scholarly journals In Situ Detection, Isolation, and Physiological Properties of a Thin Filamentous Microorganism Abundant in Methanogenic Granular Sludges: a Novel Isolate Affiliated with a Clone Cluster, the Green Non-Sulfur Bacteria, Subdivision I

2001 ◽  
Vol 67 (12) ◽  
pp. 5740-5749 ◽  
Author(s):  
Yuji Sekiguchi ◽  
Hiroki Takahashi ◽  
Yoichi Kamagata ◽  
Akiyoshi Ohashi ◽  
Hideki Harada

ABSTRACT We previously showed that very thin filamentous bacteria affiliated with the division green non-sulfur bacteria were abundant in the outermost layer of thermophilic methanogenic sludge granules fed with sucrose and several low-molecular-weight fatty acids (Y. Sekiguchi, Y. Kamagata, K. Nakamura, A. Ohashi, H. Harada, Appl. Environ. Microbiol. 65:1280–1288, 1999). Further 16S ribosomal DNA (rDNA) cloning-based analysis revealed that the microbes were classified within a unique clade, green non-sulfur bacteria (GNSB) subdivision I, which contains a number of 16S rDNA clone sequences from various environmental samples but no cultured representatives. To investigate their function in the community and physiological traits, we attempted to isolate the yet-to-be-cultured microbes from the original granular sludge. The first attempt at isolation from the granules was, however, not successful. In the other thermophilic reactor that had been treating fried soybean curd-manufacturing wastewater, we found filamentous microorganisms to outgrow, resulting in the formation of projection-like structures on the surface of granules, making the granules look like sea urchins. 16S rDNA-cloning analysis combined with fluorescent in situ hybridization revealed that the projections were comprised of the uncultured filamentous cells affiliated with the GNSB subdivision I and Methanothermobacter-like cells and the very ends of the projections were comprised solely of the filamentous cells. By using the tip of the projection as the inoculum for primary enrichment, a thermophilic, strictly anaerobic, filamentous bacterium, designated strain UNI-1, was successfully isolated with a medium supplemented with sucrose and yeast extract. The strain was a very slow growing bacterium which is capable of utilizing only a limited range of carbohydrates in the presence of yeast extract and produced hydrogen from these substrates. The growth was found to be significantly stimulated when the strain was cocultured with a hydrogen-utilizing methanogen, Methanothermobacter thermautotrophicus, suggesting that the strain is a sugar-fermenting bacterium, the growth of which is dependent on hydrogen consumers in the granules.

2007 ◽  
Vol 57 (10) ◽  
pp. 2299-2306 ◽  
Author(s):  
Takeshi Yamada ◽  
Hiroyuki Imachi ◽  
Akiyoshi Ohashi ◽  
Hideki Harada ◽  
Satoshi Hanada ◽  
...  

Thermophilic (strain GOMI-1T) and mesophilic (strain KOME-1T) strains were isolated from two different cultures of propionate-degrading consortia obtained from thermophilic digester sludge and rice paddy soil, respectively. The two strains were non-spore-forming, non-motile and Gram-negative. Both strains were obligately anaerobic micro-organisms, showing multicellular filamentous morphotypes more than 100 μm in length. The cell width for strain GOMI-1T was 0.2–0.4 μm and that of strain KOME-1T was 0.4–0.6 μm. Strain GOMI-1T could grow at 45–65 °C with a pH range of 6.0–7.5 (optimum growth at 55 °C, pH 7.0). The temperature range for growth of strain KOME-1T was 30–40 °C and the pH range was pH 5.0–8.5 (optimum growth around 37 °C, pH 7.0). Yeast extract was required for growth of both strains. Strain GOMI-1T was able to grow with a number of carbohydrates in the presence of yeast extract. In yeast extract-containing medium, strain KOME-1T could utilize proteins and a limited range of sugars for growth. The G+C contents of the DNA of strains GOMI-1T and KOME-1T were respectively 54.7 and 57.6 mol%. Major fatty acids of strain GOMI-1T were C16 : 0, C14 : 0 and iso-C15 : 0, whereas those of strain KOME-1T were iso-C15 : 0, anteiso-C15 : 0 and C14 : 0. Based on comparative analysis of 16S rRNA gene sequences of strains GOMI-1T and KOME-1T, the strains were placed in different phylogenetic positions in the class Anaerolineae of the bacterial phylum Chloroflexi. Their phenotypic and genetic traits strongly supported the conclusion that the strains should be described as two independent taxa in the class Anaerolineae. Hence, we propose the names Bellilinea caldifistulae gen. nov., sp. nov., and Longilinea arvoryzae gen. nov., sp. nov., for strains GOMI-1T and KOME-1T. The type strains of Bellilinea caldifistulae and Longilinea arvoryzae are respectively GOMI-1T (=JCM 13669T =DSM 17877T) and KOME-1T (=JCM 13670T =KTCC 5380T).


2021 ◽  
Author(s):  
Dalton J. Leprich ◽  
Beverly E. Flood ◽  
Peter R. Schroedl ◽  
Elizabeth Ricci ◽  
Jeffery J. Marlow ◽  
...  

AbstractCarbonate rocks at marine methane seeps are commonly colonized by sulfur-oxidizing bacteria that co-occur with etch pits that suggest active dissolution. We show that sulfur-oxidizing bacteria are abundant on the surface of an exemplar seep carbonate collected from Del Mar East Methane Seep Field, USA. We then used bioreactors containing aragonite mineral coupons that simulate certain seep conditions to investigate plausible in situ rates of carbonate dissolution associated with sulfur-oxidizing bacteria. Bioreactors inoculated with a sulfur-oxidizing bacterial strain, Celeribacter baekdonensis LH4, growing on aragonite coupons induced dissolution rates in sulfidic, heterotrophic, and abiotic conditions of 1773.97 (±324.35), 152.81 (±123.27), and 272.99 (±249.96) μmol CaCO3 • cm−2 • yr−1, respectively. Steep gradients in pH were also measured within carbonate-attached biofilms using pH-sensitive fluorophores. Together, these results show that the production of acidic microenvironments in biofilms of sulfur-oxidizing bacteria are capable of dissolving carbonate rocks, even under well-buffered marine conditions. Our results support the hypothesis that authigenic carbonate rock dissolution driven by lithotrophic sulfur-oxidation constitutes a previously unknown carbon flux from the rock reservoir to the ocean and atmosphere.


Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3643 ◽  
Author(s):  
Qiaochu Liang ◽  
Takahiro Yamashita ◽  
Norihisa Matsuura ◽  
Ryoko Yamamoto-Ikemoto ◽  
Hiroshi Yokoyama

Bioelectrochemical system (BES)-based reactors have a limited range of use, especially in aerobic conditions, because these systems usually produce current from exoelectrogenic bacteria that are strictly anaerobic. However, some mixed cultures of bacteria in aerobic reactors can form surface biofilms that may produce anaerobic conditions suitable for exoelectrogenic bacteria to thrive. In this study, we combined a BES with an aerobic trickling filter (TF) reactor for wastewater treatment and found that the BES-TF setup could produce electricity with a coulombic efficiency of up to 15% from artificial wastewater, even under aerobic conditions. The microbial communities within biofilms formed at the anodes of BES-TF reactors were investigated using high throughput 16S rRNA gene sequencing. Efficiency of reduction in chemical oxygen demand and total nitrogen content of wastewater using this system was >97%. Bacterial community analysis showed that exoelectrogenic bacteria belonging to the genera Geobacter and Desulfuromonas were dominant within the biofilm coating the anode, whereas aerobic bacteria from the family Rhodocyclaceae were abundant on the surface of the biofilm. Based on our observations, we suggest that BES-TF reactors with biofilms containing aerobic bacteria and anaerobic exoelectrogenic bacteria on the anodes can function in aerobic environments.


2003 ◽  
Vol 48 (6) ◽  
pp. 65-73 ◽  
Author(s):  
M.A.P. Montenegro ◽  
J.C. Araujo ◽  
R.F. Vazoller

We used in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes concurrently with microscopic examinations and methane measurements to characterize the microbial community of an anaerobic hybrid reactor treating pentachlorophenol (PCP) with a mixture of fatty acids (propionic, butyric, acetic and lactic) and methanol. Archaeal cells detected with probe ARC915 prevailed in anaerobic granular sludge without and with the addition of PCP in a range of 2.0 to 21.0 mg/L to the reactor. This group accounted for 81 and 90% of the DAPI-stained cells before and after the addition of 21 mg/L of PCP, respectively. In these conditions, cells detected with the Methanosarcinales specific probe (MSMX860) were the only methanogenic Archaea found and accounted for 59 to 87.6% of the DAPI-stained cells. No cells were detected by the Methanomicrobiales (MG1200), Methanobacteriaceae (MB1174) and Methanococcaceae (MC1109) specific probes. Bacterial cells detected with probe EUB338 were found in very low numbers, which ranged from 5.7 to 1.0% of the DAPI-stained cells. This finding agrees with the scanning electron microscope examinations, in which cells morphologically resembling Methanosaeta and Methanosarcina were predominantly observed in the granular sludge. Results contributed to the investigation of the importance of the methanogens during PCP degradation.


2014 ◽  
Vol 64 (Pt_9) ◽  
pp. 2986-2991 ◽  
Author(s):  
Xiao-Li Su ◽  
Qi Tian ◽  
Jie Zhang ◽  
Xian-Zheng Yuan ◽  
Xiao-Shuang Shi ◽  
...  

A strictly anaerobic, mesophilic, carbohydrate-fermenting, hydrogen-producing bacterium, designated strain RL-CT, was isolated from a reed swamp in China. Cells were Gram-stain-negative, catalase-negative, non-spore-forming, non-motile rods measuring 0.7–1.0 µm in width and 3.0–8.0 µm in length. The optimum temperature for growth of strain RL-CT was 37 °C (range 25–40 °C) and pH 7.0–7.5 (range pH 5.7–8.0). The strain could grow fermentatively on yeast extract, tryptone, arabinose, glucose, galactose, mannose, maltose, lactose, glycogen, pectin and starch. The main end products of glucose fermentation were acetate, H2 and CO2. Organic acids, alcohols and amino acids were not utilized for growth. Yeast extract was not required for growth; however, it stimulated growth slightly. Nitrate, sulfate, sulfite, thiosulfate, elemental sulfur and Fe(III) nitrilotriacetate were not reduced as terminal electron acceptors. Aesculin was hydrolysed but not gelatin. Indole and H2S were produced from yeast extract. The G+C content of the genomic DNA was 51.2 mol%. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0 and C16 : 0. The most abundant polar lipid of strain RL-CT was phosphatidylethanolamine. 16S rRNA gene sequence analysis revealed that the isolate belongs to the uncultured Blvii28 wastewater-sludge group (http://www.arb-silva.de/) in the family Rikenellaceae of the phylum Bacteroidetes, and shared low sequence similarities with the related species Alistipes shahii WAL 8301T (81.8 %), Rikenella microfusus ATCC 29728T (81.7 %) and Anaerocella delicata WN081T (80.9 %). On the basis of these data, a novel species in a new genus of the family Rikenellaceae is proposed, Acetobacteroides hydrogenigenes gen. nov., sp. nov. The type strain of the type species is RL-CT ( = JCM 17603T = DSM 24657T = CGMCC 1.5173T).


2004 ◽  
Vol 842 ◽  
Author(s):  
S. Kabra ◽  
H. Bei ◽  
D. W. Brown ◽  
M.A.M. Bourke ◽  
E. P. George

ABSTRACTPseudoelasticity in monocrystalline Fe3Al (23 at.% Al) was investigated by room-temperature mechanical testing along the <418> tensile and compressive axes. In tension, up to ∼10% strain is recoverable whereas only ∼5% strain is recoverable in compression. Straight, parallel, surface step lines were seen to appear/disappear as the specimens were pseudoelastically loaded/unloaded. In contrast, in the plastic region (ε >10%), wavy slip lines appeared on the specimen surfaces which did not disappear upon unloading. In-situ neutron diffraction was performed during compressive straining and the intensities of several diffraction peaks increase/decrease reversibly during loading/unloading. These changes are consistent with a deformation twin which produces large crystal rotations. They could also be indicative of a phase transformation. Unfortunately, we were able to sample only a limited range of 2θ in the present investigation and, within this range, none of the new peaks that appeared during the pseudoelastic deformation were disallowed peaks for the D03 crystal structure. Therefore we are unable at this time to distinguish between the two possible mechanisms, twinning and phase transformation.


2000 ◽  
Vol 66 (10) ◽  
pp. 4518-4522 ◽  
Author(s):  
N. D. Gray ◽  
R. Howarth ◽  
R. W. Pickup ◽  
J. Gwyn Jones ◽  
I. M. Head

ABSTRACT Combined microautoradiography and fluorescence in situ hybridization (FISH) was used to investigate carbon metabolism in uncultured bacteria from the genus Achromatium. All of theAchromatium species identified in a freshwater sediment from Rydal Water, Cumbria, United Kingdom, which were distinguishable only by FISH, assimilated both [14C]bicarbonate and [14C]acetate. This extends previous findings thatAchromatium spp. present at another location could only utilize organic carbon sources. Achromatium spp., therefore, probably exhibit a range of physiologies, i.e., facultative chemolithoautotrophy, mixotrophy, and chemoorganoheterotrophy, similar to other large sulfur bacteria (e.g., Beggiatoa spp.).


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