Insights into Clostridium tetani: From genome to bioreactors

• Published in: Biotechnology advances 2022-01, Vol.54, p.107781-107781, Article 107781
• Main Authors: Garrigues, Lucile, Do, Thuy Duong, Bideaux, Carine, Guillouet, Stéphane E., Meynial-Salles, Isabelle
• Format: Article
• Language: English
• Subjects: Allergic reactions; Annotations; Bioreactors; Biotechnology; Central metabolism map; Chemically defined medium; Clostridium tetani culture; Complex media; Fermentation; Gene sequencing; Genomes; Life Sciences; Metabolism; Nutritional requirements; Public health; Tetanus; Tetanus toxin production
• ISSN: 0734-9750; 1873-1899
• DOI: 10.1016/j.biotechadv.2021.107781

Tetanus vaccination is of major importance for public health in most countries in the world. The World Health Organization indicated that 15,000 tetanus cases were reported in 2018 (Organization, World Health, 2019). Currently, vaccine manufacturers use tetanus toxin produced by Clostridium tetani fermentation in complex media. The complex components, commonly derived from animal sources, introduce potential variability in cultures. To achieve replicable fermentation and to avoid toxic or allergic reactions from animal-source compounds, several studies have tried to switch from complex to chemically defined media without affecting toxin titers. The present review introduces the current knowledge on i) C. tetani strain diversity, whole-genome sequences and metabolic networks; ii) toxin regulation and synthesis; and iii) culture media, cultivation processes and growth requirements. We critically reviewed the reported data on metabolism in C. tetani and completed comparative genomic and proteomic analyses with other Clostridia species. We integrated genomic data based on whole-genome sequence annotation, supplemented with cofactor specificities determined by protein sequence identity, in a new map of C. tetani central metabolism. This is the first data review that integrates insights from omics experiments on C. tetani. The overview of C. tetani physiology described here could provide support for the design of new chemically defined media devoid of complex sources for toxin production. •Overview of Clostridium tetani strain diversity and genome sequences.•Schematic representation of a metabolic network including cofactor specificities•Current knowledge on toxin regulation and synthesis.•Report of C. tetani cultures and its requirements for growth and toxin synthesis.•First attempts to produce tetanus toxin in chemically defined medium.