Microalga Scenedesmus Sp Research Articles

Lipid production by microalga Scenedesmus sp. AARL G022 in the cultivation with effluent from chicken manure biogas plant

Microalgae are potential organisms in biooil production and they can accumulate higher lipid content than other oil plants. However, one of the major problems in algal oil production is its high cost. The aim of this study was to culture Scenedesmus sp. AARL G022 with the effluent from chicken manure biogas plant and evaluate its lipid accumulation. The effluent from the biogas plant was used directly or filtered through the water purifier at 6, 12, 25, 50, and 100% concentrations without additional nutrient supplementation. The highest level of growth was obtained when the microalga was cultivated with 12–25% of the non-filtered effluent. The highest level of biomass production involving Scenedesmus sp. AARL G022 was selected in order to upscale to a culture volume of 20 L using 12–25% of the non-filtered effluent. It was found that Scenedesmus sp. AARL G022 revealed the highest levels of growth as was observed using 25% of non-filtered effluent with chlorophyll a and a maximum biomass reading of 3,055.34±331.86 μg mL−1 and 0.54 ± 0.06g L−1, respectively, and a maximum lipid reading of 44.50±4.35 mg L−1. Fatty acid profiles showed that palmitic acid (C16:0) and linoleic acid (C18:2) were the major fatty acids. This study will be useful for the purposes of increasing algal biomass and lipid production, as well as in the reduction of nutrient costs and the amounts of discharged wastewater.

Bio-oil production and removal of organic load by microalga Scenedesmus sp. using culture medium contaminated with different sugars, cheese whey and whey permeate

The objective of this study was to evaluate the bio-oil production and the organic load removal using the microalga Scenedesmus sp. The cultivation was carried out in reactors with a total volume of 3 L and 0.7 vvm aeration, with illumination in photoperiods of 12 h light/12 h dark for 12 days. The following sugar concentrations were tested: 2.5, 5.0 and 10 g/L of glucose, lactose, fructose and galactose with 10% inoculum volume. After experiments were performed with cheese whey in natura and cheese whey permeate with different lactose concentrations (1.5, 2.5, 3.5 and 5.0 g/L). In these experiments the inoculum concentrations were 10, 15, 20 and 30% (v/v). The results showed that this microalga was effective for the production of lipids when it was cultivated in medium with cheese whey in natura with 2.5 g/L of lactose and 20% inoculum (v/v). Using cheese whey in natura at the concentration of 3.5 g/L of lactose and 30% (v/v) of inoculum obtained 77.9% of TOC removal and 38.447 mg of TOC removed/mg oil produced. It was also observed that when there is increased production of bio-oil, there is less removal of organic matter. The addition of glucose, fructose or galactose in the medium did not enhance the production of bio-oil by Scenedesmus sp. when compared to lactose, but increased the organic matter removal.

Nutritional Evaluation of Whole and Lipid-Extracted Biomass of the Microalga Scenedesmus sp. AMDD Isolated in Saskatchewan, Canada for Animal Feeds: Proximate, Amino Acid, Fatty Acid, Carotenoid and Elemental Composition

Nutritional Evaluation of Whole and Lipid-Extracted Biomass of the Microalga Scenedesmus sp. AMDD Isolated in Saskatchewan, Canada for Animal Feeds: Proximate, Amino Acid, Fatty Acid, Carotenoid and Elemental Composition

Digestion of settleable solids from recirculating fish tank as nutrients source for the microalga Scenedesmus sp. cultivation

The high concentration of nitrogen and phosphorus in wastewater incorporated with the ability to use carbon dioxide as the carbon source make the microalgae become more attractive in wastewater treatment process. This study evaluates the optimal conditions for the digestion of settelable solids from the recirculating aquaculture system to produce the biomass of the green microalga Scenedesmus sp. After solids separation, aerobic digestion of settleable solids under disperse condition produced nitrate as the final product of consequently ammonification and nitrification processes. With the optimal digestion procedure, nitrate concentration during aerobic digestion in 2000 mL vessel increased from 9.63±0.65 mg N/L to 58.66±0.06 mg N/L in 10 days. Thereafter, cultivation of Scenedesmus sp. was performed in 1000 mL Duran bottle with air bubbling. The highest Scenedesmus sp. specific growth rate of 0.321±0.01/d was obtained in treatment using liquid fraction after aerobic digestion as the whole culture medium for Scenedesmus sp. cultivation. With this study, digestion of 8,800±128.12 mg dry weight/L of settleable solids from fish pond finally produced 1,235±21 mg dry weight/L of Scenedesmus sp. biomass.

THE INFLUENCE OF MEDIA COMPOSITION TO THE GROWTH OF SCENEDESMUS SP. MICROALGAE IN VARIED MEDIA

Media culture is one of the important factors in the growth of microalgae. Culture medium contains macro and micro nutrition required for the growth of microalgae. Composition of nutrition and nutrition concentrations determine the production of microalgae biomass and nutrient content. The aim of this study is to evaluate the effect of medium composition variation to Scenedesmus sp growth in laboratory-scale in order to get the optimized composition of media for microalgae Scenedesmus sp. This study was conducted in a laboratory scale. The growth medium that were used in this study were: BBL sm, SS, MN, M4N, “Sederhana 2”, and “Sederhana 3” medium. The microalgae that were used in this study were mixed culture Chlorophyceae microalgae which is dominated by Scenedesmus sp. The parameters observed were pH, optical density (OD), cell density and temperature. The results show that of the 6 variations of the growth medium used in this study M4N medium is the best medium for the growth of microalgae. At the end of the operation, cell density of Scenedesmus sp. from M4N medium was 306.83 x 106 cell/mL with a dark green color for the culture. The coefficient growth of Scenedesmus sp. which is grown in M4N medium was 0,36. This is likely to be due to the composition of nutrients in the medium M4N which were more complete than other media.

Enzyme-Assisted Extraction of Oil from Wet Microalgae Scenedesmus sp. G4

The enzyme-assisted aqueous extraction of oil from wet microalgae was employed to avoid the energy consumption of a dewatering process. In this paper, oil-rich microalgae Scenedesmus sp. G4 was hydrolyzed by enzyme mixtures for oil extraction. The results showed that the algae concentration had the greatest influence on yield of extracted oil, and the temperature and the ratio of enzyme mixtures affected the results as follows: the maximum yield of oil extracted from Scenedesmus sp. G4 reached 86.1% under optimal conditions with an algae concentration at 2.5 g/L, temperature 30/50 °C, pH 3.5/4.5 and a cellulase:pectinase:hemicellulase ratio of 1:1:1 or 1:2:1 (w/w/w). The results also indicated that the enzyme mixtures had a significant impact on the integrity of microalgae cells and the crystallization index increased from 30.7% to around 36.0% after enzymatic hydrolysis treatment. The cell wall of Scenedesmus sp. G4 has a high content of cellulose Iα and low crystallization, which is beneficial to the oil extraction by the enzyme-assisted hydrolysis method.

Application of Phycoremediation Using Microalgae <i>Scenedesmus s</i><i>p. </i>as Wastewater Treatment in Removal of Heavy Metals from Food Stall Wastewater

This paper represents the results of using phycoremediation technology in treating the wastewater produced from food stall activity by using microalgae of Scenedesmus sp. in removal of heavy metals. Phycoremediation has advantages over physic-chemical approaches as it is can completely degrade organic pollutants without destroy the surrounding flora and fauna. Aim of this study is to determine the effectiveness of microalgae Scenedesmussp to assimilate the pollutant load based on the optimum time and concentration. Characteristics of food stall wastewater need to be identified and analyse before phycoremediation process taken place. The wastewater sampling was collected at food stall during peak time i.e. at 8 a.m. and 4 p.m. Microalgae Scenedesmus sp. to be injected to the batch reactor based on five (5) different concentration cells. The results shows that the optimum removal of heavy metals are dominant by concentration no. 1 (C1) compare to other concentration in the treatment i.e. removal of Ferum by 88.22% and 69.63%, Copper by 60% and 53.85% at both sampling time while removal of zinc is dominant by concentration no.4 (C4) by 75.61% and 76.63% respectively.

Bicarbonate supplementation enhanced biofuel production potential as well as nutritional stress mitigation in the microalgae Scenedesmus sp. CCNM 1077

The aim of the present study was to find out the optimum sodium bicarbonate concentration to produce higher biomass with higher lipid and carbohydrate contents in microalgae Scenedesmus sp. CCNM 1077. The role of bicarbonate supplementation under different nutritional starvation conditions was also evaluated. The results clearly indicate that 0.6g/L sodium bicarbonate was optimum concentration resulting in 20.91% total lipid and 25.56% carbohydrate along with 23% increase in biomass production compared to normal growth condition. Addition of sodium bicarbonate increased the activity of nutrient assimilatory enzymes, biomass, lipid and carbohydrate contents under different nutritional starvation conditions. Nitrogen starvation with bicarbonate supplementation resulted in 54.03% carbohydrate and 34.44% total lipid content in microalgae Scenedesmus sp. CCNM 1077. These findings show application of bicarbonate grown microalgae Scenedesmus sp. CCNM 1077 as a promising feedstock for biodiesel and bioethanol production.

Salinity induced oxidative stress enhanced biofuel production potential of microalgae Scenedesmus sp. CCNM 1077

Microalgal biomass is considered as potential feedstock for biofuel production. Enhancement of biomass, lipid and carbohydrate contents in microalgae is important for the commercialization of microalgal biofuels. In the present study, salinity stress induced physiological and biochemical changes in microalgae Scenedesmus sp. CCNM 1077 were studied. During single stage cultivation, 33.13% lipid and 35.91% carbohydrate content was found in 400mM NaCl grown culture. During two stage cultivation, salinity stress of 400mM for 3days resulted in 24.77% lipid (containing 74.87% neutral lipid) along with higher biomass compared to single stage, making it an efficient strategy to enhance biofuel production potential of Scenedesmus sp. CCNM 1077. Apart from biochemical content, stress biomarkers like hydrogen peroxide, lipid peroxidation, ascorbate peroxidase, proline and mineral contents were also studied to understand the role of reactive oxygen species (ROS) mediated lipid accumulation in microalgae Scenedesmus sp. CCNM 1077.

Effect of light level and salinity on the composition and accumulation of free and ester-type carotenoids in the aerial microalga Scenedesmus sp. (Chlorophyceae)

Composition and accumulation of stress-induced carotenoids were characterized in the aerial microalga Scenedesmus sp. KGU-Y002. The specific growth rate was 0.27d−1, in the logarithmic growth phase. Nitrate starvation and varying light levels were applied to determine the effect of stress on the carotenogenesis of the algal cells. Under 200μmolphotonsm−2s−1, the alga accumulated 34.2±3.8mgg−1dryweightcells (dwc) of total carotenoids and 2.5±0.6mgg−1dwc of total chlorophyll content after 13days of culture. Astaxanthin and adonixanthin were the main xanthophylls in the algal cells. These xanthophylls existed as fatty acid esters in the algal cells under the culture conditions. Light level had an important influence on the rate of accumulation. The addition of NaCl was also found to promote the synthesis of these free and ester-type xanthophylls. Higher light and salt stresses synergistically activated carotenogenesis in the algal cells. These results imply that the esterification of astaxanthin and adonixanthin of algal strain KGU-Y002 is modulated by culture conditions such as light level and salinity.

Development of an oven drying protocol to improve biodiesel production for an indigenous chlorophycean microalga Scenedesmus sp.

Drying of wet algal biomass is a major bottleneck in viable commercial production of the microalgal biodiesel. In the present investigation, an oven drying protocol was standardized for drying of wet Scenedesmus biomass at 60, 80 and 100°C with initial sample thickness of 5.0, 7.5 and 10.0mm. The optimum drying temperature was found to be 80°C with a maximum lipid yield of 425.0±5.9mgg−1 at 15h drying time for 5.0mm thick samples with 0.033kWh power consumption. Partial drying at 80°C up to 10% residual moisture content was efficient showing 93% lipid recovery with 8h drying and a power consumption of 0.017kWh. Scenedesmus biomass was also found to be rich in saturated and mono-unsaturated fatty acids. Thus, the drying protocol demonstrates its suitability to improve the downstream processing of biodiesel production by significantly lowering the power consumption and the drying time.

Enhanced biofuel production potential with nutritional stress amelioration through optimization of carbon source and light intensity in Scenedesmus sp. CCNM 1077

Microalgal mixotrophic cultivation is one of the most potential ways to enhance biomass and biofuel production. In the present study, first of all ability of microalgae Scenedesmus sp. CCNM 1077 to utilize various carbon sources under mixotrophic growth condition was evaluated followed by optimization of glucose concentration and light intensity to obtain higher biomass, lipid and carbohydrate contents. Under optimized condition i.e. 4g/L glucose and 150μmolm−2s−1 light intensity, Scenedesmus sp. CCNM 1077 produced 1.2g/L dry cell weight containing 23.62% total lipid and 42.68% carbohydrate. Addition of glucose shown nutritional stress ameliorating effects and around 70% carbohydrate and 25% total lipid content was found with only 21% reduction in dry cell weight under nitrogen starved condition. This study shows potential application of mixotrophically grown Scenedesmus sp. CCNM 1077 for bioethanol and biodiesel production feed stock.

High-rate biomethane production from microalgal biomass in a UASB reactor

Biomethane production from the microalga Scenedesmus sp. AMDD was demonstrated in an upflow anaerobic sludge bed (UASB) reactor. A full factorial design experiment was used to identify the effect of organic loading rate (OLR) of algal biomass and hydraulic retention time (HRT) on the volumetric rate of methane production. At an HRT of 4days and an OLR of 3.23gTVSLR−1d−1 corresponding to an influent microalgae concentration of 12g total volatile solids (TVS) L−1, the volumetric rate of CH4 production reached 0.6LSTPL−1Rd−1. A methane yield of 0.18–0.2L per gTVS of fed microalgae was estimated. A stable performance was observed throughout 3months of UASB reactor operation. Due to the short HRT and the good performance of UASB reactor, operated at influent microalgae concentrations in a range of 4–12gTVSL−1, this reactor type is suitable for coupling with photobioreactors equipped with gravitational settlers.

Wastewater from Instant Noodle Factory as the Whole Nutrients Source for the Microalga Scenedesmus sp. Cultivation

Cultivation of microalgae using wastewater exhibits several advantages such as nutrient removal and the production of high valuable products such as lipid and pigments. With this study, two types of wastewater from instant noodle factory; mixed liquor suspended solids (MLSS) and effluents after sedimentation tank were investigated for green microalga Scenedesmus sp. cultivation under laboratory condition. Optimal wastewater dilution percentage was evaluated in 24 wells microplate. MLSS and effluent without dilution showed the highest specific growth rate (μ) of 1.63±0.11 day－1 and 1.57±0.16 day－1, respectively, in which they were significantly (p < 0.05) higher than Scenedesmus sp. grown in BG11 medium (1.08±0.14 day－1). Ten days experiment was also conducted using 2000 ml Duran bottle as culture vessel under continuous light at approximately 5000 lux intensity and continuous aeration. It was found that maximum biomass density of microalgae cultivated in MLSS and effluent were 344.16 ± 105.60 mg/L and 512.89 ± 86.93 mg/L respectively and there was no significant (p < 0.05) difference on growth to control (BG11 medium). Moreover, cultivation microalgae in wastewater could reduce COD in wastewater by 39.89%-73.37%. Therefore, cultivation of Scenedesmus sp. in wastewater from instant noodle factory can yield microalgae biomass production and wastewater reclamation using photobioreactor simultaneously.

Characterization of microalga Scenedesmus sp. ISTGA1 for potential CO2 sequestration and biodiesel production

The Present study investigates the carbon sequestration potential and biodiesel production ability of a microalga isolated from a marble mining site. The microalgal isolates were grown in BG-11 medium supplemented with sodium bicarbonate (NaHCO3) as a carbon source. The growth behavior of the isolates and rates of NaH14CO3 uptake were considered as screening parameters to determine the most capable microalgal strain. The most efficient microalga was identified as Scenedesmus sp. ISTGA1 by 18S rDNA sequencing method. The growth of the isolate was studied under different concentrations of gaseous CO2 (5–15% v/v) and NaHCO3 (10–200 mM). Results revealed that the isolate attained maximum growth at 100 mM NaHCO3 and 15% CO2. In the case of 100 mM NaHCO3, chlorophyll content, biomass production and lipid content were 9 μg/L, 1508 mg/L and 301 mg/L respectively. At 15% of CO2 these characteristics were 12.1 μg/L, 1490 mg/L and 268 mg/L respectively. Lipids were transesterified and FAMEs were analyzed via GC-MS. The FAMEs consisted of saturated (33–35.8%) and unsaturated fatty acids (54–55%) in both the cases of inorganic carbon supplementation, dominated by C16 or C18 fatty acids (>80%), which are appropriate for the production of biodiesel.

Domestic wastewater treatment and biofuel production by using microalga Scenedesmus sp. ZTY1.

Cultivation of microalgae for biomass production is a promising way to dispose of wastewater and recover nutrients simultaneously. The properties of nutrient removal and biomass production in domestic wastewater of a newly isolated microalga Scenedesmus sp. ZTY1 were investigated in this study. Scenedesmus sp. ZTY1, which was isolated from a wastewater treatment plant in Beijing, grew well in both the primary and secondary effluents of a wastewater treatment plant during the 21-day cultivation, with a maximal algal density of 3.6 × 10(6) and 1.9 × 10(6) cells · mL(-1), respectively. The total phosphorus concentrations in both effluents could be efficiently removed by over 97% after the cultivation. A high removal rate (over 90%) of total nitrogen (TN) was also observed. After cultivation in primary effluent for 21 days, the lipid content of Scenedesmus sp. ZTY1 in dry weight had reached about 32.2%. The lipid and triacylglycerol (TAG) production of Scenedesmus sp. ZTY1 was increased significantly with the extension of cultivation time. The TAG production of Scenedesmus sp. ZTY1 increased from 32 mg L(-1) at 21 d to 148 mg L(-1) at 45 d in primary effluent. All the experiments were carried out in non-sterilized domestic wastewater and Scenedesmus sp. ZTY1 showed good adaptability to the domestic wastewater environment.

Enhanced energy conversion efficiency from high strength synthetic organic wastewater by sequential dark fermentative hydrogen production and algal lipid accumulation

A two-stage process of sequential dark fermentative hydrogen production and microalgal cultivation was applied to enhance the energy conversion efficiency from high strength synthetic organic wastewater. Ethanol fermentation bacterium Ethanoligenens harbinense B49 was used as hydrogen producer, and the energy conversion efficiency and chemical oxygen demand (COD) removal efficiency reached 18.6% and 28.3% in dark fermentation. Acetate was the main soluble product in dark fermentative effluent, which was further utilized by microalga Scenedesmus sp. R-16. The final algal biomass concentration reached 1.98gL(-1), and the algal biomass was rich in lipid (40.9%) and low in protein (23.3%) and carbohydrate (11.9%). Compared with single dark fermentation stage, the energy conversion efficiency and COD removal efficiency of two-stage system remarkably increased 101% and 131%, respectively. This research provides a new approach for efficient energy production and wastewater treatment using a two-stage process combining dark fermentation and algal cultivation.

Microalga Scenedesmus sp.: A Potential Low-Cost Green Machine for Silver Nanoparticle Synthesis

Bionanotechnology has revolutionized nanomaterial synthesis by providing a green synthetic platform using biological systems. Among such biological systems, microalgae have tremendous potential to take up metal ions and produce nanoparticles by a detoxification process. The present study explores the intracellular and extracellular biogenic syntheses of silver nanoparticles (SNPs) using the unicellular green microalga Scenedesmus sp. Biosynthesized SNPs were characterized by AAS, UV-Vis spectroscopy, TEM, XRD, FTIR, DLS, and TGA studies and finally checked for antibacterial activity. Intracellular nanoparticle biosynthesis was initiated by a high rate of Ag(+) ion accumulation in the microalgal biomass and subsequent formation of spherical crystalline SNPs (average size, 15-20 nm) due to the biochemical reduction of Ag(+) ions. The synthesized nanoparticles were intracellular, as confirmed by the UV-Vis spectra of the outside medium. Furthermore, extracellular synthesis using boiled extract showed the formation of well scattered, highly stable, spherical SNPs with an average size of 5-10 nm. The size and morphology of the nanoparticles were confirmed by TEM. The crystalline nature of the SNPs was evident from the diffraction peaks of XRD and bright circular ring pattern of SAED. FTIR and UV-Vis spectra showed that biomolecules, proteins and peptides, are mainly responsible for the formation and stabilization of SNPs. Furthermore, the synthesized nanoparticles exhibited high antimicrobial activity against pathogenic gram-negative and gram-positive bacteria. Use of such a microalgal system provides a simple, cost-effective alternative template for the biosynthesis of nanomaterials in a large-scale system that could be of great use in biomedical applications.

Maximizing Biomass Productivity and CO2 Biofixation of Microalga, Scenedesmus sp. by Using Sodium Hydroxide

A series of experiments were carried out with three native strains of microalgae to measure growth rates, biomass, and lipid productivities. Scenedesmus sp. IMMTCC-6 had better biomass growth rate and higher lipid production. The growth, lipid accumulation, and carbon dioxide (CO2) consumption rate of Scenedesmus sp. IMMTCC-6 were tested under different NaOH concentrations in modified BBM. The algal strain showed the maximum specific growth rate (0.474/day), biomass productivity (110.9 mg l(-1) d(-1)), and CO2 consumption rate (208.4 mg l(-1) d(-1)) with an NaOH concentration of 0.005 M on the 8(th) day of cultivation. These values were 2.03-, 6.89-, and 6.88-fold more than the algal cultures grown in control conditions (having no NaOH and CO2). The CO2 fixing efficiency of the microalga with other alternative carbon sources like Na2CO3 and NaHCO3 was also investigated and compared. The optimized experimental parameters at shake-flask scale were implemented for scaling up the process in a self-engineered photobioreactor. A significant increase in lipid accumulation (14.23% to 31.74%) by the algal strain from the logarithmic to stationary phases was obtained. The algal lipids were mainly composed of C16/C18 fatty acids, and are desirable for biodiesel production. The study suggests that microalga Scenedesmus sp. IMMTCC-6 is an efficient strain for biodiesel production and CO2 biofixation using stripping solution of NaOH in a cyclic process.

Methane production from the microalga Scenedesmus sp. AMDD in a continuous anaerobic reactor

Methane production from the microalga Scenedesmus sp. AMDD digested in a continuously operated anaerobic reactor was studied under a range of conditions. Preliminary anaerobic toxicity assays revealed that methane yields and glucose consumption were inhibited by algae/sludge ratios in excess of 0.1 (g/g). Continuous digestions of microalgae at two hydraulic retention times (16 and 58days) and two influent concentrations of algal feed (11 and 20gTVSL−1) were evaluated. Based on the amount of degraded algal biomass, a methane yield of 0.4LCH4gTVS‐1 was estimated. However, at a hydraulic retention time of 16days only 52–53% of the algal biomass was degraded, primarily due to the limited hydrolysis of the algal cellular material. An increase of retention time to 58days did not improve the degradation efficiency. Anaerobic decomposition of microalgae biomass appeared to affect composition of the microbial consortium in the digester, promoting the growth of sulfate-reducing bacteria leading to high levels of H2S in the biogas.