached 40% (Rusydi & Yakupitiyage, 2019).…”

“…Cyanobacteria Nostocmuscorum can grow well in TPW medium even if its concentration reached 40% (Rusydi & Yakupitiyage, 2019). Rhodotorula glutinis can use tofu whey wastewater to produce carotenoids and effective viable yeast and then improve the laying performance and egg quality of laying hens (Xu et al, 2023).…”