2296
The means of reducing the metals is of particular controversy , as current research using Scanning Electron Microscopy and Transmission Electron Microscopy has revealed abnormal structural protrusions resembling bacterial filaments that are thought to be involved in the metal reduction .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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