Because the biochemical characteristics were also indistinguishable from those of terrestrial and freshwater bacteria, the existence of true marine bacteria was repeatedly questioned. Thus, Korinek (1926, 1927, 1928) conducted numerous experiments concerning
the development of freshwater bacteria in seawater as well as marine bacteria in freshwater. He dealt with the breakdown of organic substances and concluded that freshwater
bacteria, despite their growth on seawater media, could hardly be significant participants
in the mineralization of organic materials in the sea under natural conditions. Thus, he
maintained it was highly improbable that freshwater bacteria adapt to saline media. Even
if they tolerate the salinity, they would succumb to other natural conditions of the sea.
Butkewitch ( 1938) and Zobell ( 1946) viewed the optimal development of isolated marine
forms at seawater concentrations and composition as satisfactory evidence of their
endemic nature.
Exhaustive research by Macleod, Onofrey and Norris (1954) and Macleod and Onofrey
(1956) revealed that the need for Na + - ions is decisive. These apparently function in the
transport of materials in the cell possibly through the activation of protease in the cell
wall. Some marine bacteria also require Cl - -ions.
In an article with the title, “The present status of some aspects of marine microbiology”
Sholes and Shewan (1964) phrased the question, “Are there true marine bacteria in the
sea ?” They deemed it pragmatic to treat marine types as variants, ecotypes or races
adapted to the marine environment. Points of contention, however, are the halophilic
nature of marine bacteria and the assumption that bacteria originate from the earth’s
primodial ocean, and terrestrial forms descend from them.
Macleod (1965) addressed this problem with his article, “The question of the existence of
specific marine bacteria” According to him the halophilic quality is determinative. Other
characteristics mentioned for many marine bacteria were abilities to develop at low
temperature and high pressures and to live well despite very low nutrient concentrations.
However, the ability to develop optimally and to permanently live in the saltwater of the
sea remains the only general, valid criterium defining marine bacteria - even under the
scrutiny of contemporary understanding. Optimal salinity fluctuates between 25 and
40 ‰ and, therewith, includes average oceanic salinity of 35 ‰. Present in brackish water
areas such as the Baltic Sea are also brackish water bacteria, whose salinity optima lie
between 5 and 20 7‰ (Rheinheimer 1971).
The earliest marine microbiologists already recognized the importance of bacteria for
recycling of materials in the sea. Above all, the path of nitrogen recycling was of interest to
the first inquiring scientists.
In 1899 Karl Brandt dedicated his rectorial address at the University of Kiel to the theme,
“On Metabolism in the Sea”. He dealt with the question of the origin of nitrate and
attributed nitrate formation to the decomposition of organic material and subsequent
nitrification of the resulting ammonia. He discovered nitrifiers in 2 of 3 sediment samples
from the Kiel Fjord but not from the open ocean (Brandt 1899, 1902).
The necessary conditions for investigating nitrification had been described some years
prior to this by Winogradsky (1890, 1891). Later, Vernon (1898) similarly detected the
presence of nitrifying bacteria in the Gulf of Naples. Not able to detect nitrifying bacteria
in the same gulf, Nathanson (1906), however, rejected Brandt’s theory.
On the basis of their researches Waksman et al. (1933) concluded that in waters beyond
the area of terrestrial influence no or very few nitrifiers appear. They further determined
that nitrite-building were more readily detectable than nitrate building bacteria.
17
the development of freshwater bacteria in seawater as well as marine bacteria in freshwater. He dealt with the breakdown of organic substances and concluded that freshwater
bacteria, despite their growth on seawater media, could hardly be significant participants
in the mineralization of organic materials in the sea under natural conditions. Thus, he
maintained it was highly improbable that freshwater bacteria adapt to saline media. Even
if they tolerate the salinity, they would succumb to other natural conditions of the sea.
Butkewitch ( 1938) and Zobell ( 1946) viewed the optimal development of isolated marine
forms at seawater concentrations and composition as satisfactory evidence of their
endemic nature.
Exhaustive research by Macleod, Onofrey and Norris (1954) and Macleod and Onofrey
(1956) revealed that the need for Na + - ions is decisive. These apparently function in the
transport of materials in the cell possibly through the activation of protease in the cell
wall. Some marine bacteria also require Cl - -ions.
In an article with the title, “The present status of some aspects of marine microbiology”
Sholes and Shewan (1964) phrased the question, “Are there true marine bacteria in the
sea ?” They deemed it pragmatic to treat marine types as variants, ecotypes or races
adapted to the marine environment. Points of contention, however, are the halophilic
nature of marine bacteria and the assumption that bacteria originate from the earth’s
primodial ocean, and terrestrial forms descend from them.
Macleod (1965) addressed this problem with his article, “The question of the existence of
specific marine bacteria” According to him the halophilic quality is determinative. Other
characteristics mentioned for many marine bacteria were abilities to develop at low
temperature and high pressures and to live well despite very low nutrient concentrations.
However, the ability to develop optimally and to permanently live in the saltwater of the
sea remains the only general, valid criterium defining marine bacteria - even under the
scrutiny of contemporary understanding. Optimal salinity fluctuates between 25 and
40 ‰ and, therewith, includes average oceanic salinity of 35 ‰. Present in brackish water
areas such as the Baltic Sea are also brackish water bacteria, whose salinity optima lie
between 5 and 20 7‰ (Rheinheimer 1971).
The earliest marine microbiologists already recognized the importance of bacteria for
recycling of materials in the sea. Above all, the path of nitrogen recycling was of interest to
the first inquiring scientists.
In 1899 Karl Brandt dedicated his rectorial address at the University of Kiel to the theme,
“On Metabolism in the Sea”. He dealt with the question of the origin of nitrate and
attributed nitrate formation to the decomposition of organic material and subsequent
nitrification of the resulting ammonia. He discovered nitrifiers in 2 of 3 sediment samples
from the Kiel Fjord but not from the open ocean (Brandt 1899, 1902).
The necessary conditions for investigating nitrification had been described some years
prior to this by Winogradsky (1890, 1891). Later, Vernon (1898) similarly detected the
presence of nitrifying bacteria in the Gulf of Naples. Not able to detect nitrifying bacteria
in the same gulf, Nathanson (1906), however, rejected Brandt’s theory.
On the basis of their researches Waksman et al. (1933) concluded that in waters beyond
the area of terrestrial influence no or very few nitrifiers appear. They further determined
that nitrite-building were more readily detectable than nitrate building bacteria.
17