Identification of microbial groups and functional genes associated with greenhouse gas emissions in prawn farms

Understanding microbial associations with greenhouse gas (GHG) emissions is essential for promoting climate-friendly prawn production, yet it remains largely unexplored. To examine microbial-GHG relationships, this study analysed CO 2 , CH 4 , and N 2 O emissions, characterised microbial communities, and measured the abundances of key functional genes ( mcrA , pmoA , amoA , and nosZ ) in water and sediment from Bangladeshi prawn farms. Results showed that microbial richness was positively correlated with CO 2 and N 2 O emissions but negatively with CH 4 emissions. Methanogenic archaea, most abundant in high-salinity farms, were positively associated with CH 4 flux; however, their negative relationship with CO 2 emission appeared insignificant. Conversely, the negative correlation between the relative abundance of anaerobic methanotrophs (ANME) and CH 4 emission suggests that CH 4 oxidation facilitated by ANME could be a promising strategy for reducing CH 4 emissions. N 2 O emission was negatively linked to most bacterial and archaeal classes; however, N 2 O-consuming Chloroflexi exhibited a positive correlation with N 2 O emission. Additionally, a strong link between the mcrA gene in water and CH 4 production may relate to previous findings of methane production in oxygenated water. This multidisciplinary study enhances our understanding and opens avenues for further research into reducing emissions by modulating microbial communities within prawn farming systems.