5985
However , most of these clusters could not be linked to taxonomically known sequences : considering OTUs ( 97 % ) ( clusters build at a sequence identity level of 97 % ) on our global data set , less than 1 % of the reads clustered with sequences from cultures , and less than 12 % clustered with reference sequences obtained previously from cloning and Sanger sequencing of environmental samples .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None