Promotion of the Hypocrellin Yield by a Co-Culture of Shiraia bambusicola (GDMCC 60438) with Arthrinium sp. AF-5 Fungus

Xiaoxiao Yan,Yongdi Wen,Menghua Hu,Zhenqiang Wu,Xiaofei Tian

doi:10.3390/fermentation7040316

Abstract

Hypocrellin is a natural 3,10-xylene-4,9-anthracene derivative compound that originates from the stroma of Shiraia bambusicola (S. bambusicola) and Hypocrella bambusae with excellent photobiological activities. Submerged fermentation with the mycelia of S. bambusicola is generally regarded as an ideal technology for hypocrellin production. This study developed a co-cultivation strategy for an obvious promotion of the hypocrellin yield by incubating S. bambusicola (GDMCC 60438) with the endophyte fungus Arthrinium sp. AF-5 isolated from the bamboo tissue. The results indicated that the yield of hypocrellin A (HA) reached a 66.75 mg/g carbon source after an 84-h co-cultivation of the two strains, which was a four-time increase of that by the fermentation only with the S. bambusicola. The microscope observation found that the mycelia of the two strains were intertwined with each other to form the mycelium pellets during the co-cultivation. Moreover, the mycelium pellets of the co-culture showed a contracted and slightly damaged morphology. The addition of H2O2 in the fermentation media could further increase the HA production by 18.31%.

Highlights

BochmanShiraia bambusicola Henn. and Hypocrella bambusae (Berk. & Broome) Sacc. (Ascomycetes) are pathogenic fungi of bamboo in east Asia [1,2,3]
After the collected FFM was freeze-dried for 10 h, fungal crude polysaccharide (FCP) of endophytic fungi were extracted by hot-water extraction
The results showed that the biomass, hypocrellin A (HA) content in the mycelium, HA conversion yield, and HA yield were significantly improved when the AF-5 strain was introduced at 12, 24, and 36 h of the fermentation (Figure 6)

Summary

Introduction

BochmanShiraia bambusicola Henn. and Hypocrella bambusae (Berk. & Broome) Sacc. (Ascomycetes) are pathogenic fungi of bamboo in east Asia [1,2,3]. A variety of secondary metabolites, such as perylene quinones, anthraquinones, and polysaccharides, were isolated from the fungal stroma [4]. The current supply of the hypocrellin source has failed to meet the increasing demand because of the limited productivity of the natural fungal stroma. The metabolic pathways’ biological synthesis of the hypocrellins is still unclear, submerged fermentation with S. bambusicola has excellent application prospects in producing hypocrellins [13]. Various methods have been developed to increase the yield of the hypocrellins through fermentation, such as genetic modification and mutagenesis of the strains, optimization of media and cultivation conditions, and chemical and physical induction [12,13,14,15]. The yield of the hypocrellins reached 90–8700 mg/L [14,15]

Methods

Results

Conclusion