(Part II) Microbiology 101 for the Farmer: Gram Positive vs. Negative
This article is part 2 of a 3-part series.
You can view part 1 of this series here.
You can view part 3 of this series here.
Gram Positive vs Negative
One of the first things we often hear about inoculant products is whether or not the organism in the product is gram positive or negative. But what does this mean?
The first thing w want you to know is this: Gram “staining” is a basic technique that microbiologists use to classify bacteria into two categories.
Please note – only bacteria can be classified as positive or negative.
When it comes to determining whether the bacteria is gram positive or negative, it all comes down to the composition of the cell wall. Staining, discussed above, simply lets the scientist know if the cell has a double layer cell wall (positive) or a single layer cell wall (negative). Through the microscope, positive bacteria will appear purple and negative bacteria will appear pink after staining.
When someone mentions an organism is “gram positive” or “negative”, know that they are referring to a bacteria and what type of cell wall the bacterium has. If they tell you anything else, such as the reaction of their fungus, just walk away slowly – smiling and nodding.
Gram Positive Gram Negative
Bacillus Bradyrhizobia
Pseudomonas
First Photo: Positive
Second Photo: Negative
