Small Open Reading Frames (sORFs) are short sequence that were previously overlooked within genomes but have gained increasing recognition for their diverse functional roles. This study investigates the landscape of sORF proteins within the secretomes of extremophilic microorganisms, focusing on cold adaptation. Through computational analysis of 17 genomes, encompassing psychrophilic, mesophilic, and thermophilic organisms, 3,058 sORFs were identified, of which 173 were classified as secretome proteins. Psychrophilic organisms exhibited the highest proportion of secretome proteins. Functional annotation revealed diverse molecular functions, biological processes, and cellular components associated with cold adaptation, including mitochondrial assembly and transmembrane transport. However, explicit annotations related to stress response pathways or cold adaptation were lacking, presenting opportunities for future investigations. This research enhances understanding of molecular mechanisms underlying cold adaptation and underscores the importance of sORF proteins in extremophilic organisms. Future works may involve exploring stress response pathways, structural bioinformatics, and machine learning algorithms to advance knowledge of microbial adaptation to extreme conditions.

Index Terms- extremophiles, mesophilic, psychrophilic, secretome, sORFs prediction, thermophilic