Microalgae as biofertilizers are major enhancing soil fertility and quality. Microalgae can create plant growth hormones, Polysaccharides, antibacterial chemicals and other metabolites.

1. MICROALGAL TECHNOLOGY
MICROALGAE AS
BIOFERTILIZERS
PREPARED BY:
SUJITHRA CHINNATHAMBI
1-MSC., MICROBIOLOGY
DEPARTMENT OF MICROBIOLOGY
VIVEKANANDHA ARTS AND SCIENCE COLLEGE FOR WOMEN
SANKAGIRI, SALEM, TAMIL NADU.

2. CONTENT:
• INTRODUCTION
• MICROLGAE AS BIOFERTILIZERS
• RECEND TREND IN AGRICULTURE PRODUCTION
• AZOLLA BIOFERTILIZERS PRODUCTION
• POTENTIAL APPLICATION IN MULTIFUNCTIONAL MICROALGAE IN SOIL
IMPROVEMENT
• MICROALGAE CULTIVATION IMPROVES SOIL ECOLOGICAL HEALTH.
• MICROALGAE IMPROVES SOIL PHYSIOCHEMICAL PROPERTIES
• ADVANTAGES AND DISADVANTAGES

3. INTRODUCTION:
• Microalgae are a kind of widespread photosynthetic organisms
including eukaryotic green algae and prokaryotic blue algae. They
have great potential to be used as biological resources in the field of
medicine, health products, feed fuel and so on. These fascinating
organisms can also be used in modern agriculture for their ability to
enrich soil nutrients and enhance utilization of macro and
micronutrients.
• The application of live cyanobacteria and microalgae as bio fertilizers
induces improvements in crop growth and production yields through
photosynthesis and nitrogen fixation that generates mineralization
effects, mobilization of organic and inorganic nutrients and the
production of different secondary metabolites such as horrmones,
polysaccharides, antimicrobial compounds, and many others

4. MICROALGAE AS BIOFERTILIZERS
• Microalgae biomass has generated a growing interest in its
application in agricultural land as a powerful biofertilizer that is
derived from the contribution of the high content of micro and
macronutrients, bioactive compounds, and phytohormones that
generate beneficial biochemical effects in the soil ecosystem.
• In addition to enhancing soil fertility and quality, microalgae can
create plant growth hormones, polysaccharides, antibacterial
chemicals, and other metabolites (e.g., Spirulina sp., Chlorella sp.,
Cyanobacteria (blue-green algae)

6. ROLE IN MICROALGAE AS A BIOFERTILIZERS
• Microalgae are beneficial for soil nutrient cycling .
• Microalgae can promote plant growth by improving nutrient
availability .
• It producing bioactive substances such as phytohormones , forming
root associations or by protecting plants against phytopathogens and
pests.

7. RECENT TREND IN AGRICULTURE
PRODUCTION
• In agricultural production, different pollutants from wastewater
Including pesticides, fertilizer, and rural domestic waste, which
contaminates the soil because of the lack of fixed pollution emissions
points. So the use of microalgae could purity different types of
microalgae would purity different types of wastewater, and harvest
micro algal biomass as a fertilizer and greatly reduce production costs.
• It can improve soil fertility through its own growth, promoting microbial
decomposition, improving the transformation and circulation of soil
materials.
• Enhance soil fertility.

8. MICROALGAE AS SOIL INDICATORS
• The majority of cyanobacteria can fix nitrogen from the atmosphere
and several species including Anabaena sp., Nostoc sp., and
Oscillatoria angustissima is known to be effective cyanobacterial
based bio fertilizers. Acutodesmus dimorphus, Spirulina platensis
Chlorella vulgaris, Scenedesmus dimorphus, Anabaena azolla, and
Nostoc sp.
• Are some of the green microalgae and cyanobacteria species that
have been successfully used as bio fertilizers to boost crop growth.
Also, Chlorella vulgaris is one of the most commonly used microalgae
in bio fertilizer studies and as a soil fertility indicator on clay and
sandy soils, and the addition of seaweed conditioner to soil can
improve its organic content, return pH to normal, and reduce C/N

9. EXAMPLES OF MICROALGAE BIOFERTILIZERS:
• Azolla consists of cyanobacteria which are used as a biofertilizer. The
leaves of Azolla consist of cyanobacteria which are algae and consist of
the enzyme nitrogenase in the heterocyst which is specialized cells in the
algae.
• They help in the fixation of nitrogen in the cells with the help of the
enzyme nitrogenase and increases the yield. The cyanobacteria produce
a range of toxins which are dangerous for the human and animals are
known as cyanotoxins contributes nitrogen up to 60 kg and enriches the
soil with organic matter. Bio fertilizers help in fixing the nutrient
availability in the soil and symbiotically gets associated with the plant
roots.

10. • They produce a large number of crops with the ability to fix nitrogen
and phosphorus that solubilize the greatest possible effect.

11. POTENTIAL APPLICATION OF MICROALGAE
BIOFERTILIZERS
• 1) microalgae cultivation for the improvement of soil ecological
health.
• 2) Using microalgae to control diseases and soil pollutants and reduce
soil crop diseases.
• 3)Employing microalgae for the wastewater treatment and their
resource utilization. This review is to provide a scientific basis for
improving soil problems in agriculture, and to provide reference for
the resource application of wastewater treatment with microalgae.

12. MICROALGAE CULTIVATION IMPROVES SOIL
ECOLOGICAL HEALTH
• Amongst other soil microbiota, the novel microalgae alone account
for about 27% of the total biomass in agricultural land .
• Cyanobacteria are more suitable as soil biological indicators for land
use and have the potential to improve soil health and fertility.
• Green algae and cyanobacteria produce abundant organic matter
during climate change increase soil organic carbon by releasing
exopolysaccharides (EPSs) during algal cell decomposition, and
become a readily available form of carbon, required for the growth of
soil microbiota

13. MASS CULTIVATION OF MICROALGAE

14. PROCESS OF MICROALGAE BIOFERTILIZERS

15. MICROALGAE IMPROVE SOIL
PHSICOCHEMICAL PROPERTIES
• Microalgae can secrete a variety of active substances, such as
carotenoids, proteins, fatty acids, plant hormones, extracellular
polysaccharides (EPSs), vitamins and antibiotics.
• Plant hormones are a class of small molecules that act as chemical
messengers to coordinate the activities of agricultural crops and
higher plant cells .
• They play important roles in plant growth and development, while
EPSs can provide nutrients for soil microorganisms, increase soil
organic carbon and thus affect soil properties.

16. MICROALGAE IMPROVE SOIL MICROBIAL
COMMUNITY STRUCTURE:
• Microalgae as the potential organic carbon have a wide range of
agricultural uses . The depletion of soil organic carbon leads to a
decrease in soil fertility and is an important factor in farmland
degradation .
• Microalgae convert carbon (including organic carbon) into sugars
through photosynthesis, which also affect soil microbial community
structure, and thus improve soil aggregation and stability
• . Moreover, the multifunctional microalgae, especially for the
cyanobacteria, can secrete plant hormones and active substances to
further control pathogens and pests

17. ADVANTAGES :
• To promote plant growth such as plant growth harmones, vitamins,
carotenoids, aminoacids and antifungal substances.
• Low cost due to less energy consumption
• Microalgae reproduce quickly and can be cultivated on a large scale,
and their biomass can be directly used for soil inoculation without
polluting the surrounding environment.
• They can prevent nutrient loss by slowly releasing nitrogen,
phosphorus, and potassium to meet the growth needs of plants.

18. DISADVANTAGES:
• Biofertilizers provide lower nutrient density than chemical fertilizers,
so more product is often required for the same effect.
• Biofertilizer production requires specific machinery.
• Biofertilizers can be difficult to store and may have a much shorter
shelf-life than chemical fertilizers.
• Very high nitrogen concentration in microalgae growth media can
cause deactivation in the production of pigments needed for
photosynthesis.
• High nutrients concentration take longer to reach a phase of growth
stability.