High efficient assimilation of NO₃⁻-N with coproduction of microalgal proteins by Chlorella pyrenoidosa / 生物工程学报
Chinese Journal of Biotechnology
; (12): 1150-1161, 2020.
Article
in Zh
| WPRIM
| ID: wpr-826863
Responsible library:
WPRO
ABSTRACT
The aim of this study was to establish a novel technology using microalgae for NO₃⁻ removal from high concentration wastewater and conversion to algal proteins. The effects of cultivation modes and illumination modes on the biomass yield, NO₃⁻ assimilation rate and algal protein yield were first investigated in shaking flasks for mixotrophic cultivation of Chlorella pyrenoidosa, and subsequently the scale-up verification in 5-L photo fermenter was successfully conducted. Fed-batch cultivation without medium recycling was the best cultivation mode in shaking flask system, in which the highest biomass yield (35.95 g/L), the average NO₃⁻ assimilation rate (2.06 g/(L·d)) and algal protein content (up to 42.44% of dry weight) were achieved. By using a staged increase of light intensity as illumination modes, the specific growth rate of cells could be significantly promoted to the highest (0.65 d⁻¹). After a 128-hour continuous cultivation in a 5-L photo fermenter, the highest biomass yield and the average NO₃⁻ assimilation rate were reached to 66.22 g/L and 4.38 g/(L·d) respectively, with the highest algal protein content at 47.13% of dry weight. Our study could provide a photo fermentation technology of microalgae for highly efficient treatment of waste industrial nitric acid and/or high concentration nitrate wastewater. This microalgae-based bioconversion process could coproduce protein-rich microalgal biomass, which facilitates the resource utilization of these type wastewater by trash-to-treasure conversion.
Key words
Full text:
1
Index:
WPRIM
Main subject:
Chemistry
/
Chlorella
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Water Purification
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Biomass
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Algal Proteins
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Wastewater
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Metabolism
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Methods
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Nitrates
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Nitrogen
Language:
Zh
Journal:
Chinese Journal of Biotechnology
Year:
2020
Type:
Article