Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformis
Abstract Background Microalgal starch is regarded as a promising alternative to crop-based starch for biorefinery such as the production of biofuels and bio-based chemicals. The single or separate use of inorganic carbon source, e.g., CO2 and NaHCO3, caused aberrant pH, which restricts the biomass a...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2019-07-01
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| Series: | Biotechnology for Biofuels |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13068-019-1523-7 |
| _version_ | 1818547449593069568 |
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| author | Man Qi Changhong Yao Binhuan Sun Xupeng Cao Qiang Fei Bobo Liang Wenyi Ran Qi Xiang Yongkui Zhang Xianqiu Lan |
| author_facet | Man Qi Changhong Yao Binhuan Sun Xupeng Cao Qiang Fei Bobo Liang Wenyi Ran Qi Xiang Yongkui Zhang Xianqiu Lan |
| author_sort | Man Qi |
| collection | DOAJ |
| description | Abstract Background Microalgal starch is regarded as a promising alternative to crop-based starch for biorefinery such as the production of biofuels and bio-based chemicals. The single or separate use of inorganic carbon source, e.g., CO2 and NaHCO3, caused aberrant pH, which restricts the biomass and starch production. The present study applied an in situ CO2–NaHCO3 system to regulate photosynthetic biomass and starch production along with starch quality in a marine green microalga Tetraselmis subcordiformis under nitrogen-depletion (−N) and nitrogen-limitation (±N) conditions. Results The CO2 (2%)–NaHCO3 (1 g L−1) system stabilized the pH at 7.7 in the −N cultivation, under which the optimal biomass and starch accumulation were achieved. The biomass and starch productivity under −N were improved by 2.1-fold and 1.7-fold, respectively, with 1 g L−1 NaHCO3 addition compared with the one without NaHCO3 addition. NaHCO3 addition alleviated the high-dCO2 inhibition caused by the single CO2 aeration, and provided sufficient effective carbon source HCO3 − for the maintenance of adequate photosynthetic efficiency and increase in photoprotection to facilitate the biomass and starch production. The amylose content was also increased by 44% under this CO2–bicarbonate system compared to the single use of CO2. The highest starch productivity of 0.73 g L−1 day−1 under −N cultivation and highest starch concentration of 4.14 g L−1 under ±N cultivation were both achieved with the addition of 1 g L−1 NaHCO3. These levels were comparable to or exceeded the current achievements reported in studies. The addition of 5 g L−1 NaHCO3 under ±N cultivation led to a production of high-amylose starch (59.3% of total starch), which could be used as a source of functional food. Conclusions The in situ CO2–NaHCO3 system significantly improved the biomass and starch production in T. subcordiformis. It could also regulate the starch quality with varied relative amylose content under different cultivation modes for diverse downstream applications that could promote the economic feasibility of microalgal starch-based biofuel production. Adoption of this system in T. subcordiformis would facilitate the CO2 mitigation couple with its starch-based biorefinery. |
| first_indexed | 2024-12-12T08:06:52Z |
| format | Article |
| id | doaj.art-cba255af7d334fb196b2cf6afe0423a3 |
| institution | Directory Open Access Journal |
| issn | 1754-6834 |
| language | English |
| last_indexed | 2024-12-12T08:06:52Z |
| publishDate | 2019-07-01 |
| publisher | BMC |
| record_format | Article |
| series | Biotechnology for Biofuels |
| spelling | doaj.art-cba255af7d334fb196b2cf6afe0423a32022-12-22T00:31:56ZengBMCBiotechnology for Biofuels1754-68342019-07-0112112110.1186/s13068-019-1523-7Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformisMan Qi0Changhong Yao1Binhuan Sun2Xupeng Cao3Qiang Fei4Bobo Liang5Wenyi Ran6Qi Xiang7Yongkui Zhang8Xianqiu Lan9Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan UniversityDepartment of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan UniversityDepartment of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan UniversityState Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of SciencesSchool of Chemical Engineering and Technology, Xi’an Jiaotong UniversitySchool of Chemical Engineering and Technology, Xi’an Jiaotong UniversityDepartment of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan UniversityDepartment of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan UniversityDepartment of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan UniversityDepartment of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan UniversityAbstract Background Microalgal starch is regarded as a promising alternative to crop-based starch for biorefinery such as the production of biofuels and bio-based chemicals. The single or separate use of inorganic carbon source, e.g., CO2 and NaHCO3, caused aberrant pH, which restricts the biomass and starch production. The present study applied an in situ CO2–NaHCO3 system to regulate photosynthetic biomass and starch production along with starch quality in a marine green microalga Tetraselmis subcordiformis under nitrogen-depletion (−N) and nitrogen-limitation (±N) conditions. Results The CO2 (2%)–NaHCO3 (1 g L−1) system stabilized the pH at 7.7 in the −N cultivation, under which the optimal biomass and starch accumulation were achieved. The biomass and starch productivity under −N were improved by 2.1-fold and 1.7-fold, respectively, with 1 g L−1 NaHCO3 addition compared with the one without NaHCO3 addition. NaHCO3 addition alleviated the high-dCO2 inhibition caused by the single CO2 aeration, and provided sufficient effective carbon source HCO3 − for the maintenance of adequate photosynthetic efficiency and increase in photoprotection to facilitate the biomass and starch production. The amylose content was also increased by 44% under this CO2–bicarbonate system compared to the single use of CO2. The highest starch productivity of 0.73 g L−1 day−1 under −N cultivation and highest starch concentration of 4.14 g L−1 under ±N cultivation were both achieved with the addition of 1 g L−1 NaHCO3. These levels were comparable to or exceeded the current achievements reported in studies. The addition of 5 g L−1 NaHCO3 under ±N cultivation led to a production of high-amylose starch (59.3% of total starch), which could be used as a source of functional food. Conclusions The in situ CO2–NaHCO3 system significantly improved the biomass and starch production in T. subcordiformis. It could also regulate the starch quality with varied relative amylose content under different cultivation modes for diverse downstream applications that could promote the economic feasibility of microalgal starch-based biofuel production. Adoption of this system in T. subcordiformis would facilitate the CO2 mitigation couple with its starch-based biorefinery.http://link.springer.com/article/10.1186/s13068-019-1523-7StarchNitrogen depletionpHBicarbonateAmyloseTetraselmis subcordiformis |
| spellingShingle | Man Qi Changhong Yao Binhuan Sun Xupeng Cao Qiang Fei Bobo Liang Wenyi Ran Qi Xiang Yongkui Zhang Xianqiu Lan Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformis Biotechnology for Biofuels Starch Nitrogen depletion pH Bicarbonate Amylose Tetraselmis subcordiformis |
| title | Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformis |
| title_full | Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformis |
| title_fullStr | Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformis |
| title_full_unstemmed | Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformis |
| title_short | Application of an in situ CO2–bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga Tetraselmis subcordiformis |
| title_sort | application of an in situ co2 bicarbonate system under nitrogen depletion to improve photosynthetic biomass and starch production and regulate amylose accumulation in a marine green microalga tetraselmis subcordiformis |
| topic | Starch Nitrogen depletion pH Bicarbonate Amylose Tetraselmis subcordiformis |
| url | http://link.springer.com/article/10.1186/s13068-019-1523-7 |
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