scholarly journals Factors affecting survival of test bacteria in sea water: marine bacteria, test bacteria and solid surfaces

1972 ◽  
Vol 23 (3) ◽  
pp. 271-285 ◽  
Author(s):  
K. Moebus
1982 ◽  
Vol 28 (4) ◽  
pp. 414-424 ◽  
Author(s):  
Richard A. Laddaga ◽  
Robert A. MacLeod

Eighteen gram-negative marine bacteria and two terrestrial species, Escherichia coli and Pseudomonas aeruginosa, were examined for their sensitivity to lysis in distilled water after exposure either to a salt solution containing a sea water concentration of Mg2+ (0.05 M) or to 0.5 M NaCl. A spectrum of lytic susceptibility was observed among the marine bacteria ranging from those organisms which lysed in distilled water after exposure to the Mg2+-containing solution, through organisms which could be sensitized to lysis by washing with the NaCl solution, to organisms which failed to lyse in distilled water even after having been washed with a solution of 0.5 M NaCl. Pseudomonas aeruginosa and E. coli fell within this spectrum, the former being capable of being induced to lyse in distilled water by washing with 0.5 M NaCl, while the latter failed to lyse in distilled water after this treatment. It was thus concluded that no overall distinction could be made between marine and terrestrial bacteria on the basis of the sensitivity of the two groups of organisms to lysis in freshwater.Quite large decreases in optical density and increases in the release of ultraviolet-absorbing material took place when cells preexposed to the Mg2+-containing solution or to 0.5 M NaCl were subsequently suspended in distilled water even though in some cases no loss of cell numbers could be detected. In most cases two to three times as much K+ as Na+ and 1/10 to 1/100 as much Mg2+ was required to prevent these changes. For three of the marine bacteria and P. aeruginosa grown in a terrestrial type medium little difference in the requirements for Na+ and K+ to prevent the optical density changes was noted. For P. aeruginosa grown in a marine type medium, cells required more K+ than Na+ to prevent these changes.


1988 ◽  
Vol 50 ◽  
pp. 147-150 ◽  
Author(s):  
SG Horrigan ◽  
A Hagstrom ◽  
I Koike ◽  
F Azam

1974 ◽  
Vol 61 (3) ◽  
pp. 737-747 ◽  
Author(s):  
TETSUYA HIRANO

1. Internal as well as external factors affecting water ingestion in the eel were analysed using oesophagus-cannulated eels. 2. Acute withdrawal of the blood induced an immediate drinking response in the freshwater eel, whereas infusion of a large amount of hypertonic saline interrupted the copious drinking observed in the seawater eel. 3. The freshwater eel responded to slow infusion of hypertonic NaCl solution by constant drinking. 4. Inhibition of drinking was observed in the seawater eel by distension of the stomach or intestine with isotonic mannitol solution. 5. The freshwater eel started drinking immediately after transfer to sea water, and stopped drinking immediately after return to fresh water. 6. Application of various salt solutions revealed that chloride ions are responsible for the induction of drinking in sea water. 7. Stimulation of drinking by chloride ions and inhibition by fresh water may be an anticipatory drinking behaviour, which facilitates adaptation of eels to both sea water and fresh water.


2000 ◽  
Vol 4 (2) ◽  
pp. 332-340 ◽  
Author(s):  
C. Drogue ◽  
N. N. Cat ◽  
J. Dazy

Abstract. In northern Vietnam, exposed carbonate rock formations cover an area of more than 50,000 km2 .Their accumulated thickness from the Cambrian to the Triassic is in some places as much as 3000 m. Numerous thermal waters (springs and wells) occur in these strongly karstified carbonate massifs. This is the result of significant ancient and present orogenic activity, as the region demonstrates by its strong seismic activity. These karstic formations are water-bearing and strongly recharged by rainfall of between 1600 mm and 2000 mm per year in 90% of the area concerned. In view of the average annual air temperatures (17°C-25°C according to the region), 23 sample springs or wells were chosen with water temperatures of between 29°C and 68°C. Hydrochemical characteristics of these thermal waters emerging in different carbonate-rock units were examined by chemical analyses of major ions. In this large region, thermal waters are divided into four hydrochemical types: the Na-Cl type resulting from the intrusion of sea water for distances of up to several kilometres inland and depths of 1000 m, the Ca-SO4 type, probably resulting from the leaching of deposits of metallic sulphides that are widely distributed in these carbonate-rock units, and finally the Ca-HCO3 and Mg-HCO3 types which are chemically similar to fresh karstic waters in limestones and dolostones. The occurrence of these thermal groundwaters as well as their chemical characteristics seem to indicate the existence of large-scale deepseated groundwater flow systems in the karstic aquifers. Keywords: Vietnam; thermal waters; karst; hydrochemistry


1999 ◽  
Vol 1999 (1) ◽  
pp. 1059-1063
Author(s):  
J. R. Bergueiro ◽  
A. Pita ◽  
M. A. Mayol ◽  
M. Rallo ◽  
J. López-Ruiz

ABSTRACT The authors have studied the biodegradation of an Arabian Light crude oil in sterile marine water by the CUES229 marine bacteria and the BIOLEN IG30 biologic activator, both in the presence and the absence of zeolites. Two different types of zeolites, a natural one (NZ) and an artificial one (Zestek56), were used to degrade the crude in the first experiment, arising a 20% increment in the degradation in the presence of natural zeolite when compared with a similar sample without zeolites, and a 9% in the artificial zeolite. Next set of experiment were made using reactors filled with 250 g of sea water and 0.02 g of zeolite and injecting CUES 229 bacteria up to 108 cells/ml. Samples were introduced in a shaker at 110 rpm and with regulated temperature at 30-C. Time evolution of the biodegradation was deduced from gas chromatography at the time intervals 1; 7 and 15 days. Later, a similar experiment, but with BIOLEN IG30, was also made. Biodegradation of aliphatic hydrocarbons was observed –after 15 days- until the C14 fractions, using zeolites plus Biolen IG30, and until the C18 fractions, using zeolite plus CUES 229 bacteria.


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