Overall, diatoms are estimated to contribute around 40% of the total primary production in the oceans, and therefore around one fifth of all the photosynthesis on Earth, similar to all terrestrial rainforests combined [1].

Oxygen and Diatoms Since humans and all other animals need oxygen to breathe, we all rely indirectly on diatoms to sustain us. By fixing carbon or converting it from carbon dioxide into sugar, diatoms also reduce the amount of carbon dioxide in the atmosphere just as terrestrial plants do.

Scientists estimate that 50-80% of the oxygen production on Earth comes from the ocean. The majority of this production is from oceanic plankton — drifting plants, algae, and some bacteria that can photosynthesize.

A type of photosynthetic bacteria called cyanobacteria (originally misnamed blue-green algae) put the first molecular oxygen in the atmosphere about 2 billion years ago, raising the oxygen level to about 10% of what it is today, allowing the ozone layer to form and oxygen-using creatures to evolve.

The ocean produces oxygen through the plants (phytoplankton, kelp, and algal plankton) that live in it. These plants produce oxygen as a byproduct of photosynthesis, a process which converts carbon dioxide and sunlight into sugars the organism can use for energy.

The answer is tiny organisms known as cyanobacteria, or blue-green algae. These microbes conduct photosynthesis: using sunshine, water and carbon dioxide to produce carbohydrates and, yes, oxygen.

Much of the CO2 dissolved into the oceans. Eventually, a simple form of bacteria developed that could live on energy from the Sun and carbon dioxide in the water, producing oxygen as a waste product. Thus, oxygen began to build up in the atmosphere, while the carbon dioxide levels continued to drop.

‘blue’), giving them their other name, “blue-green algae”, though modern botanists restrict the term algae to eukaryotes and do not apply it to cyanobacteria, which are prokaryotes. They appear to have originated in freshwater or a terrestrial environment.

But let’s start with what we know about some of the very first living things on Earth. Cyanobacteria, also known as blue-green algae, started out on Earth quite a while ago. Possible fossil examples have been found in rocks that are around 3500 million years old, in Western Australia.

blue-green algae

Cyanobacteria are Gram-negative bacteria. Five types of cyanobacteria have been identified as toxin producers, including two strains of Anabaena flosaquae, Aphanizomenon flosaquae, Microcystis aeruginosa and Nodularia species.

Gram-negative bacteria can cause many serious infections, such as pneumonia, peritonitis (inflammation of the membrane that lines the abdominal cavity), urinary tract infections, bloodstream infections, wound or surgical site infections, and meningitis.

coli is a Gram negative anaerobic, rod-shaped, coliform bacteria of the genus Escherichia, commonly found in the lower intestine of humans and animals.

Symptoms of gram-negative meningitis in adults include:

• confusion.
• high fever, sweats, and/or chills.
• lack of interest in eating or drinking.
• nausea.
• seizures.
• sensitivity to light.
• severe headache.
• sleepiness.

E. coli is Gram-negative because its cell wall is composed of a thin peptidoglycan layer and an outer membrane.

Escherichia coli is one of the most frequent causes of many common bacterial infections, including cholecystitis, bacteremia, cholangitis, urinary tract infection (UTI), and traveler’s diarrhea, and other clinical infections such as neonatal meningitis and pneumonia.

Gram negative bacteria This is because the structure of their cell wall is unable to retain the crystal violet stain so are colored only by the safranin counterstain. Examples of Gram negative bacteria include enterococci, salmonella species and pseudomonas species.