A Study on The Co-Culture of Mycelium and Anaerobic Gut Bacteria

Abstract

Natural microbial symbiosis plays a crucial role in diversifying the ecosystem. Their collective functioning as a community have been able to provide greater environmental benefits than they exist separately. This concept of mutualism has driven studies to further explore integrated microbial co-cultured systems to replace traditional processes.
In this study, mycelium and anaerobic gut bacteria were co-cultured to evaluate the impact of live mycelium on bacterial growth rate. The mycelium of Tricoderma harzinum, a fungal species widely recognized as a biocontrol agent with higher protein secretary capabilities was grown separately and inoculated with Clostridium kluyveri and Clostridium tyrobutyricum, an anaerobic gut bacterium extensively studied for its role in biological synthesis of short chain fatty acids including butyrate. The production of short chain fatty acids (SCFA), Glucose consumption of the culture media, optical density measurements were assessed to examine the bacterial growth rate when cultured with mycelium. Given the facilitated anerobic environment, in the presence of pre-grown fungal hyphae and metabolites, the growth of anaerobic bacteria was slightly hindered but not completely in co-culture system of Tricoderma harzinum with Clostridium kluyveri. In the co-culture system, Tricoderma harzinum with Clostridium tyrobutyricum, observed higher initial specific growth rate with slight reduction in final productivity, Additionally, scanning electron microscopy (SEM) images highlighted mycelial matrix of Tricoderma harzinum which could act as a possible biological scaffold for bacterial growth and adherence.
Another set of SEM images was obtained to analyze the structure of dried liquid culture mycelium of species Trichoderma harzianum, Pleurotus ostreatus, Schizophyllum commune and Ganoderma lucidum for future studies. Fourier Transform Infrared Spectrocopy (FTIR) and X-ray Diffraction (XRD) were conducted on the dried samples of the same species to identify the chemical and crystallographic properties of the mycelial matrices.
The study served as a foundational investigation into fungal- anaerobic bacterial interactions while providing insights for developing novels, integrated biosynthesis strategies for future research.

Date of Award	2025
Original language	American English
Supervisor	Srinivas Mettu (Supervisor)