To improve the efficiency of isolating and culturing lichen mycobionts, we performed a growth assay on an Australian strain of the soil-crust lichenized fungus Endocarpon pusillum Hedw. This assay determined the preferred nitrogen and carbon sources of the fungus by limiting the available nitrogen or carbon sources to single compounds found in soils, plants and lichen thalli. We found that the non-proteinaceous amino acid, GABA, produced the most growth of all nutrients when provided as the sole nitrogen source but was a poor carbon source. Fructose, glucose, cellobiose and sorbitol produced the most growth of all the carbon sources tested. Ammonium, nitrate and polyamines were poor nutrient sources. These findings correspond with reports of primary metabolite pools in other lichen species and may guide future studies involving growth of recalcitrant lichen mycobionts.

中文翻译：

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测试模型地衣真菌 Endocarpon pusillum Hedw 体外生长的碳源和氮源。

为了提高分离和培养地衣真菌的效率，我们对澳大利亚的地壳地衣真菌菌株进行了生长试验内果皮海杜。该测定通过将可用的氮或碳源限制在土壤、植物和地衣菌体中发现的单一化合物来确定真菌的优选氮和碳源。我们发现，非蛋白质氨基酸 GABA 在作为唯一氮源提供时产生了所有营养物质中最多的生长，但它是一种较差的碳源。在所有测试的碳源中，果糖、葡萄糖、纤维二糖和山梨糖醇产生了最多的增长。铵、硝酸盐和多胺是较差的营养来源。这些发现与其他地衣物种中初级代谢物库的报告相对应，并可能指导未来涉及顽固地衣真菌生物生长的研究。