2028
These forms of AC have been reported in specific bacteria ( " Prevotella ruminicola " and " Rhizobium etli " , respectively ) and have not been extensively characterized .
 Rhizobium
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Rhizobium