Expanded Diversity and Metabolic Versatility of Marine Nitrite-Oxidizing Bacteria Revealed by Cultivation- and Genomics-Based Approaches
Soo-Je Park, Adrian‐Ștefan Andrei, Paul‐Adrian Bulzu, Vinicius Kavagutti, Rohit Ghai, Annika C. Mosier
Abstract
Nitrification is a key process in the biogeochemical and global nitrogen cycle. Nitrite-oxidizing bacteria (NOB) perform the second step of aerobic nitrification (converting nitrite to nitrate), which is critical for transferring nitrogen to other organisms for assimilation or energy. Despite their ecological importance, there are few cultured or genomic representatives from marine systems. Here, we obtained two NOB (designated MSP and DJ) enriched from marine sediments and estimated the physiological and genomic traits of these marine microbes. Both NOB enrichment cultures exhibit distinct responses to various nitrite and salt concentrations. Genomic analyses suggest that these NOB are metabolically flexible (similar to other previously described NOB) yet also have individual genomic differences that likely support distinct niche distribution. In conclusion, this study provides more insights into the ecological roles of NOB in marine environments.