60 research outputs found
Prokaryotic Diversity in Aran-Bidgol Salt Lake, the Largest Hypersaline Playa in Iran
Prokaryotic diversity in Aran-Bidgol salt lake, a thalasohaline lake in Iran, was studied by fluorescence in situ hybridization (FISH), cultivation techniques, denaturing gradient gel electrophoresis (DGGE) of PCR-amplified fragments of 16S rRNA genes and 16S rRNA gene clone library analysis. Viable counts obtained (2.5–4 × 106 cells mL−1) were similar to total cell abundance in the lake determined by DAPI direct count (3–4×107 cells mL−1). The proportion of Bacteria to Archaea in the community detectable by FISH was unexpectedly high and ranged between 1:3 and 1:2. We analyzed 101 archaeal isolates and found that most belonged to the genera Halorubrum (55%) and Haloarcula (18%). Eleven bacterial isolates obtained in pure culture were affiliated with the genera Salinibacter (18.7%), Salicola (18.7%) and Rhodovibrio (35.3%). Analysis of inserts of 100 clones from the eight 16S rRNA clone libraries constructed revealed 37 OTUs. The majority (63%) of these sequences were not related to any previously identified taxa. Within this sampling effort we most frequently retrieved phylotypes related to Halorhabdus (16% of archaeal sequences obtained) and Salinibacter (36% of bacterial sequences obtained). Other prokaryotic groups that were abundant included representatives of Haloquadratum, the anaerobic genera Halanaerobium and Halocella, purple sulfur bacteria of the genus Halorhodospira and Cyanobacteria
Diversity of hydrolytic enzymes in haloarchaeal strains isolated from salt lake
Production of ten hydrolytic enzymes was qualitatively studied on the
haloarchaeal strains isolated from Aran-Bidgol hypersaline lake in the
central desert area of Iran. A total of 293 haloarchea strains were
selected among 300 extremely halophilic isolated prokaryotes.
Accordingly, 142, 141, 128, 64, 38, 16, 7, 3 and 1 archaeal isolates
were able to produce DNase, amylase, lipase, inulinase, pullulanase,
protease, cellulase, chitinase and xylanase, respectively. None was
able to produce pectinase activity. Combined hydrolytic activity was
also detected in many strains. A total of 0.3 % of the strains showed 6
hydrolytic activities, 0.3 % of the strains had 5 hydrolytic
activities, 5.4 % of the strains presented 4 hydrolytic activities, 25
% of the strains presented 3 hydrolytic activities, 28 % of the strains
presented 2 hydrolytic activities and 18 % of the strains presented 1
hydrolytic activity. According to their phenotypic characteristics and
comparative partial 16 S rRNA sequence analysis, the halophilic strains
were all identified as members of family Halobacteriaceae within 12
different taxa from the following genera: Halorubrum, Haloarcula,
Natrinema, Halovivax and Natronomonas. Most enzymes production rate was
observed in the genera Halorubrum, Haloarculaand Natrinema whereas;
there was not any detectable amount of enzyme production in the genera
Halovivax and Natronomonas. The most hydrolytic isolate with 6
combinatorial enzyme production belonged to the genus Natrinema. This
investigation showed that the extreme halophilic archaea from
Aran-Bidgol lake are a potential source of hydrolytic enzyme under
stress conditions and may have possess commercial value
Halopenitus malekzadehii sp. nov., an extremely halophilic archaeon isolated from a salt lake
Corrigendum to “Revised phylogeny of Bacteroidetes and proposal of sixteen new taxa and two new combinations including Rhodothermaeota phyl. nov” [Syst. Appl. Microbiol. 39 (7) (2016) 491–492]
Salinibacter iranicus sp. nov. and Salinibacter luteus sp. nov., isolated from a salt lake, and emended descriptions of the genus Salinibacter and of Salinibacter ruber
Saliterribacillus persicus gen. nov., sp. nov., a moderately halophilic bacterium isolated from a hypersaline lake
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