Sustainable β-carotene production from sorghum syrup using Rhodotorula glutinis: bioprocess optimization and scale-up

TL;DR

Researchers optimized β-carotene production using sorghum syrup and a yeast species, achieving high yields at a large scale, with added nutritional benefits for food and feed.

Contribution

A sustainable, scalable bioprocess for β-carotene production using low-cost sorghum syrup and Rhodotorula glutinis.

Findings

Optimized medium achieved 1,003 µg/g β-carotene in shake flasks after 10 days.

Scale-up to 7 L fermentation yielded 1,753.33 µg/g β-carotene.

Biomass contained valuable nutrients like proteins, minerals, and glucosamine.

Abstract

β-Carotene, a key provitamin A carotenoid, is widely used as an antioxidant and natural pigment. Due to animals' inability to synthesize carotenoids, dietary sources are essential. This study utilized low-cost sorghum syrup for β-carotene production via Rhodotorula glutinis fermentation. Bioprocess optimization using response surface methodology was conducted in shake flasks, then scaled to 300 mL and 7 L fermentations. The optimized medium (9.18% sorghum syrup, 0.96% yeast extract, 0.07% KH₂PO4, 0.13% (NH4)₂SO4, 0.42% MgSO4) yielded a predicted 1 003 µg/g β-carotene after 10 days. Scale-up achieved 1 153 µg/g (300 mL) and 1 753.33 µg/g (7 L). Nutritional analysis showed the presence of chelated minerals, vitamins, proteins, and glucosamine, enhancing biomass value. These results highlight sorghum syrup as an effective, sustainable substrate for β-carotene production with applications in food, feed, and nutraceutical sectors.

One Sentence Summary: Using sorghum syrup as a low-cost substrate, we optimized β-carotene production by Rhodotorula glutinis via response surface methodology and validated at 7 L scale (up to 1,753 μg/g), while profiling the nutrient-dense biomass (protein, minerals, glucosamine) for food/feed applications.

Graphical Abstract

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