Correction: Almeida-Dalmet, S.; et al. Differential Gene Expression in Response to Salinity and Temperature in a Haloarcula Strain from Great Salt Lake, Utah. Genes 2017, 9, 52.

The authors wish to make the following changes to their paper [1].[...].

Differential Gene Expression in Response to Salinity and Temperature in a Haloarcula Strain from Great Salt Lake, Utah.

Haloarchaea that inhabit Great Salt Lake (GSL), a thalassohaline terminal lake, must respond to the fluctuating climate conditions of the elevated desert of Utah. We investigated how shifting environmental factors, specifically salinity and temperature, affected gene expression in the GSL haloarchaea, NA6-27, which we isolated from the hypersaline north arm of the lake. Combined data from cultivation, microscopy, lipid analysis, antibiotic sensitivity, and 16S rRNA gene alignment, suggest that NA6-27 is a member of the Haloarcula genus. Our prior study demonstrated that archaea in the Haloarcula genus were stable in the GSL microbial community over seasons and years. In this study, RNA arbitrarily primed PCR (RAP-PCR) was used to determine the transcriptional responses of NA6-27 grown under suboptimal salinity and temperature conditions. We observed alteration of the expression of genes related to general stress responses, such as transcription, translation, replication, signal transduction, and energy metabolism. Of the ten genes that were expressed differentially under stress, eight of these genes responded in both conditions, highlighting this general response. We also noted gene regulation specific to salinity and temperature conditions, such as osmoregulation and transport. Taken together, these data indicate that the GSL Haloarcula strain, NA6-27, demonstrates both general and specific responses to salinity and/or temperature stress, and suggest a mechanistic model for homeostasis that may explain the stable presence of this genus in the community as environmental conditions shift.

Temporal Study of the Microbial Diversity of the North Arm of Great Salt Lake, Utah, U.S.

We employed a temporal sampling approach to understand how the microbial diversity may shift in the north arm of Great Salt Lake, Utah, U.S. To determine how variations in seasonal environmental factors affect microbial communities, length heterogeneity PCR fingerprinting was performed using consensus primers for the domain Bacteria, and the haloarchaea. The archaeal fingerprints showed similarities during 2003 and 2004, but this diversity changed during the remaining two years of the study, 2005 and 2006. We also performed molecular phylogenetic analysis of the 16S rRNA genes of the whole microbial community to characterize the taxa in the samples. Our results indicated that in the domain, Bacteria, the Salinibacter group dominated the populations in all samplings. However, in the case of Archaea, as noted by LIBSHUFF for phylogenetic relatedness analysis, many of the temporal communities were distinct from each other, and changes in community composition did not track with environmental parameters. Around 20-23 different phylotypes, as revealed by rarefaction, predominated at different periods of the year. Some phylotypes, such as Haloquadradum, were present year-round although they changed in their abundance in different samplings, which may indicate that these species are affected by biotic factors, such as nutrients or viruses, that are independent of seasonal temperature dynamics.

Potential for industrial products from the halophilic Archaea.

The halophilic Archaea are a group of microorganisms that have not been extensively considered for biotechnological applications. This review describes some of the enzymes and products and the potential applications of this unique group of microorganisms to various industrial processes. Specifically, the characteristics of the glycosyl hydrolases, lipases and esterases, proteases, biopolymers and surfactants, as well as some miscellaneous other activities will be described.

Halorubrum californiense sp. nov., an extreme archaeal halophile isolated from a crystallizer pond at a solar salt plant in California, USA.

A motile, rod-shaped, pink-pigmented, extremely halophilic archaeon, strain SF3-213(T), was isolated from a crystallizer pond at the Cargill Solar Salt Plant, Newark, California (USA). Analysis of the almost-complete 16S rRNA gene sequence showed that the isolate was phylogenetically related to species of the genus Halorubrum, with a close relationship to Halorubrum trapanicum NRC 34021(T) (98.6 % similarity), Halorubrum sodomense ATCC 33755(T) (98.3 %) and Halorubrum xinjiangense AS 1.3527(T) (98.2 %). The polar lipids of strain SF3-213(T) were C(20)C(20) derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a sulfated diglycosyl-diether. Strain SF3-213(T) grew in 2.5-5.0 M NaCl. The temperature and pH ranges for growth were 25-42 degrees C and 6.8-8.5, respectively. Optimal growth occurred at 3.5-4.5 M NaCl, 37 degrees C and pH 7.3. Mg(2+) was required for growth. The DNA G+C content was 69.4 mol%. DNA-DNA hybridization values lower than 70 % were obtained between strain SF3-213(T) and the closely related species of the genus Halorubrum. Based on the data presented in this study, strain SF3-213(T) represents a novel species for which the name Halorubrum californiense sp. nov. is proposed; the type strain is SF3-213(T) (=CECT 7256(T)=DSM 19288(T)=JCM 14715(T)).

Recommended minimal standards for describing new taxa of the family Halomonadaceae.

Following Recommendation 30b of the Bacteriological Code (1990 Revision), a proposal of minimal standards for describing new taxa within the family Halomonadaceae is presented. An effort has been made to evaluate as many different approaches as possible, not only the most conventional ones, to ensure that a rich polyphasic characterization is given. Comments are given on the advantages of each particular technique. The minimal standards are considered as guidelines for authors to prepare descriptions of novel taxa. The proposals presented here have been endorsed by the International Committee on Systematics of Prokaryotes Subcommittee on the Taxonomy of Halomonadaceae.

A comparison of DNA profiling techniques for monitoring nutrient impact on microbial community composition during bioremediation of petroleum-contaminated soils.

Amplicon length heterogeneity PCR (LH-PCR) and terminal restriction fragment length polymorphisms (TRFLP) were used to monitor the impact that nutrient amendments had on microbial community dynamics and structural diversity during bioremediation of petroleum-contaminated soils. Slurried soils contaminated with petroleum hydrocarbons were treated in airlift bench-scale bioreactors and were either amended with optimal inorganic nutrients or left unamended. Direct DNA extraction and PCR amplification of whole eubacterial community DNA were performed with universal primers that bracketed the first two or three hypervariable regions of the 16S rDNA gene sequences. The LH-PCR method profiled a more diverse microbial community than did the TRFLP method. The LH-PCR method also tracked differences between the communities due to nutrient amendments. An in silico database search for bacterial genera with amplicon lengths represented in the community fingerprints was performed. It was possible to qualitatively identify different groups in the microbial community based on the amplicon length variations. A similar "virtual" search was performed for the TRFLP fragments using the web-based TAP-TRFLP program. Cloning and sequencing of the PCR products confirmed the in silico database matches. The application of the LH-PCR method as a monitoring tool for bioremediation could greatly enhance and extend the current understanding of the microbial community dynamics during the biodegradation of environmental contaminants.