棉花根际亲和性高效促生细菌的分离筛选

为了从棉花根际土壤筛选能与棉花凝集素具有亲和作用的高效促生细菌,以选择性培养基从棉花根部初步筛选具有固氮能力、解磷能力及解钾能力的促生细菌,再以异硫氰酸磺(FITC)标记的棉花凝集素为复筛工具,从棉花根际促生细菌中筛选能与棉花凝集素结合的亲和性菌株,分别挑选2株固氮菌、2株解磷细菌和2株解钾细菌作为微生物肥料接种到棉花根部进行盆栽试验.观察其在根部定殖情况.结果是在选择性平板上有20%～30%的菌株具有凝集素染色阳性.盆栽试验显示,接种的6株亲和性菌株能在棉花根部成功定殖,根际细菌数量约是灭活对照的`0倍.通过初步鉴定,固氮菌株N1111为固氮菌属(Azotobacter),N2121属于德克斯氏菌属(Derxia);解磷菌株P2126属于黄单胞菌属(Xanthomonas),P1108菌株为假单胞菌属(Pseudomonas);解钾菌株K2204和K2116属于芽孢杆菌属(Bacillus).     

溶磷菌和固氮菌溶解磷矿粉时的互作效应

采用4株溶磷菌（Lx81、Dm84、Jm92、Lx191）、和3株固氮菌（ChW5、ChW6、ChO6）单独和混合接种后测定培养液有效磷含量、pH值及总有机酸含量的方法,研究溶磷菌和固氮菌溶解磷矿粉时的互作效应。结果表明,相对于单独接种溶磷菌：Lx81与3株固氮菌分别混合培养能提高磷矿粉的溶解能力,4株溶磷菌与ChW6,Lx81、Dm84、Lx191与Ch06分别混合培养及Jm92＋ChW5组合溶磷量极显著增加（P〈0．01）;Dm84＋ChW5、Lxl91＋ChW5、Jm92＋Ch06组合的溶磷量下降（P〈0．01）。除Lx81＋ChW6、Lx81＋Ch06培养液pH值降低外,混合培养的其它组合培养液pH值均较单独接种溶磷菌时升高。有机酸测定结果表明,Lx81、Jm92与ChW5、Ch06分别混合培养、ChW6＋Lx81组合有机酸含量升高（P〈0．01）,其它7种组合的有机酸含量均较单独接种溶磷菌的值下降（P〈0．01）。溶磷菌和固氮菌单菌培养时溶磷量与pH值、溶磷量与总有机酸含量及pH值与总有机酸含量之间呈现线性相关;Dm84、Lx191与3株固氮菌分别混合培养溶磷量与pH值之间、Lx81与3株固氮菌分别混合培养溶磷量与总有机酸含量之间呈现线性相关,其它组合的溶磷量与pH值、总有机酸含量间没有相关性。溶磷菌和固氮菌混合培养对溶解磷矿粉既有协同作用也有拮抗作用。     

西湖沉积物中解磷菌的分离纯化及其解磷能力

采用有机磷固体培养基和无机磷固体培养基从沉积物中分离出具有解磷能力的菌株,通过平板划线分离纯化后得到6株磷细菌,其中2株为有机P细菌（编号为OP₁、OP₂）,4株为无机磷细菌（编号分别为NOP₁、NOP₂、NOP₃、NOP₄）.测定发现,OP₁、OP₂和NOP₃溶磷能力较强,NOP₄解磷能力较微弱,而NOP₁及NOP₂在分离纯化后失去了解磷能力;菌株OP₁及OP₂具有较强的分解有机磷卵磷脂的能力,接种OP₁、OP₂菌株的培养液中水溶性磷含量分别比对照增加了38.53和64.53倍;接种NOP₃菌株的培养液中磷含量比对照增加了54.06倍.     

厚荚相思根瘤菌对盆栽苗木生长及土壤肥力的影响

从不同立地条件采集到的厚荚相思根瘤分离出9株根瘤菌株,接种于厚荚相思幼茁,6个月后测定苗木生长量及土壤N、P、K含量。试验结果表明：接菌桃株的高生长量、生物量都比对照(未接种根瘤菌)增加,其巾高生长量除R2外,增加幅度为0．89～40．18％,生物量增加52．33～147．67％,接种结瘤率、瘤的生物量也比对照高,结瘤率可达100％,根瘤生物量比对照高163．6～520％。土壤N、P、K元素分析结果表明,接种根瘤菌后土壤的营养元素发生了很大的变化,改善了土壤肥力。通过对接种不同菌株的厚荚相思苗木的茁高、生物量、土壤的全氮、速效磷、速效钾等元素的含量比较分析后筛选出R6和R7菌株为优良菌株。     

养分供给对黑青杨等杨树生长动态及养分分配的影响

探究不同养分添加对黑青杨、小黑杨和大青杨幼苗生长和养分分配的影响,旨在揭示3种杨树品种对养分的需求利用规律,为苗圃培育杨树苗木提供参考。以黑青杨、小黑杨和大青杨为材料,采用3因素3水平(N:1.5、3、6 g·株-1;P:0.75、1.5、3 g·株-1;K:0.5、1、2 g·株-1)L9(34)正交试验设计,以不施肥为对照,研究不同养分供给水平对不同杨树生长动态变化及养分分配的影响。结果表明:(1)不同养分供给对黑青杨、小黑杨和大青杨苗高、地径生长量在7月中旬开始影响差异显著。3个品种苗高、地径生长指数均在氮、磷、钾1水平时最大。黑青杨氮、磷、钾分别选择3、1、2水平时其生物量最大,小黑杨氮、磷、钾分别选择2、1、1水平时其生物量最大,大青杨氮、磷、钾均选择1水平时其生物量最大。氮、磷、钾对黑青杨和小黑杨生长指标影响排序为N大于P和K,而对大青杨生长指标影响排序为K大于N和P。(2)黑青杨、小黑杨和大青杨在根、茎和叶中氮、磷、钾积累量大小均为N大于P和K,3个品种各器官内氮的积累量都大于磷和钾的积累量。在3个杨树品种中,各器官3种养分积累量显著不同,其中3个品种的氮积累量分配比大小依次为茎、叶、根,黑青杨和小黑杨的磷积累量分配比大小依次为茎、叶、根,大青杨积累量分配比大小依次为根、茎、叶,黑青杨和大青杨钾积累量的分配比大小依次为根、茎、叶,而小黑杨钾积累量的分配比大小依次为根、茎、叶。(3)经过对各指标综合分析,评价得出氮、磷、钾配比N1P1K1为大青杨、黑青杨、小黑杨最佳施肥方案,即氮肥1.5 g·株-1,磷肥0.75 g·株-1,钾肥0.5 g·株-1。     

一株玉米根际多功能促生菌的筛选鉴定及效应研究

从郑州市砂质潮土中分离纯化出5株玉米根际促生菌,通过测定其固氮酶活性、解磷能力、解钾能力以及吲哚乙酸(IAA)合成量,筛选出能够制作高效微生物肥料的活性菌剂。摇瓶结果表明,菌株YM4具有较高的固氮酶活性,溶解无机磷、钾的能力较强,合成IAA的能力最强。其中固氮酶活性达到15.53 nmol C_2H_4/(h·m L),对磷酸三钙、难溶性硅酸钾的溶磷量和溶钾量分别达到128.90 mg/L和17.40 mg/L,IAA的合成量为37.18 mg/L。经形态观察、部分生理生化特征测定及16S rDNA的保守序列鉴定,确定该菌株为短小芽孢杆菌(Bacillus pumilus)。盆栽试验结果表明,与对照组相比,接种该菌株的盆栽土壤中IAA、矿质氮、速效磷、速效钾含量分别提高了136.36%、42.1%、67.41%和14.29%;植株根系形态也发生了显著变化,其中根系总长、总面积、总体积、根尖总数分别增加了172.24%、141.73%、112.14%和104.53%;植株鲜重、株高、SPAD值及氮、磷、钾含量分别提高了130.07%、150.65%、151.56%、120.99%、166.33%和138.21%。该菌株具有高效固氮、解磷、解钾及合成IAA的能力,在农业生产的开发利用中具有较大应用潜力。     

基于DRIS法的短枝木麻黄苗期综合营养诊断

以我国东南沿海沙地主要造林树种短枝木麻黄（Casuarina equisetifolia）一年生苗木为研究对象,应用氮（N）、磷（P）、钾（K）三元二次旋转回归法,根据现实生物量的差异,划分为2种不同的产量类型,同时结合室内养分含量分析,以高产量类型为最适值,制定了诊断施肥综合法（Diagnosis and Recommendation Integrate Sys-tem,简称DRIS）及指数法的营养诊断标准,研究氮、磷、钾不同施肥配比条件下苗木体内氮、磷、钾的养分含量及其需求程度,对短枝木麻黄进行苗期综合营养诊断分析。结果表明：施肥配比对短枝木麻黄苗木生物量积累规律有较大影响,苗木生物量最优解为19.84 g/株,对应的最佳施肥方案为氮、磷、钾分别施肥0.329 g/株、2.298 g/株、0.154 g/株。短枝木麻黄苗期小枝3种元素浓度的最佳比值范围为P/N=0.3174±0.1302;K/N=1.1010±0.506;K/P=3.5564±0.5075,以生长末期12月份各处理苗木为例,列出各元素的DRIS诊断指数及相对需肥次序,证实了营养诊断的准确性。     

基于DRIS法的短枝木麻黄苗期综合营养诊断北大核心CSCD

以我国东南沿海沙地主要造林树种短枝木麻黄(Casuarina equisetifolia)一年生苗木为研究对象,应用氮(N)、磷(P)、钾(K)三元二次旋转回归法,根据现实生物量的差异,划分为2种不同的产量类型,同时结合室内养分含量分析,以高产量类型为最适值,制定了诊断施肥综合法(Diagnosis and Recommendation Integrate Sys-tem,简称DRIS)及指数法的营养诊断标准,研究氮、磷、钾不同施肥配比条件下苗木体内氮、磷、钾的养分含量及其需求程度,对短枝木麻黄进行苗期综合营养诊断分析。结果表明:施肥配比对短枝木麻黄苗木生物量积累规律有较大影响,苗木生物量最优解为19.84 g/株,对应的最佳施肥方案为氮、磷、钾分别施肥0.329 g/株、2.298 g/株、0.154 g/株。短枝木麻黄苗期小枝3种元素浓度的最佳比值范围为P/N=0.3174±0.1302;K/N=1.1010±0.506;K/P=3.5564±0.5075,以生长末期12月份各处理苗木为例,列出各元素的DRIS诊断指数及相对需肥次序,证实了营养诊断的准确性。     

根际促生菌对石漠化地区造林苗木的促生效应

西南岩溶石漠化山区水土流失严重、养分贫瘠,导致植被恢复困难。为探究固氮菌对岩溶石漠化地区造林苗木的生长促进效应,该文以广西石漠化地区常见造林树种香樟、任豆、喜树和台湾相思苗木为材料,利用平板稀释法从石漠化乡土植物根际土壤筛选固氮菌,通过测定固氮酶活性及鉴定固氮菌菌种,选择固氮酶活性较高的菌种制成复合菌剂接种到试验苗木进行盆栽试验。结果表明:共筛选得到6株具有固氮能力的根际促生菌,分别属于根瘤菌属(Rhizobium)、中华根瘤菌属(Sinorhizobium)和黄杆菌属(Flavobacterium),其中归类为根瘤菌属的3株固氮菌酶活性较高。复合菌剂接种试验表明接种固氮菌对造林苗木的生长具有明显促进作用。与未接种处理相比,接种处理苗木的株高、叶面积、生物量以及叶绿素含量均显著增长;同时苗木的氮、磷、钾含量也有不同程度的增加。其中,香樟、任豆、喜树和台湾相思的氮含量分别提高了28.9%、53.1%、37.0%和31.6%;香樟、台湾相思的磷含量分别增加了25.6%和42.5%;任豆、台湾相思的钾含量分别增加了57.5%和49.7%。接种石漠化乡土固氮菌能够显著促进造林苗木生长和养分含量,在石漠化植被修复中具有较好的应用前景。     

氮磷营养限制影响三角褐指藻光合无机碳利用和碳酸酐酶活性

以海洋硅藻三角褐指藻为实验材料, 研究了不同氮磷比培养对其光合无机碳利用和碳酸酐酶活性的影响, 结果显示三角褐指藻生长速率在N:P=16:1时最大, 高于或低于16:1时明显下降, 表明其最适生长受到氮磷的限制。氮限制(N:P=4:1或1:1)导致叶绿素a含量分别下降30.1% 和47.6%, 磷限制(N:P=64:1或256:1)下降39.1%和52.4%, 但氮或磷限制对叶绿素c含量并没有明显影响。不同营养水平培养对光饱和光合速率具有明显的影响, 与营养充足培养相比, 在严重氮磷限制(N:P=1:1或256:1)培养下光饱和光合速率分别下降39.7%和48.0%, 光合效率与暗呼吸速率也明显下降。在氮磷限制培养下藻细胞pH补偿点明显下降; K0.5CO2值在磷限制下降低30%, 表明磷限制有助于提高细胞对CO2的亲和力, 但氮限制并没有明显影响。在氮磷限制培养的细胞反应液中Fe (CN)63-浓度下降速率较慢, 表明在氮磷限制环境中生长的细胞质膜氧化还原能力明显低于营养充足条件下生长的细胞。氮磷限制也导致胞内、外碳酸酐酶活性明显下降, 其中在氮限制下胞外碳酸酐酶活性分别下降50%和37.5%, 在磷限制下下降22.3%和42.1%。严重的氮(N:P=1:1)或磷(N:P=256:1)限制导致胞内碳酸酐酶活性下降36.5%和42.9%。研究结果表明, 三角褐指藻细胞在氮磷营养限制的环境中, 可以通过调节叶绿素含量、无机碳的利用方式和碳酸酐酶的活性以维持适度的生长。       

不同解磷菌处理下巨尾桉幼苗不同部位干质量及氮、磷、钾含量的变化

采用高效解磷菌P19和P7(解无机磷)以及YP17(解有机磷),研究不同浓度单一及混合解磷菌处理对巨尾桉( Eucalyptus grandis Hill ex Maiden × E. urophylla S. T. Blake)幼苗干质量、氮和钾含量的影响以及叶片磷含量的动态变化。结果表明：用5×106、2×106和1×106 CFU·mL-1解磷菌单一及混合处理后,巨尾桉幼苗的地上部分和地下部分干质量、总干质量以及氮含量总体上高于空白对照( CKB )和供磷对照( CKP ,添加18 mg·kg-1 KH2 PO4),且总体上差异显著(P<0.05),而仅少数处理组的幼苗钾含量显著高于CKB和CKP。随处理时间延长,不同解磷菌处理组的叶片磷含量呈现不同的变化趋势,但不同月份间叶片磷含量差异极显著(P<0.01);各处理组的叶片磷含量平均值均高于CKB ,且混菌处理组总体上高于单菌处理组。方差分析结果表明：不同解磷菌和不同菌液浓度对幼苗总干质量的影响效应均有显著差异;二者对幼苗氮含量有极显著或显著影响,但二者的交互作用对幼苗氮含量无显著影响(P>0.05);不同解磷菌、不同菌液浓度及二者间的交互作用对幼苗钾含量均有极显著影响;不同解磷菌、不同菌液浓度、不同时间及三者间的交互作用对叶片磷含量均有极显著影响。多重比较结果表明：P19-YP17、P7-YP17和P7-P19处理对幼苗氮含量和叶片磷含量平均值的提升作用明显,YP17、P19-YP17和P7-P19处理对幼苗总干质量平均值的提升作用明显,不同解磷菌对幼苗钾含量平均值无显著提升作用;不同菌液浓度下幼苗的总干质量、氮和钾含量以及叶片磷含量的平均值总体上显著高于CKB,其中,中浓度(2×106 CFU·mL-1)和低浓度(1×106 CFU·mL-1)菌液处理对叶片磷含量以及幼苗氮和钾含量平均值的提升作用明显。综合分析结果显示：P19-YP17、P7-YP17和P19-YP17解磷菌混合处理对巨尾桉幼苗生长有明显的促进作用,可作为混合解磷菌剂加以进一步开发研究。     

Relationship between ion requirements for respiration and membrane transport in a marine bacterium.

Intact cells of the marine bacterium Alteromonas haloplanktis 214 oxidized NADH, added to the suspending medium, by a process which was stimulated by Na+ or Li+ but not K+. Toluene-treated cells oxidized NADH at three times the rate of untreated cells by a mechanism activated by Na+ but not by Li+ or K+. In the latter reaction, K+ spared the requirement for Na+. Intact cells of A. haloplanktis oxidized ethanol by a mechanism stimulated by either Na+ or Li+. The uptake of alpha-aminoisobutyric acid by intact cells of A. haloplanktis in the presence of either NADH or ethanol as an oxidizable substrate required Na+, and neither Li+ nor K+ could replace it. The results indicate that exogenous and endogenous NADH and ethanol are oxidized by A. haloplanktis by processes distinguishable from one another by their requirements for alkali metal ions and from the ion requirements for membrane transport. Intact cells of Vibrio natriegens and Photobacterium phosphoreum oxidized NADH, added externally, by an Na+-activated process, and intact cells of Vibrio fischeri oxidized NADH, added externally, by a K+-activated process. Toluene treatment caused the cells of all three organisms to oxidize NADH at much faster rates than untreated cells by mechanisms which were activated by Na+ and spared by K+.     

Elemental composition of extremely alkaliphilic anaerobic bacteria

The contents of several chemical elements were assessed in the haloalkaliphilic acetogenic bacterium Natroniella acetigena and the alkaliphilic sulfate-reducing bacterium Desulfonatronum lacustre using X-ray microanalysis, stereoscanning microscopy, and mass spectrometry. The organisms were found to differ significantly in their relative contents of S, K, P, and Cl. The P/S ratio in cells of the alkaliphilic bacteria studied grown on mineral media at different pH was pH-dependent. With a pH increase from 9 to 10, potassium extrusion from cells was observed, suggesting that secondary K+/H+ antiport activity accounts for the homeostasis of cytosolic pH. Deenergization of bacterial cells in the presence of inhibitors and ionophores results in specific changes in the P/S ratio, which may be considered an indicator of the cell energetic state. In Natroniella acetigena, the content of intracellular Cl was directly proportional to the NaCl concentration in the medium. Some metals were shown to be necessary for the N. acetigena viability; the requirement for Ni and Co was absolute. Although little demand for Mg was characteristic of the bacteria studied, their growth was stimulated by an increase in Mg concentration, and the cell resistance to lysis was enhanced.     

Tistrella mobilis gen nov,sp nov,a novel polyhydroxyalkanoate-producing bacterium belonging to alpha-Proteobacteria

Strain IAM 14872, isolated from wastewater in Thailand, is capable of producing polyhydroxyalkanoate. This bacterium is Gram-negative, rod-shaped, strictly aerobic and highly motile with a single polar flagellum. Both oxidase and catalase activities are positive. The G+C content of DNA is 67.5% and Q-10 is the major quinone. The major cellular fatty acids are C(18:1)omega7c, 2-OH C(18:0) and 3-OH C(14:0). On the basis of the 16S rDNA sequence analysis and phenotypic properties, it is proposed that the strain IAM 14872 be classified in a new genus as Tistrella mobilis gen. nov., sp. nov. The type strain is IAM 14872(T) (=TISTR 1108(T)).     

Cell-bound cations of the moderately halophilic bacterium Vibrio costicola.

Over most of the range of salt concentrations in which the moderately halophilic bacterium Vibrio costicola could grow, the sum of the cell-associated Na+ + K+ ions was at least as high as in the external medium. This is in contrast to other moderate halophiles, which have substantially lower internal than external salt concentrations for most of their growth range. The relative amounts of Na+ and K+ in V. costicola varied with environmental conditions. The K+/Na+ ratio fell during anaerobic incubation or when cells were poisoned. As Na+ ions left the cells, K+ ions entered. However, movement of these ions was not tightly coupled, since K+ content of cells could increase without a corresponding decrease in Na+ content. The Mg2+ contents of cells varied little with environmental conditions.     

Metabolism of selenium in a selenium-dependent bacterium

A selenium-dependent Bacillus sp. is able to grow well up to 3% sodium selenite-containing media. The bacterium completely failed to grow on media devoid of selenium. The presence of selenium in the growth media increased the bacterial contents of proteins, carbohydrates, and lipids. The highest quantities of amino acids were detected at 2% sodium selenite-containing media. The bacterium metabolized selenite into several protein selenoamino acids such as selenomethionine and selenocysteine/selenocystine, as well as nonprotein selenoamino acids, such as selenocystathionine. Several phosphoamino acids were detected in the presence of elevated levels of selenium. The synthesized protein seems not to be affected by the presence of selenium.     

节杆菌K1108乙内酰脲酶产酶条件研究

研究了乙内酰脲酶产生菌节杆菌K1108的产酶条件。该菌乙内酰脲酶为诱导酶,存在于细胞内,乙内酰脲水解酶和N氨甲酰氨基酸水解酶是同时被诱导产生。最适诱导物为5苄基乙内酰脲,而5吲哚甲基乙内酰脲和5苯基乙内酰脲等不能诱导其酶的产生。筛选到一种安慰诱导物,诱导活性提高了2倍多。对产酶培养基进行了筛选和优化,在最适条件下,K1108产酶能力可达108U/mL。     

Sulfobacillus sibiricus sp. nov., a new moderately thermophilic bacterium

In the course of pilot industrial testing of a biohydrometallurgical technology for processing goldarsenic concentrate obtained from the Nezhdaninskoe ore deposit (East Siberia, Sakha, Yakutiya), a new gram-positive rod-shaped spore-forming moderately thermophilic bacterium (designated as strain N1) oxidizing Fe2+, S0, and sulfide minerals in the presence of yeast extract (0.02%) was isolated from a dense pulp. Physiologically, strain N1 differs from previously described species of the genus Sulfobacillus in having a somewhat higher optimal growth temperature (55 degrees C). Unlike the type strain of S. thermosulfidooxidans, strain N1 could grow on medium with 1 mM thiosulfate or sodium tetrathionate as a source of energy only within several passages and failed to grow, in the absence of an inorganic energy source, on media with sucrose, fructose, glucose, reduced glutathione, alanine, cysteine, sorbitol, sodium acetate, or pyruvate. The G + C content of the DNA of strain N1 was 48.2 mol %. The strain showed 42% homology after DNA-DNA hybridization with the type strain of S. thermosulfidooxidans and 10% homology with the type strain of S. acidophilus. The isolate differed from previously studied strains of S. thermosulfidooxidans in the structure of its chromosomal DNA (determined by the method of pulsed-field gel electrophoresis) which remained stable as growth conditions were changed. According to the results of the 16S rRNA gene analysis, the new strain forms a single cluster with the bacteria of the species Sulfobacillus thermosulfidooxidans (sequence similarity of 97.9-98.6%). Based on these genetic and physiological features, strain N1 is described as a new species Sulfobacillus sibiricus sp. nov.     

Developmental changes in the responsiveness of rat spiral ganglion neurons to neurotrophic factors in dissociated culture: differential responses for survival, neuritogenesis and neuronal morphology

The way that the development of the inner ear innervation is regulated by various neurotrophic factors and/or their combinations at different postnatal developmental stages remains largely unclear. Moreover, survival and neuritogenesis in deafferented adult neurons is important for cochlear implant function. To address these issues, developmental changes in the responsiveness of postnatal rat spiral ganglion neurons (SGNs) to neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF) and leukemia inhibitory factor (LIF) were examined by using a dissociated cell culture system. SGNs at postnatal day (P) 0, P5 and P20 (young adult) were cultured with the addition of NT-3, BDNF, or LIF or of a combination of NT-3 and BDNF (N + B) or of NT-3, BDNF and LIF (ALL factors). SGNs were analyzed for three parameters: survival, longest neurite length (LNL) and neuronal morphology. At P0, SGNs required exposure to N + B or ALL factors for enhanced survival and the ALL factors combination showed a synergistic effect much greater than the sum of the individual factors. At P5, SGNs responded to a wider range of treatment conditions for enhanced survival and combinations showed only an additive improvement over individual factors. The survival percentage of untreated SGNs was highest at P20 but combinations of neurotrophic factors were no more effective than individual factors. LNL of each SGN was enhanced by LIF alone or ALL factors at P0 and P5 but was suppressed by NT-3, BDNF and N + B at P5 in a dose-dependent manner. The LNL at P20 was enhanced by ALL factors and suppressed by N + B. Treatment with ALL factors increased the proportion of SGNs that had two or more primary neurites in all age groups. These findings suggest that NT-3, BDNF, LIF and their combinations predominantly support different ontogenetic events at different developmental stages in the innervation of the inner ear.     

Presence of a sodium-translocating ATPase in membrane vesicles of the homoacetogenic bacterium Acetobacterium woodii.

Inverted membrane vesicles of the homoacetogenic bacterium Acetobacterium woodii catalyzed the hydrolysis of ATP with a rate of 100-150 nmol.min-1.mg protein-1. The ATPase was stimulated 1.4-1.6-fold by NaCl and inhibited by N,N'-dicyclohexylcarbodiimide tributyltin or azide. The degree of inhibition caused by F0-directed but not F1-directed inhibitors was affected by the Na+ concentration in the medium. These experiments indicated the presence of a sodium-translocating ATPase. This was verified by transport studies. Upon addition of ATP to inverted vesicles, 22Na+ was actively transported into the intravesicular space up to a 24-fold accumulation. Na+ transport was inhibited by the sodium ionophore N,N,N',N',-tetracyclohexyl-1,2-phenyl-enedioxydiacetamide but stimulated by valinomycin with potassium whereas the protonophore 3,5,-di-tert-butyl-4-hydroxybenzylidenemalonitrile was without effect. N,N'-dicyclohexylcarbodiimide and tributyltin inhibited 22Na+ transport. These experiments are in accordance with a primary electrogenic Na+ transport as catalyzed by a F1F0-ATPase.