Increased pigment and lipid content, lipid variety, and cell and population size of the microalgae Chlorella spp. when co-immobilized in alginate beads with the microalgae-growth-promoting bacterium Azospirillum brasilense (original) (raw)
Related papers
Lipid content and fatty acid profiles in ten species of microalgae
Idesia (Arica), 2015
The present study aimed to evaluate the lipid content and fatty acid profiles of 9 marine species (Nannochloropsis oculata, Thalassiosira pseudonana, Phaeodactylum tricornutum, Isochrysis galbana, Tetraselmis suecica, Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira fluviatilis and Isochrysis sp.) and 1 freshwater microalga species (Chlorella vulgaris) that were cultivated in Erlenmeyer flasks with 800 mL of culture medium under stationary autotrophic conditions while exposed to a continuous photon flux density of approximately 175 μmol m -2 s -1 , a temperature of 25±2 o C and constant airflow. N. oculata and T. pseudonana exhibited the highest lipid content, although they had a high proportion of monounsaturated fatty acids relative to polyunsaturated fatty acids. C. vulgaris and Isochrysis sp. exhibited high levels of polyunsaturated fatty acids, whereas P. tricornutum, N. oculata and T. suecica exhibited the highest eicosapentaenoic acid levels, and I. galbana and C. muelleri had the highest docosahexaenoic fatty acid levels. The freshwater species C. vulgaris had the highest levels of linoleic and linolenic acids, followed by the marine species T. chuii.
Canadian Journal of Microbiology, 2000
In an agroindustrial wastewater pond, a naturally occurring unicellular microalga, Chlorella vulgaris, was closely associated with the terrestrial plant-associative N2-fixing bacterium Phyllobacterium myrsinacearum. When the two microorganisms were artificially coimmobilized in alginate beads, they shared the same internal bead cavities, and the production of five microalgal pigments increased, but there were no effects on the number of the cells or the biomass of the microalga. The association, however, reduces the ability of C. vulgaris to remove ammonium ions and phosphorus from water. The bacterium produced nitrate from ammonium in synthetic wastewater with or without the presence of the microalga, and fixed nitrogen in two culture media. Our results suggest that interactions between microalgae and associative bacteria should be considered when cultivating microalgae for wastewater treatment.
PLoS ONE, 2014
While photosynthetic microalgae, such as Chlorella, serve as feedstocks for nutritional oils and biofuels, heterotrophic cultivation can augment growth rates, support high cell densities, and increase triacylglycerol (TAG) lipid content. However, these species differ significantly in their photoautotrophic and heterotrophic characteristics. In this study, the phylogeny of thirty Chlorella strains was determined in order to inform bioprospecting efforts and detailed physiological assessment of three species. The growth kinetics and lipid biochemistry of C. protothecoides UTEX 411, C. vulgaris UTEX 265, and C. sorokiniana UTEX 1230 were quantified during photoautotrophy in Bold's basal medium (BBM) and heterotrophy in BBM supplemented with glucose (10 g L 21 ). Heterotrophic growth rates of UTEX 411, 265, and 1230 were found to be 1.5-, 3.7-, and 5-fold higher than their respective autotrophic rates. With a rapid nine-hour heterotrophic doubling time, Chlorella sorokiniana UTEX 1230 maximally accumulated 39% total lipids by dry weight during heterotrophy compared to 18% autotrophically. Furthermore, the discrete fatty acid composition of each strain was examined in order to elucidate lipid accumulation patterns under the two trophic conditions. In both modes of growth, UTEX 411 and 265 produced 18:1 as the principal fatty acid while UTEX 1230 exhibited a 2.5-fold enrichment in 18:2 relative to 18:1. Although the total lipid content was highest in UTEX 411 during heterotrophy, UTEX 1230 demonstrated a two-fold increase in its heterotrophic TAG fraction at a rate of 28.9 mg L 21 d 21 to reach 22% of the biomass, corresponding to as much as 90% of its total lipids. Interestingly, UTEX 1230 growth was restricted during mixotrophy and its TAG production rate was suppressed to 18.2 mg L 21 d 21 . This constraint on carbon flow raises intriguing questions about the impact of sugar and light on the metabolic regulation of microalgal lipid biosynthesis.
Biomass and Lipid Production Potential of Economically Important Marine Microalgal Strains
International Journal of Current Microbiology and Applied Sciences, 2022
Four marine microalgal strains viz. Pavlova sp. ABT 102, Chromulina sp. ABT 103, Thalassiosira sp. AMS 5 and Chlorella sp. AMS 6 were tested for their biomass and lipid productivities through bench-scale studies to assess their potential for production of value added products. Among the four different marine microalgal strains Pavlova sp. ABT 102 isolate showed maximum volumetric biomass productivity of 0.048 g L-1d-1 followed by Chlorella sp. AMS 6 (0.035 g L-1d-1), Thalassiosira sp. AMS 5 (0.021 g L-1d-1) and Chromulina sp. ABT 103 (0.019 g L-1d-1). The highest volumetric lipid productivity was recorded by Chromulina sp. ABT 103 (11.12 mg L-1d-1) followed by Pavlova sp. ABT 102 (10.65 mg L-1d-1), Thalassiosira sp. AMS 5 (8.77 mg L-1d-1) and Chlorella sp. AMS 6 (7.73 mg L-1d-1). Among four algal strains, Chlorella sp. AMS 6 could effectively utilise sodium bicarbonate as an external inorganic carbon source in the growth medium. It was found that the addition of inorganic carbon sou...
Selection of Microalgal Strains with Low Starch Content as Potential High Lipid-Containing Isolates
2017
In the last forty years there is an increased scientific interest in deeper understanding lipid metabolism in photosynthetic microorganisms, aiming at using the most lipid-rich strains as source for biodiesel production. One of the many constraints is the selection of strains with high lipid content. This paper presents the isolation, purification and selection of three strains of photosynthetic microorganisms by using an already known method, iodine vapour method, (Work et al., 2010) which allows to rapidly and easily select those colonies which low starch content as potential high lipidcontaining isolates. These results show that in the three selected strains, the fluorescence emission after Nile red addition is increased with different values: 7.597; 10.832 and 11.428 for strains 9.3.1, 9.8.2 and 12.9.0, respectivley.
Influence of environmental conditions on lipid accumulation by the alga Halochlorella rubescens
Lipids from microalgae have been studied for their potential application in various industries, such as cosmetics, biofuel, pharmaceuticals and animal feed. This study investigates the effects of different aspects of cultivation conditions (pH, the combination of nitrogen and phosphorus sources and their concentrations, carbon dioxide (CO2) concentration and light intensity) on lipid content and formation kinetics of the alga Halochlorella rubescens in a tubular photobioreactor. The highest lipid content (38.45 ± 1.018%) and maximum biomass production (0.3468 ± 0.004 g L− 1) were achieved in nitrogen-depleted medium at pH 9, 15% CO2 and 4000 lux after optimisation using the one variable at a time (OVAT) approach. The application of Fourier Transform Infrared Spectroscopy (FTIR) confirmed the functional groups of lipids present in the wavelength range of 3012 − 2809 cm− 1 and 1745 − 1734 cm− 1. Use of the Leudeking-Piret model revealed that lipid production by H. rubescens is growth-...
Characterization Chlorophytas microalgae with potential in the production of lipids for biofuels
CT&F - Ciencia, Tecnología y Futuro, 2012
This work is part of a megaproject that seeks to isolate microalgae of the Chlorophyta division native to Norte de Santander and identify their potential applications such as lipid production to be used as biofuel. Here we present the isolation of 11 microalgae strains from the Chlorophyta division found in two different wastewater environments. The collected strains were cultivated in selective media and purified through serial dilutions, depletion culture, and application of penicillin and gentamicin. Biomass production was evaluated and two strains were selected: CHL1 (Chlorella sp.) and DES1 (Desmodesmus sp.). The strains were cultivated on wastewater and PCG media (control), and their biomass concentration and lipid content were measured. Both strains reached similar biomass concentrations compared to their respective controls (CHL1 PCG 1.5 mg/L ± 0.035 mg/L, CHL1 AR 1.68 mg/L ± 0.036, DES1 PCG 1.66 mg/L ± 0.007, DES1 AR 2 mg/L ± 0.03) and their lipid content was slightly highe...
Physiological Limitations and Solutions to Various Applications of Microalgae
Microalgae - From Physiology to Application, 2020
Despite over a century of research, the various applications of microalgae have only been realized only since the 1940s. With a repertoire of valuable products like biodiesel, astaxanthin, canthaxanthin, lutein, β-carotene, phycocyanin, chlorophyll a, polyunsaturated fatty acids, exopolymeric substance (EPS), and biohydrogen, the commercial importance of microalgae and demand for its product is gaining increasing attention. However, successful transition of the synthesis of microalgal products from laboratory to industries has yet to be realized, even after over 70 years of extensive research. This failure of commercial success of microalgal products can be attributed to the lack of understanding of the physiological role of the products and biological constraint placed by the bioenergetics and physiology, which has been largely ignored. This chapter focuses on the physiological limitations behind synthesis of microalgal products, highlights the crucial unknowns behind the role and synthesis of these products, and hints strategies to overcome the limitations to realize the commercial dream of microalgal products.
Oceanological and Hydrobiological Studies, 2018
Screening of fourteen Baltic green algal strains provided basic data on their mass culture potential for the purpose of valuable biomass production with particular emphasis on lipid content. Selected microalgae were grown under non-stressed conditions in order to identify those characterized by efficient lipid production. The tested strains exhibited significant differences in growth patterns and lipid yields. Strains belonging to Chlorella and Stichococcus genera exhibited the highest growth rates, ranging from 0.39 d-1 to 0.50 d-1 and thus the highest final cell density (> 107 cells ml-1). Furthermore, five strains: C. minutissima BA-12, C. fusca BA-18, C. vulgaris BA-80, Monoraphidium sp. BA-165 and Chlorella sp. BA-167 were characterized by distinctively high lipid yield (> 60 mg l-1). The same strains, together with C. vulgaris BA-02, were also shown as those with the highest volumetric lipid productivity, reaching > 30 mg l-1 d-1. The tested Baltic strains performed w...