Simultaneous Utilization of Glucose and Sucrose by Thermophilic Fungi

Maheshwari, R and Balasubramanyam, PV (1988) Simultaneous Utilization of Glucose and Sucrose by Thermophilic Fungi. In: Journal of Bacteriology, 170 (7). pp. 3274-3280.

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Abstract

The utilization of mixtures of glucose and sucrose at nonlimiting concentrations was studied in batch cultures of two common thermophilic fungi, Thermomyces lanuginosus and Penicilium duponti. The sucrose-utilizing enzymes (sucrose permease and invertase) in both fungi were inducible. Both sugars were used concurrently,regardless of their relative proportion in the mixture. At the optimal growth temperature (50C), T.lanuginosus utilized sucrose earlier than it did glucose, but at a suboptimal growth temperature (30°C) the two sugars were utilized at nearly comparable rates. The coutilization of the two sugars was most likely possible because (i) invertase was insensitive to catabolite repression by glucose, (ii) the activity and affinity of the glucose transport system were lowered when sucrose was included in the growth medium, and (iii) the activity of the glucose uptake system was also subject to repression by high concentrations of glucose itself. The concurrent utilization of the available carbon sources by thermophilic fungi might be an adaptive strategy for opportunistic growth in nature under conditions of low nutrient availability and thermal fluctuations in the environment.

Item Type:	Journal Article
Publication:	Journal of Bacteriology
Publisher:	American Society for Microbiology
Additional Information:	Copyright of this article belongs to American Society for Microbiology.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	30 Sep 2010 07:14
Last Modified:	30 Sep 2010 07:14
URI:	http://eprints.iisc.ac.in/id/eprint/32548

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