Patterns of Substrate Utilization by Some Fungal Endophytes from Coniferous Foliage

Abstract
Fifty-six strains of endophytic fungi isolated from coniferous foilage in Europe and in Oregon, USA, were tested for their ability to utilize various complex substrates including cellulose, xylan, mannan, several other hemicelluloses, pectin and 2 lignin derivatives. Cultures were also assayed for lipolytic activity, laccase production, growth on gallic acid and production of darkly pigmented reaction products on gallic acid. A majority of isolates utilized xylan and pectin, showed lipolytic activity, and grew on gallic acid. Fewer isolates (54%) utilized cellulose and only a small proportion utilized hemicelluloses other than xylan. Among isolates from conifers with distinct needles, fungi occurring only in the petioles showed a broad range of substrate utilization capabilities, while those from the needle blades were more restricted in their abilities. Isolates from cuppressaceous foilage utilized xylan but varied greatly with respect to other capabilities. Different isolates of the same fungus often varied in their substrate utilization capacities. Substrate utilization patterns of all the common endophytes from a single host suggested that several endophytes may co-exist within a single leaf by biochemical partitioning of resources.