The fight for survival has led to the evolution of many strategies to obtain food, and some fungi have taken on a carnivorous lifestyle. There are over 700 species of carnivorous fungi identified that prey upon nematode worms, rotifers, and tardigrades. While fungi usually dine on decaying organic matter, sometimes that is not enough. Decaying wood, for example, does not provide enough nitrogen, and in these environments, fungi turn to carnivorism for their nitrogen needs. In case you were wondering, the Venus flytrap is also found in nitrogen-poor environments. (more…)
Year: 2018
Sourdough Citizen Science: Does San Francisco Sourdough Stay in San Francisco?
Many claim that there is something special in the water or air that gives San Francisco sourdough bread its unique tang and local bakers often say that no one outside of the area can replicate the flavor and texture of San Francisco sourdough.
Sourdough bread is made from a starter – a slurry of water and flour brimming with microorganisms. Once fed, bacteria and yeast begin to eat up the nutrients in the mixture and produce an array of compounds that give sourdough its flavor. The microbes also produce carbon dioxide, which makes the starter rise. Once the nutrients in the flour have been digested by the microbes, growth slows down and the starter falls. The starter almost seems alive. (more…)
Acute Oak Decline: A Modern Adaptation of Koch’s Postulates
In the UK, thousands of oak trees are “bleeding,” oozing dark liquid from cracks on their bark. What lies underneath are fluid-filled necrotic cavities that disrupts their life force by impeding the normal flow of nutrients and water. Taking advantage of the weakened state of the trees, are bark-boring beetles, which lay their eggs in the cracks of the bark. These are the characteristic signs of Acute Oak Decline, a disease that can kill a tree within four or five years of symptom onset.
Acute Oak Decline made its appearance in 2008. Now, scientists have found that Acute Oak Decline is caused by a polymicrobial infection – in this case, a simultaneous infection of three bacterial species: Brenneria goodwinii, Gibbsiella quercinecans, and Rahnella victoriana. With the microbes (B. goodwinii and G. quercinecans) and beetle larvae in hand, the researchers were able to replicate the characteristic signs of Acute Oak Decline. (more…)
Zombie Worms and Microbes Come Together for a Deep Sea Meal
Deep within the ocean, scientists and explorers alike have discovered all sorts of creatures almost unfathomable to our terrestrial minds. Giant octopus, electric eels, and anglerfish have all tickled our imagination over the past several centuries, and left us in awe of the capabilities of life.
A more recent discovery is that of the bone-eating worms. On one end of the worms are feathery plumes that act as gills to extract oxygen from the water. On the opposite end are root-like structures that dig deep below the bone surface. These newly discovered zombie worms were called Osedax, meaning “bone eating” in Latin. (more…)
Giant Genes for Tiny Organisms
How big can a gene be? Ten years ago in the early days of genome sequencing, researchers scoured the genomes of 580 bacterial and archaeal species for large genes. They found that 0.2% of all genes identified are longer than 5,000 bases and 80 of them are “giant genes,” those larger than 15,000 bases. To put this in perspective, the average prokaryotic gene length is between 900 and 1,200 bases.
The two longest genes were found in the green sulfur bacterium Chlorobium chlorochromatii CaD3. The genes encode proteins 36,806 and 20,647 amino acids long and their corresponding genes would be 110,418 and 61,941 bases long, respectively. At the time of this research, these giant genes are only surpassed in length by the human titin coding sequence which is 38,138 amino acids long. Now, scientists have identified a slew of genes that exceed one million bases long. (more…)