Squalene production under oxygen limitation by Schizochytrium sp. S31 in different cultivation systems

verfasst von

Lina Schütte, Patrick G. Hanisch, Nina Scheler, Katharina C. Haböck, Robert Huber, Franziska Ersoy, Ralf G. Berger

Abstract

Abstract: The triterpene squalene is widely used in the food, cosmetics and pharmaceutical industries due to its antioxidant, antistatic and anti-carcinogenic properties. It is usually obtained from the liver of deep sea sharks, which are facing extinction. Alternative production organisms are marine protists from the family Thraustochytriaceae, which produce and store large quantities of various lipids. Squalene accumulation in thraustochytrids is complex, as it is an intermediate in sterol biosynthesis. Its conversion to squalene 2,3-epoxide is the first step in sterol synthesis and is heavily oxygen dependent. Hence, the oxygen supply during cultivation was investigated in our study. In shake flask cultivations, a reduced oxygen supply led to increased squalene and decreased sterol contents and yields. Oxygen-limited conditions were applied to bioreactor scale, where squalene accumulation and growth of Schizochytrium sp. S31 was determined in batch, fed-batch and continuous cultivation. The highest dry matter (32.03 g/L) was obtained during fed-batch cultivation, whereas batch cultivation yielded the highest biomass productivity (0.2 g/L*h⁻¹). Squalene accumulation benefited from keeping the microorganisms in the growth phase. Therefore, the highest squalene content of 39.67 ± 1.34 mg/g was achieved by continuous cultivation (D = 0.025 h⁻¹) and the highest squalene yield of 1131 mg/L during fed-batch cultivation. Volumetric and specific squalene productivity both reached maxima in the continuous cultivation at D = 0.025 h⁻¹ (6.94 ± 0.27 mg/L*h⁻¹ and 1.00 ± 0.03 mg/g*h⁻¹, respectively). Thus, the choice of a suitable cultivation method under oxygen-limiting conditions depends heavily on the process requirements. Key points: • Measurements of respiratory activity and backscatter light of thraustochytrids • Oxygen limitation increased squalene accumulation in Schizochytrium sp. S31 • Comparison of different cultivation methods under oxygen-limiting conditions.

Organisationseinheit(en)

Institut für Lebensmittelchemie

Externe Organisation(en)

Hochschule für angewandte Wissenschaften München

Typ

Artikel

Journal

Applied Microbiology and Biotechnology

Band

108

Anzahl der Seiten

12

ISSN

0175-7598

Publikationsdatum

13.02.2024

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Biotechnologie, Angewandte Mikrobiologie und Biotechnologie

Ziele für nachhaltige Entwicklung

SDG 14 – Lebensraum Wasser

Elektronische Version(en)

https://doi.org/10.1007/s00253-024-13051-3 (Zugang: Offen)