Magnetotactic bacteria diversity of and magnetism contribution to sediment in Wudalianchi volcanic barrier lakes, NE China

Abstract Magnetotactic bacteria (MTB), the members of sediment microorganisms, play an important role in geochemical iron-cycling and sediment magnetism. This study aimed to investigate the diversity and magnetism contribution of MTB in three volcanic barrier lakes with different waterbody types (open waterbody, YC; semi-enclosed waterbody, WB; and enclosed waterbody, YYP). High-throughput sequencing results showed that MTB affiliated to Alphaproteobacteria, Betaproteobacteria and Nitrospira distributed widely in these lakes. The genera of Magnetococcus (98.10%) and Candidatus Magnetoovum (1.47%) were endemic to YC and WB, respectively. The changes in frequency-dependent susceptibility (χfd) values before and after magnetic collection in YC, WB and YYP samples were − 0.28%, 0.05% and − 0.22%, respectively. The magnetic susceptibility was significantly associated with Chao1 (R2 = 0.637 to 0.763, p