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Carbon Balance Studies on Selected Species of Marine Filamentous Fungi

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Date Issued:
1970
Summary:
Selected species of marine filamentous fungi, Halosphaeria mediosetigera, Humicola alopallonella, Culcitalna achraspora and Orbimyces spectabilis, grown in a semi-synthetic medium containing glucose 0.5, ammonium nitrate 0.24, tris(hydroxyrnethyl)aminomethane 0.12 and yeast extract 0.1% (Medium A) and modifications thereof have been studied with regard to cellular composition, carbon fate and growth kinetics. Cultures were aerated with sterile, carbon dioxide-free air and washed mycelia were analyzed for macroconstituent elementary composition, total carbon, protein, chitin and lipids. Culture filtrates were tested for total carbon, .extracellular carbohydrates and organic acids. Physiological profiles were obtained to ascertain and correlate the ·extent and rate of growth; and changes in pH, concentration of glucose . and anthronepositive materials. · Elementary analyses of washed fungal mycelia showed 41.0 to 49.0% carbon, 4.7 to 6.0% nitrogen and 5.4 to 6.5% · hydrogen. Optimal growth was accompanied by a concomitant fall in pH followed by a shift back to the alkaline side. Following autolysis at 8 days, almost one-third of the glucose substrate reappeared in the medium accompanied by smaller amounts of mannose with Halosphaeria. With Culcitalna, following exhaustion of glucose in the medium, autolysis was accompanied by the reappearance of glucose. Pentoses and a hexose other than glucose also were indicated by relative mobilities on thin layer chromatograms. The most profound pH changes were obtained with Humicola reaching a low of 2.4 in 15 days, but the pH at 45 days had stabilized around 5.3. Increasing the glucose concentration to 5.0% (Medium B) did not increase the mycelial yields to any substantial degree except for Halosphaeria. In all cases pH fluctuated around 4 between 10 and 25 days, hut the final pH was about 6. Production of mycelia was always accompanied by substantial utilization of the glucose in the medium. When the glucose concentration was raised to 5%, to force the buildup of metabolic products, and yeast extract omitted (Medium C), substantial amounts of glucose were utilized, but this was not manifested by parallel increases in growth. Carbon balance studies confirmed that pH changes were not due to the production of organic acids, but probably to preferential utilization of ailllllonium cations. The initial substrate carbon was found almost exclusively in the fungal mycelia and evolved carbon dioxide. Carbon recoveries obtained under standard conditions were 97.9, 97.4, 98.2 and 94.0% respectively for Halosphaeria mediosetigera, Humicola alopallonella, Culcitalna achraspora and Orbimyces spectabilis in the standard medium containing 0.5% glucose. In 5% glucose (Medium B) the recoveries were 93.0, 90.6 and 84.7% for the first three organisms mentioned. Time did not allow a complete investigation of the causes. of decreased carbon recoveries, but greater production of incompletely oxidized metabolites appeared probable. Economic coefficients were determined for three species in three media while determinations on the fourth species are in progress. Culcitalna gave values of 71 in Medium A, 40 in Medium B and 3 in Medium C; Halosphaeria gave 78 in A, 45 in B and 15 in C; Orbimyces gave 75 in A and 7 in C . The effect of omission of yeast extract and of elevated glucose concentration on the economic coeffic ients was pronounced . The only products detected under exaggerated carbon conditions were acetic acid in the culture broth of Culcitalna and a greenish pigment in the culture filtrate of Halospaeria. The analogously-suggested accumulation of 2-ketogluconic acid in the latter case could be indicative of the functioning of the hexose monophosphate shunt or another primary aerobic pathway.
Title: Carbon Balance Studies on Selected Species of Marine Filamentous Fungi.
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Name(s): Dias, Anthony P.
Sguros, Peter L., Thesis advisor
Florida Atlantic University, Degree grantor
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 1970
Date Issued: 1970
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 95 p.
Language(s): English
Summary: Selected species of marine filamentous fungi, Halosphaeria mediosetigera, Humicola alopallonella, Culcitalna achraspora and Orbimyces spectabilis, grown in a semi-synthetic medium containing glucose 0.5, ammonium nitrate 0.24, tris(hydroxyrnethyl)aminomethane 0.12 and yeast extract 0.1% (Medium A) and modifications thereof have been studied with regard to cellular composition, carbon fate and growth kinetics. Cultures were aerated with sterile, carbon dioxide-free air and washed mycelia were analyzed for macroconstituent elementary composition, total carbon, protein, chitin and lipids. Culture filtrates were tested for total carbon, .extracellular carbohydrates and organic acids. Physiological profiles were obtained to ascertain and correlate the ·extent and rate of growth; and changes in pH, concentration of glucose . and anthronepositive materials. · Elementary analyses of washed fungal mycelia showed 41.0 to 49.0% carbon, 4.7 to 6.0% nitrogen and 5.4 to 6.5% · hydrogen. Optimal growth was accompanied by a concomitant fall in pH followed by a shift back to the alkaline side. Following autolysis at 8 days, almost one-third of the glucose substrate reappeared in the medium accompanied by smaller amounts of mannose with Halosphaeria. With Culcitalna, following exhaustion of glucose in the medium, autolysis was accompanied by the reappearance of glucose. Pentoses and a hexose other than glucose also were indicated by relative mobilities on thin layer chromatograms. The most profound pH changes were obtained with Humicola reaching a low of 2.4 in 15 days, but the pH at 45 days had stabilized around 5.3. Increasing the glucose concentration to 5.0% (Medium B) did not increase the mycelial yields to any substantial degree except for Halosphaeria. In all cases pH fluctuated around 4 between 10 and 25 days, hut the final pH was about 6. Production of mycelia was always accompanied by substantial utilization of the glucose in the medium. When the glucose concentration was raised to 5%, to force the buildup of metabolic products, and yeast extract omitted (Medium C), substantial amounts of glucose were utilized, but this was not manifested by parallel increases in growth. Carbon balance studies confirmed that pH changes were not due to the production of organic acids, but probably to preferential utilization of ailllllonium cations. The initial substrate carbon was found almost exclusively in the fungal mycelia and evolved carbon dioxide. Carbon recoveries obtained under standard conditions were 97.9, 97.4, 98.2 and 94.0% respectively for Halosphaeria mediosetigera, Humicola alopallonella, Culcitalna achraspora and Orbimyces spectabilis in the standard medium containing 0.5% glucose. In 5% glucose (Medium B) the recoveries were 93.0, 90.6 and 84.7% for the first three organisms mentioned. Time did not allow a complete investigation of the causes. of decreased carbon recoveries, but greater production of incompletely oxidized metabolites appeared probable. Economic coefficients were determined for three species in three media while determinations on the fourth species are in progress. Culcitalna gave values of 71 in Medium A, 40 in Medium B and 3 in Medium C; Halosphaeria gave 78 in A, 45 in B and 15 in C; Orbimyces gave 75 in A and 7 in C . The effect of omission of yeast extract and of elevated glucose concentration on the economic coeffic ients was pronounced . The only products detected under exaggerated carbon conditions were acetic acid in the culture broth of Culcitalna and a greenish pigment in the culture filtrate of Halospaeria. The analogously-suggested accumulation of 2-ketogluconic acid in the latter case could be indicative of the functioning of the hexose monophosphate shunt or another primary aerobic pathway.
Identifier: FA00000743 (IID)
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Thesis (M.S.)--Florida Atlantic University, 1970.
Charles E. Schmidt College of Science
Subject(s): Marine fungi
Held by: Florida Atlantic University Libraries
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00000743
Sublocation: Digital Library
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Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.