The TNCC libraries use the Library of Congress (LC) Call Numbers
QR100-130 Microbial ecology
QR171 Microorganisms in the animal body
Although the subject 'Microbiology' is classified under the subclass QR, you will find some Microbiology related topics appearing under other subclassess such as QH (Biology, Genetics, Cytology, Ecology, Molecular biology etc.), QP (Physiology), QK (Botany), QL (Zoology) etc.