Enhancement of astaxanthin production from food waste by Phaffia rhodozyma screened by flow cytometry and feed application potential

Abstract

Astaxanthin is widely used in food, aquaculture, cosmetics, and pharmaceuticals due to its strong antioxidant activity and coloring ability, but its production from Phaffia rhodozyma remains the main challenge due to the high fermentation cost and low content of carotenoid. In this study, the production of carotenoids from food waste (FW) by a P. rhodozyma mutant was investigated. P. rhodozyma mutant screened by UV mutagenesis and flow cytometry could stably produce high carotenoids at 25°C, with carotenoid production (32.9 mg/L) and content (6.7 mg/g), respectively, increasing by 31.6% and 32.3% compared with 25 mg/L and 5.1 mg/g of wild strain. Interestingly, the carotenoid production reached 192.6 mg/L by feeding wet FW, which was 21% higher than batch culture. The 373 g vacuum freeze‐dried products were obtained from the fermentation of 1 kg FW by P. rhodozyma, which contained 784 mg carotenoids and 111 mg astaxanthin. The protein, total amino acids, and essential amino acids content of the fermentation products were 36.6%, 40.5%, and 18.2% (w/w), respectively, and lysine‐added fermentation products had the potential of high‐quality protein feed source. This study provides insights for the high‐throughput screening of mutants, astaxanthin production, and the development of the feed potential of FW.

Microbial bioconversion of food waste to bio-fertilizers

“…Various fermentation methods have been applied to produce astaxanthin from food waste by Phaffia rhodozyma . 127,128…”

“…Various fermentation methods have been applied to produce astaxanthin from food waste by Phaffia rhodozyma. 127,128 In another study, a 40-L-biogas reactor was utilized for biogas production from the digestion of boiled rice, boiled cassava products, bread, boiled yam, and boiled maize by using different genera of bacteria such as Escherichia, Citrobacter, Bacillus, Pseudomonas, Proteus, Klebsiella, Clostridium, Bacteroides, Enterobacter, Staphylococcus, Salmonella, Streptococcus, Aspergillus, Mucor, Rhizopus and Penicillium. 129 The biogas reactor design contained various manometers for temperature and pH control and a plastic tube for the collection of gas produced during digestion.…”