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

Abstract

Background 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. Results 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. Conclusions 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. Electronic supplementary material The online version of this article (10.1186/s12934-019-1170-5) contains supplementary material, which is available to authorized users.

Nitric Oxide and Hydrogen Peroxide Signaling in Extractive Shiraia Fermentation by Triton X-100 for Hypocrellin A Production

“…The HA-yielding strain Shiraia sp. S9 was isolated from bamboo (Brachystachyum densiorum) twigs [42] and registered in China General Microbiological Culture Collection Center as No. CGMCC 16369.…”

“…CGMCC 16369. The strain was initially incubated on a potato dextrose agar (PDA) medium in a petri dish at 28 • C for 6 day, as previously reported [42]. The subsequent experiments were carried out in shake-flask cultures on a rotary shaker at 200 rpm and at 28 • C for an overall culture period of 8-10 days.…”

Inducing secondary metabolite production of Aspergillus sydowii through microbial co-culture with Bacillus subtilis

“…However, with the progress of scientific research, researchers have found that repeated discoveries of known metabolites are increasing. The fact that the biosynthetic potential has eluded is mostly explained by the observation that many genes are transcriptionally silent under standard culture conditions, causing their products inaccessible [ 3 ]. Moreover, analyses of microbial whole genome sequences indicate that microbes contain many thousands of biosynthetic gene clusters, which encode a plethora of compounds that are not identified when cultured under standard laboratory conditions [ 4 ].…”

Inducing secondary metabolite production of Aspergillus sydowii through microbial co-culture with Bacillus subtilis

“…However, with the progress of scienti c research, researchers have found that repeated discoveries of known metabolites are increasing. The fact that the biosynthetic potential has eluded is mostly explained by the observation that many genes are transcriptionally silent under standard culture conditions, causing their products inaccessible [3]. Moreover, analyses of microbial whole genome sequences indicate that microbes contain many thousands of biosynthetic gene clusters, which encode a plethora of compounds that are not identi ed when cultured under standard laboratory conditions [4].…”

“…Routine detection wavelengths were at 235, 254, 280 and 340 nm. Twenty(20) μL of the samples was injected to a Shimadzu TC-C 18 column (10×250 mm, 5 μm), and the following gradient was used (mobile phase A: 0.2% CH3 COOH in H 2 O, mobile phase B: acetonitrile): 0-30 min (20-80% B), 30-35 min (80-100% B), 35-40 min (100% B) at 37℃ with a ow rate of 1 mL/min. Compounds were prepared by silica gel column chromatography and an LC3000 semi-preparative HPLC system (Beijing Chuang Xin Tong Heng Science and Technology Co., Ltd).…”