Comparative Analysis of Growth Media on the Enrichment of Marine Methanotrophs from Yeserke, Netherlands Coastal Sediments

Methane-oxidizing bacteria are ubiquitous yet challenging to cultivate. In this study, marine sediment from the coast of Yeserke, Netherlands, was used as inoculum for a five-day enrichment of marine methanotrophs. Two growth media, nitrate mineral salt (NMS) and ammonium mineral salt (AMS), along with their respective diluted counterparts, were used to cultivate the marine methanotroph community. The results showed that the diluted form of AMS exhibited superior growth performance compared to NMS. Given that methanotrophs from various environments are commonly grown in NMS, this finding offers a new perspective on the production of these bacteria, potentially leading to reduced production costs. This study demonstrates that a diluted form of AMS can be an effective growth medium for marine methanotrophs, promising higher cell output and broader application in bioremediation, biotechnology, and aquaculture. Importance Culturing methanotrophs remains challenging due to their specific growth requirements and sensitivity to environmental conditions, such as growth media composition, methane and oxygen concentration, inhibitory substances, temperature, pH, salinity, and microbial community interactions. This study provides new insights into which growth media are best suited for enriching methanotrophs from marine sediment, enabling producers to make informed choices for optimal cultivation. Despite these challenges, advances in understanding the environmental adaptations of methanotrophs continue to enhance cultivation techniques, unlocking their potential for bioremediation, biotechnology, and sustainable aquaculture applications.