Untargeted Global Metabolomic Analysis Reveals the Mechanism of Tripropylamine-Enhanced Lycopene Accumulation in Blakeslea trispora.

Yanlong Wang,Xin Chen,Meng Zhang,Yicun Wang,Yulong Wang,Cunping Liu,Zexu Li,Yuechao Zhao,Keying Liu

doi:10.3389/fbioe.2021.673225

Abstract

We previously determined that the cyclase inhibitor tripropylamine (TPA) significantly enhances lycopene accumulation in Blakeslea trispora. To elucidate the mechanism of TPA-enhanced lycopene accumulation, the untargeted metabolome of B. trispora treated with TPA was analyzed by UHPLC-Q-TOF/MS. Forty-two differential metabolites were identified, of which 15 significantly differential metabolites meeting the following parameters were screened: variable importance for the projection > 1, P < 0.05, and fold change > 1.5. The down-regulated metabolites were mainly cyclic dipeptides, bacteriostatic compounds, and lipids, while the up-regulated metabolites were mainly unsaturated fatty acid. Furthermore, the bacteriostatic ability was poor, the extracellular and intracellular pH levels were high, and hyphae with vesicles were swollen locally in B. trispora after treatment with TPA. Our data suggest that the TPA enhances lycopene accumulation not only by inhibiting the cyclization of β-carotene but also by down-regulating cyclic dipeptides for quorum sensing; up-regulating unsaturated fatty acids, 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine, and 4-hydroxybenzoate and down-regulating choline, resulting in locally swelling mycelium with vacuoles; and down-regulating bacteriostatic metabolites for metabolic flux redistribution.

Highlights

IntroductionA well-known member of the carotenoids, exhibits strong antioxidant activity
Lycopene, a well-known member of the carotenoids, exhibits strong antioxidant activity
We found that the TPA enhances lycopene accumulation by inhibiting the cyclization of β-carotene and by down-regulating cyclic dipeptides for quorum sensing; up-regulating unsaturated fatty acids, 1-palmitoyl-2-hydroxy-sn- glycero-3-phosphoethanolamine (PPE), and 4-hydroxybenzoate and down-regulating choline, resulting in locally swelling mycelium with vacuoles; and down-regulating bacteriostatic metabolites for metabolic flux redistribution

Summary

Introduction

A well-known member of the carotenoids, exhibits strong antioxidant activity. It has been extensively used to prevent and treat prostate, breast, pancreatic, and other cancers, as well as cardiovascular diseases (Rodriquez-Concepcion et al, 2018; Caseiro et al, 2020). A filiform aerobic fungus (class Zygomycetes, order Mucorales, family Choanophoraceae), has been proposed as an ideal natural source of lycopene. The “plus” and “minus” type strains mate to generate trisporic acid from the “plus” type and stimulate lycopene synthesis by the “minus” type (Wang et al, 2016a). During the carotenoid biosynthesis process in B. trispora, phytoene is catalyzed by phytoene desaturase to generate lycopene. The lycopene is cyclized into γ-carotene and β-carotene by lycopene cyclase. Lycopene is an intermediate of the carotenoid biosynthetic pathway

Methods

Results

Conclusion