The problem is with the assumption behind "which fairly quickly leads to the discovery of microscopic organisms". In your scenario, who learns about microscopic organisms, and when?
As a point of comparison, who discovered the existence of North America? Was it Christopher Columbus in 1492? Or was it the Vikings in 900 AD? Or was it some mix of people who first melded together in Beringia, somewhere around 20,000 BC?
Has a fact been discovered if one person learns of it? Or is it only discovered if the news spreads to all of society? If the latter, then science is a social process, not an individual one.
The historian Fernand Braudel points out that an Italian engineer, wanting to show off his skills, built an automated saw mill in Italy, back during the 1200s. The logs were slotted automatically and run through the mill automatically. This engineer had created an important part of the Industrial Revolution, 500 years early!!! Did it matter? No. The project was merely a demonstration. The abundance of wood was never used. How could it be? There was no system of transportation for the abundance of wood, there was no finance to cover operating expenses, nor any finance to support a building boom that might use the wood, nor any modern labor market from which the mill owner could hire more workers to do the initial cutting of trees, nor was there the modern strictness regarding contracts, nor were commoners allowed to bring civil suits against the nobility (in case of default, supposing a nobleman contracted to have a manor built), nor was the judiciary independent, nor... In other words, the Industrial Revolution was a social process, involving the creation of dozens of important modern institutions, and the public's acceptance of the legitimacy of those institutions. No single engineer, however brilliant, could jump start the process.