Fermentative Production of Diacylglycerol by Endophytic Fungi Screened from Taxus chinensis var. mairei

Abstract

Diacylglycerol (DAG) production by microbial fermentation has broad development prospects. In the present study, five endophytic fungi which could accumulate DAG were screened from Taxus chinensis var. mairei by using potato dextrose agar plate and flask cultivation in potato dextrose broth culture medium. The strains were biologically identified based on morphological features and semi-quantitative PCR. The identification results indicated that the five strains belonged to different genera: Fusarium annulatum (F. annulatum, coded as MLP41), Trichoderma dorotheae (T. dorotheae, coded as MLG23), Colletotrichum aeschynomenes (C. aeschynomenes, coded as MLY23), Pestalotiopsis scoparia (P. scoparia, coded as MLY31W), and Penicillium cataractarum (P. cataractarum, coded as MLGP11). The crude lipids from the strains and their corresponding triacylglycerol, 1,2-DAG, and 1,3-DAG fractions separated via thin-layer chromatography were mainly composed of palmitic acid, stearic acid, oleic acid, and linoleic acid, which in total accounted for higher than 94% of the content. The effects of fermentation conditions on the DAG productivity were discussed, and the yields of DAG were determined based on the 1H NMR spectra of crude lipids. The highest total DAG yields of F. annulatum, T. dorotheae, C. aeschynomenes, P. scoparia, and P. cataractarum were 112.28, 126.42, 189.87, 105.61, and 135.56 mg/L, respectively. C. aeschynomenes had the strongest potential to produce DAG. The results showed that this may be a new promising route for the production of DAG via fermentation by specific endophytic fungi, such as C. aeschynomenes.