Joaquín J. Nieto

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The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while(More)
Two strains that were originally isolated and characterized as members of the moderately halophilic species Halomonas elongata, strains DSM 3043 (= 1H11) and ATCC 33174 (= 1H15), were studied in detail. Their complete 16S rRNA sequences were determined and, when compared to sequences available from the databases, they showed a close phylogenetic(More)
Extracellular amylase production by the moderate halophile Halomonas meridiana was optimized and the enzyme was characterized biochemically. The highest amylase production was achieved by growing H. meridiana cultures in media with 5% salts and starch, in the absence of glucose until the end of the exponential phase. The amylase exhibited maximal activity(More)
Microorganisms produce and accumulate compatible solutes aiming at protecting themselves from environmental stresses. Among them, the wide spread in nature ectoines are receiving increasing attention by the scientific community because of their multiple applications. In fact, increasing commercial demand has led to a multiplication of efforts in order to(More)
The tolerance patterns, expressed as MICs, for 250 moderately halophilic eubacteria to 10 heavy metals were surveyed by using an agar dilution method. The moderate halophiles tested included 12 culture collection strains and fresh isolates representative of Deleya halophila (37 strains), Acinetobacter sp. (24 strains), Flavobacterium sp. (28 strains), and(More)
The osmoregulatory pathways of the moderately halophilic bacterium Halomonas elongata DSM 3043 have been investigated. This strain grew optimally at 1.5 to 2 M NaCl in M63 glucose-defined medium. It required at least 0.5 M NaCl for growth, which is a higher concentration than that exhibited by the H. elongata type strain ATCC 33173. Externally provided(More)
The phylogenetic positions of the moderately halophilic bacteria Chromohalobacter marismortui, Volcaniella eurihalina, and Deleya salina were determined by PCR amplification of rRNA genes and direct sequencing. The resulting data were compared with data for other bacteria obtained from 16S rRNA sequence databases. C. marismortui, V. eurihalina, and D.(More)
The phylogenetic positions of six Vibrio costicola strains were determined by direct sequencing and analysis of their PCR-amplified 16S ribosomal DNAs. A comparative analysis of the sequence data revealed that the moderate halophile V. costicola forms a monophyletic branch that is distinct from other Vibrio species and from moderately halophilic species of(More)
AIMS To investigate the catabolism of ectoine and hydroxyectoine, which are the major compatible solutes synthesized by Chromohalobacter salexigens. METHODS AND RESULTS Growth curves performed in M63 minimal medium with low (0.75 mol l(-1) NaCl), optimal (1.5 mol l(-1) NaCl) or high (2.5 mol l(-1) NaCl) salinity revealed that betaine and ectoines were(More)
The moderate halophile Halomonas elongata Deustche Sammlung für Mikroorganismen 3043 accumulated ectoine, hydroxyectoine, glutamate, and glutamine in response to osmotic stress (3 M NaCl). Two Tn1732-induced mutants, CHR62 and CHR63, that were severely affected in their salt tolerance were isolated. Mutant CHR62 could not grow above 0.75 M NaCl, and CHR63(More)