Abstract:
Fungi of the genera Aspergillus, Geotrichum., Mucor;: Rhizopus and
Saccharomyces 'were isolated from selected agro-industrial wastes undergoing
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biodeterioration. Media into which the wastes were incorporated served as substrates for
the growth of and amylase enzyme production by the fungal isolates. With exception of
Geotrichum carididum, other isolates demonstrated amylolytic property in soluble starch
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medium containing 2% soluble starch, 0.3% (NI-I4h S04, 0.2% peptone, 0.1% KH2P04,
0.03% Mg S04. 7H20 and 0.03% Cac12 weight per volume.
Replacing the soluble starch with dry banana peels powder yielded production of
4.0 E.U of amylase enzyme at the peak and 0.25 E. U at the lowest level.
Optimal conditions for amylase enzyme production from dry banana peels powder
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using pure culture of Rhizopus stolonifer in a medium containing 5% waste, 0.2%
peptone, 0.3% '(NH4)2 S04 weight per volume at incubation temperature of between
37°C and 40°C with an initial pH of 4. Enzymic activity was highest after 120 hours of
fermentation.
Carbohydrates specifically starch, glucose, lactose, fructose, and maltose
positively induced production of amylase enzyme. Effect produced was more noticeable
with starch and least with maltose. Sucrose, however, produced no measurable
inducement in amylase enzyme production when added. Amino acids especially
hydroxyproline positively enhanced enzyme production in Rhizopus stolonifer. Others
like lysine, glycine, isoleucine, methionine, cystine, glutamine and analine also produced
noticeable but lesser enhancement.
. Proximate composition of the dry banana peels which was ash 14.63%, crude
fibre 7.78%, protein 7.72%, fat 15.68%, total reducing sugar 1.09% and carbohydrate 47.05% explains why it could serve' as a substrate for growth of and production of
amylase enzyme by R. stolonifer. Other wastes contained similar constituents but in
different: proportions.
