SCREENING AND IMPROVEMENT OF ASPERGILLUS SPECIES FOR PECTINASE PRODUCTION
SCREENING AND IMPROVEMENT OF ASPERGILLUS SPECIES FOR PECTINASE PRODUCTION
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Date
2000-12
Authors
ELUDIRE, JIDE OLUFUNMINIYI
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Abstract
Four strains of Aspergillus Species isolated from rotten orange, pineapple.
cucumber and carrot were screened for pectolytie activities with the use of peetinase
detection media; MP - 7 and MP - 5 flooded with pectin precipitant Cetyltrimethvl
Ammonium Bromide (CTAB). Isolates from orange and pineapple showed high
level of pectolytie activity based on their zones of hydrolysis. These isolates from
orange and pineapple with high level of activity were identified to be A. flavus and
A. fumigalus respectively and subjected to physical and chemical mutagenesis for
improved pectolytie activity. Ultraviolet irradiation and Nitrous acid were used as
physical and chemical mutagens respectively (HNO2, UV-10, UV-20 and UV-30).
The wild and mutant strains of these organisms were subsequently screened for
improved peetinase (pectin lyase and polygalacturonase) production, and calabolilc
repression resistance on detection media mentioned above, with and without
glucose. Hyperproducers and calabolilc repression resistant mutants were isolated in
various cases. Aspergillus fumigants did not yield any diabolical repression resistant
mutant for polyunsaturate production, but a hyper-producer was obtained from
UV-30. In the production of pectin lyase, a hyper-producer and metabolite repression
resistant mutant were obtained from UV - 30. Mutants obtained with nitrous acid
did not yield a hyper producer but gave a metabolite repression resistant mutant.
A. flavus mutants did not show any hyper- producing ability in the production of
polyunsaturate but the nitrous acid and UV-induced mutants were metabolite
repression resistant for the enzyme production. For pectin lyase production by this
organism, hyperproducers were isolated from nitrons acid and UV-30 mutants, but
only UV-30 mutant was resistant to catabolite repression
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL AHMADU BELLO
UNIVERSITY, Z.ARIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF MASTER OF SCIENCE
DEPARTMENT OF MICROBIOLOGY
FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY
ZARIA NIGERIA
DECEMBER, 2000
Keywords
SCREENING,, IMPROVEMENT,, ASPERGILLUS,, SPECIES,, PECTINASE,, PRODUCTION