|Fungal degradation of the thermoplastic polymer poly-beta-hydroxybutyric acid (PHB) under simulated deep sea pressure|
Gonda, K.E.; Jendrossek, D.; Molitoris, H.P. (2000). Fungal degradation of the thermoplastic polymer poly-beta-hydroxybutyric acid (PHB) under simulated deep sea pressure, in: Liebezeit, G. et al. (Ed.) Life at Interfaces and Under Extreme Conditions: Proceedings of the 33rd European Marine Biology Symposium, Wilhelmshaven, Germany, 7-11 September 1998. Hydrobiologia, 426(1-3): pp. 173-183
In: Liebezeit, G.; Dittmann, S.; Kröncke, I. (Ed.) (2000). Life at Interfaces and Under Extreme Conditions: Proceedings of the 33rd European Marine Biology Symposium, Wilhelmshaven, Germany, 7-11 September 1998. Hydrobiologia, 426(1-3). Kluwer Academic: Dordrecht. 210 pp., more
In: Hydrobiologia. Springer: The Hague. ISSN 0018-8158, more
|Also published as |
- Gonda, K.E.; Jendrossek, D.; Molitoris, H.P. (2000). Fungal degradation of the thermoplastic polymer poly-beta-hydroxybutyric acid (PHB) under simulated deep sea pressure. Hydrobiologia 426: 173-183, more
Biodegradation; Deep water; Hydrostatic pressure; Aspergillus ustus (Bainier) Thom. & Church [WoRMS]; Rhodosporidium sphaerocarpum S.Y. Newell & Fell, 1970 [WoRMS]; Marine
|Authors|| || Top |
- Gonda, K.E.
- Jendrossek, D.
- Molitoris, H.P., correspondent
Little is known about marine filamentous fungi and yeasts, almost nothing about their life and metabolism under deep sea conditions. Data on growth and metabolic activity give insight into the role of organisms in the marine habitat. Degradation studies on pollutants, such as polymeric thermoplasts, provide information about the self-cleaning capacity of a habitat. Therefore, recently isolated fungal strains from the deep sea and our newly developed methods and apparatus for investigation of fungi under simulated deep sea conditions were used to study fungal growth and degradation of a commercially produced thermoplastic polymer (poly-beta-hydroxybutyric acid = PHB). Two deep sea isolates, a filamentous fungus (Aspergillus ustus) and one yeast (Rhodosporidium sphaerocarpum), and for comparison, two marine surface yeast isolates (Candida guilliermondii, Debaryomyces hansenii) and one terrestrial isolate of Aspergillus ustus were investigated. Growth (colony-forming units, dry weight), physiological parameters (oxygen saturation of the hydraulic fluid as oxygen reservoir, pH and consumption of total carbohydrate) and PHB degradation (clearing test: clearing of PHB-turbid agar medium; spectrophotometric test: PHB depolymerase activity) were followed after incubation in high-pressure autoclaves in artificial seawater medium at 27 °C and pressures of 0.1 MPa (= atmospheric pressure), 5 MPa, 10 MPa, 20 MPa, 30 MPa, 45 or 50 MPa and 100 MPa (similar to 10 000 m water depth) for a maximum of 21 days (yeasts) and 28 days (filamentous fungi), respectively. Irrespective of the marine or terrestrial origin of the isolates, growth decreased with increasing pressure with a limit between 30 MPa and 50 MPa for filamentous fungi and yeasts. Metabolic activity (consumption of medium components) started to decrease from 20 MPa, ceasing at growth-limiting pressures. Under atmospheric conditions, all strains degraded PHB in solid medium, in liquid medium degradation was less and decreased further and/or was delayed with increasing hydrostatic pressure; beyond 30 MPa, no PHB degradation could be observed. In summary, it could be shown that growth, metabolism and degradation of pollutants such as PHB by marine fungal isolates was impaired with increasing pressure, showing one aspect of the reduced self-cleaning capacity of the deep sea habitat.