TY - JOUR
T1 - Examination of photo-, mixo-, and heterotrophic cultivation conditions on haematococcus pluvialis cyst cell germination
AU - Bauer, Andreas
AU - Minceva, Mirjana
N1 - Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/8
Y1 - 2021/8
N2 - The microalgae Haematococcus pluvialis is used for the biotechnological production of astax-anthin. The red carotenoid accumulates in the cytoplasm under unfavorable conditions. Astaxanthin synthesis is associated with the transformation of motile vegetative cells into non-motile cyst cells. In the industrial process, after harvesting, the cyst cells are mechanically disrupted, dried, and finally, astaxanthin is extracted with supercritical CO2 . The germination of the cyst cells represents an interesting alternative, replacing the mechanical cyst cell wall disruption. When cyst cells are exposed to favorable growth conditions, germination of the cyst cells occurs and zoospores are released after a certain time. These zoospores show a much weaker cell matrix compared to cyst cells. In this study, germination under phototrophic, mixotrophic, and heterotrophic conditions was examined. Glucose was used as the carbon source for mixotrophic and heterotrophic germination. Applying heterotrophic conditions, up to 80% of the cells were in the zoospore stage 49 h after the start of germination, and extraction yields of up to 50% were achieved using the solvent ethyl acetate for the extraction of astaxanthin from the algal broth containing zoospores. An extraction yield of up to 64% could be achieved by doubling the nitrate concentration and combining mixotrophic and heterotrophic cultivation.
AB - The microalgae Haematococcus pluvialis is used for the biotechnological production of astax-anthin. The red carotenoid accumulates in the cytoplasm under unfavorable conditions. Astaxanthin synthesis is associated with the transformation of motile vegetative cells into non-motile cyst cells. In the industrial process, after harvesting, the cyst cells are mechanically disrupted, dried, and finally, astaxanthin is extracted with supercritical CO2 . The germination of the cyst cells represents an interesting alternative, replacing the mechanical cyst cell wall disruption. When cyst cells are exposed to favorable growth conditions, germination of the cyst cells occurs and zoospores are released after a certain time. These zoospores show a much weaker cell matrix compared to cyst cells. In this study, germination under phototrophic, mixotrophic, and heterotrophic conditions was examined. Glucose was used as the carbon source for mixotrophic and heterotrophic germination. Applying heterotrophic conditions, up to 80% of the cells were in the zoospore stage 49 h after the start of germination, and extraction yields of up to 50% were achieved using the solvent ethyl acetate for the extraction of astaxanthin from the algal broth containing zoospores. An extraction yield of up to 64% could be achieved by doubling the nitrate concentration and combining mixotrophic and heterotrophic cultivation.
KW - Astaxanthin
KW - Cultivation conditions
KW - Downstream processing
KW - Extraction
KW - Germination
KW - Haematococcus pluvialis
UR - http://www.scopus.com/inward/record.url?scp=85112076952&partnerID=8YFLogxK
U2 - 10.3390/app11167201
DO - 10.3390/app11167201
M3 - Article
AN - SCOPUS:85112076952
SN - 2076-3417
VL - 11
JO - Applied Sciences (Switzerland)
JF - Applied Sciences (Switzerland)
IS - 16
M1 - 7201
ER -