22197
Recently , alpha - ketoglutarate ( alpha KG ) , the carbon substrate for ammonia assimilation , has been observed to inhibit Escherichia coli enzyme I ( EI ) , the first component of the bacterial phosphotransferase system ( PTS ) , thereby providing a direct biochemical link between central carbon and nitrogen metabolism .
 Chemical: alpha - ketoglutarate; Chemical: alpha KG; Chemical: carbon; Chemical: ammonia; Chemical: carbon; Chemical: nitrogen
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: alpha - ketoglutarate; Chemical: alpha KG; Chemical: carbon; Chemical: ammonia; Chemical: carbon; Chemical: nitrogen