What factor contribute to the differences in appearance of Surface versus subsurface colonies?

The differences in appearance between surface and subsurface colonies are primarily influenced by factors such as nutrient availability, oxygen levels, and moisture content. Surface colonies often have better access to oxygen and light, leading to more pigmented growth and varying textures. In contrast, subsurface colonies may develop differently due to limited resources, resulting in denser, often less colorful growth with a different morphology. Additionally, the microbial community composition can vary between the two environments, further contributing to their distinct appearances.