• Energy Research

Natural resources including water, energy, and food have an increase in demand due to the global population increases. The sustainable management of these resources is an urgent global issue. These resources combined in a very vital nexus are called the water–energy–food (WEF) nexus. The field of nanotechnology offers promising solutions to overcome several problems in the WEF nexus. This review is the first report that focuses on the suggested applications of nanofibers in the WEF sectors. An economic value of nanofibers in WEF sectors was confirmed, which was mainly successfully applied for producing clean water, sustainable energy, and safe food. Biotechnological solutions of nanofibers include various activities in water, energy, and food industries. These activities may include the production of fresh water and wastewater treatment, producing, converting, and storing energy, and different activities in the food sector. Furthermore, microbial applications of nanofibers in the biomedicine sector, and the most important biotechnological approaches, mainly plant tissue culture, are the specific focus of the current study. Applying nanofibers in the field of plant tissue culture is a promising approach because these nanofibers can prevent any microbial contamination under in vitro conditions, but the loss of media by evaporation is the main challenge in this application. The main challenges of nanofiber production and application depend on the type of nanofibers and their application. Different sectors are related to almost all activities in our life; however, enormous open questions still need to be answered, especially the green approach that can be used to solve the accumulative problems in those sectors. The need for research on integrated systems is also urgent in the nexus of WEF under the umbrella of environmental sustainability, global climate change, and the concept of one’s health.

Mushrooms have always been an important source of food, with high nutritional value and medicinal attributes. With the use of biotechnological applications, mushrooms have gained further attention as a source of healthy food and bioenergy. This review presents different biotechnological applications and explores how these can support global food, energy, and water security. It highlights mushroom’s relevance to meet the sustainable development goals of the UN. This review also discusses mushroom farming and its requirements. The biotechnology review includes sections on how to use mushrooms in producing nanoparticles, bioenergy, and bioactive compounds, as well as how to use mushrooms in bioremediation. The different applications are discussed under the water, energy, and food (WEF) nexus. As far as we know, this is the first report on mushroom biotechnology and its relationships to the WEF nexus. Finally, the review valorizes mushroom biotechnology and suggests different possibilities for mushroom farming integration.

It is urgent that we increase global food production to support population growth. Food production requires significant resources, amongst them water and energy. Therefore, any losses of food or other agricultural products also means a waste of water and energy resources. A significant amount of these losses occurs during the postharvest stage, primarily during processing and storage. This is considered avoidable food waste. The water-energy-waste nexus (WEW), and its relationship to food production, needs to be investigated from a circular bioeconomy lens. Furthermore, alternative uses of the wastes should be investigated. This review focuses on agro-wastes and their management as sources for bioactive compounds, biofertilizers, biomaterials, nanomaterials, pharmaceuticals and medicinal agents, and growth media, e.g., for plant tissue culture. We also investigated the potential contribution of agro-wastes to bioenergy production (bioethanol, biogas, and biofuel). Proper management of agro-wastes may support the mitigation of climate change, produce innovative bio-ingredients and biodegradable materials, and enhance green growth and a circular bioeconomy. We argue that the management of agro-wastes cannot be discussed without referring to the role of water and energy within the food system. Thus, this review focuses on agricultural wastes and their handling, applications, environmental impacts, and potential benefits in the agricultural and medical industries in light of the WEW nexus.

The Kingdom of Plantae is considered the main source of human food, and includes several edible and medicinal plants, whereas mushrooms belong to the Kingdom of fungi. There are a lot of similar characteristics between mushrooms and higher plants, but there are also many differences among them, especially from the human health point of view. The absences of both chlorophyll content and the ability to form their own food are the main differences between mushrooms and higher plants. The main similar attributes found in both mushrooms and higher plants are represented in their nutritional and medicinal activities. The findings of this review have a number of practical implications. A lot of applications in different fields could be found also for both mushrooms and higher plants, especially in the bioenergy, biorefinery, soil restoration, and pharmaceutical fields, but this study is the first report on a comparative photographic review between them. An implication of the most important findings in this review is that both mushrooms and plants should be taken into account when integrated food and energy are needed. These findings will be of broad use to the scientific and biomedical communities. Further investigation and experimentation into the integration and production of food crops and mushrooms are strongly recommended under different environmental conditions, particularly climate change.

Is there any relationship between plant nutrition and human health? The overall response to this question is very positive, and a strong relationship between the nutrition of plants and humans has been reported in the literature. The nutritional status of edible plants consumed by humans can have a negative or positive impact on human health. This review was designed to assess the importance of plant bioactive compounds for human health under the umbrella of sustainable agriculture. With respect to the first research question, it was found that plant bioactives (e.g., alkaloids, carotenoids, flavonoids, phenolics, and terpenoids) have a crucial role in human health due to their therapeutic benefits, and their potentiality depends on several factors, including botanical, environmental, and clinical attributes. Plant bioactives could be produced using plant tissue culture tools (as a kind of agro-biotechnological method), especially in cases of underexploited or endangered plants. Bioactive production of plants depends on many factors, especially climate change (heat stress, drought, UV radiation, ozone, and elevated CO2), environmental pollution, and problematic soils (degraded, saline/alkaline, waterlogged, etc.). Under the previously mentioned stresses, in reviewing the literature, a positive or negative association was found depending on the kinds of stress or bioactives and their attributes. The observed correlation between plant bioactives and stress (or growth factors) might explain the importance of these bioactives for human health. Their accumulation in stressed plants can increase their tolerance to stress and their therapeutic roles. The results of this study are in keeping with previous observational studies, which confirmed that the human nutrition might start from edible plants and their bioactive contents, which are consumed by humans. This review is the first report that analyzes this previously observed relationship using pictorial presentation.

Global food production faces many challenges, including climate change, a water crisis, land degradation, and desertification. These challenges require research into non-traditional sources of human foods. Edible mushrooms are considered an important next-generation healthy food source. Edible mushrooms are rich in proteins, dietary fiber, vitamins, minerals, and other bioactive components (alkaloids, lactones, polysaccharides, polyphenolic compounds, sesquiterpenes, sterols, and terpenoids). Several bioactive ingredients can be extracted from edible mushrooms and incorporated into health-promoting supplements. It has been suggested that several human diseases can be treated with extracts from edible mushrooms, as these extracts have biological effects including anticancer, antidiabetic, antiviral, antioxidant, hepatoprotective, immune-potentiating, and hypo-cholesterolemic influences. The current study focuses on sustainable approaches for handling edible mushrooms and their secondary metabolites, including biofortification. Comparisons between edible and poisonous mushrooms, as well as the common species of edible mushrooms and their different bioactive ingredients, are crucial. Nutritional values and the health benefits of edible mushrooms, as well as different biomedical applications, have been also emphasized. Further research is needed to explore the economic sustainability of different medicinal mushroom bioactive compound extracts and their potential applications against emerging diseases such as COVID-19. New approaches such as nano-biofortification are also needed to supply edible mushrooms with essential nutrients and/or to increase their bioactive ingredients.

The field of biotechnology presents us with a great chance to use many organisms, such as mushrooms, to find suitable solutions for issues that include the accumulation of agro-wastes in the environment. The green biotechnology of mushrooms (Pleurotus ostreatus L.) includes the myco-remediation of polluted soil and water as well as bio-fermentation. The circular economy approach could be effectively achieved by using oyster mushrooms (Pleurotus ostreatus L.), of which the substrate of their cultivation is considered as a vital source for producing biofertilizers, animal feeds, bioenergy, and bio-remediators. Spent mushroom substrate is also considered a crucial source for many applications, including the production of enzymes (e.g., manganese peroxidase, laccase, and lignin peroxidase) and bioethanol. The sustainable management of agro-industrial wastes (e.g., plant-based foods, animal-based foods, and non-food industries) could reduce, reuse and recycle using oyster mushrooms. This review aims to focus on the biotechnological applications of the oyster mushroom (P. ostreatus L.) concerning the field of the myco-remediation of pollutants and the bio-fermentation of agro-industrial wastes as a sustainable approach to environmental protection. This study can open new windows onto the green synthesis of metal-nanoparticles, such as nano-silver, nano-TiO2 and nano-ZnO. More investigations are needed concerning the new biotechnological approaches.