scholarly journals Radioactive Fingerprinting of Microorganisms That Oxidize Atmospheric Methane in Different Soils

1999 ◽  
Vol 65 (9) ◽  
pp. 4064-4070 ◽  
Author(s):  
Peter Roslev ◽  
Niels Iversen
Keyword(s):  
Fatty Acids ◽  
The United States ◽  
Type I ◽  
Methanotrophic Bacteria ◽  
Type Ii ◽  
Atmospheric Methane ◽  
Tropical Regions ◽  
Methane Metabolism ◽  
Conversion Efficiencies ◽  
Different Soils

ABSTRACT Microorganisms that oxidize atmospheric methane in soils were characterized by radioactive labelling with14CH4 followed by analysis of radiolabelled phospholipid ester-linked fatty acids (14C-PLFAs). The radioactive fingerprinting technique was used to compare active methanotrophs in soil samples from Greenland, Denmark, the United States, and Brazil. The 14C-PLFA fingerprints indicated that closely related methanotrophic bacteria were responsible for the oxidation of atmospheric methane in the soils. Significant amounts of labelled PLFAs produced by the unknown soil methanotrophs coeluted with a group of fatty acids that included i17:0, a17:0, and 17:1ω8c (up to 9.0% of the total 14C-PLFAs). These PLFAs are not known to be significant constituents of methanotrophic bacteria. The major PLFAs of the soil methanotrophs (73.5 to 89.0% of the total PLFAs) coeluted with 18:1 and 18:0 fatty acids (e.g., 18:1ω9, 18:1ω7, and 18:0). The 14C-PLFAs fingerprints of the soil methanotrophs that oxidized atmospheric methane did not change after long-term methane enrichment at 170 ppm CH4. The 14C-PLFA fingerprints of the soil methanotrophs were different from the PLFA profiles of type I and type II methanotrophic bacteria described previously. Some similarity at the PLFA level was observed between the unknown soil methanotrophs and the PLFA phenotype of the type II methanotrophs. Methanotrophs in Arctic, temperate, and tropical regions assimilated between 20 and 54% of the atmospheric methane that was metabolized. The lowest relative assimilation (percent) was observed for methanotrophs in agricultural soil, whereas the highest assimilation was observed for methanotrophs in rain forest soil. The results suggest that methanotrophs with relatively high carbon conversion efficiencies and very similar PLFA compositions dominate atmospheric methane metabolism in different soils. The characteristics of the methane metabolism and the 14C-PLFA fingerprints excluded any significant role of autotrophic ammonia oxidizers in the metabolism of atmospheric methane.

scholarly journals Comparative Genetic Analysis of Magnaporthe oryzae Isolates Causing Gray Leaf Spot of Perennial Ryegrass Turf in the United States and Japan

Plant Disease ◽  
2007 ◽  
Vol 91 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Tosa ◽  
W. Uddin ◽  
G. Viji ◽  
S. Kang ◽  
S. Mayama
Keyword(s):  
United States ◽  
Perennial Ryegrass ◽  
Magnaporthe Oryzae ◽  
Leaf Spot ◽  
Genetic Relationships ◽  
The United States ◽  
Gray Leaf Spot ◽  
Genetic Lineage ◽  
Type I ◽  
Type Ii

Gray leaf spot caused by Magnaporthe oryzae is a serious disease of perennial ryegrass (Lolium perenne) turf in golf course fairways in the United States and Japan. Genetic relationships among M. oryzae isolates from perennial ryegrass (prg) isolates within and between the two countries were examined using the repetitive DNA elements MGR586, Pot2, and MAGGY as DNA fingerprinting probes. In all, 82 isolates of M. oryzae, including 57 prg isolates from the United States collected from 1995 to 2001, 1 annual ryegrass (Lolium multiflorum) isolate from the United States collected in 1972, and 24 prg isolates from Japan collected from 1996 to 1999 were analyzed in this study. Hybridization with the MGR586 probe resulted in approximately 30 DNA fragments in 75 isolates (designated major MGR586 group) and less than 15 fragments in the remaining 7 isolates (designated minor MGR586 group). Both groups were represented among the 24 isolates from Japan. All isolates from the United States, with the exception of one isolate from Maryland, belonged to the major MGR586 group. Some isolates from Japan exhibited MGR586 fingerprints that were identical to several isolates collected in Pennsylvania. Similarly, fingerprinting analysis with the Pot2 probe also indicated the presence of two distinct groups: isolates in the major MGR586 group showed fingerprinting profiles comprising 20 to 25 bands, whereas the isolates in the minor MGR586 group had less than 10 fragments. When MAGGY was used as a probe, two distinct fingerprint types, one exhibiting more than 30 hybridizing bands (type I) and the other with only 2 to 4 bands (type II), were identified. Although isolates of both types were present in the major MGR586 group, only the type II isolates were identified in the minor MGR586 group. The parsimony tree obtained from combined MGR586 and Pot2 data showed that 71 of the 82 isolates belonged to a single lineage, 5 isolates formed four different lineages, and the remaining 6 (from Japan) formed a separate lineage. This study indicates that the predominant groups of M. oryzae associated with the recent outbreaks of gray leaf spot in Japan and the United States belong to the same genetic lineage.

scholarly journals Comprehensive Characterization of Toxoplasma Acyl Coenzyme A-Binding Protein TgACBP2 and Its Critical Role in Parasite Cardiolipin Metabolism

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Yong Fu ◽  
Xia Cui ◽  
Sai Fan ◽  
Jing Liu ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Toxoplasma Gondii ◽  
Binding Protein ◽  
Ankyrin Repeat ◽  
Type I ◽  
Type Ii ◽  
Content Type ◽  
High K ◽  
Acyl Coenzyme A

ABSTRACT Acyl coenzyme A (CoA)-binding protein (ACBP) can bind acyl-CoAs with high specificity and affinity, thus playing multiple roles in cellular functions. Mitochondria of the apicomplexan parasite Toxoplasma gondii have emerged as key organelles for lipid metabolism and signaling transduction. However, the rationale for how this parasite utilizes acyl-CoA-binding protein to regulate mitochondrial lipid metabolism remains unclear. Here, we show that an ankyrin repeat-containing protein, TgACBP2, is localized to mitochondria and displays active acyl-CoA-binding activities. Dephosphorylation of TgACBP2 is associated with relocation from the plasma membrane to the mitochondria under conditions of regulation of environmental [K+]. Under high [K+] conditions, loss of ACBP2 induced mitochondrial dysfunction and apoptosis-like cell death. Disruption of ACBP2 caused growth and virulence defects in the type II strain but not in type I parasites. Interestingly, mitochondrial association factor-1 (MAF1)-mediated host mitochondrial association (HMA) restored the growth ability of ACBP2-deficient type II parasites. Lipidomics analysis indicated that ACBP2 plays key roles in the cardiolipin metabolism of type II parasites and that MAF1 expression complemented the lipid metabolism defects of ACBP2-deficient type II parasites. In addition, disruption of ACBP2 caused attenuated virulence of Prugniuad (Pru) parasites for mice. Taking the results collectively, these data indicate that ACBP2 is critical for the growth and virulence of type II parasites and for the growth of type I parasites under high [K+] conditions. IMPORTANCE Toxoplasma gondii is one of the most successful human parasites, infecting nearly one-third of the total world population. T. gondii tachyzoites residing within parasitophorous vacuoles (PVs) can acquire fatty acids both via salvage from host cells and via de novo synthesis pathways for membrane biogenesis. However, although fatty acid fluxes are known to exist in this parasite, how fatty acids flow through Toxoplasma lipid metabolic organelles, especially mitochondria, remains unknown. In this study, we demonstrated that Toxoplasma expresses an active ankyrin repeat containing protein TgACBP2 to coordinate cardiolipin metabolism. Specifically, HMA acquisition resulting from heterologous functional expression of MAF1 rescued growth and lipid metabolism defects in ACBP2-deficient type II parasites, manifesting the complementary role of host mitochondria in parasite cardiolipin metabolism. This work highlights the importance of TgACBP2 in parasite cardiolipin metabolism and provides evidence for metabolic association of host mitochondria with T. gondii.

Decompression Sickness Damaging the Spinal Cord in a Scuba Diver: Case Report

1987 ◽  
Vol 3 (2) ◽  
pp. 41-45
Author(s):  
B.G. Mathew
Keyword(s):  
Spinal Cord ◽  
Decompression Sickness ◽  
The United States ◽  
Neurological Involvement ◽  
Detailed Knowledge ◽  
Type I ◽  
Type Ii ◽  
Pulmonary Barotrauma ◽  
Emergency Personnel ◽  
Diving Accidents

Scuba diving has become a popular sport resulting in an increased incidence of diving accidents. A survey done by the United States Navy from 1955 to 1960 revealed that decompression sickness (D.C.S.) is the most common serious complication experienced by scuba divers and the third most likely cause of death. The major cause is drowning and the second is arterial gas embolism from pulmonary barotrauma.D.C.S. has been classified into two groups. Type I includes the less severe forms with bubbles in the skin (“itches”), joints and other tissues. Type II includes the serious conditions with neurological involvement “staggers.” A detailed knowledge of D.C.S., commonly known as “the bends,” is essential to both divers and emergency personnel in order to minimize the morbidity and mortality associated with this condition.A case of Type II bends with spinal cord damage is presented and the condition discussed.

scholarly journals Characterization and Biosynthesis of Lipids in Paulinella micropora MYN1: Evidence for Efficient Integration of Chromatophores into Cellular Lipid Metabolism

2020 ◽  
Vol 61 (5) ◽  
pp. 869-881 ◽  
Author(s):  
Naoki Sato ◽  
Toru Yoshitomi ◽  
Natsumi Mori-Moriyama
Keyword(s):  
Fatty Acids ◽  
Marine Algae ◽  
Type I ◽  
Type Ii ◽  
Cellular Lipid ◽  
Animal Cells ◽  
Fixed Carbon ◽  
Ultrastructural Evidence ◽  
Efficient Integration ◽  
Rapid Labeling

Abstract The chromatophores found in the cells of photosynthetic Paulinella species, once believed to be endosymbiotic cyanobacteria, are photosynthetic organelles that are distinct from chloroplasts. The chromatophore genome is similar to the genomes of α-cyanobacteria and encodes about 1,000 genes. Therefore, the chromatophore is an intriguing model of organelle formation. In this study, we analyzed the lipids of Paulinella micropora MYN1 to verify that this organism is a composite of cyanobacterial descendants and a heterotrophic protist. We detected glycolipids and phospholipids, as well as a betaine lipid diacylglyceryl-3-O-carboxyhydroxymethylcholine, previously detected in many marine algae. Cholesterol was the only sterol component detected, suggesting that the host cell is similar to animal cells. The glycolipids, presumably present in the chromatophores, contained mainly C16 fatty acids, whereas other classes of lipids, presumably present in the other compartments, were abundant in C20 and C22 polyunsaturated fatty acids. This suggests that chromatophores are metabolically distinct from the rest of the cell. Metabolic studies using isotopically labeled substrates showed that different fatty acids are synthesized in the chromatophore and the cytosol, which is consistent with the presence of both type I and type II fatty acid synthases, supposedly present in the cytosol and the chromatophore, respectively. Nevertheless, rapid labeling of the fatty acids in triacylglycerol and phosphatidylcholine by photosynthetically fixed carbon suggested that the chromatophores efficiently provide metabolites to the host. The metabolic and ultrastructural evidence suggests that chromatophores are tightly integrated into the whole cellular metabolism.

Methylohalobius crimeensis gen. nov., sp. nov., a moderately halophilic, methanotrophic bacterium isolated from hypersaline lakes of Crimea

2005 ◽  
Vol 55 (5) ◽  
pp. 1817-1826 ◽  
Author(s):  
Jürgen Heyer ◽  
Ursula Berger ◽  
Martin Hardt ◽  
Peter F. Dunfield
Keyword(s):  
Fatty Acids ◽  
16S Rrna ◽  
Gene Sequence ◽  
Rrna Gene ◽  
Type I ◽  
Methanotrophic Bacteria ◽  
Rrna Gene Sequence ◽  
Methanotrophic Bacterium ◽  
Hypersaline Lakes ◽  
Novel Genus And Species

A novel genus and species are proposed for two strains of methanotrophic bacteria isolated from hypersaline lakes in the Crimean Peninsula of Ukraine. Strains 10KiT and 4Kr are moderate halophiles that grow optimally at 1–1·5 M (5·8–8·7 %, w/v) NaCl and tolerate NaCl concentrations from 0·2 M up to 2·5 M (1·2–15 %). This optimum and upper limit are the highest for any methanotrophic bacterium known to date. The strains are Gram-negative, aerobic, non-pigmented, motile, coccoid to spindle-shaped bacteria that grow on methane or methanol only and utilize the ribulose monophosphate pathway for carbon assimilation. They are neutrophilic (growth occurs only in the range pH 6·5–7·5) and mesophilic (optimum growth occurs at 30 °C). On the basis of 16S rRNA gene sequence phylogeny, strains 10KiT and 4Kr represent a type I methanotroph within the ‘Gammaproteobacteria’. However, the 16S rRNA gene sequence displays <91·5 % identity to any public-domain sequence. The most closely related methanotrophic bacterium is the thermophilic strain HB. The DNA G+C content is 58·7 mol%. The major phospholipid fatty acids are 18 : 1ω7 (52–61 %), 16 : 0 (22–23 %) and 16 : 1ω7 (14–20 %). The dominance of 18 : 1 over 16 : 0 and 16 : 1 fatty acids is unique among known type I methanotrophs. The data suggest that strains 10KiT and 4Kr should be considered as belonging to a novel genus and species of type I methanotrophic bacteria, for which the name Methylohalobius crimeensis gen. nov., sp. nov. is proposed. Strain 10KiT (=DSM 16011T=ATCC BAA-967T) is the type strain.

Genotyping Dickeya dianthicola causing potato blackleg and soft rot outbreak associated with inoculum geography in the United States

Plant Disease ◽  
2020 ◽  
Author(s):  
Tongling Ge ◽  
He Jiang ◽  
Steven B Johnson ◽  
Robert Larkin ◽  
Amy O Charkowski ◽  
...  
Keyword(s):  
United States ◽  
Bacterial Pathogen ◽  
Soft Rot ◽  
The United States ◽  
Lower Percentage ◽  
Economic Losses ◽  
Type I ◽  
Type Ii ◽  
Northeastern United States ◽  
Type Iii

An outbreak of blackleg and soft rot of potato, caused primarily by the bacterial pathogen Dickeya dianthicola, has resulted in significant economic losses in the Northeastern United States since 2015. The spread of this seedborne disease is highly associated with seed distribution, therefore the pathogen likely spread with seed tubers. To describe the blackleg epidemic and track inoculum origins, a total of 1183 potato samples were collected from 11 states associated with blackleg outbreak from 2015 to 2019. Of these samples, 39.8% tested positive for D. dianthicola. Seventeen isolates of Dickeya dianthicola were recovered from these samples and the genetic diversity of these isolates was examined. Fingerprinting with BOX-PCR and phylogenetic analysis based on sequences of the 16S rRNA and gapA genes indicated that D. dianthicola isolates were divided into three genotypes, denoted Type I, II, and III. Ninety five percent of samples from Maine were Type I. Type II was found in Maine only in 2015 and 2018. Type II was present throughout the five years in some states at a lower percentage than Type I. Type III was found in Pennsylvania, New Jersey and Massachusetts, but not in Maine. Therefore, Type I appears to be associated with Maine, but Type II appeared to be endemic to the Northeastern United States. The Type II and rarer Type III strain were closer to the D. dianthicola type strain isolated from the United Kingdom. This work provides evidence that the outbreak of blackleg of potato in the Northeastern United States was caused by multiple strains of D. dianthicola. The geographic origins of these strains remain unknown.

scholarly journals Mitochondrial Fatty Acid Synthesis in Trypanosoma brucei

2006 ◽  
Vol 282 (7) ◽  
pp. 4427-4436 ◽  
Author(s):  
Jennifer L. Stephens ◽  
Soo Hee Lee ◽  
Kimberly S. Paul ◽  
Paul T. Englund
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Trypanosoma Brucei ◽  
Lipoic Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Type I ◽  
Type Ii ◽  
Acetyl Coa ◽  
Acid Product

Whereas other organisms utilize type I or type II synthases to make fatty acids, trypanosomatid parasites such as Trypanosoma brucei are unique in their use of a microsomal elongase pathway (ELO) for de novo fatty acid synthesis (FAS). Because of the unusual lipid metabolism of the trypanosome, it was important to study a second FAS pathway predicted by the genome to be a type II synthase. We localized this pathway to the mitochondrion, and RNA interference (RNAi) or genomic deletion of acyl carrier protein (ACP) and β-ketoacyl-ACP synthase indicated that this pathway is likely essential for bloodstream and procyclic life cycle stages of the parasite. In vitro assays show that the largest major fatty acid product of the pathway is C16, whereas the ELO pathway, utilizing ELOs 1, 2, and 3, synthesizes up to C18. To demonstrate mitochondrial FAS in vivo, we radio-labeled fatty acids in cultured procyclic parasites with [14C]pyruvate or [14C]threonine, either of which is catabolized to [14C]acetyl-CoA in the mitochondrion. Although some of the [14C]acetyl-CoA may be utilized by the ELO pathway, a striking reduction in radiolabeled fatty acids following ACP RNAi confirmed that it is also consumed by mitochondrial FAS. ACP depletion by RNAi or gene knockout also reduces lipoic acid levels and drastically decreases protein lipoylation. Thus, octanoate (C8), the precursor for lipoic acid synthesis, must also be a product of mitochondrial FAS. Trypanosomes employ two FAS systems: the unconventional ELO pathway that synthesizes bulk fatty acids and a mitochondrial pathway that synthesizes specialized fatty acids that are likely utilized intramitochondrially.

scholarly journals Amiodarone Induced Thyrotoxicosis: A Case of Refractory Disease Treated With Thyroidectomy

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A920-A920
Author(s):  
Malek Mushref ◽  
Kathrin Sandra Tofil ◽  
Kathie Lynn Hermayer
Keyword(s):  
Heart Failure ◽  
Mixed Type ◽  
Calcium Supplementation ◽  
The United States ◽  
High Dose ◽  
Thyroid Autoantibodies ◽  
Type I ◽  
Thyroid Function Tests ◽  
Type Ii ◽  
Thyroid Ultrasound

Abstract Amiodarone induced thyrotoxicosis (AIT) is a challenging diagnosis that affects 3-5% of patients taking amiodarone in the United States. Type I AIT is seen in patients with preexisting thyroid disease and is generally treated with thionamides while type II AIT represents a destructive thyroiditis that responds to glucocorticoids. A mixed type exists and is associated with higher mortality, especially in older adults with cardiovascular disease. Thyroidectomy is considered a last resort option for patients intolerant or refractory to medical treatment. A 70 year-old male with a history of coronary artery disease, ventricular tachycardia (VT), and heart failure was referred to the endocrine clinic for abnormal thyroid function tests that showed TSH &lt;0.0023 uIU/mL (0.4-4.7), Free T4 2.51 ng/dL (0.7-1.48) and Free T3 5.37 pg/mL (1.71-3.71). He endorsed palpitations, excessive sweating, tremors, and reported taking amiodarone for 3 years prior to presentation. Vitals showed normal pulse and blood pressure. Thyroid autoantibodies including TSI and TBII were within normal limits. Thyroid ultrasound showed mild thyromegaly with normal vascularity and no nodules. AIT was suspected and he was started on methimazole 20 mg daily, prednisone 30 mg daily and continued on his home metoprolol 100 mg daily. Methimazole and prednisone were both up titrated in a week because his labs did not improve. One month later, he presented to the hospital with acute exacerbation of heart failure. His TFTs showed (TSH &lt;0.0021 uIU/mL, FT4 &gt;5.0 ng/dL, FT3 4.61 pg/mL). Thyroid RAIU showed severely decreased uptake secondary to the high iodine content of amiodarone. He remained thyrotoxic despite using higher doses of prednisone (60 mg daily) and methimazole (90 mg daily). He was changed to PTU (900 mg daily) and started on cholestyramine, with no improvement in overall status. Several weeks after admission, a total thyroidectomy was performed. His postoperative course was unremarkable except for hypoparathyroidism. He was clinically and biochemically euthyroid one week after his procedure. At 6 months follow up, he remained stable on levothyroxine 100 mcg/day but continued to require calcitriol and calcium supplementation. We present an interesting case of mixed type AIT refractory to medical therapy associated with cardiovascular compromise. This case highlights the challenges in the diagnosis and management of such patients. Thyroid autoantibodies, thyroid ultrasound and RAIU were more indicative of Type II AIT, however, lack of response to high dose steroids was inconsistent with the diagnosis. While receiving the treatment for both Type I and II AIT, our patient had persistent clinical and biochemical thyrotoxicosis and required thyroidectomy. Although most AIT patients are treated medically, thyroidectomy is reserved for those most severe and refractory cases and is considered a viable option in such patients.

71 The Use of Medium Chain Fatty Acids to Reduce Porcine Reproductive Respiratory Syndrome Virus Replication in MARC-145 Cells

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 35-36
Author(s):  
Stacie Crowder ◽  
Roman Pogranichniy ◽  
Brenda DeRodas ◽  
Karnezos Peter ◽  
J S S Radcliffe
Keyword(s):  
Fatty Acids ◽  
Viral Replication ◽  
Respiratory Syndrome Virus ◽  
Type I ◽  
Type Ii ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Log Reduction ◽  
Virus Strains ◽  
Chain Fatty Acids

Abstract Porcine reproductive respiratory syndrome virus (PPRSV) costs the U.S. Swine Industry an estimated $664 million annually. The objective of this study was to evaluate the effect of medium chain fatty acids (MCFA) on PRRSV replication in M-145 cells. Two experiments were conducted to 1) evaluate the use of individual MCFAs (C6, C8, C10), and 2) evaluate MCFA combinations (C8/C10, C10/C12, C8/C10/C12) on viral replication of PRRSV. Experiment one used individual MCFAs at 7 concentrations from 1-1000µg/ml compared to a control. Experiment two used MCFA combinations at 6 different concentrations from 50–500µg/ml compared to a control. North American Type II P-129 PRRSV and European Type I Lelystad PRRSV strains were used. Viral replication was determined using FITC labeled IgG anti-PRRSV monoclonal antibody and TCID50 was calculated for each treatment concentration using 5 wells per treatment at each virus concentration with plates run in triplicate. Data were analyzed using Proc Mixed procedures of SAS. In experiment 1, C6 had no effect on replication of PRRSV in M145 cells. C8 induced a 3.02 and 2.02 log reduction in TCID50 for type I and type II virus strains, respectively (P &lt; 0.01) at 1000µg/ml. C10 induced a 2.85 and 3.23 log reduction in TCID50 for type I and type II virus strains, respectively (P &lt; 0.01) at 300µg/ml. In experiment 2, C8/C10 induced a 1.9 and 2.2 log reduction in TCID50 for type I and type II virus strains, respectively (P &lt; 0.01) at 200µg/ml. C10/C12 resulted in a 3.37 and 2.14 log reduction in TCID50 at 200µg/ml for type I and type II virus strains, respectively (P &lt; 0.01). C8/C10/C12 resulted in a 1.34 and 1.56 log reduction in TCID50 at 200µg/ml for type I and type II virus strains (P &lt; 0.01), respectively.

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