scholarly journals Processing Methodologies of Wet Microalga Biomass Toward Oil Separation: An Overview

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 641
Author(s):  
Vânia Pôjo ◽  
Tânia Tavares ◽  
Francisco Xavier Malcata
Keyword(s):  
Food System ◽  
Lipid Extraction ◽  
High Energy ◽  
Economic Feasibility ◽  
Alternative Source ◽  
Microalgal Biomass ◽  
Energy Demands ◽  
Chemical Profiles ◽  
System Sustainability ◽  
Industrial Level

One of the main goals of Mankind is to ensure food system sustainability—including management of land, soil, water, and biodiversity. Microalgae accordingly appear as an innovative and scalable alternative source in view of the richness of their chemical profiles. In what concerns lipids in particular, microalgae can synthesize and accumulate significant amounts of fatty acids, a great fraction of which are polyunsaturated; this makes them excellent candidates within the framework of production and exploitation of lipids by various industrial and health sectors, either as bulk products or fine chemicals. Conventional lipid extraction methodologies require previous dehydration of microalgal biomass, which hampers economic feasibility due to the high energy demands thereof. Therefore, extraction of lipids directly from wet biomass would be a plus in this endeavor. Supporting processes and methodologies are still limited, and most approaches are empirical in nature—so a deeper mechanistic elucidation is a must, in order to facilitate rational optimization of the extraction processes. Besides circumventing the current high energy demands by dehydration, an ideal extraction method should be selective, sustainable, efficient, harmless, and feasible for upscale to industrial level. This review presents and discusses several pretreatments incurred in lipid extraction from wet microalga biomass, namely recent developments and integrated processes. Unfortunately, most such developments have been proven at bench-scale only—so demonstration in large facilities is still needed to confirm whether they can turn into competitive alternatives.

scholarly journals The Multifaceted Roles of Zinc in Neuronal Mitochondrial Dysfunction

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 489
Author(s):  
Hilary Y. Liu ◽  
Jenna R. Gale ◽  
Ian J. Reynolds ◽  
John H. Weiss ◽  
Elias Aizenman
Keyword(s):  
Mitochondrial Permeability Transition ◽  
Neuronal Damage ◽  
Mitochondrial Fission ◽  
Permeability Transition ◽  
High Energy ◽  
Atp Depletion ◽  
Ros Generation ◽  
Cellular Functions ◽  
Calcium Deregulation ◽  
Energy Demands

Zinc is a highly abundant cation in the brain, essential for cellular functions, including transcription, enzymatic activity, and cell signaling. However, zinc can also trigger injurious cascades in neurons, contributing to the pathology of neurodegenerative diseases. Mitochondria, critical for meeting the high energy demands of the central nervous system (CNS), are a principal target of the deleterious actions of zinc. An increasing body of work suggests that intracellular zinc can, under certain circumstances, contribute to neuronal damage by inhibiting mitochondrial energy processes, including dissipation of the mitochondrial membrane potential (MMP), leading to ATP depletion. Additional consequences of zinc-mediated mitochondrial damage include reactive oxygen species (ROS) generation, mitochondrial permeability transition, and excitotoxic calcium deregulation. Zinc can also induce mitochondrial fission, resulting in mitochondrial fragmentation, as well as inhibition of mitochondrial motility. Here, we review the known mechanisms responsible for the deleterious actions of zinc on the organelle, within the context of neuronal injury associated with neurodegenerative processes. Elucidating the critical contributions of zinc-induced mitochondrial defects to neurotoxicity and neurodegeneration may provide insight into novel therapeutic targets in the clinical setting.

Food system sustainability investigation using system dynamics approach

2020 ◽  
Vol 277 ◽  
pp. 124040 ◽  
Author(s):  
Alireza Amiri ◽  
Yahia Zare Mehrjerdi ◽  
Ammar Jalalimanesh ◽  
Ahmad Sadegheih
Keyword(s):  
System Dynamics ◽  
Food System ◽  
System Sustainability

scholarly journals Physical Methods of Microalgal Biomass Pretreatment

2014 ◽  
Vol 28 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Agata Piasecka ◽  
Izabela Krzemińska ◽  
Jerzy Tys
Keyword(s):  
Alternative Energy ◽  
Lipid Extraction ◽  
Physical Method ◽  
Extraction Methods ◽  
Biodiesel Production ◽  
Biomass Pretreatment ◽  
Microalgal Biomass ◽  
Alternative Energy Sources ◽  
Wet Biomass ◽  
Microwave Techniques

Abstract The prospect of depletion of natural energy resources on the Earth forces researchers to seek and explore new and alternative energy sources. Biomass is a composite resource that can be used in many ways leading to diversity of products. Therefore, microalgal biomass offers great potential. The main aim of this study is to find the best physical method of microalgal biomass pretreatment that guarantees efficient lipid extraction. These studies identifies biochemical composition of microalgal biomass as source for biodisel production. The influence of drying at different temperatures and lyophilization was investigated. In addition, wet and untreated biomass was examined. Cell disruption (sonication and microwave) techniques were used to improve lipid extraction from wet biomass. Additionally, two different extraction methods were carried out to select the best method of crude oil extraction. The results of this study show that wet biomass after sonication is the most suitable for extraction. The fatty acid composition of microalgal biomass includes linoleic acid (C18:2), palmitic acid (C16:0), oleic acid (C18:1), linolenic acid (C18:3), and stearic acid (C18:0), which play a key role in biodiesel production.

scholarly journals Polymer–Lipid Pharmaceutical Nanocarriers: Innovations by New Formulations and Production Technologies

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 198
Author(s):  
Sabrina Bochicchio ◽  
Gaetano Lamberti ◽  
Anna Angela Barba
Keyword(s):  
Energy Consumption ◽  
Membrane Permeability ◽  
High Energy ◽  
Delivery Systems ◽  
Hybrid Nanoparticles ◽  
Industrial Implementation ◽  
Production Technologies ◽  
Industrial Level ◽  
High Energy Consumption ◽  
Modern Technologies

Some issues in pharmaceutical therapies such as instability, poor membrane permeability, and bioavailability of drugs can be solved by the design of suitable delivery systems based on the combination of two pillar classes of ingredients: polymers and lipids. At the same time, modern technologies are required to overcome production limitations (low productivity, high energy consumption, expensive setup, long process times) to pass at the industrial level. In this paper, a summary of applications of polymeric and lipid materials combined as nanostructures (hybrid nanocarriers) is reported. Then, recent techniques adopted in the production of hybrid nanoparticles are discussed, highlighting limitations still present that hold back the industrial implementation.

Seasonal and daily activity patterns in a Canadian population of the prairie rattlesnake, Crotalus viridus viridis

1985 ◽  
Vol 63 (1) ◽  
pp. 86-91 ◽  
Author(s):  
V. P. J. Gannon ◽  
D. M. Secoy
Keyword(s):  
Daily Activity ◽  
Activity Patterns ◽  
High Energy ◽  
Time Of Day ◽  
Energy Demands ◽  
Level Of Activity ◽  
Canadian Population ◽  
Significant Difference ◽  
Gravid Females ◽  
Daily Activity Patterns

The seasonal and daily activity patterns of a Saskatchewan population of Crotalus viridus viridis is presented. Snakes emerged from hibernation in late April and migrated into the surrounding river valley and upland regions in early May. Adult migration preceded that of immature age-classes. Several gravid females occupied a rookery near the hibernaculum during the summer months and remained there until parturition. Females did not occupy this site in successive years and may have a biennial or greater reproductive cycle. Snakes returned to the hibernaculum in early September and remained active until early October. The behaviour of snakes in a field enclosure in response to time of day and body temperature (Tb) was recorded during the spring, summer, and fall. Significant differences in the Tb values of sunning, movement, and shading behaviours were noted. Gravid females were significantly more active in all seasons. However, no significant difference in mean Tb was found between males and females in the field, enclosure study, or laboratory thermal gradient. The observed greater level of activity may reflect the high energy demands of gravid females.

scholarly journals Economic Feasibility of Energy Supply by Small Modular Nuclear Reactors on Small Islands: Case Studies of Jeju, Tasmania and Tenerife

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2587 ◽  
Author(s):  
Sanghyun Hong ◽  
Barry Brook
Keyword(s):  
Energy Demand ◽  
Nuclear Reactors ◽  
High Energy ◽  
Economic Feasibility ◽  
System Level ◽  
Small Island ◽  
Small Islands ◽  
Hydroelectric Power ◽  
Generation Cost ◽  
Electricity Grids

Small modular nuclear reactors (SMRs) offer the promise of providing carbon-free electricity and heat to small islands or isolated electricity grids. However, the economic feasibility of SMRs is highly system-dependent and has not been studied in this context. We selected three case-study islands for such an evaluation: Jeju, Tasmania and Tenerife based on their system complexity. We generated 100,000 electricity-mix cases stochastically for each island and examined the system-level generation-cost changes by incrementing the average generation cost of SMRs from USD$60 to 200 MWh−1. SMRs were found to be economically viable when average generation cost was <$100 MWh−1 for Jeju and <$140 MWh−1 for Tenerife. For Tasmania the situation was complex; hydroelectric power is an established competitor, but SMRs might be complementary in a future “battery of the nation” scenario where most of the island’s hydro capacity was exported to meet peak power demand on the mainland grid. The higher average generation cost of SMRs makes it difficult for them to compete economically with a fossil fuel/renewable mix in many contexts. However, we have demonstrated that SMRs can be an economically viable carbon-free option for a small island with a limited land area and high energy demand.

scholarly journals Novel Affordable, Reliable and Efficient Technologies to Help Addressing the Water-Energy-Food Nexus

2019 ◽  
Vol 8 (4) ◽  
pp. 1 ◽  
Author(s):  
Francesco Meneguzzo ◽  
Federica Zabini ◽  
Lorenzo Albanese ◽  
Alfonso Crisci
Keyword(s):  
Food System ◽  
Raw Materials ◽  
Sustainable Consumption ◽  
Processing Parameters ◽  
Hydrodynamic Cavitation ◽  
Strong Basis ◽  
Global Challenge ◽  
Wide Range ◽  
System Sustainability ◽  
Experimental Trials

Improving the food system sustainability and security is becoming an urgent global challenge. In this regard, one of the most effective routes is the shift of the human diet toward healthier and more sustainable consumption, involving in particular the prevalence of plant-based raw food materials. Controlled hydrodynamic cavitation (HC) technologies could help considerably in this transition. HC techniques are gaining increased scientific interest, and are quickly spreading across a wide range of technical fields, recently showing surprising performances with biological raw materials related to the food, agricultural and forestry sectors and resources. HC processes enjoy recognized advantages in the acceleration of the processing steps of plant-based food, the extraction of valuable bioactive compounds, the reduction and the valorization of waste streams, as well as the superior efficiency in resource use, energy consumption, process yield, and exergy balance than competing processes. Thus, HC is very promising candidate to help addressing the water-energy-food nexus, and, ultimately, sustainability. Findings obtained from direct experimental trials and recent literature concerning the applications of HC to food processing, provide a strong basis for novel investigation aimed at standardization, starting from the identification of the most suitable devices and the optimal processing parameters, eventually oriented to further spreading of HC applications.

scholarly journals Food System Sustainability Metrics: Policies, Quantification, and the Role of Complexity Sciences

2021 ◽  
Vol 13 (22) ◽  
pp. 12408
Author(s):  
José V. Matos ◽  
Rui J. Lopes
Keyword(s):  
Food Systems ◽  
Food System ◽  
Policy Design ◽  
Sustainability Metrics ◽  
Investment Projects ◽  
Complexity Sciences ◽  
Human Needs ◽  
Confidence Levels ◽  
System Sustainability ◽  
And Control

The rise of global attention toward sustainability and sustainable development (SD) has provided increased incentives for research development and investment in these areas. Food systems are at the center of human needs and global population growth sustainability concerns. These drives and the need to provide quantified support for related investment projects led to the proliferation of sustainability metrics and frameworks. While questions about sustainability definition and measurement still abound, SD policy design and control increasingly need adequate quantified support instruments. This paper aims to address this need, contributing to a more consistent and integrated application of food system sustainability metrics and quantified management of the implemented solutions. After presenting the relationships between sustainability, resilience, and robustness and summarizing food system sustainability quantification developments so far, we expose complexity sciences’ potential contributions toward SD quantified evaluation, addressing prediction, intangibles, and uncertainty issues. Finding a paramount need to make sense and bring existing sustainability metrics in context for operational use, we conclude that the articulated application of multiple and independent modeling approaches at the micro, meso, and macro levels can better help the development of food SD policies and implemented solution quantified management, with due regard to confidence levels of the results obtained.

scholarly journals Metabolic features of mouse and human retinas: rods vs. cones, macula vs. periphery, retina vs. RPE

2020 ◽  
Author(s):  
Bo Li ◽  
Ting Zhang ◽  
Wei Liu ◽  
Yekai Wang ◽  
Rong Xu ◽  
...  
Keyword(s):  
Aerobic Glycolysis ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Lipid Synthesis ◽  
Metabolic Stress ◽  
Tca Cycle ◽  
High Energy ◽  
Metabolic Dysfunction ◽  
Metabolic Demand ◽  
Energy Demands

AbstractPhotoreceptors, especially cones, which are enriched in the human macula, have high energy demands, making them vulnerable to metabolic stress. Metabolic dysfunction of photoreceptors and their supporting retinal pigment epithelium (RPE) is an important underlying cause of degenerative retinal diseases. However, how cones and the macula support their exorbitant metabolic demand and communicate with RPE is unclear. By profiling metabolite uptake and release and analyzing metabolic genes, we have found cone-rich retinas and human macula share specific metabolic features with upregulated pathways in pyruvate metabolism, mitochondrial TCA cycle and lipid synthesis. Human neural retina and RPE have distinct but complementary metabolic features. Retinal metabolism centers on NADH production and neurotransmitter biosynthesis. The retina needs aspartate to sustain its aerobic glycolysis and mitochondrial metabolism. RPE metabolism is directed toward NADPH production and biosynthesis of acetyl-rich metabolites, serine and others. RPE consumes multiple nutrients, including proline, to produce metabolites for the retina.

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