Uptake of ¹⁴C‐glucose by Botryodiplodia theobromae Pat and changes in its carbohydrate content during growth

Abstract

There is a rapid uptake of 14C-glucose and unlabelled glucose during the period of pigmentation of the mycelium of Botryodiplodia theobromae PAT. Incorporation of 14C-glucose into structural components of the mycelium started within 24 hours of incubation and progressively increased until the 14th day of growth.The mycelium contains glucose, isomaltose, and sucrose. There is a decrease in these carbohydrates during autolysis. Autolysis in B. theobromae occurs in an acid medium of p H 5.2.The growth of Botryodiplodia theobromae PAT, the causal organism of diseases of many economic tropical crops (ALASOADURA 1970) in culture can be divided into two distinct phases : Hyaline mycelium is produced during the first 3 -4 days of growth and this phase is followed by rapid pi gmentationof most of the mycelium. Microscopic examination of the mycelium during pigmentation shows a mixture of hyaline, thin hyphae, and pigmented stout hyphae. Observation of cross-section of wood of Antiaris africana stained blue by the fungus also reveals the two types of hyphae, with the food-storing parenchyma cells predominantly infected by the hyaline hyphae. OLOFINBOBA and LAWTON (1968) showed that the parenchyma cells of the wood of A . africana contain various carbohydrates which are rapidly utilized by the fungus. They suggested that the hyaline hyphae are nutritional in function. It was, however, not clear if rate of carbohydrate utilization was influenced by the pigmentation of some of the hyphae.Few reports (LAHOZ 1966) have appeared in recent years on the chemistry of autolysis of certain filamentous fungi. Most of the investigation was on the behaviour of nitrogenous materials present in the mycelium and the culture medium of such fungi (BENT 1964, BENT and MORTON 1964). LAHOZ et al. (1966) made the initial attempt to study the changes in carbohydrates during autolysis in Aspergillus flavus. Not so much has been reported about the changes in carbohydrates during growth and autolytic phases of fungi development.The present study is to investigate the influence of pigmentation on the utilization of glucose by B. theobromae. It is also designed to study the qualitative and quantitative changes in the carbohydrates of the mycelium of B. theobromae during growth and autolytic phases. Material and methodsUptake of 1%-glucose: The isolate used in this study was from blue-stained xylem of Antiaris africana. The culture medium consisted of the following composition (g/l distilled water): &(NO,), 0.5, KNO, 0.125, MgSO, x 7 H,O 0.125, KH,PO, 0.125. 5 ml of the 34*