scholarly journals An Easily Accessible Microfluidic Chip for High-Throughput Microalgae Screening for Biofuel Production

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1817
Author(s):  
Shubhanvit Mishra ◽  
Yi-Ju Liu ◽  
Chi-Shuo Chen ◽  
Da-Jeng Yao
Keyword(s):  
Lipid Content ◽  
High Efficiency ◽  
Lipid Production ◽  
Microfluidic System ◽  
Green Energy ◽  
Numerical Control ◽  
Biofuel Production ◽  
Micro Milling ◽  
Hanging Drop ◽  
Pump System

Microalgae are important green energy resources. With high efficiency in fixing carbon dioxide, microalgae are broadly applied for biofuel production. Integrating various cultivation parameters, we applied ultraviolet (UV) mutagenesis, one of the most common approaches, to induce genomic mutation in microalgae and thus enhance the production of lipid content, but the screening process is convoluted and labor-intensive. In this study, we aimed to develop an accessible microfluidic platform to optimize the biofuel production of microalgae. Instead of traditional lithography, we designed hanging-drop microfluidic chips that were fabricated using a cheap computer numerical control (CNC) micro-milling technique. On each chip, we cultured in parallel Botryococcus braunii, one of the most common freshwater microalgae for biofuel production, in sets of ten separated hanging drops (~30 µL each); we monitored their growth in each individual drop for more than 14 days. To optimize the culturing conditions, using drops of varied diameter, we first identified the influence of cell density on algae growth and lipid production. After introducing UV-induced random mutations, we quantified the lipid content of the microalgae in situ; the optimized UV-C dosage was determined accordingly. In comparison with wild-type B. braunii, the results showed increased biomass growth (137%) and lipid content (149%) of the microalgae mutated with the desired UV process. Moreover, we showed a capacity to modulate the illumination on an addressed chip area. In summary, without using an external pump system, we developed a hanging-drop microfluidic system for long-term microalgae culturing, which can be easily operated using laboratory pipettes. This microfluidic system is expected to facilitate microalgae mutation breeding, and to be applied for algae cultivation optimization.

scholarly journals The Use of Urea and Kelp Waste Extract is A Promising Strategy for Maximizing the Biomass Productivity and Lipid Content in Chlorella sorokiniana

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 463 ◽  
Author(s):  
Ali Nawaz Kumbhar ◽  
Meilin He ◽  
Abdul Razzaque Rajper ◽  
Khalil Ahmed Memon ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Lipid Content ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Lipid Production ◽  
Total Lipid Content ◽  
Biomass Productivity ◽  
Chlorella Sorokiniana ◽  
Biofuel Production ◽  
Promising Strategy ◽  
Waste Extract

The decline in fossil fuel reserves has forced researchers to seek out alternatives to fossil fuels. Microalgae are considered to be a promising feedstock for sustainable biofuel production. Previous studies have shown that urea is an important nitrogen source for cell growth and the lipid production of microalgae. The present study investigated the effect of different concentrations of urea combined with kelp waste extract on the biomass and lipid content of Chlorella sorokiniana. The results revealed that the highest cell density, 20.36 × 107 cells−1, and maximal dry biomass, 1.70 g/L, were achieved in the presence of 0.5 g/L of urea combined with 8% kelp waste extract. Similarly, the maximum chlorophyll a, b and beta carotenoid were 10.36 mg/L, 7.05, and 3.01 mg/L, respectively. The highest quantity of carbohydrate content, 290.51 µg/mL, was achieved in the presence of 0.2 g/L of urea and 8% kelp waste extract. The highest fluorescence intensity, 40.05 × 107 cells−1, and maximum total lipid content (30%) were achieved in the presence of 0.1 g/L of urea and 8% kelp waste extract. The current study suggests that the combination of urea and kelp waste extract is the best strategy to enhance the biomass and lipid content in Chlorella sorokiniana.

scholarly journals Biomass and lipid induction strategies in microalgae for biofuel production and other applications

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Hossein Alishah Aratboni ◽  
Nahid Rafiei ◽  
Raul Garcia-Granados ◽  
Abbas Alemzadeh ◽  
José Rubén Morones-Ramírez
Keyword(s):  
Lipid Content ◽  
Large Scale ◽  
Fossil Fuels ◽  
Low Cost ◽  
Lipid Production ◽  
Arable Land ◽  
Economic Cost ◽  
Biofuel Production ◽  
Scale Production ◽  
Microalgae Biomass

Abstract The use of fossil fuels has been strongly related to critical problems currently affecting society, such as: global warming, global greenhouse effects and pollution. These problems have affected the homeostasis of living organisms worldwide at an alarming rate. Due to this, it is imperative to look for alternatives to the use of fossil fuels and one of the relevant substitutes are biofuels. There are different types of biofuels (categories and generations) that have been previously explored, but recently, the use of microalgae has been strongly considered for the production of biofuels since they present a series of advantages over other biofuel production sources: (a) they don’t need arable land to grow and therefore do not compete with food crops (like biofuels produced from corn, sugar cane and other plants) and; (b) they exhibit rapid biomass production containing high oil contents, at least 15 to 20 times higher than land based oleaginous crops. Hence, these unicellular photosynthetic microorganisms have received great attention from researches to use them in the large-scale production of biofuels. However, one disadvantage of using microalgae is the high economic cost due to the low-yields of lipid content in the microalgae biomass. Thus, development of different methods to enhance microalgae biomass, as well as lipid content in the microalgae cells, would lead to the development of a sustainable low-cost process to produce biofuels. Within the last 10 years, many studies have reported different methods and strategies to induce lipid production to obtain higher lipid accumulation in the biomass of microalgae cells; however, there is not a comprehensive review in the literature that highlights, compares and discusses these strategies. Here, we review these strategies which include modulating light intensity in cultures, controlling and varying CO2 levels and temperature, inducing nutrient starvation in the culture, the implementation of stress by incorporating heavy metal or inducing a high salinity condition, and the use of metabolic and genetic engineering techniques coupled with nanotechnology.

scholarly journals Rapid Lipid Content Screening in Neochloris Oleoabundans by Carbon-Based Dielectrophoresis

2021 ◽  
Vol 4 (1) ◽  
pp. 41
Author(s):  
Cynthia M. Galicia-Medina ◽  
Matías Vázquez-Piñón ◽  
Sergio Camacho-León ◽  
Gibran S. Alemán-Nava ◽  
Roberto C. Gallo-Villanueva ◽  
...  
Keyword(s):  
Lipid Content ◽  
Lipid Production ◽  
Biofuel Production ◽  
Neochloris Oleoabundans ◽  
Atmospheric Concentration ◽  
Machine Material ◽  
Fixation Rate ◽  
Screening Process ◽  
High Lipid

The use of microalgae as a biomass source for biofuel production has drawn the attention of many scientists due to several associated environmental advantages over conventional terrestrial crops, including microalgae growing using wastewaters and a higher CO2 fixation rate, contributing to the reduction of atmospheric concentration. Consequently, a reliable cytoplasmic lipid screening process in microalgae is a valuable asset for harvesting optimization in mass production processes. In this study, the heterogeneous cytoplasmic lipid content of Neochloris oleoabundans was dielectrophoretically assorted in a microfluidic device using castellated carbon microelectrodes. The experiments carried out over a wide frequency window (100 kHz to 30 MHz) at a fixed amplitude of 7 VPP showed a significant contrast between the dielectrophoretic behavior of high lipid content and low lipid content cells at the low frequency range (100–800 kHz). A weak response for the mid and high frequency ranges (1–30 MHz) was also identified for high and low lipid content samples, allowing one to establish an electrokinetic footprint of the studied strain. These results suggest that the development of a reliable screening process for harvesting optimization is possible through a fast and straightforward mechanism, such as dielectrophoresis, which is a low-cost and easy-to-machine material that employs glassy carbon. The experimental setup in this study involved in vitro culturing of nitrogen-replete (N+) and nitrogen-deplete (N-) cell suspensions to promote low and high lipid production in cells, respectively. Cell populations were monitored using spectrophotometry, and the resulting lipid development among cells was quantified by Nile red fluorescence.

scholarly journals Vertical U-shaped heat exchangers for construction engineering: New promises and future challenges

2021 ◽  
pp. 113-113
Author(s):  
Yin Liu ◽  
Sensen Xu ◽  
Dongyan Yuan ◽  
Zhaofeng Meng ◽  
Long Gao
Keyword(s):  
Heat Exchangers ◽  
High Efficiency ◽  
Branch Pipe ◽  
Green Energy ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Pump System ◽  
Technical Problems ◽  
Heat Pump System ◽  
Construction Engineering

The ground source heat pump system is a promising technology for building heating and cooling by using underground energy, however, many technical problems, e.g. low energy utilization rate and inefficiency operation, have greatly hindered its wide applications. This paper studies the key technologies of vertical U-shaped heat exchangers in construction engineering to solve the bottleneck problem and optimizes the system. Three commonly used backfill methods are analyzed, and a double U-shaped branch pipe is recommended to improve construction efficiency. The paper sheds a bright light on green energy utilization with high-efficiency, energy-saving, and environmental protection.

scholarly journals Expansion of High Efficiency Region of Wind Energy Centrifugal Pump Based on Factorial Experiment Design and Computational Fluid Dynamics

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 483 ◽  
Author(s):  
Wei Li ◽  
Leilei Ji ◽  
Weidong Shi ◽  
Ling Zhou ◽  
Hao Chang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Energy ◽  
Centrifugal Pump ◽  
High Efficiency ◽  
Experiment Design ◽  
Green Energy ◽  
Factorial Experiment ◽  
Pump System ◽  
Efficient Operation

The wind energy pump system is a new green energy technology. The wide high efficiency region of pump is of great significance for energy conservation of wind power pumping system. In this study, factorial experiment design (FED) and computational fluid dynamics (CFD) are employed to optimize the hydraulic design of wind energy centrifugal pump (WECP). The blade outlet width b2, blade outlet angle β2, and blade wrap angle ψ are chosen as factors of FED. The effect of the factors on the efficiency under the conditions of 0.6Qdes, 0.8Qdes, 1.0Qdes, and 1.4Qdes is systematically analyzed. The matching feature of various volute tongue angle with the optimized impeller is also investigated numerically and experimentally. After the optimization, the pump head changes smoothly during full range of flow condition and the high efficiency region is effectively improved. The weighted average efficiency of four conditions increases by 2.55%, which broadens the high efficiency region of WECP globally. Besides, the highest efficiency point moves towards the large flow conditions. The research results provide references for expanding the efficient operation region of WECP.

scholarly journals TESTING OF CHLORELLA/SCENEDESMUS MICROALGAE CONSORTIA FOR REMEDIATION OF WASTEWATER, CO₂ MITIGATION AND ALGAE BIOMASS FEASIBILITY FOR LIPID PRODUCTION

2014 ◽  
Vol 22 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Judita Koreivienė ◽  
Robertas Valčiukas ◽  
Jūratė Karosienė ◽  
Pranas Baltrėnas
Keyword(s):  
Municipal Wastewater ◽  
Global Climate ◽  
Inorganic Nitrogen ◽  
Lipid Production ◽  
Single Species ◽  
Inorganic Phosphorus ◽  
Climatic Conditions ◽  
Biofuel Production ◽  
Treated Wastewater ◽  
Algae Biomass

Industry, transport and unsustainable agriculture result in the increased quantity of wastewater, release of nutrients and emission of carbon dioxide that promotes eutrophication of water bodies and global climate change. the application of microalgae for phycoremediation, their biomass use for human needs may increase sustainability and have a positive effect on the regional development. The experiments were carried out in order to establish the feasibility of treating the local municipal wastewater with microalgae consortia and their biomass potential for biofuel production. The results revealed that Chlorella/Scenedesmus consortium eliminated up to 99.7–99.9% of inorganic phosphorus and up to 88.6–96.4% of inorganic nitrogen from the wastewater within three weeks. The ammonium removal was more efficient than that of nitrate. Chlorella algae grew better in diluted, while Scenedesmus – in the concentrated wastewater. The consortium treated wastewater more efficiently than a single species. The maximum biomass (3.04 g/L) of algal consortium was estimated in concentrated wastewater. Algae accumulated 0.65–1.37 g of CO2/L per day in their biomass. Tus, Chlorella/Scenedesmus consortium is a promising tool for nutrients elimination from the local wastewater under the climatic conditions specific to Lithuania. However, none of the two species were able to accumulate lipids under the nitrogen starvation conditions.

scholarly journals miR-15b negatively correlates with lipid metabolism in mammary epithelial cells

2018 ◽  
Vol 314 (1) ◽  
pp. C43-C52 ◽  
Author(s):  
Meiqiang Chu ◽  
Yong Zhao ◽  
Shuai Yu ◽  
Yanan Hao ◽  
Pengfei Zhang ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Epithelial Cells ◽  
Steroid Hormones ◽  
Lipid Content ◽  
Mammary Epithelial Cells ◽  
Lipid Production ◽  
Fatty Acid Synthetase ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Lipid Formation

Mammary epithelial cells are regulated by steroid hormones, growth factors, and even microRNAs. miR-15b has been found to regulate lipid metabolism in adipocytes; however, its effects on lipid metabolism in mammary epithelial cells, the cells of lipid synthesis and secretion, are as yet unknown. The main purpose of this investigation was to explore the effect of miR-15b on lipid metabolism in mammary epithelial cells, along with the underlying mechanisms. miR-15b was overexpressed or inhibited by miRNA mimics or inhibitors; subsequently, lipid formation in mammary epithelial cells, and proteins related to lipid metabolism, were investigated. Through overexpression or inhibition of miR-15b expression, the current investigation found that miR-15b downregulates lipid metabolism in mammary epithelial cells and is expressed differentially at various stages of mouse and goat mammary gland development. Inhibition of miR-15b expression increased lipid content in mammary epithelial cells through elevation of the lipid synthesis enzyme fatty acid synthetase (FASN), and overexpression of miR-15b reduced lipid content in mammary epithelial cells with decreasing levels of FASN. Moreover, the steroid hormones estradiol and progesterone decreased miR-15b expression with a subsequent increase in lipid formation in mammary epithelial cells. The expression of miR-15b was lower during lactation and negatively correlated with lipid synthesis proteins, which suggests that it may be involved in lipid synthesis and milk production. miR-15b might be a useful target for altering lipid production and milk yield.

scholarly journals Vibration-based tool life monitoring for ceramics micro-cutting under various toolpath strategies

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 125
Author(s):  
Zsolt János Viharos ◽  
László Móricz ◽  
Máté István Büki
Keyword(s):  
Tool Path ◽  
High Efficiency ◽  
Vibration Signal ◽  
Ceramic Materials ◽  
Micro Milling ◽  
The Novel ◽  
Feature Selection Technique ◽  
Tool Condition ◽  
Signal Features ◽  
Milling Tool

The 21st century manufacturing technology is unimagined without the various CAM (Computer Aided Manufacturing) toolpath generation programs. The aims of developing the toolpath strategies which are offered by the cutting control software is to ensure the longest possible tool lifetime and high efficiency of the cutting method. In this paper, the goal is to compare the efficiency of the 3 types of tool path strategies in the very special field of micro-milling of ceramic materials. The dimensional distortion of the manufactured geometries served to draw the Taylor curve for describing the wearing progress of the cutting tool helping to determine the worn-in, normal and wear out stages. These isolations allow to separate the connected high-frequency vibration measurements as well. Applying the novel feature selection technique of the authors, the basis for the vibration based micro-milling tool condition monitoring for ceramics cutting is presented for different toolpath strategies. It resulted in the identification of the most relevant vibration signal features and the presentation of the identified and automatically separated tool wearing stages as well.

Optimization of lipid accumulation in Pleurastrum insigne for biodiesel production

2021 ◽  
Vol 16 (10) ◽  
pp. 144-155
Author(s):  
Van Lal Michael Chhandama ◽  
Belur Kumudini Satyan
Keyword(s):  
Lipid Content ◽  
Lipid Production ◽  
Statistical Design ◽  
High Growth ◽  
High Growth Rate ◽  
Biodiesel Production ◽  
Nitrogen And Phosphorus ◽  
Biodiesel Standards ◽  
High Lipid ◽  
Different Sources

Microalgae emerged as a competent feedstock for biodiesel production because of high growth rate and lipid content. This work focuses on isolation of novel microalgal strain from different sources of water for the production of biodiesel. The isolated microalgae, Pleurastrum insigne possessed high lipid content (~28 % dcw), further optimized to 57.06 % dcw using a statistical design (CCD) under Response Surface Methodology. Lipid production was optimized by nutrient (nitrogen and phosphorus) and pH stress. The different type of fatty acids present in the optimized lipid was also profiled using GCMS. Biodiesel yield was found to be 82.14 % of the total lipid and the fuel properties tested have met IS, ASTM and EN biodiesel standards.

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