1. contributing to sulfur cycling, especially in anoxic (oxygen-depleted) and sulfur-rich environments.

2. produce sulfate, which other microorganisms in the ecosystem can use, thus supporting biodiversity.

3. stabilizes sulfur compounds, preventing the accumulation of harmful substances like hydrogen sulfide, which can otherwise disrupt aquatic ecosystems.

Cyanobacteria as A Promising Alternative for Sustainable Environment: Synthesis of Biofuel and Biodegradable Plastics (2022)

https://pmc.ncbi.nlm.nih.gov/articles/PMC9325326/

Beyond Soil Inoculation: Cyanobacteria as a Fertilizer Replacement (2023)

https://www.mdpi.com/2504-3129/4/3/18

Cyanobacteria as a Valuable Natural Resource for Improved Agriculture, Environment, and Plant Protection (2023)

https://pmc.ncbi.nlm.nih.gov/articles/PMC10156578/

Cyanobacteria as Natural Therapeutics and Pharmaceutical Potential: Role in Antitumor Activity and as Nanovectors (2021)

https://pmc.ncbi.nlm.nih.gov/articles/PMC7796498/

Cyanobacteria derived compounds: Emerging drugs for cancer management (2022)

https://pubmed.ncbi.nlm.nih.gov/34747529/

Emerging Trends of Nanotechnology and Genetic Engineering in Cyanobacteria to Optimize Production for Future Applications (2022)

https://pmc.ncbi.nlm.nih.gov/articles/PMC9781209/

https://books.rsc.org/books/edited-volume/1375/chapter/1024871/The-Light-Harvesting-System-of-Purple-Anoxygenic

• No water split in the photosystem instead Hydrogen Sulphide is split into protons/electrons/sulphur

• This electron will go into the photosystem and form proton gradient to create energy

• No oxygen produced

☆Anoxygernic Bacteria as Sustainable Resource Recovery☆

https://www.sciencedirect.com/science/article/pii/S2215017X20306093

• Their versatile metabolism, ability to adapt in extreme conditions, low maintenance cost and high biomass yield make APB ideal for wastewater treatment, resource recovery and in the production of high value substances.

• Advantages of APB over algae and cyanobacteria and their applications in photo-bioelectrochemical systems, production of poly-β-hydroxyalkanoates, single-cell protein, biofertilizers and pigments.

☆Hydrogen Detoxification of anoxic environments☆

https://pubmed.ncbi.nlm.nih.gov/39056005/

Anoxygenic sulphur bacteria can be divided into two

• Green sulphur bacteria

• Purple sulphur bacteria

☆Optimization of Anoxygernic Bacteria as Feed in Fairy Shrimp Cultivation☆

https://www.sciencedirect.com/science/article/abs/pii/S0044848620339946

■ Green Sulphur Bacteria (GSB) ■

• GSB adapted to the deeper regions of water or soil

• grow better under low light intensity

• exhibit greater sensitivity to oxidise environment

• has higher concentration of H2S

• GSB deposit sulfur extracellularly

• GSB (Chlorobium limicola) is considered to be use as the electrochemical cells to generate electrical energy from the captured light energy

■PURPLE SULFUR BACTERIA (PSB)■

• PSB store sulfur in intracellular globules

• does not grow better under low light intesity

• has lower concentration of H2S

• does not exhibit great sensitivity to oxidise environment

Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC9611879/

• Cyanobacteria blooms, often referred to as harmful algal blooms (HABs), are a significant environmental concern that occurs when cyanobacteria proliferate rapidly in aquatic environments.

• These blooms can have detrimental effects on water quality, aquatic ecosystems, and human health.

• Causes of Cyanobacteria Blooms:

1. Cyanobacteria thrive in stagnant, warm, and nutrient-rich waters, particularly those high in nitrogen and phosphorus. This nutrient enrichment often results from agricultural runoff, industrial discharges, and domestic waste, leading to a phenomenon known as eutrophication.

   
   

• Key factors contributing to the increase in cyanobacterial blooms include:

1. Climate Change: Rising temperatures favor cyanobacteria over other algae, as they can thrive in warmer conditions. Increased thermal stratification of water bodies allows buoyant cyanobacteria to access sunlight more effectively than non-buoyant species.

2. Nutrient Loading: Excessive nutrients from human activities lead to rapid cyanobacterial growth. When conditions are optimal (e.g., temperatures above 20°C), blooms can form quickly, often resulting in visible surface scums that can appear green or blue-green.
   

• Impacts of Cyanobacteria Blooms:

1. Environmental Effects:
   - Decrease dissolved oxygen levelsh

   - Harming fish and other aquatic life.

   - Release toxins (cyanotoxins) that are harmful to both wildlife and humans.

   - Contribute to further eutrophication through the decomposition of dead cyanobacterial cells, releasing additional nutrients back into the water.

2. Human Health Risks:
   - Gastrointestinal symptoms from ingestion of contaminated water.

   - Skin irritations or respiratory issues from contact or inhalation of aerosolized toxins.

   - Long-term exposure may increase the risk of liver damage or neurological effects.

   
   

• Management Strategies:

1. Nutrient Management: Reducing nutrient inputs from agricultural runoff through better management practices.

2. Monitoring Programs: Implementing regular monitoring of water bodies for early detection of blooms.

3. Public Awareness: Educating communities about the risks associated with cyanobacterial blooms and promoting safe recreational practices.
   

1. Light Utilization: These bacteria use visible and near-infrared light, absorbing wavelengths from around 400–1000 nm, with specific absorption peaks varying by pigment type.

2. Pigments: They contain bacteriochlorophylls and carotenoids, which enable them to capture light at longer wavelengths compared to oxygenic phototrophs.

3. Electron Transfer: Light energy drives the production of ATP through electron transfer chains, essential for hydrogen production.

4. Adaptation: Different bacterial strains and external factors (e.g., light intensity) impact light efficiency and biohydrogen production.

5. Reaction Centers: Anoxygenic bacteria have either Type I or Type II reaction centers, specialized for electron

transport without oxygen release.

https://pdf.sciencedirectassets.com/271472/1-s2.0-S0360319923X01128/1-s2.0-S0360319922051989/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjENr%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCIQDsOI0MoElRmZQwJKy%2FI0ZSIxab9iRlXrBdN3cCnoPSlwIga9aCwL%2FqpAKLrptX1QTMfSdBrLggI1B%2BgYcR6HAvkfAqswUIUxAFGgwwNTkwMDM1NDY4NjUiDOALzuqGo7JyQDPCPyqQBWH7cedLyMw4alzJczHWoyk9v56WMz0q8AWI%2FE5qe2XAp97Mfp3DxiARasF3nnPZlz1HaCZhmaOYSKISsCeqsK%2B86qV%2BuQj67zwX5cIw3ysdb1qZBA1kjBkXGUsGmzIAp3u9I%2F6CF30cEvpxlzPMcnjKp450i%2Bh64M%2B8SSi4lUn0mbdjZrDxgI6astjp7mTBfuo41JIaH1sVhvbyCo6uHyILrqCUInzQ2ElGKVQGyl5%2B6c%2FLQEGU6cMy%2Fdg5eyKfHNY9UhYB%2F6l8IPgRkdZbRD7aCSEMLlJjCRR7T5J408exJCth96rqLo%2FhGgEUU6zku7c5AwSkMP%2BqN%2BwV8%2BuME60kRDigykALXtJiMxd3j75euYV3yWe9Js%2Fp%2BbvQLFDhByLz93xuvSQLAi9LIBw0oYpdZWjzgVsi3We5jGXTRBzIKj5GDUbdpDzd%2FXaFNLUcTIydf4vT%2BD5ymYNG4obzSwmw95C1tlhn6VgBCc5BOsgREms0aFJfzWVqd10eWk0%2BOLKTXa1SUS3ZMOUHb7pNfQOx4V8CiwZ7mA7hRFpUJojhzrla7ujCEbC3CZuNgYtQv5ihdzp7iuQdvH3EjYfBo5OfVhzqMrIIlGkb7bH2AFnMBN%2BdfXU3yovquGR%2FlFWpLv5VW%2Bm7DxfzevjckwUem2PWPHsePf%2Fkdg%2BL0nVigT%2BeO8UM2E5xLguOIEDwJaKpmgkzZCEhAJotWf9yNvuyuq5PjeA%2Bo72ukxX4RWIIfoxYVb2ICZDiNUJ2kM7I9BADgEHoytxTjOI5FX3%2F4FaLpjmJ7sDK3sE2qZE8Bn%2FWwB9z%2BpH%2BiI%2FuVVlzpLNhTqNWBBZj0JG9YacT6LBQ4umxnndQRQe0N3DoxQizlDs9aZQQMO3ygLkGOrEBEN1OK8lg%2BL%2Bf8m5idI2JFKTGzCqBt6hhR1MsVbuht9Re7Pp6qusG%2FV6phXGFe4Pp13vzeh74VdGj9eQoAomkNxBJa8fMTDTetUk2sftjRVzSbUjRaTssQkNyiOjWcd8zCuI74B1dLe%2BwpugilxXa1Jlti7OlEUpW9ykC%2Ft3RquNUI9doGaWGc%2B2Hx0svqprwDg4Vnp9uo6ARD0MPxqjanJIakOEKTBSOP%2FipcCYJJdzF&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20241029T021503Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTY5TAPS2LB%2F20241029%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=d4edcf99d4787bd40d74fd56b5d82238cfafa2d4d0a7b802338e8c462296deb2&hash=57aa97fb7729a6cefe745d783e16bababa02553e420e7b1431b6b699fd7a11db&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S0360319922051989&tid=spdf-6f9a6783-d107-4130-b65c-b923d614868c&sid=5c18b92f2f919240184808a89687bd93a2cdgxrqb&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=0b1d58015f0400510753&rr=8d9fa7d27d4da856&cc=my

https://www.sciencedirect.com/science/article/pii/S2215017X20306093

Anabaena is a genus of nitrogen-fixing blue-green algae with beadlike or barrel-like cells and interspersed enlarged spores

Characteristics of Anabaena

- Photoautotrophic

- Perform oxygenic photosynthesis

- Has heterocyst-forming cells

- During nitrogen scarcity, approximately 1 in 10 cells turns into a heterocyst, a cell specialized for nitrogen fixation.

- Forms symbiotic relationships with certain plants, such as the mosquito fern.

- Produce neurotoxins harmful to wildlife, farm animals, and pets.

Function of Anabaena

1. Nitrogen Fixation

Anabaena is capable of converting atmospheric nitrogen (N₂) into ammonia (NH₃), a form of nitrogen usable by plants. This process, known as nitrogen fixation, occurs in specialized cells called heterocysts, which create an anaerobic environment essential for the nitrogenase enzyme to function.

Effect:

Nitrogen fixation enriches soil and water with bioavailable nitrogen, which promotes the growth of other plants and microorganisms. This is particularly useful in nutrient-poor environments where nitrogen levels are low, such as rice paddies.

2. Oxygen Production

Through photosynthesis, Anabaena produces oxygen as a byproduct, which supports aerobic organisms in the ecosystem.

Effect:

Oxygen production helps maintain balanced oxygen levels in aquatic environments, contributing to overall ecosystem health.

3. Symbiotic Relationships

Anabaena forms symbiotic relationships with plants like the water fern Azolla. This relationship is especially useful in agriculture, as the nitrogen fixed by Anabaena in these partnerships boosts the nitrogen content in soils, reducing the need for chemical fertilizers.

Effect:

By naturally enhancing soil fertility, this symbiosis can improve crop yield sustainably, supporting organic farming and reducing the environmental impact of artificial fertilizers.

4. Biofertilizer Potential

Anabaena and other nitrogen-fixing cyanobacteria are used as biofertilizers in sustainable agriculture. This use has been beneficial in enhancing crop productivity without resorting to synthetic fertilizers, especially in rice cultivation.

Effect:

Using Anabaena as a biofertilizer reduces agricultural costs, limits pollution from synthetic fertilizers, and improves soil health over time.

Negative Effect of Anabena To Human Body

Anabaena produce different toxins, including anatoxin and microcystin.

Ingestion of small amounts of toxin can cause gastrointestinal distress.

1. Anatoxin Toxin

If elevated levels of the algal toxin anatoxin ingested, serious neurological damage can result.

Symptoms of anatoxin poisoning:

- numb lips

- tingling fingers and toes

- dizziness.

2. Microcystin Toxin

If elevated levels of the algal toxin microcystin are present in the water and ingested, serious liver damage can result.

Symptoms of microcystin poisoning:

- abdominal pain

- diarrhea

- vomiting

How to combat Anabaena?

Controll nutrient concentrations and the composition of phytoplankton communities, this tailored approach provides an avenue for addressing CyBs’ negative impacts on water quality.

Recent study:

Three years ago, María del Carmen Muñoz from the University of Cordoba discovered unexpected structures while studying marine cyanobacteria: membrane nanotubes. Previously unseen in this type of bacteria, these tiny tubes act like "bridges," allowing cyanobacteria to transfer substances to each other. Since the discovery of these organisms, this is the first time that physical and direct contact between then has been demonstrated. This groundbreaking discovery reveals that cyanobacteria, which produce over half of Earth's oxygen, may not function alone but as a network, interacting directly with nearby cells. This challenges previous views and highlights cyanobacteria's vital role as the ocean’s "lung" and a key to sustaining life.

https://www.sciencedaily.com/releases/2024/06/240606152330.htm

References:

1. https://www.sciencedirect.com/science/article/pii/S235251342030168X

2. https://pubs.rsc.org/en/content/articlehtml/2023/va/d2va00158f

3. https://www.mass.gov/info-details/microcystis-and-anabaena-algae-blooms#:~:text=Anabaena%20may%20produce%20a%20few,serious%20neurological%20damage%20can%20result

4. https://link.springer.com/article/10.1007/s40726-024-00322-w