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Other striking examples are the bacteria " Escherichia coli " evolving the ability to use citric acid as a nutrient in a long-term laboratory experiment , " Flavobacterium " evolving a novel enzyme that allows these bacteria to grow on the by-products of nylon manufacturing , and the soil bacterium " Sphingobium " evolving an entirely new metabolic pathway that degrades the synthetic pesticide pentachlorophenol .
 Escherichia coli, Flavobacterium
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Escherichia coli, Flavobacterium