What are the disadvantages of phosphate buffer?

There are several disadvantages of phosphate buffers and are listed in the bulleted points below. 

• Phosphate promotes algal or fungal growth as a nutrient (vulnerable to contamination)
• Phosphate will isolate and precipitate cations, (e.g., calcium and magnesium) 
• Phosphates inhibit enzymatic reactions
• Phosphate precipitates in ethanol, thus cannot be used in experiments to precipitate RNA or DNA