Aliidiomarina sanyensis from the cultivation pool for Spirulina platensis
cyanobacterium [97].
Other alkalinizing reactions include anaerobic processes, e.g., sulfate and nitrate
reduction and fermentation of the nitrogenous biopolymers such as nucleic acids and
proteins. The latter were released into surrounding medium after dying off prime
producers’ cells. Hydrolytic microflora or fermenters in case of anaerobes have
hydrolyzed biopolymers with concomitant release of ammonium ions that increase
a pH value in external medium. Although the alkalinization proceeds on a microscale, unlike a geochemical process, alkaliphiles from the outside, once getting this
favorable environment can stay in it and can, possibly, evolve inside such microbial
community provided the community is stable for enough time. Certainly, evident
alkaline localities such as alkaline lakes, soils, springs, etc. will probably contain
more alkaliphiles; however, in view of a microscale alkalinization, it is not a rule.
That is why alkaliphiles can be isolated from many neutral environments provided
microbial life is possible there. The reader can find numerous examples of obligate
alkaliphiles isolated from apparently neutral, unobvious in the sense of the search for
alkaliphiles, habitats. They include Halomonas desiderata [98], Clostridium
paradoxum [99], and Clostridium thermoalcaliphilum [100] isolated from municipal
wastewaters, anaerobic sulfate reducer Desulfotomaculum alkaliphilum from
cow/pig manure [101], CO-oxidizing anaerobic acetogen Alkalibaculum bacchi
from livestock-impacted soil [102], moderately halophilic and alkalitolerant
Natribacillus halophilus from the garden soil [103], haloalkaliphilic Alkalibacillus
silvisoli from non-saline forest soil [104], Algoriphagus trabzonensis from freshwater river [105], Bacillus marmarensis from mushroom compost [106], hydrocarbonutilizing Dietzia psychralcaliphila [107], and Exiguobacterium oxidotolerans with
an extremely high catalase activity [108], the latter two from a drain pool of a fish
processing plant. Microbiological alkalinization also seems to be responsible for
the existence of alkaliphiles in the intestine of insects, e.g., Alkalispirochaeta
odontotermitis (former Spirochaeta odontotermitis) from a termite [109],
Alkalispirochaeta cellulosivorans from a wood-eating cockroach [110], Bacillus
trypoxylicola from the larvae of the Japanese horned beetle [111]. The latter is
interesting in that it shows a preference for K
+ over Na
+
. Three isolated strains,
SU1
T , 36AC4, and 36AC6, showed good growth up to 12% (w/v) KCl. And finally,
alkaliphiles can be isolated even from cheese, as in the case of Alkalibacterium
gilvum [112].
2.7 Alkaliphilic Eukaryotes
Although this chapter is primarily devoted to alkaliphilic prokaryotes, it also mentions the alkaliphilic eukaryotic organisms. Since it is assumed that alkaline habitats
existed throughout the entire geological history of the Earth [113], eukaryotes had to
develop certain mechanisms of adaptation to life at alkaline ambient pH. And,
indeed, they are (e.g., an altered content of membrane lipids and cytoprotectant
66
V. V. Kevbrin
cyanobacterium [97].
Other alkalinizing reactions include anaerobic processes, e.g., sulfate and nitrate
reduction and fermentation of the nitrogenous biopolymers such as nucleic acids and
proteins. The latter were released into surrounding medium after dying off prime
producers’ cells. Hydrolytic microflora or fermenters in case of anaerobes have
hydrolyzed biopolymers with concomitant release of ammonium ions that increase
a pH value in external medium. Although the alkalinization proceeds on a microscale, unlike a geochemical process, alkaliphiles from the outside, once getting this
favorable environment can stay in it and can, possibly, evolve inside such microbial
community provided the community is stable for enough time. Certainly, evident
alkaline localities such as alkaline lakes, soils, springs, etc. will probably contain
more alkaliphiles; however, in view of a microscale alkalinization, it is not a rule.
That is why alkaliphiles can be isolated from many neutral environments provided
microbial life is possible there. The reader can find numerous examples of obligate
alkaliphiles isolated from apparently neutral, unobvious in the sense of the search for
alkaliphiles, habitats. They include Halomonas desiderata [98], Clostridium
paradoxum [99], and Clostridium thermoalcaliphilum [100] isolated from municipal
wastewaters, anaerobic sulfate reducer Desulfotomaculum alkaliphilum from
cow/pig manure [101], CO-oxidizing anaerobic acetogen Alkalibaculum bacchi
from livestock-impacted soil [102], moderately halophilic and alkalitolerant
Natribacillus halophilus from the garden soil [103], haloalkaliphilic Alkalibacillus
silvisoli from non-saline forest soil [104], Algoriphagus trabzonensis from freshwater river [105], Bacillus marmarensis from mushroom compost [106], hydrocarbonutilizing Dietzia psychralcaliphila [107], and Exiguobacterium oxidotolerans with
an extremely high catalase activity [108], the latter two from a drain pool of a fish
processing plant. Microbiological alkalinization also seems to be responsible for
the existence of alkaliphiles in the intestine of insects, e.g., Alkalispirochaeta
odontotermitis (former Spirochaeta odontotermitis) from a termite [109],
Alkalispirochaeta cellulosivorans from a wood-eating cockroach [110], Bacillus
trypoxylicola from the larvae of the Japanese horned beetle [111]. The latter is
interesting in that it shows a preference for K
+ over Na
+
. Three isolated strains,
SU1
T , 36AC4, and 36AC6, showed good growth up to 12% (w/v) KCl. And finally,
alkaliphiles can be isolated even from cheese, as in the case of Alkalibacterium
gilvum [112].
2.7 Alkaliphilic Eukaryotes
Although this chapter is primarily devoted to alkaliphilic prokaryotes, it also mentions the alkaliphilic eukaryotic organisms. Since it is assumed that alkaline habitats
existed throughout the entire geological history of the Earth [113], eukaryotes had to
develop certain mechanisms of adaptation to life at alkaline ambient pH. And,
indeed, they are (e.g., an altered content of membrane lipids and cytoprotectant
66
V. V. Kevbrin