Related Experiment Video
Updated: Jul 10, 2026

Environmental Sampling of Photosynthetic Microbes and Their Viruses: From Field to Lab
Published on: July 3, 2025
[Characterization of thermophilic strain SY-14 with capability to lyse bacterial cells]
Yu-dong Song1, Hong-ying Hu, Jin-ying Xi
1Division of Environmental Microbiology, Environmental Simulation and Pollution Control, State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. syd99@mails.tsinghua.edu.cn
Abstract:
One spore-forming thermophilic bacterial strain SY-14, isolated from sewage sludge compost, showed significant capability to lyse bacterial cells. The strain was identified as Geobacillus sp. based on morphological characteristics and homology identification of 16S rDNA sequence. The optimal temperature and pH for growth were about 60 degrees C and pH 6.0-7.0 respectively. The culture supernatant of SY-14 showed lytic activity against both intact and thermal inactivated bacterial cells, and the cell lysis percentages at 6 hours were 70% and 85% respectively. The lytic activity of the culture supernatant decreased significantly after heat treatment, which inferred the lytic activity mainly derived from extracellular lytic enzymes of SY-14. The lytic activity of the culture supernatants of SY-14 increased significantly during the log phase in the batch culture process, and then decreased quickly after the maximum activity was reached. The culture supernatant of SY-14 showed lytic activity against all the five tested Gram-negative strains and some tested Gram-positive strains.
Related Concept Videos
Hyperthermophilic Bacteria
Diversity of Archaea IV
Factors Influencing Microbial Growth: Temperature
Viral Replication: Lytic Cycle
Diversity of Archaea III
Diversity of Archaea I

