Science: Ocean Microbiome & Microscopic AnimaculesBy Bob Snodgrass
PASADENA VILLAGE SCIENCE Monday; SUMMARY OF May 9, 2022, meeting
Present: Dick Myers, Karen Whitmore, Joy Wilson, Bob Snodgrass
This was a most unusual meeting, the first attended by Joy Wilson, one of the first for Karen Whitmore, and Dick Myers, a loyal member who is handicapped by poor vision. Nobody had anything prepared for presentation, so we chatted for a while and I gave my prepared presentation on the ocean microbiome, a subject which interested me from my younger days, having grown up on an island and spent much time in the ocean.
Van Leeuwenhoek’s early reports of microscopic animacules that he saw in pond water, mouth secretions, etc. don’t seem to have included ocean water. He was a draper who built his own microscopes to see the quality of thread better than he could with simple magnifying glasses. He soon became captivated by all the living things that he saw. He wrote no books but sent frequent reports to the Royal Society of London (about 190 in all). Because there had been no previous reports of single celled organisms, his reports were greeted with skepticism. The Royal Society sent a group of observers to see van Leeuwenhoek and his microscope. The observers confirmed all his reports in 1677.
The modern ideas about the microbiome developed slowly. Sergei Winogradsky who was born in 1856 in Russian-controlled Kiev is usually considered the father of microbial ecology. He studied bacteria responsible for the spoilage of wine and various foods. While chief microbiologist at St. Petersburg, he discovered the process of nitrogen fixation; the process whereby soil living microbes convert free atmospheric nitrogen in stable compounds such as ammonia, nitrate and more. He insisted that organisms should be grown and studied in their natural habitat, rather than culture dishes. This wasn’t possible until science had progressed much further, with the development of electron microscope in Germany in the later 1930s, the discovery of DNA as the basis for most life (RNA serves that function in many viruses) and of DNA sequencing in the late 1970s. Sequencing was initially done by hand and was slow and laborious. Now it is done quickly by machines. Many viruses and bacteria living in the ocean and elsewhere can’t be grown in culture but can be identified by sequencing. Most viruses can’t be seen without electron microscopy.
Only in the last 15 years have systematic studies of ocean microbiomes begun. Viruses appear to be more numerous than bacteria in most Ocean regions. Ocean samples from 100 miles away are usually different as are those taken during different seasons. Most oceanic bacteria and viruses are not pathogenic to humans. The majority of viruses that infect humans and other mammals have RNA genomes. Effects of increased oceanic acidity and temperature are expected to produce significant changes in the ocean microbiome.
Our next meeting will be Monday June 13th at 4 PM- we always meet on the 2nd Monday of the month. Barbara Madden has sent me a copy of her presentation for tomorrow, on dog genomics (June 13th). Please reach our if you'd like a copy. Also, may obtain the Zoom code from Belinda in the office.