Inducing perylenequinone production from a bambusicolous fungus Shiraia sp. S9 through co-culture with a fruiting body-associated bacterium Pseudomonas fulva SB1

• Published in: Microbial cell factories 2019-07, Vol.18 (1), p.121-14, Article 121
• Main Authors: Ma, Yan Jun, Zheng, Li Ping, Wang, Jian Wen
• Format: Article
• Language: English
• Subjects: Antimicrobial agents; Ascomycota - genetics; Ascomycota - metabolism; Associated bacteria; Bacteria; Biosynthesis; Co-culture; Coculture Techniques; Culture; Exudation; Fruit bodies; Fruiting Bodies, Fungal - metabolism; Fruiting body; Fungal Proteins - genetics; Fungi; Gene expression; Genes; Genetic aspects; Hypocrellin A; Microbial Interactions; Microorganisms; Perylene - analogs & derivatives; Perylene - metabolism; Perylenequinones; Phenol; Photochemotherapy; Photodynamic therapy; Pigments; Polyketide synthase; Polyketide Synthases - genetics; Polymerase chain reaction; Pseudomonas; Pseudomonas - isolation & purification; Pseudomonas - physiology; Pseudomonas fulva; Pure culture; Quinones - metabolism; Shiraia; Spores, Fungal
• ISSN: 1475-2859; 1475-2859
• DOI: 10.1186/s12934-019-1170-5

Fungal perylenequinonoid (PQ) pigments from Shiraia fruiting body have been well known as excellent photosensitizers for medical and agricultural uses. The fruiting bodies are colonized by a diverse bacterial community of unknown function. We screened the companion bacteria from the fruiting body of Shiraia sp. S9 and explored the bacterial elicitation on fungal PQ production. A bacterium Pseudomonas fulva SB1 isolated from the fruiting body was found to stimulate the production of fungal PQs including hypocrellins A, C (HA and HC), and elsinochromes A-C (EA, EB and EC). After 2 days of co-cultures, Shiraia mycelium cultures presented the highest production of HA (325.87 mg/L), about 3.20-fold of that in axenic culture. The co-culture resulted in the induction of fungal conidiation and the formation of more compact fungal pellets. Furthermore, the bacterial treatment up-regulated the expression of polyketide synthase gene (PKS), and activated transporter genes of ATP-binding cassette (ABC) and major facilitator superfamily transporter (MFS) for PQ exudation. We have established a bacterial co-culture with a host Shiraia fungus to induce PQ biosynthesis. Our results provide a basis for understanding bacterial-fungal interaction in fruiting bodies and a practical co-culture process to enhance PQ production for photodynamic therapy medicine.