Ecological studies of the biodeterioration of a model cellulose substrate by fungi

Abstract

A technique has been described which successfully
maintains a controlled microenvironmental condition on a
cellulosic substrate by continuous perfusion with a
predetermined nutrient solution. This technique has been
used to study the effect of different ecological factors
namely pH, temperature, nitrogen sources and glucose
nutrition on the fungal colonization of a model cellulose
substrate in the form of heat rolled polythene backed cellulose
chromotography paper, buried in soil. Different successional
patterns of fungi colonizing this substrate, have been
elucidated and the role of " secondary sugar fungi" has
also been elaborated. The extent of biodeterioration of
the cellulosic substrate has been determined by its weight
loss estimations. Maximum biodeterioration was recorded
at 50 °C

The role of thermophilic actinomycetes in the cellulose
biodeterioration has been elucidated by using the perfusion
technique for their selective isolation. Five species were
identified and their cellulolytic ability was also determined.

The relative cellulolytic ability of all the fungi
isolated has been estimated by measuring the depth of clearing
of the cellulose agar columns. The effect of pH, temperature,
nitrogen sources and glucose nutrition on the relative
cellulolytic ability has also been observed.

An alteration of the perfusion technique has been
described and used to study the effect of diffusible
metabolites of cellulolytic fungi on their linear growth.
The effect of non diffusible metabolites of these fungi on their cellulolytic ability has also been studied by
growing them in mixed culture and then observing
the clearing of the cellulose agar. There were very
few cases of synergism as compared to widespread inhibition.

The perfusion technique has also been used to study
the germination and penetration of the spores of ten
cellulolytic fungi through different thicknesses of fibre
glass cloth. The mode of cellulase production and its
diffusion was also analysed by estimating the weight loss
of the different layers of a wad of five perfused cellulose
strips, after inoculating the top strip.

The perfusion technique has also been used as a
test method for screening different biocides commonly
used as textile preservatives. Its scope in detoxification
studies has also been discussed

Date of Award	1970
Original language	English