Soil Enzyme Activities and Their Relationship with Soil Physico-Chemical Properties and Oxide Minerals in Coastal Agroecosystem of Puducherry

The objectives of our research were to assess the soil enzyme activities in relation with soil physicochemical and oxide minerals in the coastal agroecosystem of Puducherry region, India. Soils from nine farms in organic (ORG), sustainable (SUS), and conventional (CON) farming were sampled. Organically managed farming system soils contain significantly higher amounts of soil total N, organic carbon, and a higher level of microbial biomass C and N. Urease, protease, β-glucosidase, cellulose, saccharase, xylanase, and alkaline phosphatase enzyme activities were higher in organic farming system soils compared to sustainable and conventional farming soils. In addition, silt, clay, Al₂O₃, CaO, Fe₂O₃, K₂O, MgO, MnO, Na₂O, and P₂O₅ oxides were higher in organic farming soil and they showed a significant positive correlation with soil enzyme activities. Our study revealed that soil enzyme activities and soil minerals were significantly affected by farm management practices. The organic farming system had improved the soil health, enzyme activities, and plant available nutrients in coastal agro-ecosystem.     

Evaluation of trace elements in forages and their effect on gastrointestinal parasite burden in grazing sheep

This study was designed to evaluate the trace elements (minerals) in forages fed to sheep and their effect on gastrointestinal parasite burdens. The ultimate objective was to determine the correlation between the burden of gastrointestinal (GI) parasites and the level of trace minerals in sheep serum as a result of the forages they grazed on. A total of 384 faecal samples were collected from sheep in each of the districts (Sialkot and Multan) and examined quantitatively using the McMaster technique. Serum collected from them and plants were pre-treated, and spectrophotometry was used to determine the concentration of trace minerals (Mn, Co, Cu, and Zn). The level of these trace elements differed significantly (P < 0.05) in forages from both districts. In the district of Sialkot, the highest concentrations (mg/Kg) of Zn (38.53 ± 0.16) were found in Cichorium intybus, Cu (41.57 ± 0.07) in Cynodon dactylon, Mn (39.61 ± 0.05) in Parthenium hysterophorus, and Co (1.42 ± 0.03) in Coronopus didymus. In the district of Multan, the highest concentrations (mg/Kg) of Zn (39.43 ± 0.46) were found in Cichorium intybus, Cu (25.76 ± 0.36) in Cynodon dactylon, Mn (34.29 ± 0.53) in Launaea nudicaulis, and Co (1.74 ± 0.08) in Brachiaria raptens. The prevalence of GI parasites in sheep populations in district Sialkot was 34%, while in district Multan, it was 32%. In tehsil Sialkot of district Sialkot, Zn and Cu were significantly (P < 0.05) correlated with eggs per gram (EPG) of faeces, while in tehsil Multan City of district Multan, only Cu was significantly (P < 0.05) correlated with EPG. The potential mechanism behind the role of trace minerals in lowering the burdens of GI parasites requires more investigation. It is recommended that plants with high content of trace minerals should be utilized as part of comprehensive preventive and control strategies against GI parasitism in ruminant animals like sheep.     

微生物介导硝酸盐还原耦合亚铁氧化过程的动力学及其影响因素

[目的]探究不同菌浓度和亚铁浓度条件下,Acidovorax sp.strain BoFeN1介导的厌氧亚铁氧化耦合硝酸盐还原过程的动力学和次生矿物.[方法]构建包含菌BoFeN1、硝酸盐、亚铁的厌氧培养体系,测试硝酸根、亚硝酸根、乙酸根、亚铁等浓度,并收集次生矿物,采用XRD、SEM进行矿物种类和形貌表征.[结果]在...     

Performance,carcass characteristics and meat quality of Nellore cattle supplemented with supranutritional doses of sodium selenite or selenium-enriched yeast

The enrichment of meat with selenium is important to improve the intake of selenium by humans. The effects of supranutritional doses of sodium selenite or selenium-enriched yeast on performance, carcass characteristics and meat quality were evaluated using 63 Nellore cattle in a completely randomized design with two sources (sodium selenite and selenium-enriched yeast), three levels (0.3, 0.9 and 2.7 mg Se/kg DM) and control treatment (without addition of selenium). Final body weight (BW), average daily gain, dry matter intake and gain to feed ratio (G : F) at the end of 84 days of supplementation were not influenced by treatments (P>0.05). Values of pH, ribeye area, back fat thickness and marbling score were also not influenced by treatments (P>0.05). Dressing percentage was greater (P=0.02) in Nellore cattle supplemented with organic Se (58.70%) compared to animals supplemented with inorganic Se (57.94%). Hot carcass weight increased (P=0.05) with the increasing of Se levels in the diet. Colour, shear force (SF), cooking and drip loss remained unchanged (P>0.05); however thiobarbituric acid reactive substances was 15.51% higher with inorganic Se compared with organic Se. The selenium concentration in the meat of animals receiving organic selenium was higher (P<0.001) than that of animals receiving sodium selenite, at all levels (0.3; 0.9 and 2.7 mg/kg DM). The meat of animals receiving 2.7 mg of organic Se/kg of DM presented concentration of 372.7 μg Se/kg in the L.dorsi muscle, and the intake of 150 g of this meat by humans provides approximately 100% of the recommended Se intake (55 μg Se/day for adults). Therefore, the use of supranutritional doses of 2.7 mg Se/kg of DM, regardless of source, is a way of naturally producing selenium-enriched meat without compromising performance, carcass characteristics and quality of Nellore bovine meat.     

Nutritional Dimorphism in New Guinea Dioecious Figs

The life history of figs (Ficus, Moraceae) involves pollination by specialized insects and seed dispersal by vertebrate frugivores. This three-way interaction raises the possibility of conflict between pollinators and seed dispersers over fig resources. The conflict might be mediated in dioecious figs by the segregation of inflorescences with specialized male and female sexual functions, termed gall figs and seed figs, on separate trees. In dioecious figs, pollinators are intimately associated with gall figs, whereas vertebrate frugivores prefer seed figs and disperse the seeds they contain. Optimal foraging theory predicts that frugivore preference for ripe seed figs is associated with superior nutritional quality when compared to gall figs. We tested this prediction comparing nutrient and mineral properties of ripe figs in 12 functionally dioecious and two monoecious species from New Guinea. Analyses of variance indicated that gall figs contain more fiber and minerals, whereas seed figs contain significantly more carbohydrates and fat. Fruit bats, the primary dispersers of dioecious figs in New Guinea, prefer carbohydrate-rich diets, and from this perspective, seed figs offer a greater nutritional reward than gall figs. More nondigestible fiber in gall figs than seed figs would appear to discourage frugivory. Parallel differences between ripe gall figs and seed figs occur in each independent dioecious lineage whereas nutritional content in monoecious figs is more similar to seed figs. This suggests that sexual dimorphism in nutritional quality might be adaptive and associated with the maintenance of functional dioecy in figs.     

Search for bioorganic compounds and organisms on Mars

A prototype of new instrument is under construction as a part of Russian Mars program to search for bioorganic compounds and microorganisms which might be frozen in rock under the places where the traces of water were found or near the poles of Mars. The proposed instrument consists of a quadrupole mass spectrometer (QMS) to detect chemical compounds and a fluorescent microscope system (FMS) to detect organisms and bioorganic compounds in bulk.     

The biodegradability of nucleic acid bases adsorbed on inorganic and organic soil components

Summary The biodegradability of nucleic acid bases (guanine, adenine, cytosine, thymine and uracil) adsorbed on montmorillonite, illite, kaolinite, soil, gibbsite, goethite and a fulvic acid (FA)-montmorillonite complex was investigated. Each material was mixed with sand, inoculated with a soil suspension and incubated in a Warburg vessel. Lag periods in O₂ uptake were observed at pH 4 and 6 but not at pH 8. Following the lag periods, adsorbed nucleic acid bases were degraded rapidly at linear rates until these levelled off. The cessation of O₂-uptake was shown to be due to the formation of excessive amounts of gaseous NH₃, which not only inhibited microbial respiration by raising the pH to 8 and higher, but also by killing bacteria and actinomycetes. The rate of biodegradation was found to depend on the type of clay or oxide, the dominant cation and the pH. Contribution No 1181     

Effects of a multivitamin mineral supplement on zinc and copper status during pregnancy

The effect of a multivitamin-mineral supplement was investigated during pregnancy according to a double-blind protocol by determining zinc and copper in maternal plasma, mononuclear and polynuclear zinc and copper at the third, sixth, eighth, and ninth months of gestation. The subjects were supplemented from the first trimester until delivery. A significant decrease was observed in plasma zinc that varied from 11.5 μmol/L to 10.8 μmol/L in the supplemented group (n=29) and from 11 μmol/L to 10 μmol/L in the placebo group (n=33) at 3 and 9 mo of gestation, respectively. In contrast, plasma copper levels increased in a way depending upon the stage of gestation in both groups: from 24.7 to 28.2 μmol/L in the treated group and from 24.9 to 30.9 μmol/L in the placebo group at 3 and 9 mo of gestation, respectively, but the difference was only significant in the placebo group. No difference between groups was observed in mononuclear and polynuclear zinc or copper levels. These trace elements were also determined in cord blood at delivery. There were no statistically significant differences in zinc and copper concentration found in placebo group and supplemented group. Finally, the beneficial effect of supplementation on muscular cramps and appearance of vergetures was noted.     

The relationship between EUF-K and soil-K fractions of different K selectivity

Summary The fraction of K released during EUF 30-35 min, 80°C, 400 V (EUF₃) and various other soil-K parameters were compared for 24 soils that range widely in clay mineral composition, clay content and percentage K saturation. When EUF₃ was compared with fractions of soil-K containing increasing amounts of non-exchangeable K (=selectively adsorbed K), the R² values decreased with increasing quantities of non-exchangeable K. This indicates that EUF₃ is a function of the exchangeable pool of K, although some initially non-exchangeable K is also involved.     

A model of Martian surface chemistry

Summary Alkaline earth and alkali metal superoxides and peroxides,-Fe₂O₃ and carbon suboxide polymer are proposed to be constituents of the Martian surface material. These reactive substances explain the water modified reactions and thermal behaviors of the Martian samples demonstrated by all of the Viking Biology Experiments. It is also proposed that the syntheses of these substances result mainly from electrical discharges between wind-mobilized particles at Martian pressures; plasmas are initiated and maintained by these discharges. Active species in the plasma either combine to form or react with inorganic surfaces to create the reactive constitutents.