Methanobacterium thermoautotrophicum AH and Marburg were adapted to grow in medium containing up to 0.65 M NaCl. From 0.01 to 0.5 M NaCl, there was a lag before cell growth which increased with increasing external NaCl. The effect of NaCl on methane production was not significant once the cells began to grow. Intracellular solutes were monitored by nuclear magnetic resonance (NMR) spectroscopy as a function of osmotic stress. In the AH strain, the major intracellular small organic solutes, cyclic-2,3-diphosphoglycerate and glutamate, increased at most twofold between 0.01 and 0.4 M NaCl and decreased when the external NaCl was 0.5 M. M. thermoautotrophicum Marburg similarly showed a decrease in solute (cyclic-2,3-diphosphoglycerate, 1,3,4,6-tetracarboxyhexane, and L-a-glutamate) concentrations for cells grown in medium containing >0.5 M NaCl. At 0.65 M NaCl, a new organic solute, which was visible in only trace amounts at the lower NaCl concentrations, became the dominant solute. Intracellular potassium in the AH strain, detected by atomic absorption and 39K NMR, was roughly constant between 0.01 and 0.4 M and then decreased as the external NaCl increased further. The high intracellular K+ was balanced by the negative charges of the organic osmolytes. At the higher external salt concentrations, it is suggested that Na+ and possibly Cl-ions are internalized to provide osmotic balance. A striking difference of strain Marburg from strain AH was that yeast extract facilitated growth in high-NaCl-containing medium. The yeast extract supplied only trace NMRdetectable solutes (e.g., betaine) but had a large effect on endogenous glutamate levels, which were significantly decreased. Exogenous choline and glycine, instead of yeast extract, also aided growth in NaCl-containing media. Both solutes were internalized with the choline converted to betaine; the contribution to osmotic balance of these species was 20 to 25% of the total small-molecule pool. These results indicate that M. thermoautotrophicum shows little changes in its internal solutes over a wide range of external NaCl. Furthermore, they illustrate the considerable differences in physiology in the AH and Marburg strains of this organism.Methanogens belonging to the archaebacterial ur-kingdom are strictly dependent on sodium ions for growth and methanogenesis (28). Methanogenic bacteria have been isolated from geothermal springs, deep sea hydrothermal vents, freshwater and marine sediments, digestive and intestinal tracts of animals, and anaerobic waste digesters (18). Given such diverse environments, there should be a wide range of strategies by which these cells cope with changes in external NaCl. Several marine (30-33), halophilic (22) ing solute. M. thermnoautotrophicum requires Na+ for growth, and it has been suggested that the establishment of a sodium gradient across the cell membrane is involved in cell bioenergetics (35,40). Under normal growth conditions, M. thennoautotrophicum is grown in low-ionic-strength medium, and its NaCl tolerance has not bee...

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The de novo genome of unique marine yeast, Wickerhamomyces anomalus isolated from seaweed along Indian coast is presented. The genome assembly was carried out using MaSurCA assembler that generated a data size ∼14.3 mb from short and long reads obtained from Illumina Hiseq 4000 and GridION-X5 respectively. This assembled genome data were used for predicting genes using Augustus gene prediction tool that reported 6720 genes and proteins. The gene sequences were used to unravel the metabolic pathway analysis using KAAS database. The protein sequences were used for secondary analysis to predict the presence of signal peptides using SignalP tool, predicting protein family, domains using Pfam tool and prediction of transmembrane helices in proteins using TMHMM tool. Presence of genes involved in plant growth–promotion and regulation (PGPR) including siderophore and IAA production, iron and sulfur transformation, zinc and phosphate solubilization, nitrogen fixation, synthesis of anti-bacterial and volatile organic compound (VOCs), were assigned. Additionally, acid and alkaline phosphatases, ACC deaminases and lytic enzymes such as β-glucanases, proteases and chitinases involved in pathogen suppression, are also reported. The study elucidates comprehensive understanding of PGP attributes of MSD1 and its potential use in agriculture as bio-fertilizer /bio-stimulant.

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When sucrose is present in the external medium, it is internalized by Methanococcus thermolithotrophicus. Sucrose internalization, as determined by both natural abundance (sup13)C nuclear magnetic resonance spectroscopy and [(sup14)C]sucrose uptake, is directly proportional to external sucrose levels. The uptake is energy independent and exhibits kinetic behavior consistent with a simple passive diffusion process. In the presence of 0.2 M sucrose, methanogenesis is inhibited as the NaCl concentration in the external medium is increased. Growth, as determined by protein content, is inhibited by 0.2 M sucrose when the external NaCl concentration is 1.4 M. These results are important because they show that (i) sucrose cannot be used as a noncharged solute to replace NaCl in experiments to evaluate how external osmotic strength affects the internal solute composition of M. thermolithotrophicus, and (ii) sucrose cannot be used as an impermeable marker for the extracellular volume in experiments to measure the intracellular volume of M. thermolithotrophicus.