The microbial world is truly stunning and diverse. There are countless numbers of micro Organisms. In this article, We’ve listed a sampling of some 5 of the strangest unicellular organisms our world has to offer.
1. Valonia ventricosa
This strange creature called Sailor’s Eyeball, also known as bubble algae is a species of alga found in tropical oceans. It is one of the largest – if not the largest – unicellular organisms.
Valonia ventricosas are neither plant nor animal (and I’m guessing, not a mineral either). It can grow up to 9 cm in diameter. Bubble algae likes (if we assume that an unicellullar creature canactually like something) to sit among coral rubble and mangroves. They come in shades of green, from bright emerald to a dark moss, and also has forms ranging from spherical to ovoid.
2. Stentor (genus)
Stentor, a genus of ciliate protozoans. They are among the largest unicellular organisms known, reaching sizes of up to 2 mm across. Their defining feature is a trumpet-like bell lined with cilia that they use to sweep their surroundings and collect food. Additionally, they have an attachment base (a foot of sorts) that keeps them rooted in a specific location.
Even though it preys on other microbes, it can occasionally absorb green algae, which then live inside it symbiotically and produce food and energy for it.
Like other ciliates, it has two kinds of nuclei: macro-nuclei and micro-nuclei. Within the micronucleus is all the cell’s genetic information, tucked away and left untouched until it has to be replicated. Within the macronucleus, DNA is actively transcribed, regulated, and modified. Think of the macronucleus as the place where all the action is.
3. Nasuia deltocephalinicola
This species holds the record for having the smallest genome of any organism. With only 137 genes, it is an obligate symbiote that can be found inside leafhoppers. Aside from basic functions like DNA replication, transcription, and translation, this bacteria literally cannot do anything on its own. It cannot synthesize lipids, it cannot make its own cell wall, and cannot even synthesize ATP through oxidative phosphorylation. It has to import all the supplies that it needs from its host. In return, Nasuia helps synthesize essential amino acids (e.g. tryptophan) that the host cannot do on its own.
4. Haloquadratum walsbyi
Haloquadratum walsbyi is a species of archaea that is, like the name suggests, shaped like a square. It is photosynthetic, and is also able to tolerate extremely high salt concentrations. Haloquadratum tend to aggregate into sheets consisting of 10 or more cells. They are also extremely flat, being only 150 nanometers thick, but somewhere around 2–5 microns wide. Their large surface area compared to their volume is thought to be helpful in nutrient exchange with the environment.
5. Agrobacterium Tumefaciens
Agrobacterium, nature’s very own genetic engineers. These bacteria make a living by parasitizing plants. They are able to transfer genes into the cells of their host, causing uncontrolled cell growth (i.e. cancer). These cancerous cells than produce food for it in the form of opines. They are a well known pest in agriculture, being responsible for crown gall disease (pictured below)
The efficiency by which Agrobacterium can transfer genetic material to its host has lately made them a subject of interest in biotechnology. Researchers are able to replace the tumor-inducing genes with their own genes of interest, and then allow the bacteria to do the rest. So far, this is one of the most reliable ways of genetically modifying plants.
