Comparison of pinoresinol diglucoside production by Phomopsis sp. XP-8 in different media and the characterisation and product profiles of the cultivation in mung bean

BACKGROUND: Phomopsis sp. XP-8 is an endophytic fungus with the ability to produce pinoresinol diglucoside (PDG) in vitro and thus has potential application in biosynthesis of PDG independent of plants. In order to enhance the production of PDG, 18 different natural materials were tested in solid-state cultivation of Phomopsis sp. XP-8. RESULTS: Most of the tested natural materials promoted the production of PDG. A supplement derived from mung beans produced the highest PDG yield and better fungal growth than the other materials. Also, pinoresinol monoglucoside, pinoresinol and other substrates (phenylalanine, p-coumaric acid, cinnamic acid, caffeic acid, and ferulic acid) were obtained after fermentation on mung beans. Furthermore, PDG production was much higher when mung beans were incorporated into solid state agar versus a liquid medium. The highest pinoresinol diglucoside production (72.1 mg kg⁻¹ in fresh culture) was obtained in 9 days using a solid state culture of Phomopsis sp. XP-8 on a mung bean grain medium containing 100 g kg⁻¹ glucose. Mung bean water-soluble polysaccharide was identified as a major promoter of PDG production by Phomopsis sp. XP-8. CONCLUSION: Mung bean, especially its water-soluble polysaccharide fraction, was an efficient natural material to promote PDG production by Phomopsis sp. XP-8.