Anaerobic metabolism of the horseshoe crab, Limulus polyphemus: tissue-specific isozymes of D-specific lactate dehydrogenase and lactate metabolism

1982 ◽  
pp. 128-129 ◽  
Author(s):  
K.H. Carlsson ◽  
G. Gäde
Keyword(s):  
Lactate Dehydrogenase ◽  
Horseshoe Crab ◽  
Anaerobic Metabolism ◽  
Limulus Polyphemus ◽  
Lactate Metabolism ◽  
Tissue Specific

scholarly journals Key Enzymes for Anaerobic Lactate Metabolism in Geobacter sulfurreducens

2020 ◽  
Vol 87 (2) ◽  
Author(s):  
Toshiyuki Ueki
Keyword(s):  
Lactate Dehydrogenase ◽  
Environmental Biotechnology ◽  
Anaerobic Metabolism ◽  
Geobacter Sulfurreducens ◽  
Full Potential ◽  
Lactate Metabolism ◽  
Content Type ◽  
Key Enzymes ◽  
Lactate Utilization ◽  
Succinyl Coa Synthetase

ABSTRACT Growth of Geobacter sulfurreducens PCA on lactate was enhanced by laboratory adaptive evolution. The enhanced growth was considered to be attributed to increased expression of the sucCD genes, encoding a succinyl-coenzyme A (CoA) synthetase. To further investigate the function of the succinyl-CoA synthetase, the sucCD genes were deleted from G. sulfurreducens. The mutant showed defective growth on lactate but not on acetate. Introduction of the sucCD genes into the mutant restored the full potential to grow on lactate. These results verify the importance of the succinyl-CoA synthetase in growth on lactate. Genome analysis of Geobacter species identified candidate genes, GSU1623, GSU1624, and GSU1620, for lactate dehydrogenase. Deletion mutants of the identified genes for d-lactate dehydrogenase (ΔGSU1623 ΔGSU1624 mutant) or l-lactate dehydrogenase (ΔGSU1620 mutant) could not grow on d-lactate or l-lactate but could grow on acetate and l- or d-lactate, respectively. Introduction of the respective genes into the mutants allowed growth on the corresponding lactate stereoisomer. These results suggest that the identified genes were essential for d- or l-lactate utilization. The lacZ reporter assay demonstrated that the putative promoter regions were more active during growth on lactate than during growth on acetate, indicating that the genes for the lactate dehydrogenases were expressed more during growth on lactate than during growth on acetate. The gene deletion phenotypes and the expression profiles indicate that there are metabolic switches between lactate and acetate. This study advances the understanding of anaerobic lactate utilization in G. sulfurreducens. IMPORTANCE Lactate is a microbial fermentation product as well as a source of carbon and electrons for microorganisms in the environment. Furthermore, lactate is a common amendment for stimulation of microbial growth in environmental biotechnology applications. However, anaerobic metabolism of lactate has been poorly studied for environmentally relevant microorganisms. Geobacter species are found in various environments and environmental biotechnology applications. By employing genomic and genetic approaches, succinyl-CoA synthetase and lactate dehydrogenase were identified as key enzymes in anaerobic metabolism of lactate in Geobacter sulfurreducens, a representative Geobacter species. Differential gene expression during growth on lactate and acetate was observed, demonstrating that G. sulfurreducens could metabolically switch to adapt to available substrates in the environment. The findings provide new insights into basic physiology in lactate metabolism as well as cellular responses to growth conditions in the environment and can be informative for the application of lactate in environmental biotechnology.

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

Correcting a 135-year error: Limulidae Leach, 1819 (Chelicerata, Xiphosura) is the proper authority, not Limulidae Zittel, 1885

2021 ◽  
pp. 1-2
Author(s):  
Philip M. Novack-Gottshall ◽  
Roy E. Plotnick
Keyword(s):  
Horseshoe Crab ◽  
Marine Species ◽  
Limulus Polyphemus ◽  
Junior Synonym ◽  
Living Fossil ◽  
New Family ◽  
The Family ◽  
The World ◽  
Modern Genus

The horseshoe crab Limulus polyphemus (Linnaeus, 1758) is a famous species, renowned as a ‘living fossil’ (Owen, 1873; Barthel, 1974; Kin and Błażejowski, 2014) for its apparently little-changed morphology for many millions of years. The genus Limulus Müller, 1785 was used by Leach (1819, p. 536) as the basis of a new family Limulidae and synonymized it with Polyphemus Lamarck, 1801 (Lamarck's proposed but later unaccepted replacement for Limulus, as discussed by Van der Hoeven, 1838, p. 8) and Xyphotheca Gronovius, 1764 (later changed to Xiphosura Gronovius, 1764, another junior synonym of Limulus). He also included the valid modern genus Tachypleus Leach, 1819 in the family. The primary authority of Leach (1819) is widely recognized in the neontological literature (e.g., Dunlop et al., 2012; Smith et al., 2017). It is also the authority recognized in the World Register of Marine Species (WoRMS Editorial Board, 2021).

scholarly journals Lactate metabolism in strictly anaerobic microorganisms with a soluble NAD + ‐dependent L‐lactate dehydrogenase

2021 ◽  
Author(s):  
Florian P. Rosenbaum ◽  
Anja Poehlein ◽  
Richard Egelkamp ◽  
Rolf Daniel ◽  
Sönke Harder ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Strictly Anaerobic ◽  
Lactate Metabolism ◽  
Anaerobic Microorganisms
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