ʻO ka Hikina Tropical North Pacific (ETNP) kahi ʻāpana haʻahaʻa oxygen nui, paʻa, a hoʻoikaika (OMZ) e helu ana i ka hapalua o ka ʻāpana holoʻokoʻa o nā OMZ honua. I loko o ke kikowaena OMZ (∼350–700 m ka hohonu), ʻo ka oxygen i hoʻoheheʻe ʻia ma kahi kokoke a i ʻole ma lalo o ka palena ʻike loiloi o nā sensor hou (∼10 nM). ʻO nā gradients oxygen kiʻekiʻe ma luna a ma lalo o ke kikowaena OMZ e alakaʻi i ka hoʻonohonoho kū pololei o nā kaiāulu microbial e ʻokoʻa hoʻi ma waena o nā ʻāpana nui e pili ana i ka particle (PA) a me nā ʻāpana ola manuahi (FL). Maanei, hoʻohana mākou i ka 16S amplicon sequencing (iTags) e kālailai i ka ʻokoʻa a me ka hoʻolaha ʻana o nā heluna prokaryotic ma waena o nā ʻāpana nui FL a me PA a ma waena o nā kūlana redox ambient. ʻOkoʻa nā kūlana hydrographic ma kā mākou wahi aʻo mai nā mea i hōʻike mua ʻia ma ka ETNP a me nā OMZ ʻē aʻe, e like me ka ETSP. Loaʻa nā ʻike oxygen trace (∼0.35 μM) ma loko o ke kikowaena OMZ ma kā mākou wahi laʻana. No laila, ʻaʻohe hōʻiliʻili nitrite i hōʻike pinepine ʻia no nā ʻōpū OMZ e like me nā moʻo no nā bacteria anammox (Brocadiales genusʻO CandidatusʻO Scalindua), i loaʻa pinepine ʻia ma nā palena oxic-anoxic i nā ʻōnaehana ʻē aʻe. Eia nō naʻe, nā hoʻolaha ʻana o ka bacteria ammonia-oxidizing (AOB) a me archaea (AOA) a me nā helu hoʻohui kalapona autotrophic kiʻekiʻe loa (1.4 μM C d–1) i kūlike me ka nui o ka ammonium i ʻike nui ʻia ma kahi kokoke i ka piko o ke kikowaena OMZ. Eia kekahi, nā lālā o ka genusNitrospina, ua loaʻa kahi clade bacteria nitrite-oxidizing (NOB) dominant e hōʻike ana e hana ʻia ka ammonia a me ka nitrite oxidation ma nā ʻano oxygen trace. Ua hōʻike ka loiloi o ka hoʻāʻo like (ANOSIM) a me Non-metric Dimensional Scaling (nMDS) he ʻokoʻa loa nā hōʻike phylogenetic bacteria a me archaeal ma waena o nā ʻāpana nui. Ma muli o nā ʻikepili ANOSIM a me iTag, ʻaʻole i hoʻopili nui ʻia ka haku mele ʻana o nā hui PA e ke ʻano biogeochemical e pili ana i ka hohonu ma mua o ka ʻāpana FL. Ma muli o ke alo o AOA, NOB a me ka trace oxygen i loko o ka OMZ core, ke kuhikuhi nei mākou he hana ikaika ka nitrification i loko o ke kaʻina hana nitrogen o kēia ʻāpana o ka ETNP OMZ.
Hoʻolauna
I ka pane ʻana i ka loli o ke aniau a me nā hana kanaka kūloko, ua emi iho ka nui o ka oxygen i hoʻoheheʻe ʻia ma ke kai ākea a ma nā ʻōnaehana kai kahakai (ʻO Breitburg et al., 2018). Ua manaʻo ʻia ka nalowale o ka oxygen mai ke kai ākea i nā makahiki 60 i hala iho nei ua ʻoi aku ma mua o 2% (Schmidtko et al., 2017), e hoʻokumu ana i nā hopohopo e pili ana i nā hopena o ka hoʻonui ʻana o ka ʻāpana i hoʻopau ʻia e ka oxygen (ʻO Paulmier lāua ʻo Ruiz-Pino, 2009). Hoʻokumu ʻia nā OMZ moana ākea i ka wā e hoʻoulu ai ka hana mua o ka ʻili kiʻekiʻe i ka koi oxygen olaola i loko o nā wai o lalo o ka ʻilikai e ʻoi aku ana ma mua o ka nui o ka ea kino ma ka hohonu. Hiki i nā ʻano oxygen i loko o nā kolamu wai OMZ ke loaʻa nā gradients kiʻekiʻe (oxycline) ma luna a ma lalo o ke kumu i hoʻopau ʻia e ka oxygen e hana ana i nā papa hypoxic (maʻamau ma waena o 2 a me ∼90 μM), suboxic (<2 μM) a me anoxic (ma lalo o ka palena ʻike (∼10 nM) o nā ana like ʻole (ʻO Bertagnolli lāua ʻo Stewart, 2018). Alakaʻi nā gradients oxygen i ke kūkulu kū pololei ʻana o nā kaiāulu metazoan a me microbial a me nā kaʻina hana biogeochemical ma kēia mau oxyclines ākea (ʻO Belmar et al., 2011).
Ua hoʻopaʻa ʻia kekahi o nā helu kiʻekiʻe loa o ka nalowale ʻana o ka naikokene ma nā OMZ o ka Eastern Tropical North Pacific (ETNP) a me ka South Pacific (ETSP) (Callbeck et al., 2017;Penn et al., 2019), ke kīʻaha ʻo Cariaco i hoʻopaʻa mau ʻia (Montes et al., 2013), ke Kai ʻArabia (Ward et al., 2009), a me ka OMZ o ka ʻōnaehana upwelling Benguela (Kuypers et al., 2005). I loko o kēia mau ʻōnaehana, ʻo nā kaʻina hana microbial o ka canonical denitrification (ka hōʻemi heterotrophic o ka nitrate i nā mea waena nitrogen a pinepine i ke kinoea dinitrogen) a me ka anammox (anaerobic ammonium oxidation) e alakaʻi i nā pohō nitrogen hiki ke kaupalena i ka hana mua (Ward et al., 2007). Eia kekahi, ʻo ka hoʻokuʻu ʻana o ka nitrous oxide moana (kahi kinoea ʻōmaʻomaʻo ikaika) mai ka microbial denitrification e hana nei ma OMZs ua manaʻo ʻia no ka liʻiliʻi o hoʻokahi hapakolu o nā hoʻokuʻu nitrous oxide kūlohelohe o ka honua (Naqvi et al., 2010).
ʻO ka ETNP OMZ kahi ʻāpana haʻahaʻa oxygen nui, paʻa, a hoʻoikaika nui e helu ana no ka hapalua o ka ʻāpana holoʻokoʻa o nā OMZ honua, aia ma waena o 0-25°N latitude a me 75 a me 180°W longitude (ʻO Paulmier lāua ʻo Ruiz-Pino, 2009;Schmidtko et al., 2017). Ma muli o ko lākou koʻikoʻi ecological, ua aʻo nui ʻia ka biogeochemistry a me ke ʻano like ʻole o ka microbial o nā ʻāpana ETNP OMZ like ʻole (e.g.,ʻO Beman lāua ʻo Carolan, 2013;ʻO Duret et al., 2015;Ganesh et al., 2015;ʻO Chronopoulou et al., 2017;Pack et al., 2015;Peng et al., 2015). Ua hōʻike nā haʻawina mua ua kokoke a ma lalo paha o nā palena ʻike loiloi (∼10 nM) ka oxygen i hoʻoheheʻe ʻia i loko o kēia kikowaena OMZ (∼250–750 m ka hohonu) (ʻO Tiano et al., 2014;Garcia-Robledo et al., 2017). Eia nō naʻe, ma ka ʻaoʻao ʻākau o ka OMZ o ka ETNP (kahi o ke kahua noiʻi ~22°N) hiki i nā nui o ka oxygen ma 500 m ke hiki i nā awelika makahiki ma waena o 10 a me 20 μM (ʻO Paulmier lāua ʻo Ruiz-Pino, 2009ʻIkepili mai ka World Ocean Atlas 2013)1. I ka wā o ka hoʻolaha kahua i hōʻike ʻia ma ʻaneʻi, ua ana mākou i ka oxygen ma ka OMZ core ma nā ʻano lawa (0.35 μM) e kākoʻo i nā kaʻina hana microbial aerobic, e like me ka ammonium a me ka nitrite oxidation, a kāohi hapa i nā kaʻina hana microbial anaerobic koʻikoʻi. Ua ʻike mua ʻia nā kaʻina hana microbial aerobic ma nā papa suboxic a i ʻole anoxic o ka ETNP OMZ (Peng et al., 2015;Garcia-Robledo et al., 2017;Penn et al., 2019Eia nō naʻe, ʻaʻole maopopo loa nā kumu e kaohi ana i ka hoʻolaha ʻana a me nā hana o nā hui hana kikoʻī o nā microorganism i loko o OMZ.
ʻO ke alo o nā nitrifiers kahi i ʻike ʻole ʻia ai ka oxygen i loko o kahi OMZ hiki ke wehewehe ʻia e nā loli hou i ke kūlana kū pololei o ka oxycline ma muli o ka ea oxygen kū pololei episodic, hiki ke alakaʻi i nā pae oxygen trace ephemeral i loko o nā cores OMZ (Muller-Karger et al., 2001;ʻUlloa et al., 2012;Garcia-Robledo et al., 2017). Hiki ke hoʻohana ʻia kēlā mau kūlana transient e nā heluna aerobic a i ʻole microaerophilic, me nā nitrifiers. Eia kekahi, ʻo nā ʻāpana e piholo ana mai ka epipelagic (nā cell i hoʻohui ʻia, nā pellets fecal, a me nā mea organik paʻakikī) hiki ke loaʻa nā pae liʻiliʻi o ka oxygen (Ganesh et al., 2014). No laila, hiki ke lawe ʻia ka oxygen a me nā microbes aerobic i nā wai anoxic ʻē aʻe, e ʻae ana i nā metabolism aerobic no kekahi manawa e hana pū me nā ʻāpana. Ua ʻike ʻia nā ʻāpana he mau wahi wela o ka microbial biogeochemical cycling (Simon et al., 2002;Ganesh et al., 2014) a hiki ke kākoʻo i nā kaʻina hana microbial anaerobic a aerobic paha i ʻike ʻole ʻia ma ke kūlana ola manuahi (ʻAlldredge lāua ʻo Cohen, 1987;Wright et al., 2012;Suter et al., 2018).
Ma ke aʻo ʻana o kēia manawa, ke noiʻi nei mākou i nā kaiāulu prokaryotic e noho ana ma ka palena ʻākau o ka OMZ o ka ETNP a me nā mea pili i ke kaiapuni e hoʻohuli paha i kā lākou hoʻolaha kū pololei me ka hoʻohana ʻana i ka 16S amplicon sequencing (iTags) i hui pū ʻia me nā helu helu multivariate. Ua nānā mākou i ʻelua mau ʻāpana nui; ka ʻāpana ola manuahi (0.2–2.7 μm), a me ka ʻāpana pili i ka ʻāpana (>2.7 μm, e hopu ana i nā ʻāpana a me nā cell protistan) ma nā hohonu he nui ma ka oxycline e pili ana i nā kūlana redox like ʻole.
Hiki iā mākou ke hāʻawi i nā mea ʻike oxygen i hoʻoheheʻe ʻia me nā palena like ʻole, i hiki ke nānā ʻia ka nui o ka molekala i ka manawa maoli. Welina e kūkākūkā
https://www.alibaba.com/product-detail/Wifi-4G-Gprs-RS485-4-20mA_1600559098578.html?spm=a2747.product_manager.0.0.169671d29scvEu
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Ka manawa hoʻouna: Iulai-05-2024