to be alkaliphilic. The former composes three species, S. tronii, S. magadii, and
S. alkalinus, and all of them are alkaliphilic. Interestingly, all the isolated strains
could only be recovered if the soil clumps put directly on the medium instead of the
common suspending in the medium. In summary, by now, the list of known
alkaliphilic fungi (noteworthy, all are within the Ascomycota division) includes
Acremonium alcalophilum (isolated from pig feces compost in Japan) [123];
Gliocladium cibotii, Phialophora geniculata, Stachylidium bicolor, and Stilbella
annulata (from slightly alkaline grassland in Indonesia) [122]; Acremonium
sp. and Chrysosporium sp. (from limestone cave in Japan) [129]; Emericellopsis
minima, Neosartorya stramenia, and Melanospora zamiae (from different soil types
including Natracualf, in Argentina) [126]; Sodiomyces (from alkaline soils including
solonchak type of soils of Russia, Mongolia, Kenya, Tanzania); and Thielavia
sp. (from alkaline soils of Russia and Armenia) [124]. There is no doubt that the
search for alkaliphilic fungi will be continued, since the fungi in general are valued
producers of many biologically active substances and are widely used in the
bioindustry.
Of course, in one review, it is impossible to embrace all alkaliphiles in all habitats
and a world experience based on published papers has convincingly shown that
alkaliphiles habit many various biocoenoses. In this sense, alkaliphiles, similar to
neutralophiles, follow the known Beijerinck’s principle, but not all taxa or physiological groups are existing in any habitats. Now and before, choosing the “right”
sample for isolation is mostly a matter of an intuition and experience of a particulate
microbiologist.
3 Isolation, Media, and Cultivation
How to isolate an alkaliphile? The techniques of isolation for alkaliphiles are mostly
the same as for neutralophilic microorganisms, and it includes getting enrichments
on an appropriate substrate, physical separation on solid media (getting colonies),
serial dilutions, selective inhibition by antibiotics or inhibitors, etc., and any peculiarities in relation to alkaliphiles are mainly related to the preparation of media.
Before to start isolation, it is very important to understand which media will
contribute to isolating a particular strain and to what physiological group the target
isolate will belong to, because the current diversity of alkaliphiles is too high to
isolate “simply” alkaliphile. In this connection, a matter of importance is a choice for
the natural or man-made source where putative alkaliphile can live.
How to prepare a medium for the isolation and subsequent maintenance of an
alkaliphile? Looking through a large number of published papers relating to
alkaliphilic microorganisms, the reader will discover the same great variety of
media used. Apparently, there are no universal formulations, although an attempt
was made by Grant to standardize the medium formulations for the isolation of
aerobic heterotrophic alkaliphiles [130]. Nevertheless, one point is obvious: to be
successful in isolation of alkaliphiles, it is necessary that the pH of the medium for
68
V. V. Kevbrin
S. alkalinus, and all of them are alkaliphilic. Interestingly, all the isolated strains
could only be recovered if the soil clumps put directly on the medium instead of the
common suspending in the medium. In summary, by now, the list of known
alkaliphilic fungi (noteworthy, all are within the Ascomycota division) includes
Acremonium alcalophilum (isolated from pig feces compost in Japan) [123];
Gliocladium cibotii, Phialophora geniculata, Stachylidium bicolor, and Stilbella
annulata (from slightly alkaline grassland in Indonesia) [122]; Acremonium
sp. and Chrysosporium sp. (from limestone cave in Japan) [129]; Emericellopsis
minima, Neosartorya stramenia, and Melanospora zamiae (from different soil types
including Natracualf, in Argentina) [126]; Sodiomyces (from alkaline soils including
solonchak type of soils of Russia, Mongolia, Kenya, Tanzania); and Thielavia
sp. (from alkaline soils of Russia and Armenia) [124]. There is no doubt that the
search for alkaliphilic fungi will be continued, since the fungi in general are valued
producers of many biologically active substances and are widely used in the
bioindustry.
Of course, in one review, it is impossible to embrace all alkaliphiles in all habitats
and a world experience based on published papers has convincingly shown that
alkaliphiles habit many various biocoenoses. In this sense, alkaliphiles, similar to
neutralophiles, follow the known Beijerinck’s principle, but not all taxa or physiological groups are existing in any habitats. Now and before, choosing the “right”
sample for isolation is mostly a matter of an intuition and experience of a particulate
microbiologist.
3 Isolation, Media, and Cultivation
How to isolate an alkaliphile? The techniques of isolation for alkaliphiles are mostly
the same as for neutralophilic microorganisms, and it includes getting enrichments
on an appropriate substrate, physical separation on solid media (getting colonies),
serial dilutions, selective inhibition by antibiotics or inhibitors, etc., and any peculiarities in relation to alkaliphiles are mainly related to the preparation of media.
Before to start isolation, it is very important to understand which media will
contribute to isolating a particular strain and to what physiological group the target
isolate will belong to, because the current diversity of alkaliphiles is too high to
isolate “simply” alkaliphile. In this connection, a matter of importance is a choice for
the natural or man-made source where putative alkaliphile can live.
How to prepare a medium for the isolation and subsequent maintenance of an
alkaliphile? Looking through a large number of published papers relating to
alkaliphilic microorganisms, the reader will discover the same great variety of
media used. Apparently, there are no universal formulations, although an attempt
was made by Grant to standardize the medium formulations for the isolation of
aerobic heterotrophic alkaliphiles [130]. Nevertheless, one point is obvious: to be
successful in isolation of alkaliphiles, it is necessary that the pH of the medium for
68
V. V. Kevbrin