TY - JOUR
T1 - Fixing N2 into cyanophycin
T2 - continuous cultivation of Nostoc sp. PCC 7120
AU - Trentin, Giulia
AU - Piazza, Francesca
AU - Carletti, Marta
AU - Zorin, Boris
AU - Khozin-Goldberg, Inna
AU - Bertucco, Alberto
AU - Sforza, Eleonora
N1 - Publisher Copyright:
© 2022, The Author(s).
PY - 2023/1/1
Y1 - 2023/1/1
N2 - Abstract: Two diazotrophic cyanobacteria (Anabaena cylindrica PCC 7122 and Nostoc sp. PCC 7120) were cultivated to produce cyanophycin, a nitrogen reserve compound, under nitrogen fixing conditions. In preliminary continuous experiments, Nostoc sp. was shown to be more efficient, accumulating a higher amount of cyanophycin and showing a greater capability to fix atmospheric nitrogen in the biomass (67 mgN d−1 of fixed nitrogen per liter of culture). The operating conditions were then optimized to maximize the cyanophycin productivity: the effect of incident light intensity, residence time and nitrogen availability were investigated. Nitrogen availability and/or pH played a major role with respect to biomass production, whereas phosphorus limitation was the main variable to maximize cyanophycin accumulation. In this way, it was possible to achieve a stable and continuous production of cyanophycin (CGP) under diazotrophic conditions, obtaining a maximum cyanophycin productivity of 15 mgCGP L−1 d−1. Key points: • Diazotrophic cyanobacteria produce stable amount of cyanophycin in continuous PBR. • Nostoc sp. proved to be more efficient in producing cyanophycin than Anabaena sp. • P deprivation is the major variable to increase cyanophycin productivity in continuous.
AB - Abstract: Two diazotrophic cyanobacteria (Anabaena cylindrica PCC 7122 and Nostoc sp. PCC 7120) were cultivated to produce cyanophycin, a nitrogen reserve compound, under nitrogen fixing conditions. In preliminary continuous experiments, Nostoc sp. was shown to be more efficient, accumulating a higher amount of cyanophycin and showing a greater capability to fix atmospheric nitrogen in the biomass (67 mgN d−1 of fixed nitrogen per liter of culture). The operating conditions were then optimized to maximize the cyanophycin productivity: the effect of incident light intensity, residence time and nitrogen availability were investigated. Nitrogen availability and/or pH played a major role with respect to biomass production, whereas phosphorus limitation was the main variable to maximize cyanophycin accumulation. In this way, it was possible to achieve a stable and continuous production of cyanophycin (CGP) under diazotrophic conditions, obtaining a maximum cyanophycin productivity of 15 mgCGP L−1 d−1. Key points: • Diazotrophic cyanobacteria produce stable amount of cyanophycin in continuous PBR. • Nostoc sp. proved to be more efficient in producing cyanophycin than Anabaena sp. • P deprivation is the major variable to increase cyanophycin productivity in continuous.
KW - Arginine
KW - Aspartic acid
KW - CGP
KW - Diazotrophic
KW - Polypeptide
UR - http://www.scopus.com/inward/record.url?scp=85142926484&partnerID=8YFLogxK
U2 - 10.1007/s00253-022-12292-4
DO - 10.1007/s00253-022-12292-4
M3 - Article
C2 - 36435857
AN - SCOPUS:85142926484
SN - 0175-7598
VL - 107
SP - 97
EP - 110
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
IS - 1
ER -