Genomic and Transcriptomic Insights into Calcium Carbonate Biomineralization by Marine Actinobacterium Brevibacterium linens BS258

Abstract

Calcium carbonate (CaCO3) biomineralization has been investigated due to its wide range of scientific and technological implications, however, the molecular mechanisms of this important geomicrobiological process are largely unknown. Here, a urease-positive marine actinobacterium Brevibacterium linens BS258 was demonstrated to effectively form CaCO3 precipitates. Surprisingly, this bacterium could also dissolve the formed CaCO3 with the increase of the Ca2+ concentration. To disclose the mechanisms of biomineralization, the genome of B. linens BS258 was further completely sequenced. Interestingly, the expression of three carbonic anhydrases was significantly up-regulated along with the increase of Ca2+ concentration and the extent of calcite dissolution. Moreover, transcriptome analyses revealed that increasing concentration of Ca2+ induced KEGG pathways including quorum sensing (QS) in B. linens BS258. Notably, most up-regulated genes related to QS were found to encode peptide/nickel ABC transporters, which suggested that nickel uptake and its associated urease stimulation were essential to boost CaCO3 biomineralization. Within the genome of B. linens BS258, there are both cadmium and lead resistance gene clusters. Therefore, the sequestration abilities of Cd2+ and Pb2+ by B. linens BS258 were checked. Consistently, Pb2+ and Cd2+ could be effectively sequestered with the precipitation of calcite by B. linens BS258. To our knowledge, this is the first study investigating the microbial CaCO3 biomineralization from both genomic and transcriptomic insights, which paves the way to disclose the relationships among bacterial metabolisms and the biomineralization.

Calcium transcriptionally regulates movement, recombination and other functions of Xylella fastidiosa under constant flow inside microfluidic chambers

“…Our results also suggest that Ca is an important signal messenger in this bacterium since many DEGs were associated with signal binding, transport and transcriptional regulation. Similar results were observed in other transcriptome analysis of bacterial responses to Ca (Oomes et al, 2009;Gode-Potratz et al, 2010;Parker et al, 2016;Zhu et al, 2017).…”

Calcium carbonates: induced biomineralization with controlled macromorphology

“…The cell surface can act as a nucleation site for mineralization in induced biomineralization (SchultzeLam et al, 1996). Since properties are different for gram positives and gram negatives, both binding divalent cations such as Mg 2+ or Ca 2+ , a determination of the microbial clades is necessary (Chahal et al, 2011;Douglas and Beveridge, 1998;Zhu et al, 2017). Depending on different cell surface structures, different crystal morphologies have been reported (Cao et al, 2016;Seifan et al, 2016).…”

Biofouling Formation and Bacterial Community Structure in Hybrid Moving Bed Biofilm Reactor-Membrane Bioreactors: Influence of Salinity Concentration

“…For the constant salinity condition, the identified phylotypes with >1% relative abundance reported for calcite precipitation were Nocardioides (1.163% to 1.694%) [31], Brevibacterium (0.604% to 2.324%) [32], and Pseudomonas (0.671% to 2.284%) [33]. For the case of struvite precipitation, the identified phylotypes were Corynebacterium (0.492% to 2.374%) [34], Brevibacterium (0.604% to 2.324%) [35], and Ochrobactrum (0.671% to 2.284%) [15].…”

“…Genomic insights into the formation of calcite by Brevibacterium linens have shown that this species regulates three carbonic anhydrases in response to Ca 2+ concentration in the precipitation medium [32]. The relative abundance of Brevibacterium in the biofouling of the variable salinity scenario ranged from 0.007% to 0.009%.…”