scholarly journals Investigations of the cation binding to nucleotides by monitoring the hairpin-duplex equilibrium of a self-complementary sequence

2009 ◽  
Vol 53 (1) ◽  
pp. 229-230 ◽  
S.-i. Nakano ◽  
H. Hirayama ◽  
N. Sugimoto
1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Frances Westall

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

Fanxin ZENG ◽  
Xiaoping ZENG ◽  
Zhenyu ZHANG ◽  
Guixin XUAN

1986 ◽  
Vol 21 (4) ◽  
pp. 486-495 ◽  
R.F.G. Selle Sardi ◽  
W. Bulani ◽  
W.L. Cairns ◽  
N. Kosaric

Abstract Ion exchanger beads are explored as aids in accelerating the development of anaerobic biofilms for use in advanced anaerobic reactors. Initial adhesion and subsequent changes in adhesion and growth of anaerobic biofilms (as reflected in total supported biomass and metabolic activity) were monitored on different ion exchangers (strong cation, strong anion and weak anion) over a period of 12 days. Metabolic activity was recorded for the first time in this type of study using ATP biolumininescence assays which allowed monitoring of rapid changes in the biofilm development. Results indicate that the strong cation exchanger is a better overall substratum for anaerobic biofilm development due to its favorable property of dialent cation binding and adsorption of volatile fatty acid substrate for methanogens.

2018 ◽  
Vol 15 (12) ◽  
pp. 1037-1041
Slim Mannai ◽  
Yang Kim ◽  
Abdullah Sulaiman Al-Ayed ◽  
Lassaad Baklouti ◽  
Abdelwaheb Hamdi

2008 ◽  
Vol 47 (3) ◽  
pp. 1218-1223 ◽  
Mei-Jin Li ◽  
Zuofeng Chen ◽  
Nianyong Zhu ◽  
Vivian Wing-Wah Yam ◽  
Yanbing Zu

1989 ◽  
Vol 264 (16) ◽  
pp. 9271-9277 ◽  
L A Selden ◽  
J E Estes ◽  
L C Gershman

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