a-small-volume-bioassay-to-assess-bacterialphytoplankton-co-culture

A Small Volume Bioassay to Assess Bacterial/Phytoplankton Co-culture Using WATER-Pulse-Amplitude-Modulated (WATER-PAM) Fluorometry

Conventional methods for experimental manipulation of microalgae have employed large volumes of culture (20 ml to 5 L), so that the culture can be ...

University of Alberta

&#x73B0;&#x5728;&#x5DF2;&#x77E5;&#x6A2A;&#x5411;&#x57FA;&#x56E0;&#x8F6C;&#x79FB; (LGT) &#x539F;&#x6838;&#x57FA;&#x56E0;&#x7EC4;&#x8FDB;&#x5316;&#x7684;&#x4E3B;&#x8981;&#x529B;&#x91CF;&#x3002;&#x5230;&#x76EE;&#x524D;&#x4E3A;&#x6B62;&#xFF0C;&#x5927;&#x591A;&#x6570;&#x7684;&#x5206;&#x6790;&#x96C6;&#x4E2D;&#x5728; (a) &#x6838;&#x5B9E;&#x4E2A;&#x4EBA;&#x57FA;&#x56E0; phylogenies &#x8BA4;&#x4E3A;&#x5DF2;&#x88AB;&#x8F6C;&#x79FB;&#xFF0C;&#x6216; (b) &#x4F30;&#x8BA1;&#x53EF;&#x80FD;&#x91C7;&#x53D6;&#x7684;&#x8F6C;&#x79FB;&#x4E2A;&#x4EBA;&#x57FA;&#x56E0;&#x7EC4;&#x7684;&#x5206;&#x6570;&#x3002;&#x4E24;&#x79CD;&#x65B9;&#x6CD5;&#x6CA1;&#x6709;&#x53F8;&#x6CD5; LGT &#x5230;&#x57FA;&#x672C;&#x751F;&#x7269;&#x5B66;&#x6548;&#x5E94;&#x5927;&#x89C4;&#x6A21;&#x548C;&#x590D;&#x6742;&#x8F6C;&#x6362;&#x7684;&#x80FD;&#x529B;&#x3002;&#x5728;&#x67D0;&#x4E9B;&#x60C5;&#x51B5;&#x4E0B;&#xFF0C;&#x8FD9;&#x79CD;&#x8F6C;&#x53D8;&#x5C06;&#x5206;&#x4EAB;&#x7684;&#x5176;&#x4ED6;&#x5C5E;&#x6027; &#xFF08;&#x4EE3;&#x8C22;&#x3001; &#x5F62;&#x6001;&#xFF0C;&#x6216;&#x5206;&#x5B50;&#xFF0C;&#x4F8B;&#x5982;&#x5C0F;&#x4E9A;&#x57FA;&#x6838;&#x7CD6;&#x4F53; RNA &#x5E8F;&#x5217;&#xFF09; &#x7684;&#x7ECF;&#x5178;&#x5B9A;&#x4E49;&#x7684;&#x7EC4;&#x6210;&#x5458;&#x4E4B;&#x95F4;&#x8868;&#x73B0;&#x4E3A;&#x770B;&#x4F3C;&#x57FA;&#x672C;&#x5C5E;&#x6027; &#xFF08;&#x5982;&#x597D;&#x6C27;&#x6216;&#x56FA;&#x6C2E;) &#x7684;&#x96F6;&#x6563;&#x5206;&#x5E03;&#x3002;&#x5728;&#x5176;&#x4ED6;&#x60C5;&#x51B5;&#x4E0B;&#xFF0C;&#x53EF;&#x80FD;&#x770B;&#x5230;&#x7684;&#x6536;&#x4EF6;&#x4EBA;&#xFF0C;&#x56E0;&#x6B64;&#x6539;&#x53D8;&#x6CBF;&#x88AD;&#x7EC4;&#x6210;&#x4E00;&#x7EC4;&#x65B0;&#x7684;&#x9AD8;&#x5206;&#x7C7B;&#x6392;&#x540D; &#xFF08;&quot;&#x7C7B;&quot;&#x6216;&#x751A;&#x81F3;&quot;&#x52A8;&#x7269;&#x95E8;&quot;&#xFF09;&#x3002;&#x5728;&#x8FD9;&#x91CC;&#x6211;&#x4EEC;&#x68C0;&#x8BA8; LGT &#x5149;&#x5408;&#x4F5C;&#x7528;&#x3001; &#x6709;&#x6C27;&#x547C;&#x5438;&#x3001; &#x56FA;&#x6C2E;&#x3001; &#x786B;&#x9178;&#x76D0;&#x8FD8;&#x539F;&#x3001; methylotrophy&#x3001; &#x841C;&#x3001; &#x611F;&#x5E94;&#x3001; &#x6D6E;&#x9009; &#xFF08;&#x6C14;&#x4F53;&#x6CE1;)&#x3001; thermophily&#x3001; &#x53D1;&#x5C55;&#x8FC7;&#x7A0B;&#x4E2D;&#x7684;&#x91CD;&#x8981;&#x4F5C;&#x7528;&#x7684;&#x8BC1;&#x636E;&#x548C; halophily&#x3002;&#x6709;&#x65F6;&#x590D;&#x6742;&#x57FA;&#x56E0;&#x7C07;&#x7684;&#x8F6C;&#x79FB;&#x53EF;&#x80FD;&#x5DF2;&#x7ECF;&#x6D89;&#x53CA;&#xFF0C;&#x800C;&#x5176;&#x4ED6;&#x65F6;&#x95F4;&#x5206;&#x5F00;&#xFF0C;&#x5219;&#x5FC5;&#x987B;&#x8C03;&#x7528;&#x8BB8;&#x591A;&#x57FA;&#x56E0;&#x4EA4;&#x6D41;&#x3002;

&#x6A2A;&#x5411;&#x57FA;&#x56E0;&#x8F6C;&#x79FB;&#x4E0E;&#x539F;&#x6838;&#x7EC4;&#x7684;&#x8D77;&#x6E90;&#x3002;

Lateral gene transfer (LGT) is now known to be a major force in the evolution of prokaryotic genomes. To date, most analyses have focused on either (a) verifying phylogenies of individual genes thought to have been transferred, or (b) estimating the fraction of individual genomes likely to have been introduced by transfer. Neither approach does justice to the ability of LGT to effect massive and complex transformations in basic biology. In some cases, such transformation will be manifested as the patchy distribution of a seemingly fundamental property (such as aerobiosis or nitrogen fixation) among the members of a group classically defined by the sharing of other properties (metabolic, morphological, or molecular, such as small subunit ribosomal RNA sequence). In other cases, the lineage of recipients so transformed may be seen to comprise a new group of high taxonomic rank ("class" or even "phylum"). Here we review evidence for an important role of LGT in the evolution of photosynthesis, aerobic respiration, nitrogen fixation, sulfate reduction, methylotrophy, isoprenoid biosynthesis, quorum sensing, flotation (gas vesicles), thermophily, and halophily. Sometimes transfer of complex gene clusters may have been involved, whereas other times separate exchanges of many genes must be invoked.

Lateral gene transfer and the origins of prokaryotic groups.

Transferts de g&egrave;nes lat&eacute;raux (LGT) est maintenant connu pour &ecirc;tre une force majeure dans l&#39;&eacute;volution des g&eacute;nomes procaryotes. A ce jour, la plupart des analyses ont port&eacute; sur (a) v&eacute;rifier les phylog&eacute;nies des g&egrave;nes individuels suppos&eacute;s ont &eacute;t&eacute; transf&eacute;r&eacute;s, ou (b) estimation de la fraction des g&eacute;nomes individuels susceptibles d&#39;ont &eacute;t&eacute; introduites par transfert. Aucune approche rend justice &agrave; la capacit&eacute; de LGT &agrave; effet massif et complexe des transformations en biologie fondamentale. Dans certains cas, cette transformation se manifestera comme le morcellement de la r&eacute;partition d&#39;une propri&eacute;t&eacute; apparemment fondamentale (tels qu&#39;a&eacute;robiose ou fixation de l&#39;azote) parmi les membres d&#39;un groupe classiquement d&eacute;fini par le partage d&#39;autres propri&eacute;t&eacute;s (m&eacute;taboliques, morphologiques ou mol&eacute;culaires, comme la s&eacute;quence d&#39;ARN ribosomique petite sous-unit&eacute;). Dans d&#39;autres cas, on peut consid&eacute;rer la lign&eacute;e des r&eacute;cipiendaires ainsi transform&eacute; pour former un nouveau groupe de haut rang taxonomique (&laquo; class &raquo; ou m&ecirc;me &laquo; embranchement &raquo;). Ici nous passons en revue les &eacute;l&eacute;ments de preuve pour un r&ocirc;le important de LGT dans l&#39;&eacute;volution de la photosynth&egrave;se, la respiration a&eacute;robie, fixation de l&#39;azote, r&eacute;duction du sulfate, methylotrophy, la biosynth&egrave;se des isopr&eacute;no&iuml;des, quorum sensing, flottation (v&eacute;sicules gazeuses), thermophilie et halophily. Parfois transfert de groupes de g&egrave;nes complexes ont pu participer, tandis que les autres fois s&eacute;parent doivent &ecirc;tre &eacute;mis pour &eacute;changes de nombreux g&egrave;nes.

Transferts de g&egrave;nes lat&eacute;raux et les origines des groupes procaryotiques.

Lateralen Gentransfer und die Urspr&#xFC;nge der prokaryotischen Gruppen.

Trasferimento genico laterale (LGT) ora &egrave; conosciuto per essere una forza importante nell&#39;evoluzione dei genomi eucarioti. Ad oggi, la maggior parte delle analisi sono concentrati su (a) verifica la filogenesi dei singoli geni si pensiero siano state trasferite, oppure (b) stimare la frazione di genomi individuali probabilmente sono state introdotte dal trasferimento. N&eacute; l&#39;approccio fa giustizia alla capacit&agrave; di LGT trasformazioni massiccio e complesso effetto nella biologia di base. In alcuni casi, tale trasformazione sar&agrave; essere manifestata come la distribuzione irregolare di una propriet&agrave; apparentemente fondamentale (ad esempio aerobiosi o fissazione dell&#39;azoto) tra i membri di un gruppo definito classicamente la condivisione di altre propriet&agrave; (metabolica, morfologica o molecolare, come la sequenza di RNA ribosomiale di piccole subunit&agrave;). In altri casi, il lignaggio dei destinatari cos&igrave; trasformata pu&ograve; essere visto a comprendono un nuovo gruppo di alto rango tassonomico (&quot;classe&quot; o anche &quot;phylum&quot;). Qui recensiamo le prove per un importante ruolo di LGT nell&#39;evoluzione della fotosintesi, respirazione aerobica, fissazione dell&#39;azoto, riduzione del solfato, methylotrophy, isoprenoid biosintesi, quorum sensing, flottazione (vescicole di gas), thermophily e halophily. A volte trasferimento dei cluster complessi gene potrebbe essere stato coinvolto, mentre altre volte separano gli scambi di molti geni devono essere richiamati.

Trasferimento genico laterale e le origini dei gruppi prokaryotic.

&#x907A;&#x4F1D;&#x5B50;&#x306E;&#x6C34;&#x5E73;&#x79FB;&#x52D5; &#xFF08;LGT&#xFF09; &#x306F;&#x3001;&#x73FE;&#x5728;&#x306E;&#x539F;&#x6838;&#x751F;&#x7269;&#x30B2;&#x30CE;&#x30E0;&#x306E;&#x9032;&#x5316;&#x306B;&#x5927;&#x304D;&#x306A;&#x529B;&#x77E5;&#x3089;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x65E5;&#x4ED8;&#x3059;&#x308B;&#x306B;&#x306F;&#x3001;&#x591A;&#x304F;&#x306E;&#x89E3;&#x6790; (a) &#x500B;&#x3005; &#x306E;&#x907A;&#x4F1D;&#x5B50;&#x306E;&#x7CFB;&#x7D71;&#x3092;&#x8EE2;&#x9001;&#x3055;&#x308C;&#x3066;&#x3044;&#x308B;&#x3068;&#x8003;&#x3048;&#x3089;&#x308C;&#x3066;&#x306E;&#x78BA;&#x8A8D;&#x307E;&#x305F;&#x306F; (b) &#x500B;&#x4EBA;&#x30B2;&#x30CE;&#x30E0;&#x4F1D;&#x9054;&#x306B;&#x3088;&#x3063;&#x3066;&#x5C0E;&#x5165;&#x3055;&#x308C;&#x3066;&#x3044;&#x308B;&#x53EF;&#x80FD;&#x6027;&#x304C;&#x9AD8;&#x3044;&#x306E;&#x5272;&#x5408;&#x306E;&#x63A8;&#x5B9A;&#x306B;&#x7126;&#x70B9;&#x3092;&#x5F53;&#x3066;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x3069;&#x3061;&#x3089;&#x306E;&#x30A2;&#x30D7;&#x30ED;&#x30FC;&#x30C1;&#x3082;&#x6B63;&#x7FA9; LGT &#x306E;&#x529B;&#x57FA;&#x790E;&#x751F;&#x7269;&#x5B66;&#x306B;&#x304A;&#x3051;&#x308B;&#x52B9;&#x679C;&#x306E;&#x5927;&#x898F;&#x6A21;&#x304B;&#x3064;&#x8907;&#x96D1;&#x306A;&#x5909;&#x63DB;&#x3092;&#x884C;&#x3044;&#x307E;&#x3059;&#x3002;&#x3044;&#x304F;&#x3064;&#x304B;&#x306E;&#x30B1;&#x30FC;&#x30B9;&#x3067;&#x306F;&#x3001;&#x3053;&#x306E;&#x3088;&#x3046;&#x306A;&#x5909;&#x63DB; (aerobiosis &#x3084;&#x7A92;&#x7D20;&#x56FA;&#x5B9A;&#xFF09; &#x306A;&#x3069;&#x4E00;&#x898B;&#x57FA;&#x672C;&#x7684;&#x306A;&#x7279;&#x6027;&#x306E;&#x6591;&#x72B6;&#x306E;&#x5206;&#x5E03;&#x3068;&#x3057;&#x3066;&#x53E4;&#x5178;&#x7684;&#x306A;&#x305D;&#x306E;&#x4ED6;&#x306E;&#x30D7;&#x30ED;&#x30D1;&#x30C6;&#x30A3; (&#x4EE3;&#x8B1D;&#x3001;&#x5F62;&#x614B;&#x3001;&#x307E;&#x305F;&#x306F;&#x5206;&#x5B50;&#x5C0F;&#x30B5;&#x30D6;&#x30E6;&#x30CB;&#x30C3;&#x30C8; &#x30EA;&#x30DC;&#x30BD;&#x30FC;&#x30E0; RNA &#x30B7;&#x30FC;&#x30B1;&#x30F3;&#x30B9;&#x306A;&#x3069;) &#x306E;&#x5171;&#x6709;&#x306B;&#x3088;&#x3063;&#x3066;&#x5B9A;&#x7FA9;&#x3055;&#x308C;&#x305F;&#x30B0;&#x30EB;&#x30FC;&#x30D7;&#x306E;&#x30E1;&#x30F3;&#x30D0;&#x30FC;&#x306E;&#x9593;&#x3067;&#x660E;&#x3089;&#x304B;&#x306B;&#x3055;&#x308C;&#x307E;&#x3059;&#x3002;&#x4ED6;&#x306E;&#x30B1;&#x30FC;&#x30B9;&#x3067;&#x306F;&#x3001;&#x3057;&#x305F;&#x304C;&#x3063;&#x3066;&#x5909;&#x63DB;&#x53D7;&#x4FE1;&#x8005;&#x306E;&#x7CFB;&#x7D71;&#x5206;&#x985E;&#x5B66;&#x7684;&#x4E0A;&#x4F4D; (&#x300C;&#x30AF;&#x30E9;&#x30B9;&#x300D;&#x307E;&#x305F;&#x306F;&#x5076;&#x6570;&#x300C;&#x9580;&#x300D;) &#x306E;&#x65B0;&#x3057;&#x3044;&#x30B0;&#x30EB;&#x30FC;&#x30D7;&#x3092;&#x69CB;&#x6210;&#x3059;&#x308B;&#x306E;&#x306B;&#x898B;&#x3089;&#x308C;&#x308B;&#x304B;&#x3082;&#x3057;&#x308C;&#x306A;&#x3044;&#x3002;&#x3053;&#x3053;&#x3067;&#x306F; LGT &#x5149;&#x5408;&#x6210;&#x3001;&#x597D;&#x6C17;&#x547C;&#x5438;&#x3001;&#x7A92;&#x7D20;&#x56FA;&#x5B9A;&#x3001;&#x786B;&#x9178;&#x9084;&#x5143;, methylotrophy, &#x30A4;&#x30BD;&#x30D7;&#x30EC;&#x30CE;&#x30A4;&#x30C9;&#x751F;&#x5408;&#x6210;&#x3001;&#x30AF;&#x30AA;&#x30E9;&#x30E0;&#x30BB;&#x30F3;&#x30B7;&#x30F3;&#x30B0;&#x3001;&#x6D6E;&#x9078; (&#x30AC;&#x30B9;&#x5C0F;&#x80DE;)&#x3001;thermophily &#x306E;&#x9032;&#x5316;&#x306B;&#x304A;&#x3044;&#x3066;&#x91CD;&#x8981;&#x306A;&#x5F79;&#x5272;&#x306E;&#x305F;&#x3081;&#x306E;&#x8A3C;&#x62E0;&#x3092;&#x78BA;&#x8A8D;&#x3057;&#x3001;halophily&#x3002;&#x6642;&#x3005; &#x8907;&#x96D1;&#x306A;&#x907A;&#x4F1D;&#x5B50;&#x30AF;&#x30E9;&#x30B9;&#x30BF;&#x30FC;&#x306E;&#x79FB;&#x8EE2;&#x304C;&#x95A2;&#x4E0E;&#x3057;&#x3066;&#x3044;&#x308B;&#x53EF;&#x80FD;&#x6027;&#x304C;&#x3042;&#x308A;&#x307E;&#x3059;&#x3001;&#x4ED6;&#x306E;&#x56DE;&#x3092;&#x5206;&#x3051;&#x308B;&#x4E00;&#x65B9;&#x591A;&#x304F;&#x306E;&#x907A;&#x4F1D;&#x5B50;&#x306E;&#x4EA4;&#x63DB;&#x3092;&#x547C;&#x3073;&#x51FA;&#x3059;&#x5FC5;&#x8981;&#x304C;&#x3042;&#x308A;&#x307E;&#x3059;&#x3002;

&#x907A;&#x4F1D;&#x5B50;&#x306E;&#x6C34;&#x5E73;&#x79FB;&#x52D5;&#x3068;&#x539F;&#x6838;&#x751F;&#x7269;&#x30B0;&#x30EB;&#x30FC;&#x30D7;&#x306E;&#x8D77;&#x6E90;&#x3002;

&#xC218;&#xD3C9;&#xC801; &#xC720;&#xC804;&#xC790; &#xC774;&#xB3D9; (LGT) &#xC9C0;&#xAE08; prokaryotic &#xC720;&#xC804;&#xC790;&#xC758; &#xC9C4;&#xD654;&#xC5D0; &#xD070; &#xD798; &#xB420; &#xC54C;&#xB824;&#xC838; &#xC788;&#xB2E4;. &#xC9C0;&#xAE08;&#xAE4C;&#xC9C0; &#xB300;&#xBD80;&#xBD84;&#xC758; &#xBD84;&#xC11D; (a) &#xD655;&#xC778; &#xAC1C;&#xBCC4; &#xC720;&#xC804;&#xC790;&#xC758; phylogenies &#xC804;&#xC1A1; &#xB41C; &#xAC83;&#xC73C;&#xB85C; &#xC0DD;&#xAC01; &#xD558;&#xAC70;&#xB098; (b) &#xAC1C;&#xBCC4; &#xC720;&#xC804;&#xC790; &#xC804;&#xC1A1;&#xC744; &#xD558; &#xC5EC; &#xB3C4;&#xC785; &#xAC00;&#xB2A5;&#xC131;&#xC774; &#xC77C;&#xBD80; &#xC608;&#xCE21;&#xC5D0; &#xC9D1;&#xC911; &#xD588;&#xB2E4;. &#xB450; &#xC811;&#xADFC; &#xAE30;&#xBCF8; &#xC0DD;&#xBB3C;&#xD559;&#xC5D0;&#xC11C; &#xD6A8;&#xACFC; &#xB300;&#xADDC;&#xBAA8; &#xBC0F; &#xBCF5;&#xC7A1; &#xD55C; &#xBCC0;&#xD658; &#xD558;&#xB294; LGT&#xC758; &#xAE30;&#xB2A5;&#xC744; &#xC815;&#xC758; &#xD55C;&#xB2E4;. &#xC5B4;&#xB5A4; &#xACBD;&#xC6B0;&#xC5D0; &#xACE0;&#xC804;&#xC801;&#xC778; &#xC815;&#xC758; (&#xB300;&#xC0AC;, &#xD615;&#xD0DC;&#xD559;, &#xB610;&#xB294; &#xBD84;&#xC790;, &#xC791;&#xC740; &#xC18C; &#xB2E8;&#xC704; ribosomal RNA &#xC21C;&#xC11C; &#xB4F1;) &#xB2E4;&#xB978; &#xC18D;&#xC131;&#xC744; &#xACF5;&#xC720; &#xD558; &#xC5EC; &#xADF8;&#xB8F9; &#xAD6C;&#xC131;&#xC6D0; &#xAC04;&#xC758; &#xC774;&#xB7EC;&#xD55C; &#xBCC0;&#xD658; &#xAC89;&#xBCF4;&#xAE30; &#xAE30;&#xBCF8;&#xC801;&#xC778; &#xC18D;&#xC131; (&#xC608;: aerobiosis &#xB610;&#xB294; &#xC9C8;&#xC18C; &#xACE0;&#xC815;)&#xC758; &#xB204; &#xB355; &#xB204; &#xB355; &#xBC30;&#xAE09;&#xC73C;&#xB85C; &#xAC70;&#xBD80; &#xB098;&#xD0C0;&#xB0A9;&#xB2C8;&#xB2E4;. &#xB2E4;&#xB978; &#xACBD;&#xC6B0;&#xC5D0; &#xADF8;&#xB798;&#xC11C; &#xBCC0;&#xD658; &#xD558;&#xB294; &#xBC1B;&#xB294; &#xC0AC;&#xB78C;&#xC758; &#xD608;&#xD1B5; &#xB192;&#xC740; taxonomic &#xC21C;&#xC704; (&quot;&#xD074;&#xB798;&#xC2A4;&quot; &#xB610;&#xB294; &#xC2EC;&#xC9C0;&#xC5B4; &quot;&#xBB38;&quot;)&#xC758; &#xC0C8; &#xADF8;&#xB8F9;&#xC744; &#xAD6C;&#xC131; &#xD558; &#xAC8C; &#xBCFC; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. LGT&#xC758; &#xAD11;&#xD569;&#xC131;, &#xD638; &#xAE30;&#xC131; &#xD638;&#xD761;, &#xC9C8;&#xC18C; &#xACE0;&#xC815;, &#xD669;&#xC0B0; &#xC5FC; &#xAC10;&#xC18C;, methylotrophy, isoprenoid &#xC0DD; &#xD569;&#xC131;, &#xCFFC;&#xB7FC; &#xC13C; &#xC2F1;, &#xBD80;&#xC591; (&#xAC00;&#xC2A4; &#xC18C;&#xD3EC;), thermophily&#xC758; &#xC9C4;&#xD654;&#xC5D0; &#xC911;&#xC694; &#xD55C; &#xC5ED;&#xD560;&#xC5D0; &#xB300; &#xD55C; &#xC99D;&#xAC70;&#xB97C; &#xAC80;&#xD1A0; &#xD558;&#xB294; &#xC5EC;&#xAE30;&#xC640; halophily. &#xAC00;&#xB054; &#xBCF5;&#xC7A1; &#xD55C; &#xC720;&#xC804;&#xC790; &#xD074;&#xB7EC;&#xC2A4;&#xD130; &#xC804;&#xC1A1; &#xAD00;&#xB828; &#xB418;&#xC5C8;&#xC744; &#xC218;&#xB3C4; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;, &#xADF8;&#xB9AC;&#xACE0; &#xB9CE;&#xC740; &#xC720;&#xC804;&#xC790;&#xC758; &#xAD50;&#xB958;&#xB97C; &#xD638;&#xCD9C; &#xD574;&#xC57C; &#xD569;&#xB2C8;&#xB2E4; &#xB2E4;&#xB978; &#xC2DC;&#xAC04; &#xAD6C;&#xBD84; &#xD558;&#xB294; &#xBC18;&#xBA74;.

&#xC218;&#xD3C9;&#xC801; &#xC720;&#xC804;&#xC790; &#xC774;&#xB3D9; &#xBC0F; prokaryotic &#xADF8;&#xB8F9;&#xC758; &#xAE30;&#xC6D0;.

Transferencia lateral del gene (LGT) ahora es conocida por ser una fuerza importante en la evoluci&oacute;n de los genomas procariotas. Hasta la fecha, la mayor&iacute;a de los an&aacute;lisis se han centrado en (a) verificar filogenias de genes individuales se cree que han sido transferidos, o (b) estimaci&oacute;n de la fracci&oacute;n de genomas individuales que se han introducido por transferencia. Ni enfoque hace a justicia a la capacidad de la LGT para efectuar transformaciones masivas y complejos en biolog&iacute;a b&aacute;sica. En algunos casos, tal transformaci&oacute;n se se manifiesta como la distribuci&oacute;n desigual de una propiedad aparentemente fundamental (como aerobiosis o fijaci&oacute;n de nitr&oacute;geno) entre los miembros de un grupo cl&aacute;sicamente definido por el intercambio de otras propiedades (metab&oacute;licos, morfol&oacute;gicas o moleculares, como la secuencia de ARN ribosomal subunidad peque&ntilde;a). En otros casos, puede verse el linaje de los destinatarios as&iacute; transform&oacute; para formar un nuevo grupo de alto rango taxon&oacute;mico (&quot;clase&quot; o incluso &quot;filo&quot;). Aqu&iacute; repasamos evidencia un importante papel de la LGT en la evoluci&oacute;n de la fotos&iacute;ntesis, respiraci&oacute;n aer&oacute;bica, la fijaci&oacute;n de nitr&oacute;geno, reducci&oacute;n del sulfato, methylotrophy, bios&iacute;ntesis de isoprenoides, quorum sensing, flotaci&oacute;n (ves&iacute;culas de gas), thermophily y halophily. A veces, transferencia de racimos de gene complejo pudieran estar implicado, mientras que otras veces separan deben invocarse intercambios de muchos genes.

Transferencia lateral del gene y los or&iacute;genes de grupos procari&oacute;ticos.

Several characteristics of the 16S rRNA gene, such as its essential function, ubiquity, and evolutionary properties, have allowed it to become the most commonly used molecular marker in microbial ecology. However, one fact that has been overlooked is that multiple copies of this gene are often present in a given bacterium. These intragenomic copies can differ in sequence, leading to identification of multiple ribotypes for a single organism. To evaluate the impact of such intragenomic heterogeneity on the performance of the 16S rRNA gene as a molecular marker, we compared its phylogenetic and evolutionary characteristics to those of the single-copy gene rpoB. Full-length gene sequences and gene fragments commonly used for denaturing gradient gel electrophoresis were compared at various taxonomic levels. Heterogeneity found between intragenomic 16S rRNA gene copies was concentrated in specific regions of rRNA secondary structure. Such "heterogeneity hot spots" occurred within all gene fragments commonly used in molecular microbial ecology. This intragenomic heterogeneity influenced 16S rRNA gene tree topology, phylogenetic resolution, and operational taxonomic unit estimates at the species level or below. rpoB provided comparable phylogenetic resolution to that of the 16S rRNA gene at all taxonomic levels, except between closely related organisms (species and subspecies levels), for which it provided better resolution. This is particularly relevant in the context of a growing number of studies focusing on subspecies diversity, in which single-copy protein-encoding genes such as rpoB could complement the information provided by the 16S rRNA gene.

Use of 16S rRNA and rpoB genes as molecular markers for microbial ecology studies.

AHL-driven quorum-sensing circuits: their frequency and function among the Proteobacteria.

Host-pathogen interactions have been widely studied in humans and terrestrial plants, but are much less well explored in marine systems. Here we show that a marine macroalga, Delisea pulchra, utilizes a chemical defence - furanones - to inhibit colonization and infection by a novel bacterial pathogen, Ruegeria sp. R11, and that infection by R11 is temperature dependent. Ruegeria sp. R11 formed biofilms, invaded and bleached furanone-free, but not furanone-producing D. pulchra thalli, at high (24°C) but not low (19°C) temperatures. Bleaching is commonly observed in natural populations of D. pulchra near Sydney, Australia, during the austral summer when ocean temperatures are at their peak and the chemical defences of the alga are reduced. Furanones, produced by D. pulchra as a chemical defence, inhibit quorum sensing (QS) in bacteria, and this may play a role in furanone inhibition of R11 infection of furanone-free thalli as R11 produces QS signals. This interplay between temperature, an algal chemical defence mechanism and bacterial virulence demonstrates the complex impact environmental change can have on an ecosystem.

Temperature induced bacterial virulence and bleaching disease in a chemically defended marine macroalga.

Emiliania huxleyi, &#xD658;&#xACBD;&#xC801;&#xC73C;&#xB85C; &#xC911;&#xC694; &#xD55C; &#xD574;&#xC591; microalga &#xB098;&#xD0C0;&#xB098;&#xACE0; &#xD1F4;&#xC0C9;&#xC744; &#xB300;&#xADDC;&#xBAA8; &#xC870;&#xB958; &#xAF43; &#xAF43;&#xACFC; &#xBC14;&#xC2A4; &#xD2B8; &#xC0DD;&#xD65C;&#xC744; &#xD558;&#xACE0;&#xC788;&#xB2E4;. Phaeobacter gallaeciensis roseobacter clade &alpha;-Proteobacteria&#xC758;, &#xADF8; &#xC911; huxleyi&#xB294; &#xC641; &#xC2A4; &#xBC0F; &#xAC10;&#xD1F4; &#xC778;&#xAD6C;&#xC5D0; &#xC18D;&#xD55C;&#xB2E4;. Roseobacter biosynthesizing &#xBC0F; &#xD56D;&#xC0DD;&#xC81C;&#xC640; &#xC131;&#xC7A5; &#xC790;&#xADF9; (auxins) &#xC740;&#xB2C9; &#xD558; &#xC5EC; &#xC870;&#xB958;&#xC758; &#xC131;&#xC7A5;&#xC744; &#xCD09;&#xC9C4; &#xD558; &#xC0DD;&#xAC01; &#xB41C;&#xB2E4;. &#xC5EC;&#xAE30;&#xB294; &#xD53C; &#xBCF4;&#xC5EC; gallaeciensis &#xC804;&#xD658; &#xBE44; &#xC791;&#xC740; &#xBD84;&#xC790; &#xB300;&#xC0AC;&#xB294; &#xAC15;&#xB825; &#xD558; &#xACE0; &#xC120;&#xD0DD;&#xC801;&#xC778; algaecides, p coumaric &#xC0B0;, &#xC870;&#xB958; &#xB9AC;&#xADF8; &#xB2CC; &#xBD84;&#xD574; &#xC81C;&#xD488;&#xC785;&#xB2C8;&#xB2E4; &#xC870;&#xB958; &#xB178;&#xD654;&#xC758; &#xC99D;&#xC0C1;&#xC5D0; &#xB300; &#xD55C; &#xC751;&#xB2F5; roseobacticides&#xC758; &#xC0DD;&#xC0B0;. &#xC774; &#xC2A4;&#xC704;&#xCE58; &#xBCC0;&#xD658; &#xC870;&#xB958; &#xD638;&#xC2A4;&#xD2B8;&#xC758; &#xAE30;&#xD68C; &#xBCD1;&#xC6D0; &#xCCB4; P. gallaeciensis&#xC744; &#xC0AC;&#xC6A9; &#xD569;&#xB2C8;&#xB2E4;.

Phaeobacter gallaeciensis&#xC758; &#xC9C0;&#xD0AC;&#xACFC; &#xD558;&#xC774;&#xB4DC; &#xD654;&#xD559;.

&#x7403;&#x77F3;&#x85FB;&#x5728;&#x5730;&#x533A;&#xFF0C;&#x73AF;&#x5883;&#x4E0A;&#x91CD;&#x8981;&#x7684;&#x6D77;&#x6D0B;&#x5FAE;&#x85FB;&#xFF0C;&#x5DF2;&#x7EFD;&#x653E;&#x6CE1;&#x6CAB;&#x7834;&#x706D;&#x751F;&#x6D3B;&#x65B9;&#x5F0F;&#x7684;&#x5927;&#x89C4;&#x6A21;&#x85FB;&#x7C7B;&#x5927;&#x91CF;&#x7E41;&#x6B96;&#x51FA;&#x73B0;&#x548C;&#x6D88;&#x5931;&#x3002;Phaeobacter gallaeciensis &#x6240;&#x5C5E;&#x7684; &alpha; Proteobacteria roseobacter &#x8FDB;&#x5316;&#x3001; &#x4E0E; E.&#x5730;&#x533A;&#x54EA;&#x4E9B;&#x8721;&#x548C;&#x8870;&#x843D;&#x7684;&#x4EBA;&#x53E3;&#x3002;Roseobacter &#x8BA4;&#x4E3A;&#xFF0C;&#x4FC3;&#x8FDB;&#x85FB;&#x7C7B;&#x751F;&#x957F;&#x7684;&#x91CD;&#x548C;&#x5206;&#x6CCC;&#x6297;&#x751F;&#x7D20;&#x548C;&#x589E;&#x957F;&#x5174;&#x594B;&#x5242; (&#x751F;&#x957F;&#x7D20;)&#x3002;&#x5728;&#x8FD9;&#x91CC;&#x6211;&#x4EEC;&#x8868;&#x660E;&#x4F53;&#x80B2; gallaeciensis &#x5C06;&#x5176;&#x5206;&#x6CCC;&#x7684;&#x5C0F;&#x5206;&#x5B50;&#x4EE3;&#x8C22;&#x5207;&#x6362;&#x5230;&#x751F;&#x4EA7;&#x7684;&#x5F3A;&#x5927;&#x548C;&#x9009;&#x62E9;&#x6027;&#x9632;&#x9709;&#x9632;&#x85FB;&#x5242;&#xFF0C;roseobacticides-&#x9999;&#x8C46;&#x9178;&#x3001; &#x85FB;&#x7C7B;&#x6728;&#x8D28;&#x7D20;&#x5206;&#x89E3;&#x4EA7;&#x7269;&#x5373;&#x75C7;&#x72B6;&#x6027;&#x8001;&#x5316;&#x85FB;&#x7C7B;&#x7684;&#x56DE;&#x5E94;&#x3002;&#x6B64;&#x5F00;&#x5173;&#x5C06;&#x4F53;&#x80B2; gallaeciensis &#x8F6C;&#x6362;&#x6210;&#x5176;&#x85FB;&#x4E3B;&#x673A;&#x673A;&#x4F1A;&#x4E3B;&#x4E49;&#x75C5;&#x539F;&#x3002;

&#x6770;&#x57FA;&#x5C14;&#x6D77;&#x5FB7;&#x5316;&#x5B66;&#x6210;&#x5206; Phaeobacter gallaeciensis&#x3002;

Emiliania huxleyi, an environmentally important marine microalga, has a bloom-and-bust lifestyle in which massive algal blooms appear and fade. Phaeobacter gallaeciensis belongs to the roseobacter clade of Î±-Proteobacteria, the populations of which wax and wane with that of E. huxleyi. Roseobacter are thought to promote algal growth by biosynthesizing and secreting antibiotics and growth stimulants (auxins). Here we show that P. gallaeciensis switches its secreted small molecule metabolism to the production of potent and selective algaecides, the roseobacticides, in response to p-coumaric acid, an algal lignin breakdown product that is symptomatic of aging algae. This switch converts P. gallaeciensis into an opportunistic pathogen of its algal host.

The Jekyll-and-Hyde chemistry of Phaeobacter gallaeciensis.

Emiliania huxleyi, un micro-algue marine de l&#x26;#39;environnement importante, a un mode de vie fleurs et de r&#xE9;cession dans laquelle massives efflorescences algales apparaissent et se fanent. Phaeobacter gallaeciensis appartient au clade roseobacter des &#x3B1;-prot&#xE9;obact&#xE9;ries, dont les populations croissent et d&#xE9;croissent avec celle de E. huxleyi. Roseobacter sont pens&#xE9;s pour favoriser la croissance des algues par biosynth&#xE8;se et des antibiotiques et s&#xE9;cr&#xE9;tant stimulants de la croissance (auxines). Ici, nous montrons que gallaeciensis P. passe son m&#xE9;tabolisme petite mol&#xE9;cule s&#xE9;cr&#xE9;t&#xE9;e &#xE0; la production d&#x26;#39;algicides puissants et s&#xE9;lectifs, les roseobacticides, en r&#xE9;ponse &#xE0; l&#x26;#39;acide p-coumarique, un produit de lignine algues r&#xE9;partition qui est symptomatique du vieillissement des algues. Ce commutateur convertit gallaeciensis P. en un pathog&#xE8;ne opportuniste de son h&#xF4;te d&#x26;#39;algues.

La chimie Jekyll et Mr Hyde de Phaeobacter Gallaeciensis

Emiliania Huxleyi, ein &ouml;kologisch wichtige marine Mikroalge hat einen Bl&uuml;te-Bust-Lebensstil in dem massiven Algenbl&uuml;te erscheinen und verschwinden. Phaeobacter Gallaeciensis geh&ouml;rt zu der Roseobacter-Gruppe der &alpha;-Proteobakterien, die Bev&ouml;lkerung davon Wachs und schwinden mit der E. Huxleyi. Roseobacter werden gedacht, um Algenwachstum zu f&ouml;rdern, durch Biosynthesizing und sezernierende Antibiotika und Wachstum Stimulanzien (Auxine). Hier zeigen wir, dass s. Gallaeciensis schaltet seine sezernierte niedermolekularer Stoffwechsel auf die Produktion von potenter und selektiver Algenbek&auml;mpfungsmittel, Roseobacticides, Reaktion auf p-Cumars&auml;ure S&auml;ure, eine Algenbl&uuml;te Lignin-Abbauprodukt, das ist symptomatisch f&uuml;r die alternde Algen. Dieser Switch wandelt p Gallaeciensis in eine opportunistische Erreger der Algen Host.

Die Jekyll-und-Hyde-Chemie der Phaeobacter Gallaeciensis.

Emiliania huxleyi, una microalga Marina ecologicamente importante, ha uno stile di vita di bloom e busto in cui massicce fioriture algali appaiono e svanire. Phaeobacter gallaeciensis appartiene al clade roseobacter di &alpha;-Proteobacteria, le popolazioni di cui cera e wane con quella di E. huxleyi. Roseobacter sono pensato per promuovere la crescita delle alghe biosynthesizing e secernenti antibiotici e stimolanti di crescita (auxine). Qui vi mostriamo che P. gallaeciensis passa il suo metabolismo piccola molecola secreta alla produzione di alghicidi potente e selettivo, il roseobacticides, in risposta all&#39;acido p-coumaric, un prodotto di degradazione della lignina algale che &egrave; sintomatico dell&#39;invecchiamento delle alghe. Questa opzione converte p. gallaeciensis in un patogeno opportunistico del suo ospite algale.

La chimica di Jekyll e Hyde di Phaeobacter gallaeciensis.

Emiliania huxleyi&#x3001;&#x74B0;&#x5883;&#x7684;&#x306B;&#x91CD;&#x8981;&#x306A;&#x6D77;&#x6D0B;&#x5FAE;&#x7D30;&#x85FB;&#x985E;&#x306F;&#x3001;&#x5927;&#x898F;&#x6A21;&#x306A;&#x85FB;&#x985E;&#x304C;&#x8868;&#x793A;&#x3055;&#x308C;&#x3001;&#x30D5;&#x30A7;&#x30FC;&#x30C9;&#x3057;&#x305F;&#x82B1;&#x3068;&#x3001;&#x30D0;&#x30B9;&#x30C8;&#x306E;&#x30E9;&#x30A4;&#x30D5;&#x30B9;&#x30BF;&#x30A4;&#x30EB;&#x3092;&#x6301;&#x3063;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002; Phaeobacter gallaeciensis&#x306F;&#x30EF;&#x30C3;&#x30AF;&#x30B9;&#x306E;&#x3B1;-&#x30D7;&#x30ED;&#x30C6;&#x30AA;&#x30D0;&#x30AF;&#x30C6;&#x30EA;&#x30A2;&#x3001;&#x96C6;&#x56E3;&#x306E;roseobacter&#x306E;&#x30AF;&#x30EC;&#x30FC;&#x30C9;&#x306B;&#x5C5E;&#x3057;&#x3001;E. huxleyi&#x306E;&#x305D;&#x308C;&#x3068;&#x8870;&#x9000;&#x3002; Roseobacter&#x306F;&#x3001;&#x751F;&#x5408;&#x6210;&#x3068;&#x5206;&#x6CCC;&#x306E;&#x6297;&#x751F;&#x7269;&#x8CEA;&#x3084;&#x6210;&#x9577;&#x306E;&#x899A;&#x305B;&#x3044;&#x5264;&#xFF08;&#x30AA;&#x30FC;&#x30AD;&#x30B7;&#x30F3;&#xFF09;&#x306B;&#x3088;&#x3063;&#x3066;&#x85FB;&#x985E;&#x306E;&#x6210;&#x9577;&#x3092;&#x4FC3;&#x9032;&#x3059;&#x308B;&#x3068;&#x8003;&#x3048;&#x3089;&#x308C;&#x3066;&#x3044;&#x308B;&#x3002;&#x3053;&#x3053;&#x3067;&#x306F;&#x3001;P.&#x306E;gallaeciensis&#x306F;&#x3001;p-&#x30AF;&#x30DE;&#x30EB;&#x9178;&#x3001;&#x85FB;&#x985E;&#x306E;&#x8001;&#x5316;&#x306E;&#x5FB4;&#x5019;&#x3067;&#x3042;&#x308B;&#x85FB;&#x985E;&#x306E;&#x30EA;&#x30B0;&#x30CB;&#x30F3;&#x5206;&#x89E3;&#x7523;&#x7269;&#x306B;&#x53CD;&#x5FDC;&#x3057;&#x3066;&#x5F37;&#x529B;&#x304B;&#x3064;&#x9078;&#x629E;&#x7684;&#x306A;&#x6BBA;&#x85FB;&#x5264;&#x3001;roseobacticides&#x306E;&#x751F;&#x7523;&#x3078;&#x306E;&#x5206;&#x6CCC;&#x5C0F;&#x5206;&#x5B50;&#x4EE3;&#x8B1D;&#x3092;&#x5207;&#x308A;&#x66FF;&#x3048;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;&#x3053;&#x306E;&#x30B9;&#x30A4;&#x30C3;&#x30C1;&#x306F;&#x3001;&#x85FB;&#x985E;&#x306E;&#x5BBF;&#x4E3B;&#x306E;&#x65E5;&#x548C;&#x898B;&#x75C5;&#x539F;&#x4F53;&#x3078;&#x306E;P. gallaeciensis&#x306B;&#x5909;&#x63DB;&#x3057;&#x307E;&#x3059;&#x3002;

Phaeobacter Gallaeciensis&#x306E;&#x30B8;&#x30AD;&#x30EB;&#x3068;&#x30CF;&#x30A4;&#x30C9;&#xB7;&#x5316;&#x5B66;

Emiliania huxleyi, una microalga marina ambientalmente importante, tiene un estilo de vida floraci&#xF3;n y ca&#xED;da en la que masivas floraciones de algas aparecen y se desvanecen. Phaeobacter gallaeciensis pertenece al clado Roseobacter de &#x3B1;-Proteobacteria, las poblaciones de las cuales crecen y decrecen con la de E. huxleyi. Roseobacter se piensa que promueven crecimiento de las algas y los antibi&#xF3;ticos biosynthesizing secretoras y estimulantes de crecimiento (auxinas). Aqu&#xED; nos muestran que gallaeciensis p conmuta su metabolismo peque&#xF1;a mol&#xE9;cula secretada a la producci&#xF3;n de alguicidas potentes y selectivos, los roseobacticides, en respuesta a &#xE1;cido p-cum&#xE1;rico, un producto lignina descomposici&#xF3;n de las algas que es un s&#xED;ntoma de envejecimiento algas. Este modificador convierte gallaeciensis P. en un pat&#xF3;geno oportunista de su anfitri&#xF3;n de algas.

La qu&#xED;mica de Jekyll y Hyde de Phaeobacter Gallaeciensis

We have examined the biosynthesis and accumulation of cyanobacterial sunscreening pigment scytonemin within intertidal microbial mat communities using a combination of chemical, molecular, and phylogenetic approaches. Both laminated (layered) and nonlaminated mats contained scytonemin, with morphologically distinct mats having different cyanobacterial community compositions. Within laminated microbial mats, regions with and without scytonemin had different dominant oxygenic phototrophs, with scytonemin-producing areas consisting primarily of Lyngbya aestuarii and scytonemin-deficient areas dominated by a eukaryotic alga. The nonlaminated mat was populated by a diverse group of cyanobacteria and did not contain algae. The amplification and phylogenetic assignment of scytonemin biosynthetic gene scyC from laminated mat samples confirmed that the dominant cyanobacterium in these areas, L. aestuarii, is likely responsible for sunscreen production. This study is the first to utilize an understanding of the molecular basis of scytonemin assembly to explore its synthesis and function within natural microbial communities.

The biosynthesis of cyanobacterial sunscreen scytonemin in intertidal microbial mat communities.

A few major discoveries have influenced how ecologists and evolutionists study microbes. Here, in the format of an interview, we answer questions that directly relate to how these discoveries are perceived in these two branches of microbiology, and how they have impacted on both scientific thinking and methodology.The first question is "What has been the influence of the 'Universal Tree of Life' based on molecular markers?" For evolutionists, the tree was a tool to understand the past of known (cultured) organisms, mapping the invention of various physiologies on the evolutionary history of microbes. For ecologists the tree was a guide to discover the current diversity of unknown (uncultured) organisms, without much knowledge of their physiology.The second question we ask is "What was the impact of discovering frequent lateral gene transfer among microbes?" In evolutionary microbiology, frequent lateral gene transfer (LGT) made a simple description of relationships between organisms impossible, and for microbial ecologists, functions could not be easily linked to specific genotypes. Both fields initially resisted LGT, but methods or topics of inquiry were eventually changed in one to incorporate LGT in its theoretical models (evolution) and in the other to achieve its goals despite that phenomenon (ecology).The third and last question we ask is "What are the implications of the unexpected extent of diversity?" The variation in the extent of diversity between organisms invalidated the universality of species definitions based on molecular criteria, a major obstacle to the adaptation of models developed for the study of macroscopic eukaryotes to evolutionary microbiology. This issue has not overtly affected microbial ecology, as it had already abandoned species in favor of the more flexible operational taxonomic units. This field is nonetheless moving away from traditional methods to measure diversity, as they do not provide enough resolution to uncover what lies below the species level.The answers of the evolutionary microbiologist and microbial ecologist to these three questions illustrate differences in their theoretical frameworks. These differences mean that both fields can react quite distinctly to the same discovery, incorporating it with more or less difficulty in their scientific practice.

Molecular musings in microbial ecology and evolution.

Nautella sp. R11, a member of the marine Roseobacter clade, causes a bleaching disease in the temperate-marine red macroalga, Delisea pulchra. To begin to elucidate the molecular mechanisms underpinning the ability of Nautella sp. R11 to colonize, invade and induce bleaching of D. pulchra, we sequenced and analyzed its genome. The genome encodes several factors such as adhesion mechanisms, systems for the transport of algal metabolites, enzymes that confer resistance to oxidative stress, cytolysins, and global regulatory mechanisms that may allow for the switch of Nautella sp. R11 to a pathogenic lifestyle. Many virulence effectors common in phytopathogenic bacteria are also found in the R11 genome, such as the plant hormone indole acetic acid, cellulose fibrils, succinoglycan and nodulation protein L. Comparative genomics with non-pathogenic Roseobacter strains and a newly identified pathogen, Phaeobacter sp. LSS9, revealed a patchy distribution of putative virulence factors in all genomes, but also led to the identification of a quorum sensing (QS) dependent transcriptional regulator that was unique to pathogenic Roseobacter strains. This observation supports the model that a combination of virulence factors and QS-dependent regulatory mechanisms enables indigenous members of the host alga's epiphytic microbial community to switch to a pathogenic lifestyle, especially under environmental conditions when innate host defence mechanisms are compromised.

Rebecca J. Case

Department of Biological Sciences

University of Alberta

A Small Volume Bioassay to Assess Bacterial/Phytoplankton Co-culture Using WATER-Pulse-Amplitude-Modulated (WATER-PAM) Fluorometry