Yeasts and molds that are capable of growth at or below a water activity (aw) of 0.85 are known as:

Xerophilic fungi are defined as microorganisms that grow at low water activity (aw) levels. 
Yeasts and molds, Known as Xerophiles, are capable of growth in high concentrations of solute, or at aw ≤ 0.85.
Example – "Mold growth on bread" is an example of food spoilage by Xerophilic organisms.

🔴Additional Information:
Xerophilic Fungi (Osmophiles)
-A Xerophile which is derived from the Greek word xeros “dry”, and philos “loving”, is an extremophilic organism that can grow and reproduce in conditions with low availability of water, also known as water activity 'aw'.
-Xerophiles can survive in environments with a water activity below 0.8.
-Moderate xerophiles of the genera Aspergillus, Eurotium, and Penicillium are economically important spoilage organisms.

🔑Key Points:
Water Activity  
-The water activity (aw) of a food is that the ratio between the pressure of the food itself, once in an exceedingly fully undisturbed balance with the encircling air media, and therefore the pressure of H2O below identical conditions.
-A water activity of 0.80 means that the pressure is 80 % of that of pure water.
-It increases with temperature.
-It is the amount of free or available water in the product.
 

• Formula:
aw=(P/Po)T=% ERH100
Where,
P = Vapor Pressure of water in the substance
Po = Vapor pressure of pure water
T = Temperature 
ERH = Equilibrium Relative Humidity 
Bacteria usually require At least 0.91, Fungi requires 0.7