EFFECT OF ASPERGILLUS NIGER AMYLASES ON CASSAVA STARCH HYDROLYSIS
EFFECT OF ASPERGILLUS NIGER AMYLASES ON CASSAVA STARCH HYDROLYSIS
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Date
2013-02
Authors
NELSON, AKEME-ESUOMINI OSARIBIE
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Abstract
The enzymatic hydrolysis of cassava starch to glucose has been studied. Aspergillus
niger was isolated from deteriorated groundnut seeds and used as the amylase producer
source. The effect of various process variables such as culture age, mycelia mass
loading, pH, temperature and substrate (cassava starch) concentration were investigated
in order to optimize the hydrolysis process. The A. niger amylases exhibited optimum
activity at pH and temperature of 4.8 and 60oC respectively. The cells appear most
viable on the fifth day. Results obtained from this study indicated that increase in
cassava starch concentration from 0.3 to 1.5 g/l was accompanied with a proportionate
increase in glucose concentration from 0.239 to 0.310 g/l and decrease in glucose yield,
falling from 74% to 18%. In addition, increase in mycelia mass loading resulted to
increase in both the concentration and yield of glucose. An initial rate method was
employed in estimating the kinetic parameters using Michealis-Menten model. The
Langmuir form of the Michealis-Menten model gave a high regression coefficient
(0.9939) and the values of the maximum reaction velocity (rmax) and Michaelis constant
(Km) were found to be 2.42*10-3 g/l.min and 0.221 g/l respectively
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES,
AHMADU BELLO UNIVERSITY, ZARIA
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD
OF A
MASTER DEGREE IN CHEMICAL ENGINEERING.
DEPARTMENT OF CHEMICAL ENGINEERING,
FACULTY OF ENGINEERING
AHMADU BELLO UNIVERSITY, ZARIA
NIGERIA
FEBRUARY, 2013
Keywords
EFFECT,, ASPERGILLUS NIGER AMYLASES,, CASSAVA STARCH,, HYDROLYSIS.