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Effects of nonionic surfactants on pigment excretion and cell morphology in extractive fermentation of Monascus sp. NJ1

Yang, Xuelian, Dong, Ye, Liu, Guorong, Zhang, Chan, Cao, YanPing, Wang, Chengtao
Journal of the science of food and agriculture 2019 v.99 no.3 pp. 1233-1239
Monascus, biocompatibility, droplets, excretion, lipids, membrane permeability, mycelium, nonionic surfactants, pigments, secretion, submerged fermentation, temperature
BACKGROUND: Different nonionic surfactants in submerged fermentation of Monascus sp. demonstrate significant differences regarding increasing pigment yield. In this study, 15 surfactants from five series were analyzed to investigate the influence of nonionic surfactants on Monascus pigments, with the aim of simultaneously obtaining a novel nonionic surfactant. RESULTS: Addition of the novel surfactant Brij 35 greatly enhanced pigment excretion and demonstrated good biocompatibility. Extracellular red, orange and yellow pigments increased by 1.47‐, 1.71‐ and 2.07‐fold respectively. Production of extracellular pigments was not only related to the hydrophile–lipophile balance value (HLB) but also affected by the cloud point temperature (CP) of the fermentation medium. It was found that nonionic surfactants can improve cell membrane permeability and cell storage capacity by modifying the cell walls of Monascus mycelium and by increasing lipid droplet levels, enhancing pigment excretion. Different nonionic surfactants modify Monascus mycelium to different degrees. CONCLUSION: The novel surfactant Brij 35, which has good capacity for pigment extraction and biocompatibility, was identified in the analysis. The effects of nonionic surfactants on the secretion of pigments are related to not only the modification of the cell wall and internal structure but also the CP and HLB. © 2018 Society of Chemical Industry