Nutrition and distribution of salt response in populations of moderately halophilic bacteria

1970 ◽  
Vol 16 (4) ◽  
pp. 253-261 ◽  
Author(s):  
M. P. Forsyth ◽  
D. J. Kushner
Keyword(s):  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Nutrient Supply ◽  
Nutritional Requirements ◽  
Glucose Medium ◽  
Salt Tolerant ◽  
Replica Plating ◽  
Ph Values ◽  
Salt Response ◽  
Moderately Halophilic Bacteria

Cultures of Micrococcus halodenitrificans and Vibrio costicolus can grow in the presence of 0.4–3.5 M NaCl. Three lines of investigation: attempts to select for more or less salt-tolerant cells; colony counts at different salt concentrations; and replica plating experiments, suggested that populations of these organisms were genetically homogeneous in their salt response. That is, each cell in a population could grow over the whole range of salt concentration in which the culture grew.The nutritional requirements of V. costicolus were studied. This organism can grow in a minimal (salts–glucose) medium at pH values above 6.0 and in a salt concentration range 0.5–2.2 M. Increasing the concentration of phosphate buffer greatly increased cell yield. The range of salt concentration in which V. costicolus could grow depended on the nutrient supply, being widest in complex media. A wider range was possible in the presence of amino acids than in a salts–glucose medium. All growth factors permitting growth to occur at high salt concentrations were not identified.

Influence of salt concentration on the susceptibility of moderately halophilic bacteria to antimicrobials and its potential use for genetic transfer studies

1995 ◽  
Vol 31 (6) ◽  
pp. 365-371 ◽  
Author(s):  
Mar�a-Jos� Coronado ◽  
Carmen Vargas ◽  
Hans J�rg Kunte ◽  
Erwin A. Galinski ◽  
Antonio Ventosa ◽  
...  
Keyword(s):  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Genetic Transfer ◽  
Moderately Halophilic ◽  
Potential Use ◽  
Moderately Halophilic Bacteria

The Synthesis of Poly-β-Hydroxybutyrate by Moderately Halophilic Bacteria Halomonas venusta

2014 ◽  
Vol 1033-1034 ◽  
pp. 306-310 ◽  
Author(s):  
Shuang Gao ◽  
Ling Hua Zhang
Keyword(s):  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Carbon Sources ◽  
Dry Weight ◽  
Phosphate Concentration ◽  
Two Phase ◽  
Moderately Halophilic ◽  
Initial Carbon ◽  
Carbon Nitrogen Ratio ◽  
Moderately Halophilic Bacteria

In this study, poly-β-hydroxybutyrate (PHB) was synthesized by moderately halophilic bacteria Halomonas venusta and identified by 1H-NMR. The effects of different carbon sources, salt concentration, initial carbon nitrogen quality ratio, initial phosphate concentration were studied on the synthesis of PHB. The optimum conditions of the PHB synthesis were detemined. Glucose was as carbon source with the concentration of 80 g/L and salt concentration, initial carbon nitrogen ratio, initial phosphate concentration was 3%, 15 and 1.9 g/L respectively. Under the above conditions, a two-phase synthesis system of PHB was constructed. The PHB synthesis amount and yield of cell dry weight was reached up to 1.5 g/L and 69.19 wt.%, respectively. The efficient synthesis of PHB was realized.

TURBIDITY OF SUSPENSIONS AND MORPHOLOGY OF RED HALOPHILIC BACTERIA AS INFLUENCED BY SODIUM CHLORIDE CONCENTRATION

1960 ◽  
Vol 6 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Dinah Abram ◽  
N. E. Gibbons
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Morphological Changes ◽  
Halophilic Bacteria ◽  
Chloride Concentration ◽  
Chloride Content ◽  
Wall Structure ◽  
Abrupt Decrease ◽  
High Sodium ◽  
Rigid Cell Wall

The optical densities of suspensions of cells of Halobacterium cutirubrum, H. halobium, or H. salinarium, grown in media containing 4.5 M sodium chloride, increase as the salt concentration of the suspending medium decreases, until a maximum is reached at about 2 M; below this concentration there is an abrupt decrease in optical density. The cells are rod shaped in 4.5 M salt and change, as the salt concentration decreases, through irregular transition forms to spheres; equal numbers of transition forms and spheres are present at the point of maximum turbidity, while spheres predominate at lower salt concentrations. Cells suspended in 3.0 M salt, although slightly swollen, are viable, but viability decreases rapidly with the more drastic changes in morphology at lower salt concentrations. Cells grown in the presence of iron are more resistant to morphological changes but follow the same sequence. Cells "fixed" with formaldehyde, at any point in the sequence, act as osmometers and do not rupture in distilled water although their volume increases 10–14 times. The results indicate that the red halophilic rods require a high sodium chloride content in their growth or suspending medium to maintain a rigid cell wall structure.

scholarly journals Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov., moderately halophilic bacteria isolated from a deep-sea methane cold seep

2007 ◽  
Vol 57 (6) ◽  
pp. 1243-1249 ◽  
Author(s):  
Ngoc-Phuc Hua ◽  
Atsuko Kanekiyo ◽  
Katsunori Fujikura ◽  
Hisato Yasuda ◽  
Takeshi Naganuma
Keyword(s):  
Deep Sea ◽  
Sequence Similarity ◽  
Halophilic Bacteria ◽  
Cold Seep ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
High Sequence Similarity ◽  
Moderately Halophilic ◽  
Type Strains ◽  
Moderately Halophilic Bacteria

Two Gram-positive, rod-shaped, moderately halophilic bacteria were isolated from a deep-sea carbonate rock at a methane cold seep in Kuroshima Knoll, Japan. These bacteria, strains IS-Hb4T and IS-Hb7T, were spore-forming and non-motile. They were able to grow at temperatures as low as 9 °C and hydrostatic pressures up to 30 MPa. Based on high sequence similarity of their 16S rRNA genes to those of type strains of the genus Halobacillus, from 96.4 % (strain IS-Hb7T to Halobacillus halophilus NCIMB 9251T) to 99.4 % (strain IS-Hb4T to Halobacillus dabanensis D-8T), the strains were shown to belong to this genus. DNA–DNA relatedness values of 49.5 % and 1.0–33.0 %, respectively, were determined between strains IS-Hb4T and IS-Hb7T and between these strains and other Halobacillus type strains. Both strains showed the major menaquinone MK7 and l-orn–d-Asp cell-wall peptidoglycan type. Straight-chain C16 : 0, unsaturated C16 : 1 ω7c alcohol and C18 : 1 ω7c and cyclopropane C19 : 0 cyc fatty acids were predominant in both strains. The DNA G+C contents of IS-Hb4T and IS-Hb7T were respectively 43.3 and 42.1 mol%. Physiological and biochemical analyses combined with DNA–DNA hybridization results allowed us to place strains IS-Hb4T (=JCM 14154T=DSM 18394T) and IS-Hb7T (=JCM 14155T=DSM 18393T) in the genus Halobacillus as the respective type strains of the novel species Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov.

scholarly journals Molecular response of canola to salt stress: insights on tolerance mechanisms

2018 ◽  
Author(s):  
Reza Shokri-Gharelo ◽  
Pouya Motie-Noparvar
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Edible Oils ◽  
Biodiesel Fuel ◽  
Molecular Response ◽  
Salt Tolerant ◽  
Tolerance Mechanisms ◽  
Brassica Napus L ◽  
Salt Response ◽  
The Many

Canola (Brassica napus L.) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as ‘salt-tolerant’, plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests where researchers should focus future studies.

Behavior of Listeria monocytogenes at 4 and 22°C in Whey and Skim Milk Containing 6 or 12% Sodium Chloride

1989 ◽  
Vol 52 (9) ◽  
pp. 625-630 ◽  
Author(s):  
DEMETRIOS K. PAPAGEORGIOU ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Sodium Chloride ◽  
Skim Milk ◽  
Salt Tolerant ◽  
Ph Values ◽  
Generation Times ◽  
Order Of Magnitude ◽  
Entire Experiment

Autoclaved samples of skim milk and deproteinated whey were fortified with 6 or 12% NaCl, inoculated with Listeria monocytogenes strains Scott A or California (CA), to contain ca. 1.0 × 103 cfu/ml (in the products with 6% salt) or ca. 5.0 × 103 cfu/ml (in the products with 12% salt) and incubated at 4 and 22°C. The pH values of the 6% salted whey, 6% salted skim milk, 12% salted whey, and 12% salted skim milk were 5.65, 6.20, 5.50, and 6.00 respectively. These values remained relatively constant during the entire experiment. Listeria counts were obtained by surface-plating appropriate dilutions and/or undiluted samples on Trypticase Agar (TA). Samples in which L. monocytogenes was not detected, were re-examined after 2, 4, 6 and 8 weeks of cold-enrichment. Generation times of L. monocytogenes in 6% salted whey at 22°C (3.67 h and 3.56 h for strains Scott A and CA, respectively) were significantly shorter than those in 6% salted skim milk at 22°C (4.31 and 4.42 h for the two strains, respectively). Generation times in 6% salted products at 4°C ranged between 37.49 h and 49.43 h. Maximum populations reached at 22 and 4°C ranged from 7.58 to 8.10 Log10 cfu/ml, and were significantly higher in 6% salted whey than in 6% salted skim milk. In 12% salted whey and skim milk incubated at 22°C, L. monocytogenes gradually decreased in numbers. Strain CA was inactivated within 85 d in 12% salted skim milk or within 110 d in 12% salted whey, and was significantly less salt tolerant than strain Scott A which survived for more than 130 d under the same conditions. Loss of viability by both strains was similar in 12% salted whey and skim milk after 130 d of storage at 4°C, and the decreases in population were less than 0.7 order of magnitude.

scholarly journals WGCNA Analysis of Salt-Responsive Core Transcriptome Identifies Novel Hub Genes in Rice

Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 719 ◽  
Author(s):  
Mingdong Zhu ◽  
Hongjun Xie ◽  
Xiangjin Wei ◽  
Komivi Dossa ◽  
Yaying Yu ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Biological Processes ◽  
Salt Tolerant ◽  
Hub Genes ◽  
Pathway Gene ◽  
Salt Response ◽  
Genes Encoding ◽  
Bioinformatic Approaches ◽  
Salt Tolerant Cultivars ◽  
And Control

Rice, being a major staple food crop and sensitive to salinity conditions, bears heavy yield losses due to saline soil. Although some salt responsive genes have been identified in rice, their applications in developing salt tolerant cultivars have resulted in limited achievements. Herein, we used bioinformatic approaches to perform a meta-analysis of three transcriptome datasets from salinity and control conditions in order to reveal novel genes and the molecular pathways underlying rice response to salt. From a total of 28,432 expressed genes, we identify 457 core differentially expressed genes (DEGs) constitutively responding to salt, regardless of the stress duration, genotype, or the tissue. Gene co-expression analysis divided the core DEGs into three different modules, each of them contributing to salt response in a unique metabolic pathway. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses highlighted key biological processes and metabolic pathways involved in the salt response. We identified important novel hub genes encoding proteins of different families including CAM, DUF630/632, DUF581, CHL27, PP2-13, LEA4-5, and transcription factors, which could be functionally characterized using reverse genetic experiments. This novel repertoire of candidate genes related to salt response in rice will be useful for engineering salt tolerant varieties.

scholarly journals Exploring the hydrolytic potential of cultured halophilic bacteria isolated from the Atacama Desert

2019 ◽  
Vol 366 (17) ◽  
Author(s):  
Robert Ruginescu ◽  
Cristina Purcărea ◽  
Cristina Dorador ◽  
Paris Lavin ◽  
Roxana Cojoc ◽  
...  
Keyword(s):  
Halophilic Bacteria ◽  
Agar Plate ◽  
Atacama Desert ◽  
Industrial Processes ◽  
Biotechnological Applications ◽  
Bacterial Isolates ◽  
Salt Tolerant ◽  
Essential Step ◽  
Extremophilic Microorganisms ◽  
Biological Sources

ABSTRACT Considering that most industrial processes are carried out under harsh physicochemical conditions, which would inactivate enzymes from commonly isolated mesophilic organisms, current studies are geared toward the identification of extremophilic microorganisms producing enzymes resistant to extreme salt concentrations, temperature and pH. Among the extremophiles, halophilic microorganisms are an important source of salt-tolerant enzymes that can be used in varying biotechnological applications. In this context, the aim of the present work was to isolate and identify halophiles producing hydrolases from the Atacama Desert, one of the harshest environments on Earth. Isolates were recovered from halite samples and screened for the presence of seven different hydrolase activities (amylase, caseinase, gelatinase, lipase, pectinase, cellulase and inulinase) using agar plate-based assays. From a total of 23 halophilic bacterial isolates, most showed lipolytic (19 strains) and pectinolytic (11 strains) activities. The molecular identification of eight selected isolates showed a strong similarity to members of the Halomonas and Idiomarina genera. Therefore, the present study represents a preliminary, but essential, step to identify novel biological sources of extremozymes in an environment once thought to be devoid of life.

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