Explain why it is important to study ocean microbes with regard to the biosphere.

Throughout the history of time, b acteria have caused more human deaths on Earth than any other known cause, directly through the diseases of cholera, dysentery, meningitis, measles, pneumonia, scarlet fever, tuberculosis, and others. At the same time, the Good is that microbes provide many essential services to Earth, including allowing plant productivity (the dominant base of Earth's food web) to be sustainable, and allowing humans to live - basically, without microbes, humans wouldn't be alive. Finally, microbial organisms are collectively incredibly powerful at the global scale - 50% of the total oxygen produced over the history of the Earth is from bacteria; 75% of additions of nitrogen to the atmosphere, and 92% of removal from the atmosphere are due to bacteria. And of that nitrogen, bacteria produce 88% of the nitrous oxide released to the atmosphere, N2O, which is 300 times more potent than CO2 as a greenhouse gas. Microbes are also responsible for ~70% of the methane production on Earth (25x more potent than CO2), and ~50% of the CO2 put into the atmosphere comes from bacteria.

In this lecture we will learn about the diversity of microbes, how different microbes function to gain energy, and we will specifically learn about the "Good" aspects of microbes and the impacts of microbes on ecosystems and on our globe.

The Take Home Messages are: Microbes can do anything they want, wherever they want and Without microbes, humans wouldn't be alive.