scholarly journals Microalgae: A promising bioresource for a sustainable future

2021 ◽  
Vol 01 (01) ◽  
pp. 06-09
Author(s):  
Thilini U. Ariyadasa ◽  

Microalgae are highly diverse unicellular photosynthetic organisms found in aquatic environments. Microalgae produce oxygen during their proliferation, contributing to nearly 50% of the total oxygen production in the world. Concurrently, microalgae consume carbon dioxide in the atmosphere, thereby serving as carbon sinks to alleviate the effects of global warming. In comparison to terrestrial plants, microalgae exhibit rapid growth rates, higher photosynthetic efficiency, shorter harvesting time and higher biomass productivities. Moreover, they do not require arable land or potable water to facilitate their growth, hence becoming a more sustainable feedstock as compared to conventional crops. Altogether, microalgae have been identified as a bioresource with great industrial potential due to their ability to accumulate commercially valuable metabolites that can be extracted and subsequently processed into diverse bioproducts such as biofuels, pharmaceuticals/nutraceuticals, biofertilizer and animal feed.

2021 ◽  
Vol 6 (1) ◽  
pp. 24-36
Author(s):  
Raquel P. F. Guiné ◽  
Paula Correia ◽  
Catarina Coelho ◽  
Cristina A. Costa

Abstract This review is focused on the utilization of insects as a new opportunity in food and feed products, including their commercialization both in traditional and new markets. It has been suggested that insects are considerably more sustainable when compared with other sources of animal protein, thus alleviating the pressure over the environment and the planet facing the necessity to feed the world population, constantly increasing. Many chefs have adhered to the trend of using insects in their culinary preparations, bringing insects to the plan of top gastronomy, highlighting their organoleptic qualities allied to a recognized high nutritional value. However, in some markets, insects or insect-based products are not readily accepted because of neophobia and disgust. Moreover, the insect markets, farming, and commercialization are experiencing a huge growth, in which the domain of animal feed is undoubtedly a very strong component. The future of insects as human food and animal feed seems promising in view of the recent trends and challenges.


2014 ◽  
Vol 592-594 ◽  
pp. 2409-2415 ◽  
Author(s):  
S. Naga Sarada ◽  
Banoth Hima Bindu ◽  
Sri Rama R. Devi ◽  
Ravi Gugulothu

In recent years with the exacerbation of energy shortage, water crisis increases around the world. With the continuous increase in the level of greenhouse gas emissions, the use of various sources of renewable energy is increasingly becoming important for sustainable development. Due to the rising oil price and environmental regulations, the demand of utilizing alternative power sources increased dramatically. Alternative energy and its applications have been heavily studied for the last decade. Energy and water are essential for mankind that influences the socioeconomic development of any nation. Pure water resources become more and more scarce every day as rivers, lakes wells and even seawater pollution rapidly increases. Solar energy is one promising solution to secure power and potable water to future generation. The process of distillation can be used to obtain fresh water from salty, brackish or contaminated water. Water is available in different forms such as sea water, underground water, surface water and atmospheric water. Clean water is essential for good health. The search for sustainable energy resources has emerged as one of the most significant and universal concerns in the 21st century. Solar energy conversion offers a cost effective alternative to our traditional usages. Solar energy is a promising candidate in many applications. Among the alternative energy sources used for electricity production, wind and solar energy systems have become more attractive in recent years. For areas where electricity was not available, stand alone wind and solar systems have been increasingly used. The shortage of drinking water in many countries throughout the world is a serious problem. Humankind has depended for ages on river, sea water and underground water reservoirs for its fresh water needs. But these sources do not always prove to be useful due to the presence of excessive salinity in the water. To resolve this crisis, different methods of solar desalination have been used in many countries. Distillation is a well known thermal process for water purification, most importantly, water desalination. Most of the conventional water distillation processes are highly energy consuming and require fossil fuels as well as electric power for their operation. Single basin solar still is a popular solar device used for converting available brackish or waste water into potable water. Because of its lower productivity, it is not popularly used. Numbers of works are under taken to improve the productivity and efficiency of the solar still. There are large numbers of PCMs that melt and solidify at wide range of temperatures, making them attractive in a number of applications. PCMs have been widely used in latent heat thermal storage systems for heat pumps, solar engineering and spacecraft thermal control applications. The use of PCMs for heating and cooling applications for buildings has been investigated within the past decade. The experimental results computed in the field of water distillation process using solar energy in the presence of energy storage materials sodium sulphate and sodium acetate are discussed in this paper. Keywords: solar energy, saline water, distillation, phase change material.


Author(s):  
Olga Markova ◽  
Valentina Maslennikova

The largest countries of the world are inevitably involved in various global processes, both natural and socio-economic. These countries have common features and characteristic differences in the state of their territorial resources; the study of these characteristics is of interest for the global prospects of sustainable development. A large territory provides a variety of natural conditions and resources for the country; however, not in all countries it is possible to effectively use them in the economy throughout the all country. An analysis of their territorial resources was carried out for the six largest countries of the world according to the following parameters: area, efficiency, environmental load on the territory of the country, number, density, forecast of population growth or decline for 2050, main agricultural land (arable land, pastures, the provision of the population, degradation and pollution of the soils), forest resources (including security per capita, share in the area of countries), fresh water resources (including per capita provision and availability), greenhouse gas emissions, including per capita, the proportion of mammals endangered, proportion of areas of preserved ecosystems. The data obtained was displayed on the maps; a common legend is built for them in tabular form. A number of other parameters of the state of territorial resources and the environment were also studied. In the process of research, the most important cities of these countries were also studied and diagrams showing their similarities and differences in a number of indicators were constructed: area, population and population density, time of foundation, climatic and landscape parameters, the presence of UNESCO World Heritage Sites, high-rise construction parameters. The developed methodology is effective for assessing a variety of data on territorial resources that can be used to build models of sustainable development of the largest countries and regions of the Earth.


2021 ◽  
Author(s):  
Zerguine Karima

The family of Chironomidae is a group of Diptera insects belonging to the suborder of Nematocera, commonly called “non-biting midges” in the adult stage and “bloodworms” in the larval stage. The Chironomidae are often the most abundant group of macroinvertebrates, in number of species and individuals, encountered in all aquatic environments of freshwater, brackish, terrestrial and even the sea. Likewise, Chironomidae occur in all the continents. The Chironomidae family is divided into 11 sub-families that have diffrent ecological statues. Despite the wealth of data on Chironomidae in the Holarctic region, other parts of the world are poorly studied and few guides to identifying Chironomidae have been produced. This chapter includes a theoretical synthesis on the Chironomidae, it deals with the Biology (life cycle and description of different stages), description of all subfamilies and the ecology of this important family of Diptera.


2021 ◽  
Vol 7 (3) ◽  
pp. 33-41
Author(s):  
G. Djalilova ◽  
F. Mamatkulova ◽  
Z. Mamatkulova

Rational use of natural resources and preservation of environment in good conditions are the basis of stable state of the ecosystem. Mountain soil erosion is the most common process of degradation. Soil protection from erosion is becoming a global problem in the world, and in Uzbekistan, in particular. Natural conditions of the region create a potential danger of soil erosion. The reason for its manifestation is the misuse of land, non-compliance with necessary requirements for soil protection. In most cases, it is due to the location of homesteads and crops on erosion-prone soils that poorly protect soil from erosion, improper cultivation of soils on arable land, unregulated grazing of pastures, and damage to soil protective plantations.


Significance President Xi Jinping last year called for "a sense of crisis about food security”. Behind such statements lies an awareness of environmental threats and natural disasters, a shrinking and ageing farm labour force, shortages of water and arable land, and food waste on an enormous scale. Impacts China cannot avoid dependence on imports of animal feed as its population's demand for meat rises further. Beijing will make greater efforts to diversify foreign sources of feed imports. China is immutably locked into overseas dependence for soybeans, and potentially maize and barley, too.


In this chapter the emphasis was put on the analysis of indicators of Agri-food sector at the global level, aimed to point out readers to the level of global competitiveness and comparative advantage of Agri-food sector. After reading this chapter readers will be informed on the current structure of agricultural production. They will be able to understand the connection between changes in arable land in the world with the current trend in agricultural production. Readers will be able to understand the role and significance of agricultural and food products production, as the potential for the performance on international market. Indicators of trade of agri-food products, volume of export/import, balance and the coverage of import by export will be analysed. Readers will be able to evaluate the role of some products in turnover globally. They will understand which products are the carriers of export/import in the world and whether such position is in correlation with the existence of a positive comparative advantage of export and intra-industrial exchange. Readers will find out that the foreign exchange of food has a negative balance, which affects the existence of a negative comparative advantage of agri-food products export. They will be introduced also to other authors' attitudes. Special contribution of this chapter is in defining the directives for future research.


World on Fire ◽  
2021 ◽  
pp. 172-188
Author(s):  
Mark Rowlands

Underlying human-caused extinctions, past and present, is a vast biomass reallocation program. Before our Neolithic forebears began changing the world, biomass was distributed quite evenly among species of animals and plants. The tenure of humans has seen a marked change in this, as biomass became progressively concentrated into a small number of species—us and animals we eat. Today, 96% of all mammalian biomass consists in humans and the mammals that humans farm. An additional 70% of all avian biomass consists in domestic fowl. This biomass reallocation is the most significant driver of species extinction. The number-one driver of species extinction today is change in land use. The most significant driver of change in land use is agricultural expansion. By far the most prominent form of agricultural expansion is pastoral farming and the growing of animal feed crops. Eating animals is, therefore, the most important driver of species extinction.


Author(s):  
Maura C. Flannery

This chapter deals with what are commonly called seaweed, but are more correctly termed algae, that is, photosynthetic organisms that live in aquatic environments. Algae are visually beautiful and therefore a good subject for a biology teacher looking to explore the intersection of art and science with students. These connections run deep into knowledge production because drawing is fundamental not only to communicating information about organisms but also to investigating their characteristics. Observation and comparison are key tools in learning about the living world, and drawing is essential to these processes. Also discussed here will be the importance of relating texts, photographs, specimens, and drawings in assisting students to learn about algae. In addition, online sources for these tools will be explored.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1370
Author(s):  
Dilrukshi S. K. Nagahatenna ◽  
Jingwen Tiong ◽  
Everard J. Edwards ◽  
Peter Langridge ◽  
Ryan Whitford

Ferrochelatase (FC) is the terminal enzyme of heme biosynthesis. In photosynthetic organisms studied so far, there is evidence for two FC isoforms, which are encoded by two genes (FC1 and FC2). Previous studies suggest that these two genes are required for the production of two physiologically distinct heme pools with only FC2-derived heme involved in photosynthesis. We characterised two FCs in barley (Hordeum vulgare L.). The two HvFC isoforms share a common catalytic domain, but HvFC2 additionally contains a C-terminal chlorophyll a/b binding (CAB) domain. Both HvFCs are highly expressed in photosynthetic tissues, with HvFC1 transcripts also being abundant in non-photosynthetic tissues. To determine whether these isoforms differentially affect photosynthesis, transgenic barley ectopically overexpressing HvFC1 and HvFC2 were generated and evaluated for photosynthetic performance. In each case, transgenics exhibited improved photosynthetic rate (Asat), stomatal conductance (gs) and carboxylation efficiency (CE), showing that both FC1 and FC2 play important roles in photosynthesis. Our finding that modified FC expression can improve photosynthesis up to ~13% under controlled growth conditions now requires further research to determine if this can be translated to improved yield performance under field conditions.


Sign in / Sign up

Export Citation Format

Share Document