Characterization and chillproofing activity of two enzymes from Streptomyces species


C.A. Etok and O.U. Eka (1996). J. Basic Microbiol 36:83-88

Two enzymes, amylase and protease of streptmyces species were purifies by a combination of ion exchange chromatography and gel filtration and characterized. The amylase has an exoaction on starch yielding maltose as a major end product and was identified as β-amylase. The purified amylase had a molecular weight of 40,000 and as maximally active at 35 °C and at pH 6.0. On the other hand, protease had a molecualr weight of 21,000 and was most active at pH 10.0 and at a temperature of 30 °C. The Km or MICHEALIS constant of amylase for maize starch was 0.333mg/ml while that of protease for cascin was 2.5mg/ml. The feasibility of using the purified protease for various industrial application especially in the chillproofing of beer is discussed.
The charaterization of amylase and proteases of different microorganisms and their application to industrial processes have been the subject of many researches (CAYLE 1962, Moriyama et. al. 1980, WILSON and INGLEDOW 1982, LOFFLER 1986). The introduction of a highly thermostable amylase which hydrolyses starch at temperatures of 110 °C aroused a new interest in this area (MORGAN and PRIEST 1981).
In this study, the properties of each enzyme were determined and the protease enzyme was used in chillproofing, a process of clearing beer of haziness and due to proteinaceous substances.

Prof. Comfort Etok

Professor Comfort Etok is a Professor of Microbiology from University of Uyo. Her area of specialization is Industrial/Food Biology. She has obtained her BSc, MSc. and Ph.D in Microbiology from University of Calabar..

She has been a recipient of several awards, one of which was the Professor Nduka Okafor’s prize for Best Graduating Student in Microbiology. She has served and is still serving in various committees in the University, State and National frontier. She has supervised and is still supervising intelligent undergraduate and postgraduate researches in Microbiology. One of such research worthy of note is “Fermentation And Amino Acid Profile Of Maize Pomace And Rice Husk And Their Dietary Effects On Broilers Chicken”.

She holds Membership in several Professional Bodies like American Society for Microbiolgy, Nigerian Society for Microbiology etc. She has published highly rated Journal Articles, Book Chapters etc. One of such publication shaking her field is “Bdellevibrio and Like Organisms: The much Anticipated “Magic Bullet”.” published by World News of National Science.
Visit her personal knowledgebase at to more about this great scholar.

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