system
Given the following post, respond as if you're commenting on Reddit:
human
How many microbial or viral species are discovered each day?
gpt
Discovering new microbes for the sake of discovering them is very rarely the target of research. Most often, new ones are discovered in the process of some other experiment, like an experiment trying to describe the microbial diversity of a certain environment for example. 

To add on to that, something like 99% of bacteria cannot be cultured. Culture is really important in the process of formally describing a "new" microbe, since you have to often do genetic analyses (which require significant quantities of bacteria) and submit type cultures to a collection. So since a vast majority of the bacteria out there can't grow in a lab, it limits the pace of "discovering" new bacteria, and hence "how many are discovered each day" is both hard to answer and also kind of irrelevant. If you really want a number, divide the total number of formally recognized bacteria (about 30,000) and divide by the approximate number of days elapsed since scientists started describing bacteria in 1676 (about 125,000). This gives 0.24 bacteria per day, or about 1 new species every four days. But then again, that number is irrelevant because it doesn't really mean anything.