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Title: The proteolytic and saccharolytic activity of some natural waters and their associated bacteria
Author: Whalley, Peter
ISNI:       0000 0001 3566 4251
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 1987
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This study is concerned with the relationship between two hydrolytic enzyme activities, saccharase and protease and other limnological factors, including bacterial flora, in natural waters of varying degrees of organic pollution. Published methodologies for measuring proteolytic and saccharolytic activities were employed to yield data whose statistical distribution was found to be modelled by a log-normal distribution. Natural activities were correlated with biochemical oxygen demand, suspended solids, viable bacteria, combined nitrogen, dissolved solids, flow and temperature. Regression equations are formulated with biochemical oxygen demand and bacterial numbers either singly or combined explaining most of the variation in enzyme activity. Other contributory factors were suspended solids, flow and temperature. These equations could predict enzyme activity at other sites with acceptable levels of confidence. The best predictive equations for enzyme activities were: log Saccharase = 0.2 log BOD + 0.1 log Suspended solids + 0.8 log Viable count + 0.9 Protease = -469 Temperature + 56708 Flow + 443 BOD - 1.54 Viable count + 6853 Aquatic bacteria producing enzyme activity were isolated from watercourses and identified as belonging to the genera Pseudomonas. Flavobacterium and Flexibacter. When grown in defined media, enzyme production was stimulated by the addition of sucrose or casein to the medium. In the case of one organism casein could act as sole source of carbon and nitrogen. Extracts of cell suspension were shown to have enzyme activities. When investigated these activities had maximum values dependent on pH and temperature. This pH and temperature profile of activity was also demonstrated in samples of river water. Enzyme extracts followed Mlchaelis-Menten reaction kinetics with Michaelis' constants similar to those reported in comparable extracts.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QR Microbiology