In nutrient-rich environments (like your mouth), bacteria can use the provided amino acids to synthesize their proteins. however, should the environmental conditions change and become nutrient-poor, bacteria would need to synthesize their amino acids. they can do this using available hint(s)in nutrient-rich environments (like your mouth), bacteria can use the provided amino acids to synthesize their proteins. however, should the environmental conditions change and become nutrient-poor, bacteria would need to synthesize their amino acids. they can do this using acid cycle 3-phosphate