Comparison of Sensitivity of Tropical Freshwater Microalgae to Environmentally Relevant Concentrations of Cadmium and Hexavalent Chromium in Three Types of Growth Media

Algae with potential biotechnological applications in different industries are commonly isolate from the environment in order to obtain pure (axenic) stocks that can be safely stored for long periods of time. To obtain axenic cultures, antibiotics are frequently used, and cryopreservation is applied to keep standing stocks. However, many of these now standard methods were developed using strains coming from pristine-to-low intervened environments and cold-to-temperate regions. Thus, it is still not well understand the potential effect of said methods on the life cycle and biochemical profile of algae isolates from hiper-eutrophic and constant high-temperature tropical regions, which could potentially render them unsuitable for their intended biotechnological application. In this study, we conducted a genetic characterization (18S rRNA) and evaluated the effect of purification (use of the antibiotic chloramphenicol, CPA) and cryopreservation (dimethyl sulfoxide (DMSO)-sucrose mix and Glycerol) on the growth rate and lipid content of four new tropical freshwater algal isolates: Chorella sp. M2, Chlorella sp. M6, Scenedesmus sp. R3, and Coelastrella sp. A2, from the Ecuadorian coast. The genetic characterization showed a clear discrimination between strains. All strains cultured with CPA had a lower growth rate. After cryopreservation Coelastrella sp. A2 did not grow with both methods; Chorella sp. M2, Chlorella sp. M6 and Scenedesmus sp. R3 presented no significant difference in growth rate between the cryopreservants. A significantly higher lipid content was observed in biomass cryopreserved with glycerol in relation to DMSO-sucrose, with Chorella sp. M2 and Chlorella sp. M6 having twice as much in the first treatment. The results highlight the relevance of choosing an appropriate method for storage as the materials used can affect the biological performance of different tropical species, although is still to determine if the effects observed here are long lasting in subsequent cultures of these algae.

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Optimization of Various Growth Media to Freshwater Microalgae for Biomass Production

Biotechnology(Faisalabad) ◽

10.3923/biotech.2011.540.545 ◽

2011 ◽

Vol 10 (6) ◽

pp. 540-545 ◽

Cited By ~ 35

Author(s):

A. Ilavarasi ◽

D. Mubarakali ◽

R. Praveenkum ◽

E. Baldev ◽

N. Thajuddin

Keyword(s):

Biomass Production ◽

Growth Media ◽

Freshwater Microalgae

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Characterization of the lipid accumulation in a tropical freshwater microalgae Chlorococcum sp.

Bioresource Technology ◽

10.1016/j.biortech.2012.06.098 ◽

2012 ◽

Vol 121 ◽

pp. 54-60 ◽

Cited By ~ 30

Author(s):

Theresia Umi Harwati ◽

Thomas Willke ◽

Klaus D. Vorlop

Keyword(s):

Lipid Accumulation ◽

Freshwater Microalgae ◽

Tropical Freshwater

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Short-term deleterious effects of standard isolation and cultivation methods on new tropical freshwater microalgae strains

PeerJ ◽

10.7717/peerj.5143 ◽

2018 ◽

Vol 6 ◽

pp. e5143

Author(s):

M. Magdalena Aray-Andrade ◽

Miguel I. Uyaguari-Diaz ◽

J. Rafael Bermúdez

Keyword(s):

Growth Rate ◽

Lipid Content ◽

Potential Effect ◽

Morphological Characterization ◽

Tropical Species ◽

Freshwater Microalgae ◽

Lower Growth ◽

Tropical Regions ◽

Significant Difference ◽

Tropical Freshwater

Algae with potential biotechnological applications in different industries are commonly isolated from the environment in order to obtain pure (axenic) stocks that can be safely stored for long periods of time. To obtain axenic cultures, antibiotics are frequently employed, and cryopreservation is applied to preserve standing stocks. However, many of these now standard methods were developed using strains derived from pristine to near-pristine environments and cold to temperate regions. The potential effect of the said methods on the life cycle and biochemical profile of algae isolates from hyper-eutrophic and constant high-temperature tropical regions is not well understood. These effects could potentially render them unsuitable for their intended biotechnological application. In this study, we conducted a genetic characterization (18S rRNA) and evaluated the effect of purification (the use of the antibiotic chloramphenicol, CAP) and cryopreservation (dimethyl sulfoxide; DMSO–sucrose mix and glycerol) on the growth rate and lipid content of three new tropical freshwater algal isolates: Chorella sp. M2, Chlorella sp. M6, and Scenedesmus sp. R3, obtained from the Ecuadorian coast. The genetic and morphological characterization revealed a clear discrimination between these strains. All strains cultured with CAP exhibited a lower growth rate. Subsequent to cryopreservation, Chorella sp. M2, Chlorella sp. M6, and Scenedesmus sp. R3 presented no significant difference in growth rate between the cryopreservants. Further, a significantly higher lipid content was observed in the biomass cryopreserved with glycerol in relation to the DMSO–sucrose, with Chorella sp. M2 and Chlorella sp. M6 having twice as much as they had in the first treatment. These results highlight the relevance of selecting an appropriate method for storage, as the materials used can affect the biological performance of different tropical species, although it is still to be determined if the effects observed in this study are long lasting in subsequent cultures of these algae.

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A novel nanoemulsion based microalgal growth medium for enhanced biomass production

10.21203/rs.3.rs-43578/v2 ◽

2020 ◽

Author(s):

Harshita Nigam ◽

Anushree Malik ◽

Vikram Singh

Keyword(s):

Biomass Production ◽

Biochemical Characterization ◽

Silicone Oil ◽

Algal Growth ◽

Morphological Characteristics ◽

Biomass Productivity ◽

Growth Media ◽

Freshwater Microalgae ◽

Microalgal Biomass ◽

And Control

Abstract Background: Microalgae are well-established feedstocks for applications ranging from biofuels to valuable pigments and therapeutic proteins. However, the low biomass productivity using commercially available growth mediums is a roadblock for its mass production. This work describes a strategy to boost algal biomass productivity by using an effective CO2 supplement.Results: In the present study, a novel nanoemulsion-based media has been tested for the growth of freshwater microalgae strain Chlorella pyrenoidosa. Two different nanoemulsion-based media were developed using 1% silicone oil nanoemulsion (1% SE) and 1% paraffin oil nanoemulsion (1% PE) supplemented in Blue-green 11 media (BG11). After 12 days of cultivation, biomass yield was found highest in 1% PE followed by 1% SE and control i.e, 3.20, 2.75, and 1.03 g L-1, respectively. The chlorophyll-a synthesis was improved by 76% in 1% SE and 53% in 1% PE compared with control. The respective microalgal cell numbers for 1% PE, 1% SE and control measured using the cell counter were 3.00 × 106, 2.40 × 106, and 1.34 × 106 cells mL-1. The effective CO2 absorption tendency of the emulsion was highlighted as the key mechanism for enhanced algal growth and biomass production. On the biochemical characterization of the produced biomass, it was found that the nanoemulsion cultivated C. pyrenoidosa had increased lipid (1% PE =26.80%, 1% SE =23.60%) and carbohydrates (1% PE =17.20%, 1% SE =18.90%) content compared to the control (lipid =18.05%, carbohydrates =13.60%).Conclusions: This study describes a novel nanoemulsion which potentially acts as an effective CO2 supplement for microalgal growth media thereby increasing the growth of microalgal cells. Further, nanoemulsions cultivated microalgal biomass depict an increase in lipid and carbohydrate content. The approach provides high microalgal biomass productivity without altering morphological characteristics like cell shape and size as revealed by Field Emission Scanning Electron Microscope (FESEM) images.

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Short-term deleterious effects of standard isolation and cultivation methods on new tropical freshwater microalgae strains

10.7287/peerj.preprints.2881v1 ◽

2017 ◽

Author(s):

M. Magdalena Aray-Andrade ◽

Miguel I Uyaguari-Diaz ◽

J. Rafael Bermúdez Monsalve

Keyword(s):

Growth Rate ◽

Lipid Content ◽

Potential Effect ◽

Tropical Species ◽

Freshwater Microalgae ◽

Lower Growth ◽

Tropical Regions ◽

Chlorella Sp ◽

Biological Performance ◽

Tropical Freshwater

Algae with potential biotechnological applications in different industries are commonly isolate 5 from the environment in order to obtain pure (axenic) stocks that can be safely stored for long 6 periods of time. To obtain axenic cultures, antibiotics are frequently used, and cryopreservation 7 is applied to keep standing stocks. However, many of these now standard methods were 8 developed using strains coming from pristine-to-low intervened environments and cold-to- 9 temperate regions. Thus, it is still not well understand the potential effect of said methods on the 10 life cycle and biochemical profile of algae isolates from hiper-eutrophic and constant high- 11 temperature tropical regions, which could potentially render them unsuitable for their intended 12 biotechnological application. In this study, we did a genetic characterization (18s mDNA) and 13 evaluated the effect of purification (use of the antibiotic chloramphenicol, CPA) and 14 cryopreservation (dimethyl sulfoxide (DMSO)-sucrose mix and Glycerol) on the growth rate and 15 lipid content of four new tropical freshwater algal isolates: Chorella sp. M2, Chlorella sp. M6, 16 Scenedesmus sp. R3, and Coelastrella sp. A2, from the Ecuadorian coast. The genetic 17 characterization showed a clear discrimination between strains. All strains cultured with CPA 18 had a lower growth rate. After cryopreservation Coelastrella sp. A2 did not grow with both 19 methods; Chorella sp. M2, Chlorella sp. M6 and Scenedesmus sp. R3 presented no significant 20 difference in growth rate between the cryopreservants. A significantly higher lipid content was 21 observed in biomass cryopreserved with glycerol in relation to DMSO-sucrose, with Chorella sp. 22 M2 and Chlorella sp. M6 having twice as much in the first treatment. The results highlight the 23 relevance of choosing an appropriate method for storage as the materials used can affect the 3 1 biological performance of different tropical species, although is still to determine if the effects 2 observed here are long lasting in subsequent cultures of these algae.

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A novel nanoemulsion-based microalgal growth medium for enhanced biomass production

Biotechnology for Biofuels ◽

10.1186/s13068-021-01960-8 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Harshita Nigam ◽

Anushree Malik ◽

Vikram Singh

Keyword(s):

Biomass Production ◽

Biochemical Characterization ◽

Silicone Oil ◽

Algal Growth ◽

Morphological Characteristics ◽

Biomass Productivity ◽

Growth Media ◽

Freshwater Microalgae ◽

Microalgal Biomass ◽

And Control

Abstract Background Microalgae are well-established feedstocks for applications ranging from biofuels to valuable pigments and therapeutic proteins. However, the low biomass productivity using commercially available growth mediums is a roadblock for its mass production. This work describes a strategy to boost algal biomass productivity by using an effective CO2 supplement. Results In the present study, a novel nanoemulsion-based media has been tested for the growth of freshwater microalgae strain Chlorella pyrenoidosa. Two different nanoemulsion-based media were developed using 1% silicone oil nanoemulsion (1% SE) and 1% paraffin oil nanoemulsion (1% PE) supplemented in Blue-green 11 media (BG11). After 12 days of cultivation, biomass yield was found highest in 1% PE followed by 1% SE and control, i.e., 3.20, 2.75, and 1.03 g L−1, respectively. The chlorophyll-a synthesis was improved by 76% in 1% SE and 53% in 1% PE compared with control. The respective microalgal cell numbers for 1% PE, 1% SE and control measured using the cell counter were 3.00 × 106, 2.40 × 106, and 1.34 × 106 cells mL−1. The effective CO2 absorption tendency of the emulsion was highlighted as the key mechanism for enhanced algal growth and biomass production. On the biochemical characterization of the produced biomass, it was found that the nanoemulsion-cultivated C. pyrenoidosa had increased lipid (1% PE = 26.80%, 1% SE = 23.60%) and carbohydrates (1% PE = 17.20%, 1% SE = 18.90%) content compared to the control (lipid = 18.05%, carbohydrates = 13.60%). Conclusions This study describes a novel nanoemulsion which potentially acts as an effective CO2 supplement for microalgal growth media thereby increasing the growth of microalgal cells. Further, nanoemulsion-cultivated microalgal biomass depicts an increase in lipid and carbohydrate content. The approach provides high microalgal biomass productivity without altering morphological characteristics like cell shape and size as revealed by field emission scanning electron microscope (FESEM) images. Graphical abstract

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