The authors have declared that no competing interests exist.
Cyanobacteria are considered as one of the important group of organisms having significant ecological, industrial, and biotechnological importance. Cyanobacteria have gained a lot of atten ion in recent years because of their potential applications in biotechnology. This review presents an overview of uses of cyanobacteria in industry agriculture, environment pharmaceutical and medicinal roles and to provide future prospects of the field of cyanobacteria biotechnology.
Nowadays cyanobacteria have gained attention researchers because of their various potential applications such as food and feed pharmaceutical industries in medicine, in bioremediation, soil conditioning, as biopolymers, bio adhesives, bioenergy and biofertilizers. Due to presence of wide spectrum of bioactive compounds cyanobacteria has possesses antiviral, antibacterial, antifungal and anticancer activities. Several strains of cyanobacteria are also rich in food supplements. Further nitrogen fixing and soil conditioning capacity of cyanobacteria attracted researchers. Recent studies have also shown that cyanobacteria have capability to degrade environmental pollutants and are also being used as a promising source of alternative energy. Cyanobacteria has also its limitations through bloom production it influnces on the nutrient availability and usage of phytoplankton plants. This review is an effort to forward the valuable information about the qualities of cyanobacteria and their potential role in solving the agricultural and environmental problems for the future welfare of the planet.Thus more efforts should be made in search of more potential strains of cyanobacteria to ensure maximum production of the desired products.
Cyanobacteria are a group of aquatic organisms officially classified as bacteria, but they display characteristics of algae and bacteria. Cyanobacteria produce their own nutrients via photosynthesis. The color of the chlorophyll required for this process produces the coloration that has led to their common name, ‘blue green algae
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Using water as an electron donor during photosynthesis resulting in the release of oxygen is another important characteristic of these tiny organisms. Furthermore, Number of findings reported that cyanobacteria have the ability to fix nitrogen. Cyanobacteria have been recognized as an opulent source of various bioactive compounds possessing anti bacterial, anti viral, anti fungal and anti cancer activities. They are also contributing positively in bioremediation and sustainable development of ecosystem. In view of the above, the objectives of the current review is to pointout overall contribution of cyanobacteria and their potential role in sustainable development of agriculture and ecosystem. This is also an effort to give the valuable information about multifunctional roll of cyanobacteria and their potential role in solving the agricultural and environmental problems for the future welfare of the planet.
The global population explosion has resulted in the need to look for alternative sustainable sources of food apart from conventional agricultural products. This has promoted interest in the use of functional foods to meet the nutritional demands of the growing human population.
Micro organisms, especially cyanobacteria, are an untapped resource as their secondary metabolites have nutritional or therapeutic values. Commercial exploitation of cyanobacteria since the establishment of human civilization is owing to its different properties which make it a suitable source of functional foods. According to
Research findings from
There are numerous records of historical usage of cyanobacteria and microalgae in the human diet as it was reported by
As photosynthetic microorganisms, cyanobacteria harvest light as their energy source through a wide variety of photosynthetic capability that are rich in pigments have been reported to have beneficial health effects, e.g., providing micronutrients and macronutrients, aiding in digestion, etc. Among the most widely used species is the halo tolerant Spirulina spp due to high nutritional value and high digestibility and their richness in various nutrients and high protein content with additional health benefits as a source of antioxidants, coenzymes and vitamins
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The bioactive compounds available in cyanobacteria possess several medicinal benefits as it was suggested by
Other findings by
In human clinical trials, supplementation with several species of Spirulina exhibited lipid lowering effects. In patients with diabetic type 2 diabetes its consumption showed significant reduction in ratios of total cholesterol and plasma lipids
Findings by
Nowadays agricultural practices heavily dependent on the application of synthetic fertilizers and pesticides, intensive tillage, and over irrigation, to meet the food requirement; nevertheless the effect on environmental, health, soil fertility, and increased cost of agricultural production.
Similar reports suggested by
Some cyanobacteria have a capability have to solubilize soil phosphate since phosphorus (P) is the second important nutrient after nitrogen for plants and microorganisms,thus algae are particularly adapted to scavenge their environments for resources through structural changes, storage or increased resource utilization efficiency
N fixers cyanobacteria increase the N content through nitrogen fixation in natural desert soils and released to the surrounding environment which make it available to plants or either released to the atmosphere in the form of N2O, or NO and HONO, which influence ozone and OH reactivity at the atmosphere
Cyanobacteria also influence the availability of P which is the second important nutrient to plants as they have the ability to transform non usable forms of inorganic P to a usable form through biological processes. Soil surface inoculated with different heterocystous and non heterocystous cyanobacteria has been reported to enhance total N, available N, and available P
Many research papers demonstrate the mechanisms of fungal and Oomycete growth inhibition by the activity of cyanobacteria extracts. Several extracts from, Anabaena spp., Fischerella sp., Nostoc spp., and Oscillatoria spp inhibited Aspergillus and mycelial growth due to methanol, acetone, diethyl ether, ethyl acetate, ethanol and methyl chloride extract depending on cyanobacteria
Cyanobacteria are known to produce metabolites with diverse biological activities such as anti bacterial, anti fungal and anti viral activities. Several reports
The rapid growing population of the world continuously increases the global demand for fuel energy. The intensive use of fossil fuels worldwide leads to its depletion and will bring them close to the point of exhaustion due to unsustainable and nonrenewable nature. Thus, bio fuels are now a growing opportunity throughout the world as alternative to fossil fuels. Thus advantageous features of biofuels produced from microalgae biomass are renewability and a significantly smaller contribution to environmental pollution and global warming. The emission of greenhouse gases mainly CO2 from burning of fossil fuels are the main cause of global warming by releasing 29giga tons/year release of CO2
Large quantities of synthetic pesticides, inorganic fertilizers and manure and/or bio solids amendments (usually containing pharmaceuticals and antibiotics residues) are regularly applied in agricultural land
Microalgae based systems have recently demonstrated to be very efficient in treating different types of wastewater, including domestic and agricultural runoff, removing not only nutrients such as nitrate, phosphate or ammonium, but also contaminants of emerging concern such as pharmaceuticals, pesticides or UV filters
The following cyanobacterial genera such as Anabaena, Arthrospira, Aphanothece, Chroococcus Fischerella, Lyngbya, Limnothrix, Nostoc, Oscillatoria and Phormidium were involved to remove various nutrients such as NO3-, NH3, PO43 and metals Cd, Co, Cr, Cu, Ni, Pb and Zn from different wastewaters (ground water, domestic and industrial sewage, synthetic, plating industry, urban, swine, agro industrial and animal wastewater
Cyanobacteria also play an important role in the biological treatment of wastewater, called “phyco remediation” by accumulating organic and inorganic toxic substances, as well as radioactive materials, in their cells and self purification of municipal, industrial, and agro industrial wastewater by developing several detoxifying mechanisms, including biosorption, bioaccumulation, biotransformation, bio mineralization, and in situ and/or ex situ biodegradation
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Cyanobacteria, have the potential to produce renewable biopolymers from natural resources such as, solar energy, water and CO2, reducing the need for fertile soils, fertilizers, herbicides and potable water for crop production. Among the cyanobacteria species Arthrospira (Spirulina), Synechococcus, and Synechocystis, are widely employed in biodegradable polymers such as PHAs production
One of the challenges of cyanobacteria application is bioaccumulation process possibly affected by various factors, including the exposure route, duration, and concentration of Microcystin in their food resources, as well as bioaccumulation capacity and incomplete depuration after contact
Studies conducted by 49:50 reported that the toxin accumulates on the seafloor in snail, in fish tissues, in various mammal organs, including muscle, liver, kidney, heart, lung, spleen, gastrointestinal tract and gonads, consequently leading to potential damage.
Similar research findings from 51:52 reported that Microcystin also affects vegetables and soils cereals, corn, peanuts, soybeans, and spices, among others during maturation, storage, and transportation. This toxin biomagnifies and persists in the medium of co occurrence, and poses a large potential ecological risk within the food chains which require urgent attention.
Eutrophication is characterized by excessive algal growth due to the increased availability of one or more limiting growth factors needed for photosynthesis such as sunlight, carbondioxide, and nutrient fertilizers.
Eutrophication occurs naturally over centuries as lakes age and are filled in with sediments
The most conspicuous effect of cultural eutrophication is the creation of dense blooms of noxious, foul smelling phytoplankton that reduce water clarity and harm water quality. Algal blooms limit light penetration, reducing growth and causing die-offs of plants in littoral zones while also lowering the success of predators that need light to pursue and catch prey
Algal pollution led to water quality degradation associated with nutrient enrichment, eutrophication which continues to pose a serious threat to potable drinking water sources, fisheries, and recreational water bodies. It is mandatory to employ a variety of strategies to minimize the effects of cultural eutrophication, including; diversion of excess nutrients altering nutrient ratios, physical mixing, shading water bodies with opaque liners or water based stains, and application of potent algaecides and herbicides 57. Another alternative for improving water quality in nutrient rich lakes has been biomanipulation the alteration of a food web to restore ecosystem health as it was reported 58
Cyanobacteria, known as “blue green algae”, are one of the oldest photosynthetic prokaryotes on planet earth, with the ability to live and flourish in a diverse range of environments from hot springs to underneath of ice pack in frozen lacks, and under the surfaces of rocks in deserts
Cyanobacteria, like higher plants, are capable of converting light energy into chemical energy and generate O2. Due to interaction with other of microorganisms and their environment, cyanobacteria also produce a wide variety of secondary metabolites applied in feedstock for biofuel production, bioremediation agents to eliminate toxic wastes from contaminated sites including soil, water, wastewater, and sediments, bio fertilizers to improve soil fertility in agriculture, supplement for animal and aqua cultural feed, as well as human nutrition, and also in the pharmaceutical, food, and cosmetic industries. In recent year cyanobacteria have gained importance in various areas of research such as drug discovery, treatment of deadly disease such as HIV and cancer. A cyanobacteria also get attention due to their ability to fix atmospheric nitrogen and degrading pollutants and removing heavy metals by agriculturalist and environmentalist respectively. Cyanobacteria like Spirulina, Anabaena and Nostoc also are used to solve problem of food crisis and malnutrition in different contents. Thus the possibility of producing novel biopolymer blends, biofuel components, and pharmaceutical compounds that are capable of meeting the demands of a biotechnologically based society. Though cyanobacteria has various applications, conversely it has some limitations because of its bloom which in one or another way affect the ecosystem. To achieve these target great strides in the cyanobacteria production sector, a synergistic approach should be adopted by cyanobacteria-related companies so that more fruitful results will come out.