Mixotrophic cultivation of Chlorella vulgaris in sugarcane molasses preceding nitrogen starvation: Biomass productivity, lipid content, and fatty acid analyses

Microalgae are a promising feedstock for biodiesel production. Microalgal biodiesel can be obtained under three major cultivation modes, namely, photoautotrophic, heterotrophic, and mixotrophic cultivation. Reported studies of microalgal biodiesel production are mainly based on photoautotrophic cultivation, mixotrophic cultivation has rarely been researched. This paper compared the biomass productivity, lipid content, and lipid productivity of Scenedesmus sp. under photoautotrophic, heterotrophic, and mixotrophic cultivation. Glucose was added as organic carbon source at five concentrations (0.1, 0.5, 1.0, 2.0, 5.0% glucose w/v). Results displayed that microalgal growth was significantly improved in glucose supplied cultures. Synergetic effect of photoautotrophy and heterotrophy existed in all mixotrophic cultures. Highest biomass productivity of 1.307 g·L-1·d-1 and highest lipid productivity of 316 mg·L-1·d-1 was respectively observed under mixotrophic cultivation with 5.0% and 1.0% (w/v) glucose addition. Lipid content of Scenedesmus sp. under mixotrophic cultivation was mostly higher in stationary phase than in exponential phase. Highest lipid content of 27.73% was observed in 1.0% mixotrophic culture, followed by 24.66% in 1.0% heterotrophic culture.

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Isolation and Characterization of Microalgae from Diverse Pakistani Habitats: Exploring Third-Generation Biofuel Potential

Energies ◽

10.3390/en12142660 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2660 ◽

Cited By ~ 2

Author(s):

Muhammad Maqsood Alam ◽

Abdul Samad Mumtaz ◽

Megan Russell ◽

Melanie Grogger ◽

Don Veverka ◽

...

Keyword(s):

Fatty Acid ◽

Lipid Content ◽

Algal Growth ◽

Acid Methyl Ester ◽

Biomass Productivity ◽

Biodiesel Production ◽

Local Conditions ◽

Isolation And Characterization ◽

Rich Diversity

Production of microalgae as feedstock for biofuels must deal with a number of challenges including constraints imposed by local conditions. One solution is to use indigenous strains adapted to local climatic conditions. The present report describes the isolation, identification, and characterization of 32 microalgal strains from different ecological habitats: desert freshwater channels, northern region, and saline regions of Pakistan. The effects of temperature on algal growth rates, biomass productivity, and lipid content were determined through growth at 12, 20, and 35 °C for 15 days under 2% CO2 Responses to temperature varied among species with 20 °C being the optimum temperature in general, although, exceptionally, the best overall growth rate was found for strain S29 (0.311 d−1) at 12 °C. In some cases high biomass productivity was observed at 35 °C, and, depending upon the strain, the maximum lipid content was obtained at different temperatures, including 12 °C. Fatty acid methyl ester (FAME) analysis showed that the major fatty acids present were palmitic, stearic, oleic, linoleic, and linolenic. Oleic acid (C18:1) was the predominant fatty acid, with the specific FAME profile varying with strain. Thus, there is a rich diversity of microalgal strains native to Pakistan, some of which, characterized here, could be suitable for biodiesel production or other biotechnological applications.

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Potential of Mixotrophic Cultivation of Chlorella sorokiniana for Biodiesel Production

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.779-780.1509 ◽

2013 ◽

Vol 779-780 ◽

pp. 1509-1513

Author(s):

Jing Han Wang ◽

Hai Zhen Yang ◽

Feng Wang

Keyword(s):

Lipid Content ◽

Synergetic Effect ◽

Biomass Productivity ◽

Chlorella Sorokiniana ◽

Lipid Productivity ◽

Biodiesel Production ◽

Biofuel Production ◽

Mixotrophic Cultivation ◽

Promising Alternative ◽

Microalgal Biodiesel

Biodiesel from microalgae provides a promising alternative for biofuel production. Microalgal biodiesel can be produced under three major cultivation modes, namely, photoautotrophic, heterotrophic, and mixotrophic cultivation. Studies of biodiesel production from microalgae have been reported mostly focusing on photoautotrophic cultivation, mixotrophic cultivation has rarely been researched. This paper compared the biomass productivity, lipid content, and lipid productivity ofChlorella sorokinianaunder photoautotrophic, heterotrophic, and mixotrophic cultivation. Glucose was adopted as organic carbon source at five concentrations (0.1, 0.5, 1.0, 2.0, 5.0% glucose w/v). Results displayed that microalgal growth was significantly improved in glucose supplied cultures. Synergetic effect of photoautotrophy and heterotrophy existed in mixotrophic cultivation except for 5.0% culture. Highest biomass productivity of 1.178 g·L-1·d-1and highest lipid productivity of 582 mg·L-1·d-1was observed under mixotrophic cultivation with 2.0% (w/v) glucose addition. Lipid content ofC. sorokinianawas mostly higher in stationary phase than in exponential phase. Highest lipid content of 49.37% was observed in 2.0% mixotrophic culture, followed by 47.09% in 2.0% heterotrophic culture.

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Maximizing Biomass and Lipid Production in Heterotrophic Culture of Chlorella vulgaris: Techno-Economic Assessment

Recent Patents on Food Nutrition & Agriculturee ◽

10.2174/2212798410666180911100034 ◽

2019 ◽

Vol 10 (2) ◽

pp. 115-123 ◽

Cited By ~ 1

Author(s):

Mohammad H. Morowvat ◽

Younes Ghasemi

Keyword(s):

Chlorella Vulgaris ◽

Lipid Content ◽

Shake Flask ◽

Biomass Productivity ◽

Biodiesel Production ◽

Potential Candidate ◽

Heterotrophic Culture ◽

Heterotrophic Cultivation ◽

Dry Cell Weight ◽

Autotrophic Culture

Background: Nowadays, chlorophycean microalgae have attained a broad-spectrum attention as a potential candidate for biomass and bioenergy production. Despite their appreciated benefits, one of major problems is their low biomass and lipid productivity. Here we investigated the heterotrophic culture in shake flasks and stirred tank bioreactor to improve the lipid and biomass production in a naturally isolated strain of Chlorella vulgaris. Methods: A naturally isolated C. vulgaris strain was cultivated in BG-11 medium in shake flask and bioreactor. Its biochemical composition and growth kinetic parameters were investigated. Results: The biomass productivity was improved (3.68 fold) under heterotrophic culture compared to basal autotrophic culture condition in shake flask experiment. The total lipid content increased to 44% of total Dry Cell Weight (DCW) during heterotrophic growth after 21 days. Moreover, a great Fatty Acid Methyl Esters (FAME) yield was observed under heterotrophic cultivation. Total biomass and lipid content of microalgae in bioreactor experiment increased to 4.95 and 2.18 g L-1 respectively, during 5 days of the experiment compared to its basic autotrophic culture. Conclusion: The techno-economic aspects of exploiting C. vulgaris as a biodiesel feedstock werealso evaluated. The results imply that heterotrophic cultivation could compensate the low biomass productivity in microalgae for green energy production. Ever growing rates of established patents on application of various genetic and bioengineering-based methods have made it possible to achieve higher lipid contents with reduced total costs for microalgal biodiesel production as well.

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Effect of Different Cultivation Modes (Photoautotrophic, Mixotrophic, and Heterotrophic) on the Growth of Chlorella sp. and Biocompositions

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.774143 ◽

2021 ◽

Vol 9 ◽

Author(s):

Hyun-Sik Yun ◽

Young-Saeng Kim ◽

Ho-Sung Yoon

Keyword(s):

Chlorella Vulgaris ◽

Lipid Content ◽

Inorganic Carbon ◽

Biomass Yield ◽

Carbon Sources ◽

Biomass Productivity ◽

Chlorella Sorokiniana ◽

Raw Material ◽

Heterotrophic Cultivation ◽

Mixotrophic Conditions

In the past, biomass production using microalgae culture was dependent on inorganic carbon sources as microalgae are photosynthetic organisms. However, microalgae utilize both organic and inorganic carbon sources, such as glucose. Glucose is an excellent source of organic carbon that enhances biomass yield and the content of useful substances in microalgae. In this study, photoautotrophic, mixotrophic, and heterotrophic cultivation conditions were applied to three well-known strains of Chlorella (KNUA104, KNUA114, and KNUA122) to assess biomass productivity, and compositional changes (lipid, protein, and pigment) were evaluated in BG11 media under photoautotrophic, mixotrophic, and heterotrophic conditions utilizing different initial concentrations of glucose (5, 10, 15, 20, and 25 g L−1). Compared to the photoautotrophic condition (biomass yield: KNUA104, 0.35 ± 0.04 g/L/d; KNUA114, 0.40 ± 0.08 g/L/d; KNUA122, 0.38 ± 0.05 g/L/d) glucose was absent, and the biomass yield improved in the mixotrophic (glucose: 20 g L−1; biomass yield: KNUA104, 2.99 ± 0.10 g/L/d; KNUA114, 5.18 ± 0.81 g/L/d; KNUA122, 5.07 ± 0.22 g/L/d) and heterotrophic conditions (glucose: 20 g L−1; biomass yield: KNUA104, 1.72 ± 0.26 g/L/d; KNUA114, 4.26 ± 0.27 g/L/d; KNUA122, 4.32 ± 0.32 g/L/d). All strains under mixotrophic and heterotrophic conditions were optimally cultured when 15–20 g L−1 initial glucose was provided. Although bioresourse productivity improved under both mixotrophic and heterotrophic conditions where mixotrophic conditions were found to be optimal as the yields of lipid and pigment were also enhanced. Protein content was less affected by the presence of light or the concentration of glucose. Under mixotrophic conditions, the highest lipid content (glucose: 15 g L−1; lipid content: 68.80 ± 0.54%) was obtained with Chlorella vulgaris KNUA104, and enhanced pigment productivity of Chlorella sorokiniana KNUA114 and KNUA122 (additional pigment yield obtained with 15 g L−1 glucose: KNUA 114, 0.33 ± 0.01 g L−1; KNUA122, 0.21 ± 0.01 g L−1). Also, saturated fatty acid (SFA) content was enhanced in all strains (SFA: KNUA104, 29.76 ± 1.31%; KNUA114, 37.01 ± 0.98%; KNUA122, 33.37 ± 0.17%) under mixotrophic conditions. These results suggest that mixotrophic cultivation of Chlorella vulgaris and Chlorella sorokiniana could improve biomass yield and the raw material quality of biomass.

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Starch and triacylglycerol accumulation in the cells of the stain Chlorella sp. IPPAS C-1210

Issues of modern algology (Вопросы современной альгологии) ◽

10.33624/2311-0147-2021-2(26)-1-7 ◽

2021 ◽

pp. 1-7

Author(s):

Lidia A. Bobrovnikova ◽

Maria S. Pakholkova ◽

Roman A. Sidorov ◽

Maria A. Sinetova

Keyword(s):

Carbon Dioxide ◽

Lipid Content ◽

Food Industry ◽

Nitrogen Starvation ◽

Total Lipid Content ◽

Biomass Productivity ◽

Chlorella Sp ◽

Phosphorus Source ◽

Triacylglycerol Accumulation ◽

In Cells

Strain Сhlorella sp. IPPAS C-1210 is an effective lipid and triacilglycerols (TAG) producer. The strain could be used eventually in such industries as bioenergetics, food industry and agriculture. The objective of this work was investigation of conditions in which the strain Сhlorella sp. IPPAS C-1210 accumulates the most starch and TAG in cells with a view to optimise its growth and productivity. The following cultivation parameters were investigated in order to figure out their influence on accumulation of starch and TAG: nitrogen- and phosphorous-starvation and cultivation on media with different nitrogen (nitrate, urea) and carbon (carbon dioxide, bicarbonate) sources. Pigments, starch, protein and lipid content in cells were measured. The exclusion of nitrogen or phosphorus source from medium decreased the biomass productivity significantly, caused chlorosis and reduction of protein content. Total lipid content increased slightly after phosphorous starvation and stayed almost constant under nitrogen starvation, however a greater TAG increase was observed during nitrogen starvation. Both nitrogen and phosphorous starvations caused the increase of the amount of reserve carbohydrates: during phosphorous starvation increase was insignificant, whereas the latter almost doubled the amount of reserve carbohydrates. The highest biomass and lipid productivity was observed in cells grown in bicarbonate supplement medium and the highest starch productivity was observed in cells grown in standard BBM-3N medium.

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Utilisation of CO2 from Sodium Bicarbonate to Produce Chlorella Vulgaris Biomass in Tubular Photobioreactors for Biofuel Purposes

Sustainability ◽

10.3390/su13169118 ◽

2021 ◽

Vol 13 (16) ◽

pp. 9118

Author(s):

Patryk Ratomski ◽

Małgorzata Hawrot-Paw ◽

Adam Koniuszy

Keyword(s):

Sodium Bicarbonate ◽

Carbon Content ◽

Optical Density ◽

Chlorella Vulgaris ◽

Lipid Content ◽

Biomass Productivity ◽

Culture Conditions ◽

Fixation Rate ◽

Spectrophotometric Methods ◽

Wide Range

Microalgae are one of the most promising sources of renewable substrates used for energy purposes. Biomass and components accumulated in their cells can be used to produce a wide range of biofuels, but the profitability of their production is still not at a sufficient level. Significant costs are generated, i.a., during the cultivation of microalgae, and are connected with providing suitable culture conditions. This study aims to evaluate the possibility of using sodium bicarbonate as an inexpensive alternative CO2 source in the culture of Chlorella vulgaris, promoting not only the increase of microalgae biomass production but also lipid accumulation. The study was carried out at technical scale using 100 L photobioreactors. Gravimetric and spectrophotometric methods were used to evaluate biomass growth. Lipid content was determined using a mixture of chloroform and methanol according to the Blight and Dyer method, while the carbon content and CO2 fixation rate were measured according to the Walkley and Black method. In batch culture, even a small addition of bicarbonate resulted in a significant (p ≤ 0.05) increase in the amount of biomass, productivity and optical density compared to non-bicarbonate cultures. At 2.0 g∙L–1, biomass content was 572 ± 4 mg·L−1, the maximum productivity was 7.0 ± 1.0 mg·L–1·d–1, and the optical density was 0.181 ± 0.00. There was also an increase in the lipid content (26 ± 4%) and the carbon content in the biomass (1322 ± 0.062 g∙dw–1), as well as a higher rate of carbon dioxide fixation (0.925 ± 0.073 g·L–1·d–1). The cultivation of microalgae in enlarged scale photobioreactors provides a significant technological challenge. The obtained results can be useful to evaluate the efficiency of biomass and valuable cellular components production in closed systems realized at industrial scale.

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