Author Type

Graduate Student

Date of Award

1971

Document Type

Thesis

Publication Status

Version of Record

Submission Date

October 2026

Thesis/Dissertation Advisor [Chair]

Sguros, Peter L.

Abstract

Halosphaeria mediosetigera and Culcitalna achraspora have been studied to elucidate the mechanism by which they degrade cellulosic materials in the sea. H. mediosetigera (700 LC 1), a C1-less variant, was also employed in this work. Standardized shake-cultures were grown on cellulose and cellulose derivatives supplemented with NH4N03, tris(hydroxymethyl)aminomethane and yeast extract in artificial sea water (Lyman and Fleming), pH 7.5, at 25 C. Induced C1 and Cx enzyme and cellobiase activities were determined calorimetrically by correlation with cotton fiber weight loss, by the formation of reducing sugars from carboxymethylcellulose and by Glucostat, respectively. Optimum pH values for both Cx enzyme and cellobiase of C. achraspora were 6.0 at 37 C while those for H. mediosetigera (700 LC 1) were 5.0 and 6.0, respectively, at 37 C. In both cultures, Cx enzymes had a variable optimum temperature ( 37-50 C) at pH 6.0, depending on the length of the incubation period, while cellobiases had the same optimum temperature (50 C) at pH 6.0. Thermostability observations on Cx enzyme and cellobiase of C. achraspora showed almost complete deactivation at 100 C in 15 min for the former and 50 C in 15 min for the latter. Thermostability observations on Cx enzyme and cellobiase of H. mediosetigera (700 LC 1) showed almost complete deactivation at 45 C in 15 min for the former and at 50 C in 15 min for the latter. Data indicate that at least three enzymatic functions are involved in cellulose breakdown by these cultures.

Extent

100 p.

Comments

Thesis (M.S.)--Florida Atlantic University, 1971.|Charles E. Schmidt College of Science|FAU Electronic Theses and Dissertations Collection|Thesis (M.S.)--Florida Atlantic University, 1971.

Identifier

FADT13434

Format

pdf

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