An Investigation into the Suitability of Sulfate-Reducing Bacteria as Models for Martian Forward Contamination

The NASA Planetary Protection policy requires interplanetary space missions do not compromise the target body for a current or future scientific investigation and do not pose an unacceptable risk to Earth, including biologic materials. Robotic missions to Mars pose a risk to planetary protection in the forms of forward and reverse contamination. To reduce these risks, a firm understanding of microbial response to Mars conditions is required. Sulfate-reducing bacteria are prime candidates for potential forward contamination on Mars. Understanding the potential for forward-contamination of sulfate-reducers on Mars calls for the characterization of sulfate-reducers under Mars atmosphere, temperature, and sulfate-brines. This study investigated the response of several sulfate-reducing bacteria, including spore formers and psychrophiles. The psychrophile Desulfotalea psychrophila was found to inconsistently survive positive control lab conditions, attributed to an issue shipping pure cultures. Desulfotomaculum arcticum, a spore-forming mesophilic sulfate-reducer, and Desulfuromusa ferrireducens, an iron and sulfate-reducer, were metabolically active under positive control lab conditions with complex and minimal growth medium. A wastewater treatment sulfate-reducing bacteria (SRB) isolate was subjected to sulfate + growth-medium solutions of varied concentrations (0.44 & 0.55% wt. SO42-). The wastewater SRB displayed higher cellular light-absorbance levels at delayed rates in 0.55% sulfate solutions, suggesting a greater total culture reproduction, but with increased lag time. Additional SRB were isolated from marine sediments, subjected to a shock pressure of 8.73 GPa, and returned to ideal conditions. The sulfate-concentration patterns in the impacted SRB culture suggests a destruction of culture occurred somewhere during the preparation process. The response of SRB in this investigation to Ca and Na sulfate-brines suggests that Martian sulfate deposits offer a viable energy sink to terrestrial microorganisms, and the studied SRB are capable of replication at reduced water-activity. Further investigation (i.e. sulfate cations and concentrations, temperature, pressure, etc.) may identify Martian locations at risk to forward contamination

Effects of a synthetic bioactive peptide on neurite growth and nerve growth factor release in chondroitin sulfate hydrogels.

Previous work has revealed robust dorsal root ganglia neurite growth in hydrogels of chondroitin sulfate. In the current work, it was determined whether addition of a synthetic bioactive peptide could augment neurite growth in these matrices via enhanced binding and sequestering of growth factors. Fluorescence recovery after photobleaching studies revealed that addition of peptide slowed nerve growth factor diffusivity in chondroitin sulfate gels, but not in control gels of hyaluronic acid. Furthermore, cultures of chick dorsal root ganglia in gels of hyaluronic acid or chondroitin sulfate revealed enhanced growth in chondroitin sulfate gels only upon addition of peptide. Taken together, these results suggest a synergistic nerve growth factor-binding activity between this peptide and chondroitin sulfate

User-friendly mathematical model for the design of sulfate reducing H2/CO2 fed bioreactors

The paper presents three steady-state mathematical models for the design of H2/CO2 fed gas-lift reactors aimed at biological sulfate reduction to remove sulfate from wastewater. Models 1A and 1B are based on heterotrophic sulfate reducing bacteria (HSRB), while Model 2 is based on autotrophic sulfate reducing bacteria (ASRB) as the dominant group of sulfate reducers in the gas-lift reactor. Once the influent wastewater characteristics are known and the desired sulfate removal efficiency is fixed, all models give explicit mathematical relationships to determine the bioreactor volume and the effluent concentrations of substrates and products. The derived explicit relationships make application of the models very easy, fast and no iterative procedures are required. Model simulations show that the size of the H2/CO2 fed gas-lift reactors aimed at biological sulfate removal from wastewater highly depends on the number and type of trophic groups growing in the bioreactor. In particular, if the biological sulfate reduction is performed in a bioreactor where ASRB prevail, the required bioreactor volume is much smaller than that needed with HSRB. This is because ASRB can out-compete methanogenic archarea (MA) for H2 (assuming sulfate concentrations are not limiting), whereas HSRB do not necessarily out-compete MA due to their dependence on homoacetogenic bacteria (HB) for organic carbon. The reactor sizes to reach the same sulfate removal efficiency by HSRB and ASRB are only comparable when methanogenesis is inhibited. Moreover, model results indicate that acetate supply to the reactor influent does not affect the HSRB biomass required in the reactor, but favours the dominance of MA on HB as a consequence of a lower HB requirement for acetate supply

Hepatic heparan sulfate is a master regulator of hepcidin expression and iron homeostasis in human hepatocytes and mice.

Hepcidin is a liver-derived peptide hormone that controls systemic iron homeostasis. Its expression is regulated by the bone morphogenetic protein 6 (BMP6)/SMAD1/5/8 pathway and by the proinflammatory cytokine interleukin 6 (IL6). Proteoglycans that function as receptors of these signaling proteins in the liver are commonly decorated by heparan sulfate, but the potential role of hepatic heparan sulfate in hepcidin expression and iron homeostasis is unclear. Here, we show that modulation of hepatic heparan sulfate significantly alters hepcidin expression and iron metabolism both in vitro and in vivo Specifically, enzymatic removal of heparan sulfate from primary human hepatocytes, CRISPR/Cas9 manipulation of heparan sulfate biosynthesis in human hepatoma cells, or pharmacological manipulation of heparan sulfate-protein interactions using sodium chlorate or surfen dramatically reduced baseline and BMP6/SMAD1/5/8-dependent hepcidin expression. Moreover inactivation of the heparan sulfate biosynthetic gene N-deacetylase and N-sulfotransferase 1 (Ndst1) in murine hepatocytes (Ndst1 f/f AlbCre +) reduced hepatic hepcidin expression and caused a redistribution of systemic iron, leading to iron accumulation in the liver and serum of mice. Manipulation of heparan sulfate had a similar effect on IL6-dependent hepcidin expression in vitro and suppressed IL6-mediated iron redistribution induced by lipopolysaccharide in vivo These results provide compelling evidence that hepatocyte heparan sulfate plays a key role in regulating hepcidin expression and iron homeostasis in mice and in human hepatocytes

Effect of Addition Catalyst Sulfate Acid and Solvents (Ch3oh) Biodiesel Production Process of Seeds Nyamplung (Calophyllum Inophyllum)

Biodiesel is made by taking the oil from the seeds by pressing nyamplung then processed through two stages of esterification and transesterification of the oil with solvent ratio between 1:1, 1:2, 1:3, 1:4 and 1:6 and added catalyst H2SO4 at process of esterification and transesterification catalyst NaOH in the process. In the process of varying the acid catalyst esterification 0.4%, 0.5%, 0.6%, 0.7% and 0.8% of the seed oil nyamplung. Operating condition is maintained at a temperature of 70 ° C, process time of 60 minutes with a time separation of 3 hours. Biodiesel products that meet the Indonesian National Standard is the composition ratio nyamplung seed oil and methanol is 1:1, the catalyst is used as much as 0.5% with an analysis of the quality of the density of 0.8870 g / ml, pH 7.30, level water 0.0616%, 1.3387 refractive index, 3.7480 cSt viscosity, Flash Point 56oC, calorific value of 9001 cal / g and 48.03 Cetane number

Thermophilic Sulfate Reduction in Hydrothermal Sediment of Lake Tanganyika, East Africa

In environments with temperatures above 60 degrees C, thermophilic prokaryotes are the only metabolically active life-forms. By using the (SO42-)-S-35 tracer technique, we studied the activity of sulfate-reducing microorganisms (SRM) in hot sediment from a hydrothermal vent site in the northern part of freshwater Lake Tanganyika (East Africa). Incubation of slurry samples at 8 to 90 degrees C demonstrated meso- and thermophilic sulfate reduction with optimum temperatures of 34 to 45 degrees C and 56 to 65 degrees C, respectively, and with an upper temperature limit of 80 degrees C. Sulfate reduction was stimulated at all temperatures by the addition of short-chain fatty acids and benzoate or complex substrates (yeast extract and peptone). A time course experiment showed that linear thermophilic sulfate consumption occurred after a lag phase (12 h) and indicated the presence of a large population of SRM in the hydrothermal sediment. Thermophilic sulfate reduction had a pH optimum of about 7 and was completely inhibited at pH 8.8 to 9.2. SRM could be enriched from hydrothermal chimney and sediment samples at 60 and 75 degrees C. In lactate-grown enrichments, sulfide production occurred at up to 70 and 75 degrees C, with optima at 63 and 71 degrees C, respectively. Several sporulating thermophilic enrichments were morphologically similar to Desulfotomaculum spp. Dissimilatory sulfate reduction in the studied hydrothermal area of Lake Tanganyika apparently has an upper temperature limit of 80 degrees C

p-Cresyl sulfate

If chronic kidney disease (CKD) is associated with an impairment of kidney function, several uremic solutes are retained. Some of these exert toxic effects, which are called uremic toxins. p-Cresyl sulfate (pCS) is a prototype protein-bound uremic toxin to which many biological and biochemical (toxic) effects have been attributed. In addition, increased levels of pCS have been associated with worsening outcomes in CKD patients. pCS finds its origin in the intestine where gut bacteria metabolize aromatic amino acids, such as tyrosine and phenylalanine, leading to phenolic end products, of which pCS is one of the components. In this review we summarize the biological effects of pCS and its metabolic origin in the intestine. It appears that, according to in vitro studies, the intestinal bacteria generating phenolic compounds mainly belong to the families Bacteroidaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Enterococcaceae, Eubacteriaceae, Fusobacteriaceae, Lachnospiraceae, Lactobacillaceae, Porphyromonadaceae, Staphylococcaceae, Ruminococcaceae, and Veillonellaceae. Since pCS remains difficult to remove by dialysis, the gut microbiota could be a future target to decrease pCS levels and its toxicity, even at earlier stages of CKD, aiming at slowing down the progression of the disease and decreasing the cardiovascular burden

The effects of zinc sulfate on ethyl glucuronide immunoassay urine testing

Published research in the Journal of Analytical Toxicology and the American Society for Clinical Pathology has confirmed that the presence of Zinc Sulfate in adulterated urine samples can influence the testing results using EMIT and ELISA immunoassay testing when testing for Cannabinoids (THC), Cocaine (Benzoylecgonine), Methamphetamines, Opiates (Morphine, Methadone, and Propoxyphene), Phencyclidine (PCP), and Ethanol (Alcohol Dehydrogenase). This research included adding Zinc Sulfate directly to urine samples. In 2006, the Substance Abuse and Mental Health Service Administration (SAMHSA) released an advisory that the use of Ethyl glucuronide (EtG) as a new biomarker as an indicator for the past-use of alcohol was promising and warranted more research. Ethyl glucuronide is a direct metabolite of the biotransformation of ethanol in the human body. This compound is excreted in urine and can be used as a specific biomarker for the ingestion of alcohol. Because EtG is only produced when ethanol is metabolized, there are no false positives due to fermentation and a much longer detection window exists for its detection. Scientific literature states that EtG can be present in urine long after ethanol has been eliminated. Testing for EtG is commonly referred to as the “80 hour test” for the ability of EtG to be measured up to 80 hours after consuming alcohol. It was hypothesized that if the presence of Zinc Sulfate added to urine falsely reduced urine alcohol level when measuring for Alcohol Dehydrogenase enzyme, will the presence of Zinc Sulfate added to SurineTM falsely reduce the urine alcohol level when measuring for EtG? Since it is very likely that EtG would still be present in the body after ethanol has been eliminated, samples contained either no ethanol or 5% (5g/dL) of ethanol. Samples were spiked at 10mg/mL, 15mg/mL or contained 0mg/mL of Zinc Sulfate. Additionally, duration testing was conducted to see if there was any observed differences between testing the samples fresh and then after a one week duration in a refrigerator and brought to room temperature prior to testing. Two different immunoassay EtG tests were used to perform the analysis. It was concluded that Zinc Sulfate directly added to the sample affected one of the immunoassay test regardless of whether EtG or ethanol were present, by fading the Test and Control regions. Additionally, it is concluded that SurineTM samples containing Zinc Sulfate could easily be distinguished from samples free of Zinc Sulfate because of the presence of a white cloudy precipitate

Genetic and Metabolic Controls for Sulfate Metabolism in \u3cem\u3eNeurospora crassa\u3c/em\u3e: Isolation and Study of Chromate-Resistant and Sulfate Transport-Negative Mutants

Mutants of Neurospora resistant to chromate were selected and all were found to map at a single genetic locus designated as cys-13. The chromate-resistant mutants grow at a wild-type rate on minimal media but are partially deficient in the transport of inorganic sulfate, especially during the conidial stage. An unlinked mutant, cys-14, is sensitive to chromate but transports sulfate during the mycelial stage at only 25% of the wild-type rate; cys-14 also grows at a fully wild-type rate on minimal media. The double-mutant strain, cys-13;cys-14, cannot utilize inorganic sulfate for growth and completely lacks the capacity to transport this anion. The only biochemical lesion that has been detected for the double-mutant strain is its loss in capacity for sulfate transport. Neurospora appears to possess two distinct sulfate permease species encoded by separate genetic loci. The transport system (permease I) encoded by cys-13 predominates in the conidial stage and is replaced by sulfate permease II, encoded by the cys-14 locus, during outgrowth into the mycelial phase. The relationship of these new mutants to cys-3, a regulatory gene that appears to control their expression, is discussed