Applied Microbiology and Biotechnology

, Volume 54, Issue 3, pp 319–325

Polymer production by two newly isolated extremely halophilic archaea: application of a novel corrosion-resistant bioreactor

  • F. F. Hezayen
  • B. H. A. Rehm
  • R. Eberhardt
  • A. Steinbüchel
ORIGINAL PAPER

DOI: 10.1007/s002530000394

Cite this article as:
Hezayen, F., Rehm, B., Eberhardt, R. et al. Appl Microbiol Biotechnol (2000) 54: 319. doi:10.1007/s002530000394

Abstract

A novel corrosion-resistant bioreactor composed of polyetherether ketone (PEEK), tech glass and silicium nitrite ceramics was constructed and applied for the cultivation of two newly isolated, extremely halophilic archaea producing poly(γ-glutamic acid) (PGA), or poly(β-hydroxy butyric acid) (PHB), respectively. These bacteria were isolated from hypersaline soil close to Aswan (Egypt). The isolate strain 40, which is related to the genus Natrialba, produced large amounts of PGA when cultivated on solid medium. Culture conditions were optimised applying the corrosion-resistant bioreactor. PGA production was dependent on NaCl concentration and occurred about at 20% (w/v) NaCl in the medium. A maximum cell density of about 1.6 g cell dry matter/l was obtained when the bioreactor was stirred and aerated in a batch fermentation process using proteose-peptone medium. The supernatant was monitored with respect to PGA formation, and after 90 h a maximum of 470 mg/l culture volume was detected by HPLC analysis. Culture conditions were optimized for the isolate 56, which accumulated PHB as intracellular granules. Batch fermentations in the stirred and aerated bioreactor applying acetate and n-butyric acid as carbon sources led to cell density of 2.28 g cell dry matter/l and a maximum PHB accumulation contributing to about 53% of cellular dry weight. About 4.6 g PHB were isolated from 10.6 g dried cells of strain 56, which exhibited a weight average molar mass of 2.3 × 105 g mol−1 and a polydispersity of about 1.4.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • F. F. Hezayen
    • 1
  • B. H. A. Rehm
    • 1
  • R. Eberhardt
    • 2
  • A. Steinbüchel
    • 1
  1. 1.Institut für Mikrobiologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, 48149 Münster, Germany e-mail: steinbu@uni-muenster.de Tel.: +49-251-8339821 Fax: +49-251-833-8388DE
  2. 2.FairMen Tec GmbH, Berliner Strasse 1, 37073 Göttingen, GermanyDE