Brock Rewrite for The Board Exam

This is my attempt to rewrite the textbook Brock Biology of Microorganisms, 16th Edition into a format that I can actually enjoy to reread, in preparation for my board exam. It's an attempt to process the information in a fun way. I'm AuHD, so it's going to be filled with references and tangents and may be a little weird... Also: I will write for my future self, so I will not talk very long about topics I already understand. You have been warned.

Unit 1: The Foundations of Microbiology

Chapter 1: The Microbial World

1.1. Microbes, the cool kids

Date Finished: October 11, 2024

The Plastics— cough, cough, cough... I mean, the cool kids.

Have you ever looked around you in nature and thought, "wow, this world is incredible"? Well, there's an entire world under the surface that you can't even see because they're way too small. We humans have always been fascinated with the world, but once you add a microscope to the mix, it's like it becomes a whole different ballgame. The day Anton van Leeuwenhoek looked through his simple microscope and saw these little creatures he dubbed 'wee animalcules', this opened up an entire different world.

Bacteria! Viruses! Cells! Proteins! Enzymes! Genes! Whatever else! Lots of things we can understand more if we look at their building blocks, their basest nature. I think that's why microbiology is so thrilling and fascinating to me, aside from the fact that it's minimal fieldwork. (I just wanna work in the cool confines of a laboratory! Leave me alone!)

Anyway, microbes are amazing. You may think, 'ew, germs and diseases', but actually, only 1% of microbial organisms are pathogenic. The rest are just doing their own thing, just chilling, fixing nitrogen to help plants, curdling milk to make our cheeses, decomposing poop so that we don't have to live in a world filled with dinosaur dung. Imagine a world where poop and dead animals don't decompose back into the earth. That's nasty. Tsk. Tsk. Tsk.

When we say microbiology, people often just think of bacteria. But archaea and viruses are under microbiology too. Not to mention the microscopic fungi, protozoa, and animals! Are there microscopic plants? I don't think so... (EDIT: There is! The phytoplanktons and algae! I can't belive I forgot) Lots of what we know about how our own cells work comes from studies of bacteria (particularly good ole Escherichia coli, the poop bacteria) because they are much simpler and thus make it easier to study cellular processes and metabolism. Microbiologists have developed a lot of tools and techniques in order to study these bacteria. The specialized equipment I will hopefully talk about more later in this book (blog?). But the most basic of basics, of course, is Microscopy and Culturing.

Microscopy is self-explanatory. Who hasn't heard of a microscope? There are lots of types of microscopes, but that's a story for another day. Culturing, on the other hand...

You see, bacteria live in these microbial communities. They're your typical neighborhood, you know? A colony of bacteria could be like the household, and the surrounding colonies the neighborhood. Maybe there's a household nearby that's their relatives. Maybe another is a friend. Maybe another is their rival across the street, competing for the good parking spot because neither of them had a garage, and the Homeowner's Association will fine them if they dared double-park. That's just how life is, you know? These microbial cells communicate, interact, help each other, or compete for resources.

The thing is that in order to study bacteria, you have to isolate it from these communities, put it in a culture media where it can grow nice and strong without the asshole neighbors, and study it like that. That is what I meant by culturing. You literally culture them like you would a rice field, only miniature, typically in an agar plate. The problem is that a majority of the microorganisms are not culturable. They're too picky with their environment. They just won't grow! Which is why despite all of our efforts, it's very likely that scientists will never be able to study all of the microorganisms there are in detail, even if given an eternity.

This is a culture. The glass container is the agar plate. The red and orange jello are the culture media. Each gray circle is a colony. Different microorganisms can look different on the agar plate. Some can be circular, some irregular, some filamentous, some white, some green, etc. Those traits are called their colonial morphology.

When you think about growth, most people think about someone getting older, getting taller, becoming more mature. In microbiology, because the cells we study are so simple, growth simply means that the number of cells in the colony has increased. There are A LOT of cells in a colony. Like... from a few cells to a million! Microbes are fast growing, after all. They're such simple creatures, and that's why it doesn't take a lot for them to proliferate.

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