A Fungal Diterpene Synthase Is Responsible for Sterol Biosynthesis for Growth

Abstract

A conserved open reading frame, dps , is described in Pestalotiopsis microspora , sharing a remarkable similarity with fungal diterpene synthases whose function is less studied. Loss-of-function approach manifested that dps was necessary for the growth and the development of the fungus. A deletion strain, dps Δ, showed a fundamental retardation in growth, which could deliberately be restored by the addition of exogenous sterols to the media. Gas chromatography–mass spectrometry analysis confirmed the loss of the ability to produce certain sterols. Thus, the tolerance and the resistance of dps Δ to several stress conditions were impaired. Secondary metabolites, such as the polyketide derivative dibenzodioxocinones, were significantly diminished. At the molecular level, the deletion of dps even affected the expression of genes in the mevalonate pathway. This report adds knowledge about fungal diterpene synthases in Pestalitiopsis microspora .

Machine learning‐based automated fungal cell counting under a complicated background with ilastik and ImageJ

“…Spores are an integral part of the life cycle of the majority of fungi, and fungal spore concentration is of vital importance to fermentation engineering, scientific research and even our environment [22, 25]. Taking into consideration that it is difficult to separate the spores from the hyphae completely, we wonder the effectiveness and accuracy of the automated fungal cell counting pipeline in calculation of spore concentrations.…”

“…The yeast C. deneoformans JEC21 (serotype D) and the filamentous fungus P. microspora NK17 [20–23] were used as the representative strains of fungi in this paper. Yeast extract‐peptone‐dextrose medium (YPD; 2% glucose, 2% peptone, 1% yeast extract, and pH 6.0) were used for routine growth of yeast cells and spotting tests.…”

“…Taking the yeast Cryptococccus deneoformans [20, 21] and the filamentous fungus Pestalotiopsis microspora NK17 [22, 23] as examples, a new rapid automated fungal cell counting method using ilastik and ImageJ was assessed in this study. As an opportunistic pathogenic fungus, the spotting test is frequently used to study the sensitivity of C. deneoformans cells to various environmental stresses and drugs [24], in which cell counting is the first step.…”