Astaxanthin biosynthesis promotion with pH shock in the green microalga, Haematococcus lacustris

2020 ◽  
Vol 314 ◽  
pp. 123725 ◽  
Author(s):  
Sang-Il Han ◽  
Sun Hyoung Chang ◽  
Changsu Lee ◽  
Min Seo Jeon ◽  
Young Mok Heo ◽  
...  
Keyword(s):  
Haematococcus Lacustris ◽  
Green Microalga ◽  
Ph Shock

scholarly journals The Dynamics of the Bacterial Community of the Photobioreactor-Cultivated Green Microalga Haematococcus lacustris during Stress-Induced Astaxanthin Accumulation

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 115
Author(s):  
Konstantin Chekanov ◽  
Anna Zaytseva ◽  
Ilgar Mamedov ◽  
Alexei Solovchenko ◽  
Elena Lobakova
Keyword(s):  
Bacterial Contamination ◽  
Algal Growth ◽  
Growth Conditions ◽  
Community Members ◽  
Potential Significance ◽  
Haematococcus Lacustris ◽  
Green Microalga ◽  
Associated Species ◽  
First Time ◽  
Insight Into

Haematococcus lacustris is a natural source of a valuable ketocarotenoid astaxanthin. Under autotrophic growth conditions, it exists in the form of a community with bacteria. The close coexistence of these microorganisms raises two questions: how broad their diversity is and how they interact with the microalga. Despite the importance these issues, little is known about microorganisms existing in Haematococcus cultures. For the first time, we characterize the dynamic of the H. lacustris microbiome of the microbiome of Haematococcus (a changeover of the bacterial associated species as function of the time) cultivated autotrophically in a photobioreactor based on 16S rRNA metabarcoding data. We found that Proteobacteria and Bacteroidetes are predominant phyla in the community. The Caulobacter bacterium became abundant during astaxanthin accumulation. These data were supported by microscopy. We discuss possible roles and interactions of the community members. These findings are of potential significance for biotechnology. They provide an insight into possible bacterial contamination in algal biomass and reveal the presence of bacteria essential for the algal growth.

scholarly journals Combined Production of Astaxanthin and β-Carotene in a New Strain of the Microalga Bracteacoccus aggregatus BM5/15 (IPPAS C-2045) Cultivated in Photobioreactor

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 643
Author(s):  
Konstantin Chekanov ◽  
Daniil Litvinov ◽  
Tatiana Fedorenko ◽  
Olga Chivkunova ◽  
Elena Lobakova
Keyword(s):  
Bubble Column ◽  
Biomass Accumulation ◽  
Natural Antioxidants ◽  
Gas Chromatography Mass Spectrometry ◽  
Stage Scheme ◽  
Green Microalga ◽  
Animal Feeding ◽  
Carotenoid Synthesis ◽  
Bubble Column Photobioreactor ◽  
Β Carotene

Carotenoids astaxanthin and β-carotene are widely used natural antioxidants. They are key components of functional food, cosmetics, drugs and animal feeding. They hold leader positions on the world carotenoid market. In current work, we characterize the new strain of the green microalga Bracteacoccus aggregatus BM5/15 and propose the method of its culturing in a bubble-column photobioreactor for simultaneous production of astaxanthin and β-carotene. Culture was monitored by light microscopy and pigment kinetics. Fatty acid profile was evaluated by tandem gas-chromatography–mass spectrometry. Pigments were obtained by the classical two-stage scheme of autotrophic cultivation. At the first, vegetative, stage biomass accumulation occurred. Maximum specific growth rate and culture productivity at this stage were 100–200 mg∙L−1∙day−1, and 0.33 day−1, respectively. At the second, inductive, stage carotenoid synthesis was promoted. Maximal carotenoid fraction in the biomass was 2.2–2.4%. Based on chromatography data, astaxanthin and β-carotene constituted 48 and 13% of total carotenoid mass, respectively. Possible pathways of astaxanthin synthesis are proposed based on carotenoid composition. Collectively, a new strain B. aggregatus BM5/15 is a potential biotechnological source of two natural antioxidants, astaxanthin and β-carotene. The results give the rise for further works on optimization of B. aggregatus cultivation on an industrial scale.

Effects of pH shock on microaerobic activated sludge system with a graphene oxide/nano-magnetic powder composite

2020 ◽  
Vol 35 (3) ◽  
pp. 457-463
Author(s):  
Huixia Lan ◽  
Xiangzhi Wang ◽  
Shixin Qi ◽  
Da Yang ◽  
Hao Zhang
Keyword(s):  
Graphene Oxide ◽  
Activated Sludge ◽  
High Throughput Sequencing ◽  
Impact Resistance ◽  
Magnetic Powder ◽  
Blank Group ◽  
Activated Sludge System ◽  
Ph Shock ◽  
Dominant Bacteria ◽  
The Impact

AbstractUsing the acclimated activated sludge from the pulping middle-stage effluent, the effect of pH shock on the micro-oxygen activated sludge system with a nano-magnetic powder/graphene oxide composite was studied. The results showed that the removal rates of chemical oxygen demand (CODCr) and ultraviolet adsorption at 254 nm (UV254) decreased. Also, the sludge settling performance was poor due to the impact of pH, but the impact resistance of nano-magnetic powder/graphene oxide group (MGO group) was higher and the recovery was faster. Results of high throughput sequencing indicated that the diversity of microbial community was reduced by the impact of pH, but it was significantly higher in MGO group than in the blank group. The dominant bacteria after pH shock or recovery in both of the system had a large difference. The percentage of the dominant bacteria in the MGO group was higher than that in the blank group. The MGO group had higher electron transfer system (ETS) activity which made the system having a strong pH impact resistance.

Programmed cell death in the coccoid green microalga Ankistrodesmus densus Korshikov (Sphaeropleales, Selenastraceae)

2021 ◽  
pp. 1-14
Author(s):  
Marcelo M. Barreto Filho ◽  
Pierre M. Durand ◽  
Nathan E. Andolfato ◽  
Anine Jordaan ◽  
Hugo Sarmento ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Green Microalga

scholarly journals Metabolic, Physiological, and Transcriptomics Analysis of Batch Cultures of the Green Microalga Chlamydomonas Grown on Different Acetate Concentrations

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1367 ◽  
Author(s):  
Bogaert ◽  
Perez ◽  
Rumin ◽  
Giltay ◽  
Carone ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Biomass Yield ◽  
Fatty Acid Content ◽  
Biological Significance ◽  
Exponential Phase ◽  
Low Light ◽  
Batch Mode ◽  
Batch Cultures ◽  
Green Microalga ◽  
Transcriptomics Data

Acetate can be efficiently metabolized by the green microalga Chlamydomonas reinhardtii. The regular concentration is 17 mM, although higher concentrations are reported to increase starch and fatty acid content. To understand the responses to higher acetate concentrations, Chlamydomonas cells were cultivated in batch mode in the light at 17, 31, 44, and 57 mM acetate. Metabolic analyses show that cells grown at 57 mM acetate possess increased contents of all components analyzed (starch, chlorophylls, fatty acids, and proteins), with a three-fold increased volumetric biomass yield compared to cells cultivated at 17 mM acetate at the entry of stationary phase. Physiological analyses highlight the importance of photosynthesis for the low-acetate and exponential-phase samples. The stationary phase is reached when acetate is depleted, except for the cells grown at 57 mM acetate, which still divide until ammonium exhaustion. Surprisal analysis of the transcriptomics data supports the biological significance of our experiments. This allows the establishment of a model for acetate assimilation, its transcriptional regulation and the identification of candidates for genetic engineering of this metabolic pathway. Altogether, our analyses suggest that growing at high-acetate concentrations could increase biomass productivities in low-light and CO2-limiting air-bubbled medium for biotechnology.

Botryoxanthin B and α-botryoxanthin A from the green microalga Botryococcus braunii Kawaguchi-1

1998 ◽  
Vol 47 (6) ◽  
pp. 1111-1115 ◽  
Author(s):  
Shigeru Okada ◽  
Izumi Tonegawa ◽  
Hisashi Matsuda ◽  
Masahiro Murakami ◽  
Katsumi Yamaguchi
Keyword(s):  
Botryococcus Braunii ◽  
Green Microalga
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