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Microbiological Research 2002The results of the first inventory of Myxomycetes from the subtropical region Upper Egypt are reported. The substrates were wood, bark of living and dead tree and leaf...
The results of the first inventory of Myxomycetes from the subtropical region Upper Egypt are reported. The substrates were wood, bark of living and dead tree and leaf litter. 20 species belonging to 17 genera of Myxomycetes were identified. Wood was the best substrate for Myxomycetes colonization. Ceratiomyxa fruticulosa, Didymiun melanospermum, Licea biforis and Lycogala epidendrum were the most common species. Brief description and classification of species are provided.
Topics: Egypt; Geography; Myxomycetes; Plant Bark; Plant Leaves; Trees; Tropical Climate; Wood
PubMed: 11911614
DOI: 10.1078/0944-5013-00131 -
Genome Biology and Evolution May 2020Major phenotypic innovations in social amoeba evolution occurred at the transition between the Polysphondylia and group 4 Dictyostelia, which comprise the model organism...
Major phenotypic innovations in social amoeba evolution occurred at the transition between the Polysphondylia and group 4 Dictyostelia, which comprise the model organism Dictyostelium discoideum, such as the formation of a new structure, the basal disk. Basal disk differentiation and robust stalk formation require the morphogen DIF-1, synthesized by the polyketide synthase StlB, the des-methyl-DIF-1 methyltransferase DmtA, and the chlorinase ChlA, which are conserved throughout Dictyostelia. To understand how the basal disk and other innovations evolved in group 4, we sequenced and annotated the Polysphondylium violaceum (Pvio) genome, performed cell type-specific transcriptomics to identify cell-type marker genes, and developed transformation and gene knock-out procedures for Pvio. We used the novel methods to delete the Pvio stlB gene. The Pvio stlB- mutants formed misshapen curly sorogens with thick and irregular stalks. As fruiting body formation continued, the upper stalks became more regular, but structures contained 40% less spores. The stlB- sorogens overexpressed a stalk gene and underexpressed a (pre)spore gene. Normal fruiting body formation and sporulation were restored in Pvio stlB- by including DIF-1 in the supporting agar. These data indicate that, although conserved, stlB and its product(s) acquired both a novel role in the group 4 Dictyostelia and a role opposite to that in its sister group.
Topics: Genome, Protozoan; Myxomycetes; Polyketide Synthases; Protozoan Proteins
PubMed: 32386295
DOI: 10.1093/gbe/evaa079 -
Research in Microbiology Nov 2001Even for humans it is not easy to solve a maze. But the plasmodium of true slime mold, an amoeba-like unicellular organism, has shown an amazing ability to do so. This... (Review)
Review
Even for humans it is not easy to solve a maze. But the plasmodium of true slime mold, an amoeba-like unicellular organism, has shown an amazing ability to do so. This implies that an algorithm and a high computing capacity are included in the unicellular organism. In this report, we discuss information processing in the microorganism to focus on the issue as to whether the maze-solving behavior is akin to primitive intelligence.
Topics: Animals; Maze Learning; Physarum
PubMed: 11763236
DOI: 10.1016/s0923-2508(01)01259-1 -
Proceedings of the National Academy of... Aug 1999
Review
Topics: Animals; Biological Evolution; Chimera; Models, Biological; Myxomycetes; Social Behavior; Urochordata
PubMed: 10430843
DOI: 10.1073/pnas.96.16.8801 -
Plasmodium development in the myxomycete Physarum polycephalum: genetic control and cellular events.Microbiology (Reading, England) Oct 1995
Review
Topics: Animals; Cell Cycle; Cell Differentiation; Eukaryotic Cells; Gene Expression; Mating Factor; Mutation; Peptides; Physarum polycephalum
PubMed: 7581996
DOI: 10.1099/13500872-141-10-2355 -
BMC Biotechnology Aug 2015The myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production. The present study evaluated the use of rice bran as...
BACKGROUND
The myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production. The present study evaluated the use of rice bran as a carbon source and determined the medium components for optimum growth and lipid production for this organism.
RESULTS
Optimization of medium components by response surface methodology showed that rice bran and yeast extract had significant influences on lipid and biomass production. The optimum medium consisted of 37.5 g/L rice bran, 0.79 g/L yeast extract and 12.5 g/L agar, and this yielded 7.5 g/L dry biomass and 0.9 g/L lipid after 5 days. The biomass and lipid production profiles revealed that these parameters increased over time and reached their maximum values (10.5 and 1.26 g/L, respectively) after 7 days. Physarum polycephalum growth decreased on the spent medium but using the latter increased total biomass and lipid concentrations to 14.3 and 1.72 g/L, respectively.
CONCLUSIONS
An effective method for inoculum preparation was developed for biomass and lipid production by P. polycephalum on a low-cost medium using rice bran as the main carbon source. These results also demonstrated the feasibility of scaling up and reusing the medium for additional biomass and lipid production.
Topics: Biofuels; Biomass; Carbon; Dietary Fiber; Fermentation; Lipids; Oryza; Physarum polycephalum
PubMed: 26231053
DOI: 10.1186/s12896-015-0188-y -
Biochimica Et Biophysica Acta. General... Jun 2023Physarum polycephalum is an unusual macroscopic myxomycete expressing a large range of glycosyl hydrolases. Among them, enzymes from the GH18 family can hydrolyze...
BACKGROUND
Physarum polycephalum is an unusual macroscopic myxomycete expressing a large range of glycosyl hydrolases. Among them, enzymes from the GH18 family can hydrolyze chitin, an important structural component of the cell walls in fungi and in the exoskeleton of insects and crustaceans.
METHODS
Low stringency sequence signature search in transcriptomes was used to identify GH18 sequences related to chitinases. Identified sequences were expressed in E. coli and corresponding structures modelled. Synthetic substrates and in some cases colloidal chitin were used to characterize activities.
RESULTS
Catalytically functional hits were sorted and their predicted structures compared. All share the TIM barrel structure of the GH18 chitinase catalytic domain, optionally fused to binding motifs, such as CBM50, CBM18, and CBM14, involved in sugar recognition. Assessment of the enzymatic activities following deletion of the C-terminal CBM14 domain of the most active clone evidenced a significant contribution of this extension to the chitinase activity. A classification based on module organization, functional and structural criteria of characterized enzymes was proposed.
CONCLUSIONS
Physarum polycephalum sequences encompassing a chitinase like GH18 signature share a modular structure involving a structurally conserved catalytic TIM barrels decorated or not by a chitin insertion domain and optionally surrounded by additional sugar binding domains. One of them plays a clear role in enhancing activities toward natural chitin.
GENERAL SIGNIFICANCE
Myxomycete enzymes are currently poorly characterized and constitute a potential source for new catalysts. Among them glycosyl hydrolases have a strong potential for valorization of industrial waste as well as in therapeutic field.
Topics: Chitinases; Physarum polycephalum; Myxomycetes; Escherichia coli; Chitin; Sugars
PubMed: 36933625
DOI: 10.1016/j.bbagen.2023.130343 -
Scientific Reports Mar 2022Biogenic amorphous calcium carbonate (ACC) is typically metastable and can rapidly transform through aging, dehydration, and/or heating to crystalline calcium carbonate....
Biogenic amorphous calcium carbonate (ACC) is typically metastable and can rapidly transform through aging, dehydration, and/or heating to crystalline calcium carbonate. Gaining insight into its structure and properties is typically hampered by its tendency to crystallize over short time periods once isolated from the host organism, and also by the small quantities that are usually available for study. Here we describe an exceptionally stable hydrated ACC (HACC) precipitated by the cosmopolitan slime mold Fuligo septica (L.) F.H. Wigg. (1780). A single slime mold can precipitate up to a gram of HACC over the course of one night. Powder x-ray diffraction (XRD) patterns, transmission electron microscopy images, infrared absorption spectra, together with the lack of optical birefringence are consistent with an amorphous material. XRD simulations, supported by thermogravimetric and evolved gas analysis data, are consistent with an intimate association of organic matter with ~ 1-nm-sized ACC units that have monohydrocalcite- and calcite-like nano-structural properties. It is postulated that this association imparts the extreme stability of the slime mold HACC by inhibiting loss of HO and subsequent crystallization. The composition, structure, and thermal behavior of the HACC precipitated by F. septica collected over 8000 km apart and in markedly different environments, suggests a common structure, as well as similar biochemical and biomineralization mechanisms.
Topics: Animals; Calcium Carbonate; Chemical Phenomena; Crystallization; Dogs; Myxomycetes; Physarida; X-Ray Diffraction
PubMed: 35256681
DOI: 10.1038/s41598-022-07648-9 -
Proceedings of the National Academy of... Sep 2021
Topics: Physarum polycephalum
PubMed: 34470820
DOI: 10.1073/pnas.2105928118 -
European Journal of Biochemistry Jan 19791. During synchronous growth of the acellular slime mould Physarum polycephalum the free amino pool had two maxima, one of 650 units [nmol/plasmodium dry weight (mg)] at...
1. During synchronous growth of the acellular slime mould Physarum polycephalum the free amino pool had two maxima, one of 650 units [nmol/plasmodium dry weight (mg)] at metaphase and the other of 780 units in mid G2 with minima of 550 units before and after mitosis. 2. Proline formed 20--25% of the total pool with aspartic acid, glutamic acid, threonine, valine, leucine, lysine and arginine making up 55% of the pool. 3. The fluctuation of proline during the mitotic cycle was quite different from that of the other amino acids and was transiently very low during telophase.
Topics: Amino Acids; Cell Cycle; Mitosis; Physarum; Proline; Time Factors
PubMed: 436826
DOI: 10.1111/j.1432-1033.1979.tb12802.x