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- Title
- Carbon Balance Studies on Selected Species of Marine Filamentous Fungi.
- Creator
- Dias, Anthony P., Sguros, Peter L., Florida Atlantic University
- Abstract/Description
-
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...
Show moreSelected 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.
Show less - Date Issued
- 1970
- PURL
- http://purl.flvc.org/fau/fd/FA00000743
- Subject Headings
- Marine fungi
- Format
- Document (PDF)
- Title
- Interactions between Microorganisms Isolated from Aquatic Environments and the Cyclodiene Organochlorine Pesticides Aldrin and Dieldrin.
- Creator
- Quevedo, Rafael A., Sguros, Peter L., Florida Atlantic University
- Abstract/Description
-
Decomposition of the pesticides aldrin and dieldrin by aquatic microorganisms may result in more harmful products affecting the ecosystem. Isolates from fresh, brackish, and littoral water were cultured using, variously, selective media, enriched laboratory ecosystems, and impregnated wood strips and assessed qualitatively and quantitatively for action on pesticides by thin-layer chromatography, gas-liquid chromatography, and 14C-labeled pesticide autoradiography. Growth was measured in terms...
Show moreDecomposition of the pesticides aldrin and dieldrin by aquatic microorganisms may result in more harmful products affecting the ecosystem. Isolates from fresh, brackish, and littoral water were cultured using, variously, selective media, enriched laboratory ecosystems, and impregnated wood strips and assessed qualitatively and quantitatively for action on pesticides by thin-layer chromatography, gas-liquid chromatography, and 14C-labeled pesticide autoradiography. Growth was measured in terms of dry wt and cell nitrogen. Small amounts of possible metabolites were indicated in most isolate preparations. Cellulolytic Z. xylestrix grew well in media containing 10-500 ug/ml pesticide. Growth was stimulated by small quantities of the chemical and the fungus accumulated pesticides to levels 2000 times higher than the original medium concentration. Uptake increased linearly with increasing pesticide concentration. A significant portion of the pesticides appeared to be chemically altered, but the products were not specifically identified.
Show less - Date Issued
- 1974
- PURL
- http://purl.flvc.org/fau/fd/FA00000815
- Subject Headings
- Pesticides--Environmental aspects
- Format
- Document (PDF)
- Title
- Soluble NAD- and NADP-Linked Oxidoreductases in Filamentous Marine Fungi: Adaptation of Fluorescent Screening Technique and Development of Supporting Methodology.
- Creator
- Rodrigues, Joanna, Sguros, Peter L., Florida Atlantic University
- Abstract/Description
-
The metabolism of filamentous marine fungi has received little attention either from the specific or comparative standpoints. As part of an overall investigation of the carbon metabolism of this heterogeneous group of Ascomycetes and Deuteromycetes, a rapid, semi-quantitative method has been adapted to the screening of their NAD- and NADP-linked dehydrogenases. The Ascomycete, Halosphaeria mediosetigera (700), and Deteromycetes, Culcitalna achraspora (230) and Humicola alopallonella (710),...
Show moreThe metabolism of filamentous marine fungi has received little attention either from the specific or comparative standpoints. As part of an overall investigation of the carbon metabolism of this heterogeneous group of Ascomycetes and Deuteromycetes, a rapid, semi-quantitative method has been adapted to the screening of their NAD- and NADP-linked dehydrogenases. The Ascomycete, Halosphaeria mediosetigera (700), and Deteromycetes, Culcitalna achraspora (230) and Humicola alopallonella (710), were grown in a semi-synthetic, artificial sea water broth in submerged culture, from quantitatively standardized inocula, and harvested in the linear growth phase when respirometric data indicated maximum endogenous oxygen uptakes. Based upon dry weight, culture 700 gave QO2 maxima of 9.3-14.6 at 72 hr growth, while culture 710 values were 12.4-16.2 for the same time; culture 230 gave values of 13.8-18.4 at 96 hr growth. Harvested mycelia were washed, quantitated and subjected to sonic disintegration at 21 kHz for 20 minutes at 5-10 C in pH 7.0 phosphate buffer containing cysteine. Debris was removed by centrifuging at 12,000 X g at 4 C for 30 minutes and the resulting turbid, yellow supernatant fraction clarified by two successive 2 hr centrifugings at 4 C and 41,000 X g. Whatman #1 filter paper sheets, divided into 1 cm. squares, were pretreated with pH 8.0 Tris buffer containing MgCl2, and air-dried. The papers were spotted at the grid intersections with appropriate substrates. Cell extracts were mixed with NAD or NADP in Tris and the mixture superimposed upon the substrates. Within 2 hr the papers were viewed under ultraviolet light at 3600 A for spot fluorescence from the reduced coenzymes. In all extracts (5-10 mg protein per ml), dehydrogenases were indicated for glucose, glucose-6-phosphate, gluconate, 6-phosphogluconate, isocitrate and malate. Less definite were indications of oxidoreductases for galactose, lactate and glycerol. It is therefore indicated that these filamentous marine fungi utilize glucose carbon via the hexose monophosphate pathway and the tricarboxylic acid cycle.
Show less - Date Issued
- 1970
- PURL
- http://purl.flvc.org/fau/fd/FA00000821
- Subject Headings
- Marine fungi, Dehydrogenases
- Format
- Document (PDF)
- Title
- THE EFFECT OF TEMPERATURE, HYDROGEN ION AND CERTAIN GROWTH SUBSTRATES ON THE ACTIVITY OF THE CELLULOLYTIC ENZYME COMPLEX IN SELECTED MARINE FUNGI.
- Creator
- JENSEN, JAMES ROBERT, Florida Atlantic University, Sguros, Peter L., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
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...
Show moreHalosphaeria 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.
Show less - Date Issued
- 1971
- PURL
- http://purl.flvc.org/fcla/dt/13434
- Subject Headings
- Marine fungi, Cellulose--Biodegradation
- Format
- Document (PDF)
