scholarly journals Towards Sustainable Bioinoculants: A Fermentation Strategy for High Cell Density Cultivation of Paraburkholderia sp. SOS3, a Plant Growth-Promoting Bacterium Isolated in Queensland, Australia

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Ian Petersen ◽  
Chanyarat Paungfoo-Lonhienne ◽  
Esteban Marcellin ◽  
Lars Keld Nielsen ◽  
Axayacatl Gonzalez

Paraburkholderia sp. SOS3 is a plant growth-promoting bacterium (PGPB) that displays pleiotropic effects and has the potential to be applied at a large scale across several agronomically important crops. The use of SOS3 is a suitable option to reduce the use of chemical fertilisers. While the benefits of SOS3 have been demonstrated in vitro, its potential applications at large scale are limited due to low biomass yield in current batch culture systems. Here, we developed a strategy for high-cell density cultivation of SOS3 in instrumented bioreactors, moving from low-biomass yield in a complex medium to high-biomass yield in a semi-defined medium. We achieved a 40-fold increase in biomass production, achieving cell densities of up to 11 g/L (OD600 = 40). This result was achieved when SOS3 was cultivated using a fed-batch strategy. Biomass productivity, initially 0.02 g/L/h in batch cultures, was improved 12-fold, reaching 0.24 g/L/h during fed-batch cultures. The biomass yield was also improved 10-fold from 0.07 to 0.71 gbiomass/gsolids. Analysis of the fermentation profile of SOS3 indicated minimal production of by-products and accumulation of polyhydroxybutyrate (PHB) during the exponential growth phase associated with nitrogen limitation in the medium. By implementing proteomics analysis in fed-batch cultures, we identified the expression of four metabolic pathways associated with growth-promoting effects, which may be used as a qualitative parameter to guarantee the efficacy of SOS3 when used as a bioinoculant. Ultimately, we confirmed that the high-cell density cultures maintained their plant growth-promoting capacity when tested in sorghum and maize under glasshouse conditions.

2005 ◽  
Vol 90 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Rikke Ankerstjerne Schmidt ◽  
Marilyn G. Wiebe ◽  
Niels Thomas Eriksen

1994 ◽  
Vol 42 (4) ◽  
pp. 516-521 ◽  
Author(s):  
M. Hensing ◽  
H. Vrouwenvelder ◽  
C. Hellinga ◽  
R. Baartmans ◽  
H. van Dijken

2010 ◽  
Vol 76 (13) ◽  
pp. 4486-4496 ◽  
Author(s):  
Petr Hyka ◽  
Thomas Züllig ◽  
Claudia Ruth ◽  
Verena Looser ◽  
Christian Meier ◽  
...  

ABSTRACT Matching both the construction of a recombinant strain and the process design with the characteristics of the target protein has the potential to significantly enhance bioprocess performance, robustness, and reproducibility. The factors affecting the physiological state of recombinant Pichia pastoris Mut+ (methanol utilization-positive) strains and their cell membranes were quantified at the individual cell level using a combination of staining with fluorescent dyes and flow cytometric enumeration. Cell vitalities were found to range from 5 to 95% under various process conditions in high-cell-density fed-batch cultures, with strains producing either porcine trypsinogen or horseradish peroxidase extracellularly. Impaired cell vitality was observed to be the combined effect of production of recombinant protein, low pH, and high cell density. Vitality improved when any one of these stress factors was excluded. At a pH value of 4, which is commonly applied to counter proteolysis, recombinant strains exhibited severe physiological stress, whereas strains without heterologous genes were not affected. Physiologically compromised cells were also found to be increasingly sensitive to methanol when it accumulated in the culture broth. The magnitude of the response varied when different reporters were combined with either the native AOX1 promoter or its d6* variant, which differ in both strength and regulation. Finally, the quantitative assessment of the physiology of individual cells enables the implementation of innovative concepts in bioprocess development. Such concepts are in contrast to the frequently used paradigm, which always assumes a uniform cell population, because differentiation between the individual cells is not possible with methods commonly used.


2012 ◽  
Vol 17 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Amir Maghsoudi ◽  
Safoura Hosseini ◽  
Seyed Abbas Shojaosadati ◽  
Ebrahim Vasheghani-Farahani ◽  
Mohsen Nosrati ◽  
...  

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