Members of the epsilonproteobacterial genus Arcobacter have been identified to be potentially important sulfide oxidizers in marine coastal, seep, and stratified basin environments. In the highly productive upwelling waters off the coast of Peru, Arcobacter cells comprised 3 to 25% of the total microbial community at a near-shore station where sulfide concentrations exceeded 20 μM in bottom waters. From the chemocline where the Arcobacter population exceeded 106 cells ml-1 and where high rates of denitrification (up to 6.5 ± 0.4 μM N day-1) and dark carbon fixation (2.8 ± 0.2 μM C day-1) were measured, we isolated a previously uncultivated Arcobacter species, Arcobacter peruensis sp. nov. (BCCM LMG-31510). Genomic analysis showed that A. peruensis possesses genes encoding sulfide oxidation and denitrification pathways but lacks the ability to fix CO2 via autotrophic carbon fixation pathways. Genes encoding transporters for organic carbon compounds, however, were present in the A. peruensis genome. Physiological experiments demonstrated that A. peruensis grew best on a mix of sulfide, nitrate, and acetate. Isotope labeling experiments further verified that A. peruensis completely reduced nitrate to N2 and assimilated acetate but did not fix CO2, thus coupling heterotrophic growth to sulfide oxidation and denitrification. Single-cell nanoscale secondary ion mass spectrometry analysis of samples taken from shipboard isotope labeling experiments also confirmed that the Arcobacter population in situ did not substantially fix CO2 The efficient growth yield associated with the chemolithoheterotrophic metabolism of A. peruensis may allow this Arcobacter species to rapidly bloom in eutrophic and sulfide-rich waters off the coast of Peru.IMPORTANCE Our multidisciplinary approach provides new insights into the ecophysiology of a newly isolated environmental Arcobacter species, as well as the physiological flexibility within the Arcobacter genus and sulfide-oxidizing, denitrifying microbial communities within oceanic oxygen minimum zones (OMZs). The chemolithoheterotrophic species Arcobacter peruensis may play a substantial role in the diverse consortium of bacteria that is capable of coupling denitrification and fixed nitrogen loss to sulfide oxidation in eutrophic, sulfidic coastal waters. With increasing anthropogenic pressures on coastal regions, e.g., eutrophication and deoxygenation (D. Breitburg, L. A. Levin, A. Oschlies, M. Grégoire, et al., Science 359:eaam7240, 2018, https://doi.org/10.1126/science.aam7240), niches where sulfide-oxidizing, denitrifying heterotrophs such as A. peruensis thrive are likely to expand.

译文

epsilonproteobacterial arcobter属的成员已被确定为在海洋沿海,渗漏和分层盆地环境中潜在的重要硫化物氧化剂。在秘鲁沿海高产的上升流水域中,近岸站的硫化物浓度超过20 μ m的近岸站,细菌细胞占微生物群落总数的3至25%。从细菌种群超过106个细胞ml-1的化学趋向线,以及高反硝化率 (高达6.5   ±   0.4  μ m N day-1) 和暗碳固定 (2.8   ±   0.2  μ m C day-1) 被测量,我们分离了以前未培养的细菌物种,秘鲁细菌11月(BCCM LMG-31510)。基因组分析表明,peruensis具有编码硫化物氧化和反硝化途径的基因,但缺乏通过自养碳固定途径固定CO2的能力。但是,在秘鲁A. peruensis基因组中存在编码有机碳化合物转运蛋白的基因。生理实验表明,peruensis在硫化物,硝酸盐和乙酸盐的混合物中生长最佳。同位素标记实验进一步证实,佩鲁氏杆菌将硝酸盐完全还原为N2并吸收了乙酸盐,但没有固定CO2,因此将异养生长与硫化物氧化和反硝化耦合。从船上同位素标记实验中采集的样品的单细胞纳米级二次离子质谱分析也证实,原位的Arcobacter种群并没有实质性地固定CO2。与peruensis的化学趋化异养代谢相关的有效生长产量可能使这种Arcobacter物种在富营养化和富硫化物的水域中迅速开花秘鲁海岸。重要性我们的多学科方法为新分离的环境细菌物种的生态生理学提供了新的见解,以及Arcobacter属和海洋最小氧气区 (omz) 内的硫化物氧化反硝化微生物群落的生理灵活性。化学生物异养物种perucobacter peruensis可能在多种细菌联盟中发挥重要作用,该细菌联盟能够将反硝化作用和固定氮损失与富营养化,硫化物沿海水域的硫化物氧化耦合。随着沿海地区人为压力的增加,例如富营养化和脱氧 (D. Breitburg,L. A. Levin,A. Oschlies,M. Gr é goire等,科学359:eaam7240,2018,https://doi.org/10.1126/Science.aam7240),硫化物氧化的生态位,反硝化的异养生物 (例如A. peruensis) 很可能会扩展。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录