Abstract:
Chitinases are enzymes that break down the β-(1→4) -glycoside bond of N-acetyl d-glucosamine
in chitin to produce mono- and oligomers. Chitin is the second most abundant biopolymer in
nature. The main aim of this thesis was to isolate and characterize bacterial strains from the
Hulauka and Taltile river banck soils, and optimization of the conditions for the enzyme
production. The soil samples were collected from the study site and serially diluted and spread
plated on colloidal chitin media. The isolated bacterial strains were characterized
morphologically and biochemically. Ten isolates were selected from 29 total chitinolytic strains
for chitinase production based on the zone of clearance on colloidal chitin agar, those ten
strains were submitted to MALID-TOF MS and eight species were identified at species level as
Rhodococcus marinonascens HSI1, Aeromonas media HSII1, Lilliottia amnigena HSII2, No
peaks found HSII3, Pseudomonas congelans HSII4, Ligilactobacillus salivarius HSIII1,
Lactobacillus amylovorus HSIII2, Stenotrophomonas maltophilia TSI1 and Pseudomonas putida
TSIII3 based on MALID-TOF Biotyper analysis. Furthermore, those eight identified species
were optimized at different parameters to select the best conditions for enzyme production.
However, optimization of temperature, pH and incubation time in all isolates were showed the
highest chitinase enzyme production at 45oC, in pH 7 and 96hr. The effect of carbon source;
glucose and lactose were enhanced the production of chitinase enzyme and sucrose were slightly
reduced catinase activity. The addition of nitrogen source; yeast extract, beef extract and
peptone significantly reduced chetinase enzyme activity. The results of this thesis revealed that
bacterial species with high chitinase activities were present in the soils collected from Huluka
and Taltale River bank which will be used for mass production of chitinase enzyme for its
application in various sector.
