碩士 / 大葉工學院 / 食品工程研究所 / 84 / Shrimp and crab shell powder (SCSP) containing chitin,
protein, and calcium carbonate etc. is pretreated by size
reduction, deproteination and demineralization to yield a chitin
material suitable for bioconversion or other uses. Chitin and
its derivatives are of interest because they have various
biological activities and agrochemicals. Chitinase producing
strains have been reported by many workers from soils and marine
muds by using chitin, colloidal chitin or other chitin materials
as a major carbon source for chitinase production. However,
isolation of an alkali-tolerant chitinase producing strain by
using SCSP as a major carbon source has not been reported.
The production of inexpensive chitinolytic enzymes is an
important element in the utilization of shrimp processing waste,
and utilization of an alkali-tolerant chitinase producing strain
is also useful in freeing the processing wastes of odors
generally encountered as a pollution problem. Effective
utilization of such marine wastes not only solves environmental
problems, but also promotes the economic value of the marine
products. In this study, shrimp and crab shell powder
prepared by treating shrimp and crab processing waste with
boiling and crashing was used as a substrate for isolating
alkali-tolerant chitinolytic microorganisms. Maximum
chitinase activity was obtained when the strain was grown
aerobically in a medium consisting of 3.0％ shrimp and crab
shell powder, 0.1％ CMC, 0.1％ (NH4)2SO4, 0.1％ K2HPO4, 0.1％
MgSO4．7H2O and 0.1％ ZnSO4 (pH 9), at 45℃ after 3 days. The
optimum pH and temperature of the enzyme reaction were 7 and
40℃, respectively. The chitinase was stable at pH from 5 to 10,
and was stable under 60℃ . Two chitinases (FI, FII) were
purified from the culture supernatant of Pseudomonas aeruginosa
K-187 by ammonium sulfate fractionatoin, DEAE-Sepharose CL-6B
and Econo-Pac q column chromatography. The purified enzymes
estimated by SDS-PAGE have a molecular weight of 30,000 and
32,000, respectively.The pIs for FI and FII were 5.2 and 4.8,
respectively. The optimum pH, optimum temperature, pH stability,
and thermal stability of FI and FII were (8, 50 C, 6-9, 50 C)
and (7, 40 C, 5-10, 60 C), respectively. The activities of both
enzymes were strongly activated by Cu+2, but strongly inhibited
by Mn+2, Mg+2, Zn+2, and comlete inhibited by the presence of
glutathione, dithiothreitol, and 2-mercaptoethanol. Both
chitinase showed potent lysozyme activity using Micrococcus
lysodeikticus cells as a substrate, it also showed lytic
activity toward Staphylococcus, E.coli, and Pseudomonas
aeruginosa.
| Identifer | oai:union.ndltd.org:TW/084DYU00250010 |
| Date | January 1996 |
| Creators | Chang, Wun-Tsu, 張文智 |
| Contributors | Wang San-Lang, 王三郎 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 129 |
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