Genetic Potential of Dissulfurimicrobium hydrothermale, an Obligate Sulfur-Disproportionating Thermophilic Microorganism

The biochemical pathways of anaerobic sulfur disproportionation are only partially deciphered, and the mechanisms involved in the first step of S0-disproportionation remain unknown. Here, we present the results of sequencing and analysis of the complete genome of Dissulfurimicrobium hydrothermale strain Sh68T, one of two strains isolated to date known to grow exclusively by anaerobic disproportionation of inorganic sulfur compounds. Dissulfurimicrobium hydrothermale Sh68T is a motile, thermophilic, anaerobic, chemolithoautotrophic microorganism isolated from a hydrothermal pond at Uzon caldera, Kamchatka, Russia. It is able to produce energy and grow by disproportionation of elemental sulfur, sulfite and thiosulfate. Its genome consists of a circular chromosome of 2,025,450 base pairs, has a G + C content of 49.66% and a completion of 97.6%. Genomic data suggest that CO2 assimilation is carried out by the Wood–Ljungdhal pathway and that central anabolism involves the gluconeogenesis pathway. The genome of strain Sh68T encodes the complete gene set of the dissimilatory sulfate reduction pathway, some of which are likely to be involved in sulfur disproportionation. A short sequence protein of unknown function present in the genome of strain Sh68T is conserved in the genomes of a large panel of other S0-disproportionating bacteria and was absent from the genomes of microorganisms incapable of elemental sulfur disproportionation. We propose that this protein may be involved in the first step of elemental sulfur disproportionation, as S0 is poorly soluble and unable to cross the cytoplasmic membrane in this form.

Novel peptide natural products from the NZ thermophilic microorganism Thermogemmatispora strain T81

<p><b>Genome mining of the newly described Thermogemmatispora strain T81, a thermophile from the Taupo Volcanic Zone, NZ, revealed the potential to produce novel ribosomally synthesised and post-translationally modified peptide natural products. Previous work established that strain T81 exhibits antimicrobial activity against a wide range of extremophilic bacteria. This thesis describes the mass spectrometry-guided screening of strain T81, and the subsequent isolation and structure elucidation of a novel lanthipeptide, tikitericin (32).</b></p> <p>Tikitericin is a class II lanthipeptide which bears no sequence homology to known lanthipeptides. Comprised of 35 amino acids, the three-dimensional structure of tikitericin is conformationally restricted by four macrocyclic structures formed by the non-proteinogenic residues methyllanthionine and lanthionine. The amino acid sequence, predicted through bioinformatic analysis, was confirmed by chemical degradation experiments and subsequent tandem mass spectrometry. Characterisation of tikitericin’s ring topology was performed by tandem mass spectrometry and stereochemical configuration of the (methyl)lanthionine residues was determined by gas chromatography mass spectrometry.</p>

Novel peptide natural products from the NZ thermophilic microorganism Thermogemmatispora strain T81

<p><b>Genome mining of the newly described Thermogemmatispora strain T81, a thermophile from the Taupo Volcanic Zone, NZ, revealed the potential to produce novel ribosomally synthesised and post-translationally modified peptide natural products. Previous work established that strain T81 exhibits antimicrobial activity against a wide range of extremophilic bacteria. This thesis describes the mass spectrometry-guided screening of strain T81, and the subsequent isolation and structure elucidation of a novel lanthipeptide, tikitericin (32).</b></p> <p>Tikitericin is a class II lanthipeptide which bears no sequence homology to known lanthipeptides. Comprised of 35 amino acids, the three-dimensional structure of tikitericin is conformationally restricted by four macrocyclic structures formed by the non-proteinogenic residues methyllanthionine and lanthionine. The amino acid sequence, predicted through bioinformatic analysis, was confirmed by chemical degradation experiments and subsequent tandem mass spectrometry. Characterisation of tikitericin’s ring topology was performed by tandem mass spectrometry and stereochemical configuration of the (methyl)lanthionine residues was determined by gas chromatography mass spectrometry.</p>

Involvement of a Quorum Sensing Signal Molecule in the Extracellular Amylase Activity of the Thermophilic Anoxybacillus amylolyticus

Anoxybacillus amylolyticus is a moderate thermophilic microorganism producing an exopolysaccharide and an extracellular α-amylase able to hydrolyze starch. The synthesis of several biomolecules is often regulated by a quorum sensing (QS) mechanism, a chemical cell-to-cell communication based on the production and diffusion of small molecules named “autoinducers”, most of which belonging to the N-acyl homoserine lactones’ (AHLs) family. There are few reports about this mechanism in extremophiles, in particular thermophiles. Here, we report the identification of a signal molecule, the N-butanoyl-homoserine lactone (C4-HSL), from the milieu of A. amylolyticus. Moreover, investigations performed by supplementing a known QS inhibitor, trans-cinnamaldehyde, or exogenous C4-HSL in the growth medium of A. amylolyticus suggested the involvement of QS signaling in the modulation of extracellular α-amylase activity. The data showed that the presence of the QS inhibitor trans-cinnamaldehyde in the medium decreased amylolytic activity, which, conversely, was increased by the effect of exogenous C4-HSL. Overall, these results represent the first evidence of the production of AHLs in thermophilic microorganisms, which could be responsible for a communication system regulating thermostable α-amylase activity.

Whole-Genome Sequence of Geobacillus thermoleovorans ARTRW1, Isolated from Armutlu Geothermal Spring, Turkey

ABSTRACT The thermophilic microorganism Geobacillus thermoleovorans ARTRW1 was isolated from water samples collected in the Armutlu hot spring in Turkey. Here, the whole-genome sequence and its annotations are reported.

Isolation and optimization of the growth conditions of thermophilic microorganism from hot springs

The aim of this study was to isolate and optimize the growth conditions of thermophilic microorganism from hot springs. The isolation was conducted by using the mineral salt basal medium supplemented with 0.6% yeast extract at 50oC. Totally, 33 isolates of thermophilic microorganism were isolated from hot springs at Truong Xuan (Khanh Hoa province) and Binh Chau (Ba Ria - Vung Tau province). The effects of temperature (45 - 80oC), pH (pH 6 - 9) and carbon sources (malate, pyruvate, acetate, glucose, fructose, or carbon dioxide) on the growth of isolates were examined. In addition, the isolate morphology was also investigated by Gram and spore staining. The isolated thermophilic microorganism showed the diversity in colony morphology and color appearance. Most of them were rod shaped, spore-forming and most grew well at 50oC and pH 7. The highest growth of all isolates was observed under malate, glucose, or fructose, as an organic carbon source and unable to use carbon dioxide. Six out of 33 thermophilic microorganism isolates (namely BM7, BS5, NS1, NS3, NS4, and NW6) grew rapidly under high temperatures from 50 - 55oC and their morphology characteristics showed high similarity to Bacillus sp. The study evidenced the polymorphic diversity of thermophiles in the geothermal hot spring ecosystems.

SCREENING OF THERMOPHYLIC MICROORGANISM FROM IJEN CRATER BANYUWANGI AS PHYTASE ENZYME PRODUCER

Phytase is enzyme which hydrolysis phytic acid to anorganic phosphate and myo-inositol pentakis-, tetrakis-, tris-, bis-, and monophosphate. The use of phytase in feed industry can overcome environment and nutrition problems which were arisen from unmetabolism phytic acid or its salt by poultry, swine and fish. The feed industry needs a thermostable enzyme due to the need of high temperature in pelleting process, i.e. 81 °C. By using thermostabile phytase, the pelleting process will not affect the enzyme activity. Thermostabile phytase can be isolated from microorganism live in hot spring water or volcano crater. In this study, the screening of thermophylic microorganism having thermostabile phytase activity in Ijen Crater, Banyuwangi, has been done. From this process, it was obtained 33 isolates that produce phytase enzyme. Isolate was code by AP-17 yields highest phytase activity, that is 0.0296 U/mL, so this isolate was choosen for further study. The activity of crude phytase enzyme was measured based on the amount of anorganic phosphate that was produced in enzymatic reaction using UV-VIS spectrophotometer at 392 nm. Based on morphology test to identify the gram type of microorganism, isolate AP-17 has a bacill cell type and identified as positive gram bacteria. This isolate was assumed as Bacillus type. Keywords: Phytase, thermophilic microorganism, phytase activity