Saccharibacteria, formerly known as TM7, belong to a phylum within the Candidate Phylum Radiation (CPR), consisting of ultrasmall parasitic bacteria. These organisms are ubiquitously found in diverse environments, including soil, the human oral microbiome, and wastewater. They are obligate epiparasites of Actinobacterial hosts, some of which are problematic in wastewater treatment plants. Despite their prevalence, the physiology, lifestyle, ecological roles and parasitic behaviour of many Saccharibacteria remain poorly understood, therefore more research surrounding these characteristics is required. This study investigates the replication and survivability of Saccharibacteria within wastewater communities, focusing on Candidatus Mycosynbacter amalyticus, a recently cultured and isolated member of the phylum. Notably, Ca. M. amalyticus exhibits host lysis when co-cultivated with its Actinobacteria host, Gordonia amarae, a phage-resistant organism known for contributing to wastewater foaming. Through digital PCR analysis, we demonstrate that Ca. M. amalyticus relies on the replication of its host to proliferate but remains viable and capable of reinfection even in the absence of its host replication. This study quantifies Saccharibacteria and host growth under various conditions and community settings, aiming to elucidate the growth dynamics of Saccharibacteria in wastewater environments. Furthermore, this research explores the replication of Ca. M. amalyticus in response to different conditions, including inoculated in sewerage and mixed microbial communities. These findings aid in enhancing our understanding of these elusive bacteria, potentially leading to the development of effective biocontrol strategies for managing Gordonia-mediated wastewater foaming.