start-ver=1.4 cd-journal=joma no-vol=94 cd-vols= no-issue=1 article-no= start-page=39 end-page=45 dt-received= dt-revised= dt-accepted= dt-pub-year=2005 dt-pub=20050201 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=ATP-citrate Lyase: The key enzyme of the reductive TCA cycle kn-title=還元的 ＴＣＡ 回路の鍵酵素 ATP-citrate lyase について en-subtitle= kn-subtitle= en-abstract= kn-abstract=Almost all organic compounds which construct life are derived from carbon dioxide (CO2) assimilated by autotrrophic organisms.The reductive tricarboxylic acid (RTCA) cycle functions as a carbon dioxide fixation pathway, distinct from Calvin cycle, in a green sulfur bacterium Chlorobium limicola. ATP-citrate lyase (ACL) is one of the key enzymes of this cycle. The enzyme of C. limicola (Cl-ACL) was encoded in two adjacent open reading frames, aclB(1197bp) and aclA(1827bp), whose products showed signficant similarity to the N- and C-terminal regions of the human enzyme, respectively. Heterologous expression of these genes in Escherichia coli proved that both gene products were essential for ACL activity. Kinetic examination of the enzyme revealed that the enzyme displayed typical Michaelis-Monten kinetics toward ATP with an apparent Km value of 0.19mM. However, strong negative cooperativity was observed with respect to citrate binding. ADP was a competitive inhibitor of ATP with a Kj value of 0.036mM. Together with the feature that the enzyme catalyzed the reaction only in the direction of citrate cleavage, these kinetic properties indicated that Cl-ACL can regulate both the direction and carbon flux of the RTCA cycle in C. limicola. en-copyright= kn-copyright= en-aut-name=KanaoTadayoshi en-aut-sei=Kanao en-aut-mei=Tadayoshi kn-aut-name=金尾忠芳 kn-aut-sei=金尾 kn-aut-mei=忠芳 aut-affil-num=1 ORCID= affil-num=1 en-affil= kn-affil=岡山大学 en-keyword=CO2 fixation kn-keyword=CO2 fixation en-keyword=Reductive TCA cycle kn-keyword=Reductive TCA cycle en-keyword=ATP-citrate lyase kn-keyword=ATP-citrate lyase END start-ver=1.4 cd-journal=joma no-vol=95 cd-vols= no-issue=1 article-no= start-page=7 end-page=11 dt-received= dt-revised= dt-accepted= dt-pub-year=2006 dt-pub=200602 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=16S-23S rDNA スペーサー領域の制限断片長多型解析によるAcidithiobacillus 属3種、A.ferroxidans、A.thiooxidans およびA.caldus の識別 kn-title=Discrimination among the Three Acidithiobacillus Species, A. ferrooxidans, A. thiooxidans and A. caldus, Based on Restriction Fragment Length Polymorphism Analysis of the 16S-23S rDNA Intergenic Spacer Region en-subtitle= kn-subtitle= en-abstract=Acidithiobacillus ferrooxidans，A.thiooxidansおよびA.caldusの16S-23S rDNAスペーサー領域の塩基配列を決定し，これらのバクテリアの識別・同定への有効性を評価した．A.ferrooxidans，A.thiooxidansおよびA.caldusのスペーサー領域の長さは，それぞれ441，456および379bpであった．３種のAcidithiobacillusスペーサー領域では，tRNA，tRNAをコードする遺伝子の塩基配列が高度に保存されていた．PCR増幅した16S-23S rDNAスペーサー領域をHaeおよびAluで酵素処理することによって得られた断片の解析によって，A.ferrooxidansをA.thiooxidansとA.caldusから識別できた．Acidithiobacillus種の16S-23S rDNAスペーサー領域の制限断片長多型解析は，Acidithiobacillus属の種の同定およびA.ferrooxidansに属する株の同定のための迅速で，技術的に簡便な方法であることが明らかとなった． kn-abstract=The PCR-amplified 16S-23S rDNA intergenic spacer regions (ISRs) of Acidithiobacillus ferrooxidans, A. thiooxidans, and A. caldus strains were scquenced and evaluated for differentiation and identification of these bacteria. The total length of the 16S-23S ISRs of A. ferrooxidans and A. thiooxidans strains and A.caldus GO-1 were 441, 456, nd 379bp, respectively. Two genes. encoding tRNA and tRNA, and the box A-like sequences were highly conserved in the ISRs of all Acidithiobacillus species. The restriction fragment length polymorphism (RFLP) profiles of the PCR-amplified 16S-23S rDNA ISRs digested by HaeIII and AluI could clearly discriminate A. ferrooxidans from A. thiooxidans and A. caldus. The results indicated that RFLP analysis of the 16S-23S ISRs is an easy and rapid method for discrimination and identification of Acidithiobacillus species. en-copyright= kn-copyright= en-aut-name=WakaiSatoshi en-aut-sei=Wakai en-aut-mei=Satoshi kn-aut-name=岩井暁 kn-aut-sei=岩井 kn-aut-mei=暁 aut-affil-num=1 ORCID= en-aut-name=YamamotoKentaro en-aut-sei=Yamamoto en-aut-mei=Kentaro kn-aut-name=山本健太郎 kn-aut-sei=山本 kn-aut-mei=健太郎 aut-affil-num=2 ORCID= en-aut-name=KanaoTadayoshi en-aut-sei=Kanao en-aut-mei=Tadayoshi kn-aut-name=金尾忠芳 kn-aut-sei=金尾 kn-aut-mei=忠芳 aut-affil-num=3 ORCID= en-aut-name=SugioTsuyoshi en-aut-sei=Sugio en-aut-mei=Tsuyoshi kn-aut-name=杉尾剛 kn-aut-sei=杉尾 kn-aut-mei=剛 aut-affil-num=4 ORCID= en-aut-name=KamimuraKazuo en-aut-sei=Kamimura en-aut-mei=Kazuo kn-aut-name=上村一雄 kn-aut-sei=上村 kn-aut-mei=一雄 aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=岡山大学 affil-num=2 en-affil= kn-affil=岡山大学 affil-num=3 en-affil= kn-affil=岡山大学 affil-num=4 en-affil= kn-affil=岡山大学 affil-num=5 en-affil= kn-affil=岡山大学 en-keyword=Acidithiobacillu kn-keyword=Acidithiobacillu en-keyword=16S-23S rDNA kn-keyword=16S-23S rDNA en-keyword=RFLP analysis kn-keyword=RFLP analysis en-keyword=tRNA kn-keyword=tRNA END start-ver=1.4 cd-journal=joma no-vol=15 cd-vols= no-issue=3 article-no= start-page=403 end-page=410 dt-received= dt-revised= dt-accepted= dt-pub-year=2011 dt-pub=201105 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Characterization of an OmpA-like outer membrane protein of the acidophilic iron-oxidizing bacterium, Acidithiobacillus ferrooxidans en-subtitle= kn-subtitle= en-abstract= kn-abstract=An OmpA family protein (FopA) previously reported as one of the major outer membrane proteins of an acidophilic iron-oxidizing bacterium Acidithiobacillus ferrooxidans was characterized with emphasis on the modification by heat and the interaction with peptidoglycan. A 30-kDa band corresponding to the FopA protein was detected in outer membrane proteins extracted at 75A degrees C or heated to 100A degrees C for 10 min prior to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). However, the band was not detected in outer membrane proteins extracted at a parts per thousand currency sign40A degrees C and without boiling prior to electrophoresis. By Western blot analysis using the polyclonal antibody against the recombinant FopA, FopA was detected as bands with apparent molecular masses of 30 and 90 kDa, suggesting that FopA existed as an oligomeric form in the outer membrane of A. ferrooxidans. Although the fopA gene with a sequence encoding the signal peptide was successfully expressed in the outer membrane of Escherichia coli, the recombinant FopA existed as a monomer in the outer membrane of E. coli. FopA was detected in peptidoglycan-associated proteins from A. ferrooxidans. The recombinant FopA also showed the peptidoglycan-binding activity. en-copyright= kn-copyright= en-aut-name=ManchurMohammed Abul en-aut-sei=Manchur en-aut-mei=Mohammed Abul kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KikumotoMei en-aut-sei=Kikumoto en-aut-mei=Mei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KanaoTadayoshi en-aut-sei=Kanao en-aut-mei=Tadayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakadaJun en-aut-sei=Takada en-aut-mei=Jun kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KamimuraKazuo en-aut-sei=Kamimura en-aut-mei=Kazuo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University affil-num=2 en-affil= kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University affil-num=3 en-affil= kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University affil-num=4 en-affil= kn-affil=Division of Chemical and Biological Technology, Graduate School of Natural Science and Technology, Okayama University affil-num=5 en-affil= kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University en-keyword=Acidithiobacillus ferrooxidans kn-keyword=Acidithiobacillus ferrooxidans en-keyword=Iron-oxidizing bacterium kn-keyword=Iron-oxidizing bacterium en-keyword=Acidophile kn-keyword=Acidophile en-keyword=Outer membrane protein kn-keyword=Outer membrane protein en-keyword=OmpA kn-keyword=OmpA END start-ver=1.4 cd-journal=joma no-vol=104 cd-vols= no-issue= article-no= start-page=5 end-page=12 dt-received= dt-revised= dt-accepted= dt-pub-year=2015 dt-pub=20150201 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=好酸性鉄酸化細菌 Acidithiobacillus ferrooxidans の染色体凝集・分配タンパク質（ScpB）の性質 kn-title=Characterization of a putative chromosome segregation and condensation protein (ScpB) in an acidophilic iron‒oxidizing bacterium Acidithiobacillus ferrooxidans en-subtitle= kn-subtitle= en-abstract=　Acidithiobacillus ferrooxidans は，低品位の銅鉱石から銅を回収するバイオリーチングにおいて使用される微生物 の一つである．この細菌は，エネルギー源として二価鉄イオンや還元型無機硫黄化合物（RISC）を使用する．鉄の酸化に関与する遺伝子の転写は，A. ferrooxidans が RISC で生育したときには抑制されるが，RISC の酸化に関与すると考えられている遺伝子の転写は活性化されることが知られている．硫黄やテトラチオン酸で生育したときにその発現が上方制御される硫化水素：キノン酸化還元酵素のすぐ上流に，ヘリックスターンへリックスモティーフを持つ，ScpB と推定されるタンパク質をコードする遺伝子が存在していた．鉄，硫黄，テトラチオン酸生育細胞から調製した cDNA を用いた半定量的 PCR 分析の結果，硫黄やテトラチオン酸で生育した細胞内の scpB 遺伝子の転写は，鉄生育細胞と比較すると上方制御されていた．組換え ScpB タンパク質を用いたゲルシフトアッセイ法で，ScpB が転写制御因子として機能するかどうかを調べた．その結果，ScpB は DNA に結合したが，結合の特異性はなかった．ScpB が直接 DNA と相互作用する報告はこれまでになかった． kn-abstract=　Acidithiobacillus ferrooxidans is one of the most widely used microorganisms in bioleaching operations to recover copper from low-grade copper sulfide. This bacterium uses ferrous iron and reduced inorganic sulfur compounds (RISCs) as energy sources. Transcriptions of genes thought to be involved in the oxidation of RISCs have been known to be highly activated in A. ferrooxidans cells grown on RISCs, while transcriptions of genes involved in the iron oxidation were repressed in the cells grown on RISCs. A gene encoding a putative chromosome segregation and condensation protein (ScpB) with a helix-turn-helix motif was found in the upstream region of sulfide : quinone oxidoreductase gene, whose expression was up-regulated in cells grown in sulfur and tetrathionate. A semi-quantitative PCR analysis using cDNA prepared from iron-, sulfur-, or tetrathionate-grown cells revealed that the transcription of scpB was up-regulated in cells grown on sulfur or tetrathionate as the energy source. Electrophoretic mobility shift assays were employed to examine whether the ScpB functions as a transcription factor. The result indicated that the recombinant His-tagged ScpB protein was able to nonspecifically bind in vitro to DNA. This is the first report on a direct association of ScpB with DNA. en-copyright= kn-copyright= en-aut-name=KamimuraKazuo en-aut-sei=Kamimura en-aut-mei=Kazuo kn-aut-name=上村一雄 kn-aut-sei=上村 kn-aut-mei=一雄 aut-affil-num=1 ORCID= en-aut-name=NagataNozomu en-aut-sei=Nagata en-aut-mei=Nozomu kn-aut-name=長田臨 kn-aut-sei=長田 kn-aut-mei=臨 aut-affil-num=2 ORCID= en-aut-name=KikumotoMei en-aut-sei=Kikumoto en-aut-mei=Mei kn-aut-name=菊本愛生 kn-aut-sei=菊本 kn-aut-mei=愛生 aut-affil-num=3 ORCID= en-aut-name=SharminSultana en-aut-sei=Sharmin en-aut-mei=Sultana kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=WakaiSatoshi en-aut-sei=Wakai en-aut-mei=Satoshi kn-aut-name=若井暁 kn-aut-sei=若井 kn-aut-mei=暁 aut-affil-num=5 ORCID= en-aut-name=KanaoTadayoshi en-aut-sei=Kanao en-aut-mei=Tadayoshi kn-aut-name=金尾忠芳 kn-aut-sei=金尾 kn-aut-mei=忠芳 aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=岡山大学大学院環境生命科学研究科 affil-num=2 en-affil= kn-affil=岡山大学大学院環境生命科学研究科 affil-num=3 en-affil= kn-affil=岡山大学大学院環境生命科学研究科 affil-num=4 en-affil= kn-affil=岡山大学大学院環境生命科学研究科 affil-num=5 en-affil= kn-affil=神戸大学自然科学系先端融合研究環 affil-num=6 en-affil= kn-affil=神戸大学自然科学系先端融合研究環 en-keyword=Acidithiobacillus ferrooxidans kn-keyword=Acidithiobacillus ferrooxidans en-keyword=Acidophile kn-keyword=Acidophile en-keyword=ScpB kn-keyword=ScpB en-keyword=transcription factor kn-keyword=transcription factor END start-ver=1.4 cd-journal=joma no-vol=109 cd-vols= no-issue= article-no= start-page=29 end-page=36 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200201 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Development of Effective Biological Treatment Process for Acid Mine Drainage kn-title=酸性鉱山廃水の 効果的な生物的処理プロセスの開発 en-subtitle= kn-subtitle= en-abstract= kn-abstract= Acid mine drainage (AMD) is acidic and generally enriched with iron, aluminum, sulfate and heavy metals, such as lead and cadmium. AMD is a growing problem of emerging concern that cause detrimental effects to the environment and living organisms. Yanahara mine in Misaki Town, Okayama, Japan, had mainly produced pyrite for sulfuric acid manufacture. Although it was closed in 1991, AMD is being generated from the mine now. A passive treatment based on the biological oxidation of ferrous iron is a promising strategy for AMD remediation. AMD from Yanahara mine is treated in a plant using iron-oxidizing bacteria, Acidithiobacillus ferrooxidans and Ferrovum spp. The AMD generation continues for several centuries with dramatic consequences on the receiving environments. Therefore, the development of sustainable and cost effective treatment process is required. A development of the effective biological treatment process with an iron oxidation reactor operated at pH 3.5 is described in this report. Economic aspects are also discussed. en-copyright= kn-copyright= en-aut-name=KamimuraKazuo en-aut-sei=Kamimura en-aut-mei=Kazuo kn-aut-name=上村一雄 kn-aut-sei=上村 kn-aut-mei=一雄 aut-affil-num=1 ORCID= en-aut-name=KanaoTadayoshi en-aut-sei=Kanao en-aut-mei=Tadayoshi kn-aut-name=金尾忠芳 kn-aut-sei=金尾 kn-aut-mei=忠芳 aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil=岡山大学大学院環境生命科学研究科 affil-num=2 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil=岡山大学大学院環境生命科学研究科 en-keyword=acid mine drainage kn-keyword=acid mine drainage en-keyword=bioremediation kn-keyword=bioremediation en-keyword=iron-oxidizing bacteria kn-keyword=iron-oxidizing bacteria en-keyword=microbial community kn-keyword=microbial community en-keyword=Acidithiobacillus ferrooxidans kn-keyword=Acidithiobacillus ferrooxidans END start-ver=1.4 cd-journal=joma no-vol=15 cd-vols= no-issue= article-no= start-page=1338669 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240129 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Tetrathionate hydrolase from the acidophilic microorganisms en-subtitle= kn-subtitle= en-abstract= kn-abstract=Tetrathionate hydrolase (TTH) is a unique enzyme found in acidophilic sulfur-oxidizing microorganisms, such as bacteria and archaea. This enzyme catalyzes the hydrolysis of tetrathionate to thiosulfate, elemental sulfur, and sulfate. It is also involved in dissimilatory sulfur oxidation metabolism, the S-4-intermediate pathway. TTHs have been purified and characterized from acidophilic autotrophic sulfur-oxidizing microorganisms. All purified TTHs show an optimum pH in the acidic range, suggesting that they are localized in the periplasmic space or outer membrane. In particular, the gene encoding TTH from Acidithiobacillus ferrooxidans (Af-tth) was identified and recombinantly expressed in Escherichia coli cells. TTH activity could be recovered from the recombinant inclusion bodies by acid refolding treatment for crystallization. The mechanism of tetrathionate hydrolysis was then elucidated by X-ray crystal structure analysis. Af-tth is highly expressed in tetrathionate-grown cells but not in iron-grown cells. These unique structural properties, reaction mechanisms, gene expression, and regulatory mechanisms are discussed in this review. en-copyright= kn-copyright= en-aut-name=KanaoTadayoshi en-aut-sei=Kanao en-aut-mei=Tadayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= affil-num=1 en-affil=Department of Agricultural and Biological Chemistry, Graduate School of Environment, Life, Natural Science, and Technology, Okayama University kn-affil= en-keyword=tetrathionate hydrolase kn-keyword=tetrathionate hydrolase en-keyword=reduced inorganic sulfur compounds kn-keyword=reduced inorganic sulfur compounds en-keyword=dissimilatory sulfur metabolism kn-keyword=dissimilatory sulfur metabolism en-keyword=S4-intermediate pathway kn-keyword=S4-intermediate pathway en-keyword=acidophiles kn-keyword=acidophiles en-keyword=chemoautotroph kn-keyword=chemoautotroph END