Content Of NH3 Research Articles

Effect of Pre-Stressing on the Acid-Stress Response in Bifidobacterium Revealed Using Proteomic and Physiological Approaches.

Weak acid resistance limits the application of Bifidobacteria as a probiotic in food. The acid tolerance response (ATR), caused by pre-stressing cells at a sublethal pH, could improve the acid resistance of Bifidobacteria to subsequent acid stress. In this study, we used Bifidobacterium longum sub. longum BBMN68 to investigate the effect of the ATR on the acid stress response (ASR), and compared the difference between the ATR and the ASR by analyzing the two-dimensional-PAGE protein profiles and performing physiological tests. The results revealed that a greater abundance of proteins involved in carbohydrate metabolism and protein protection was present after the ASR than after the ATR in Bifidobacterium. Pre-stressing cells increased the abundance of proteins involved in energy production, amino acid metabolism, and peptidoglycan synthesis during the ASR of Bifidobacterium. Moreover, after the ASR, the content of ATP, NH3, thiols, and peptidoglycan, the activity of H+-ATPase, and the maintenance of the intracellular pH in the pre-stressed Bifidobacterium cells was significantly higher than in the uninduced cells. These results provide the first explanation as to why the resistance of Bifidobacterium to acid stress improved after pre-stressing.

Environmental impact of electricity from selected geothermal power plants in Italy

Abstract Geothermal plants supply a significant contribution to the electricity balance from renewable sources in Tuscany. However, this electricity conversion is not exempt from environmental drawbacks. In our study, the electricity production phases of four geothermal electricity plants are analyzed by means of a careful airborne emissions assessment carried out over the entire LCA of the plants. The impact categories considered are global warming (GWP), acidification (ACP) and human toxicology (HTP). The functional unit used is 1 MWh of electric energy produced from geothermal power plants in Mount Amiata area. For the environmental impact categories considered, the impact potentials are evaluated for each of the four geothermal power plants as follows: 380–1045 kg CO2 eq/MWh for GWP, 0.1–44.8 kg SO2 eq/MWh for ACP and 1.1–31.6 kg, 1.4-DB eq/MWh for HTP. The main contributions to the impact are associated with the high content of NH3, H2S, CH4 and CO2 gases present in the effluents of each plant. The impact change in relation to the geothermal site has a strong correlation to the basin of fluid withdrawal and is related to the technologies used for pollutants depletion. In some cases the impact is higher than that found for production of electricity from fossil fuels (for example, a coal plant of comparable power).

Effect of dietary protein concentration on ammonia and greenhouse gas emitting potential of dairy manure

Two experiments were conducted to investigate the effect of dietary crude protein concentration on ammonia (NH3) and greenhouse gas (GHG; nitrous oxide, methane, and carbon dioxide) emissions from fresh dairy cow manure incubated in a controlled environment (experiment 1) and from manure-amended soil (experiment 2). Manure was prepared from feces and urine collected from lactating Holstein cows fed diets with 16.7% (DM basis; HCP) or 14.8% CP (LCP). High-CP manure had higher N content and proportion of NH3- and urea-N in total manure N than LCP manure (DM basis: 4.4 vs. 2.8% and 51.4 vs. 30.5%, respectively). In experiment 1, NH3 emitting potential (EP) was greater for HCP compared with LCP manure (9.20 vs. 4.88mg/m2 per min, respectively). The 122-h cumulative NH3 emission tended to be decreased 47% (P=0.09) using LCP compared with HCP manure. The EP and cumulative emissions of GHG were not different between HCP and LCP manure. In experiment 2, urine and feces from cows fed LCP or HCP diets were mixed and immediately applied to lysimeters (61×61×61cm; Hagerstown silt loam; fine, mixed, mesic Typic Hapludalf) at 277kg of N/ha application rate. The average NH3 EP (1.53 vs. 1.03mg/m2 per min, respectively) and the area under the EP curve were greater for lysimeters amended with HCP than with LCP manure. The largest difference in the NH3 EP occurred approximately 24h after manure application (approximately 3.5 times greater for HCP than LCP manure). The 100-h cumulative NH3 emission was 98% greater for HCP compared with LCP manure (7,415 vs. 3,745mg/m2, respectively). The EP of methane was increased and that of carbon dioxide tended to be increased by LCP compared with HCP manure. The cumulative methane emission was not different between treatments, whereas the cumulative carbon dioxide emission was increased with manure from the LCP diet. Nitrous oxide emissions were low in this experiment and did not differ between treatments. In the conditions of these experiments, fresh manure from dairy cows fed a LCP diet had substantially lower NH3 EP, compared with manure from cows fed a HCP diet. The LCP manure increased soil methane EP due to a larger mass of manure added to meet plant N requirements compared with HCP manure. These results represent effects of dietary protein on NH3 and GHG EP of manure in controlled laboratory conditions and do not account for environmental factors affecting gaseous emissions from manure on the farm.

Degradation of Water-Soluble Fraction of Jellyfish by a Marine Bacterium, Brevibacterium sp. JCM 6894.

We used Brevibacterium sp. JCM 6894, which was isolated from seawater, to degrade the water-soluble fraction of jellyfish. After 27 h of incubation, the protein content in the supernatant was reduced from 1.97 to 1.31 mg/ml with an increase in cell yield of 0.40 mg cell protein/ml. The missing protein content in the fraction was 0.26 mg/ml. By the cell growth, the content of NH3 was increased from 0.38 to 4.57 μmol/ml. The value of chemical oxygen demand, which is a marker of remaining organic compounds in the fraction, was reduced from 890 to 431 mg O2/liter.

Preparation of the Precursor of the Zirconium Oxide in EDTA−Ammonia Solution by the Sol−Gel Method

The sol−gel method was employed to prepare the precursor of zirconium oxide by the reaction of zirconyl chloride octahydrate (ZrOCl2·8H2O and EDTA in ammonia. The reaction of ZrOCl2· 8H2O and the ionized complexing agent R(COO-)n was achieved through sequential hydrolysis (4ZrOCl2·8H2O + 20H2O → [Zr4(OH)8(OH2)16]8+ + 8Cl-) and polymerization ([Zr4(OH)8(OH2)16]8+ + R(COO-)n → [Zr4(OH)8-n(OH2)16(−OOC)nR]8+ and [Zr4(OH)8(OH2)16-n(−OOC)nR]8+). The effect of the reaction conditions, including temperature, the molar ratio of ZrOCl2·8H2O, the content of NH3, and the agitation speed on the particle size distribution, the average size of particle, and the viscosity of the sol are investigated in detail. A rational reaction mechanism, which accounts for the formation and the growth of the particles and the viscosity of the sol, is proposed to explain the experimental results satisfactorily.

Propranolol enhances adenine nucleotide degradation in human muscle during exercise.

Eight healthy men cycled to exhaustion [4.1 +/- 0.3 (SE) min] during beta-adrenoceptor blockade (beta B) with propranolol. The exercise was repeated on another day with the same power output and duration but without propranolol (control). The total adenine nucleotide (TAN) content in muscle (quadriceps femoris) decreased during exercise, and the decrease was more pronounced during beta B (delta TAN = 4.8 +/- 1.0 mmol/kg dry wt) than during control (delta TAN = 2.8 +/- 0.9; P less than 0.01, beta B vs. control). The decrease in TAN corresponded with a similar increase in inosine 5'-monophosphate (IMP). The increase in IMP was more pronounced during beta B (delta IMP = 5.1 +/- 1.2 mmol/kg dry wt) than during control (delta IMP = 2.8 +/- 0.7; P less than 0.05, beta B vs. control). Similarly, the increase in the content of NH3 in muscle was twice as high during beta B vs. control (P less than 0.01). The increase in muscle lactate and the decrease in phosphocreatine during exercise were similar between treatments, but postexercise hexose phosphates were approximately twofold higher (P less than 0.05) during control than during beta B. It is concluded that beta B enhances the degradation of TAN and the production of NH3 and IMP in muscle during intense exercise. This indicates that the imbalance between the rates of utilization and resynthesis of ATP is more pronounced during beta B possibly because of a decreased O2 transport to the contracting muscle and a diminished activation of glycolysis by the hexose phosphates.(ABSTRACT TRUNCATED AT 250 WORDS)

The ammonia of the gastric juice. (Preliminary communication.)

Recently Carlson reported some observations on the occurrence of NH3 in the gastric juice of man and of dogs. Further observations have been made and a few of the results are given below. Three series of experiments were conducted: (a) On dogs with Pawlow stomachs; (b) on normal human individuals, and (c) on human individuals with gastric disturbances. The NH3-content of the gastric juice of normal dogs varied in different dogs between 0.5-3.5 mg. NH3 per 100 c.c. of juice, there being some variation from day to day, and at different times during the same day in the same dog. The juice was collected for a period before feeding and one-hour periods after feeding. The addition of NH4Cl to the dogs'food caused in each instance an increase in the NH3-content of the gastric juice collected from the Pawlow pouch. Three dogs, in which gastric ulcers had been produced experimentally showed an increase in the NH3-content at irregular intervals. After a time two of these dogs refused to eat and the juice collected during this time showed a progressively increasing content of NH3. At autopsy these dogs showed either active or healed ulcers, usually located in the Pawlow pouch. b. The experiments on normal healthy individuals were conducted on men who were connected with the laboratory. The juice was collected by means of the Rhefus stomach tube before and after feeding on Ewald meal. With three exceptions the NH3-content of the juices from these men ranged between 0.5-3.5 mg. of NH3 per 100 C.C. of juice. In these three men the NH3-content ranged between 1-15 mg. NH3 per 100 C.C. of juice.