Comparative study on immunomodulatory and growth enhancing effects of three prebiotics (galactooligosaccharide,fructooligosaccharide and inulin) in common carp (Cyprinus carpio)

This study investigated the effects of different prebiotics, including galactooligosaccharide (GOS), fructooligosaccharide (FOS) and inulin (INL), on skin mucosal immune parameters, humoral immune responses as well as performance of common carp (Cyprinus carpio). Two hundred and forty specimens (13.85 ± 0.85 g) were stocked in 12 fibreglass tanks assigned into three treatments and a control group. The experimental diets were formulated to have equal level (2%) of the prebiotics. At the end of the feeding trial, the highest skin mucus lysozyme activities and total immunoglobulin (total Ig) were observed in GOS‐fed group (P < 0.05). However, skin mucus protease activity showed no significant difference among different dietary groups (P < 0.05). Blood respiratory burst activity was significantly increased in all prebiotic‐fed fish compared to the control group (P < 0.05); the highest activity was observed in GOS treatment. Furthermore, evaluation of humoral immune response revealed that feeding with GOS‐supplemented diet significantly increased lysozyme and alternative complement (ACH50) activity as well as total Ig compared to the control and other prebiotic groups. While no significant difference was observed between FOS and INL groups, common carps fed GOS‐supplemented displayed improved (P < 0.05) growth performance, including final weight, weight gain, specific growth rate (SGR) and feed conversion ratio (FCR), compared to the control treatment. These results revealed that different prebiotics modulate carp growth and immune response in different manner, and GOS seems to be the most suitable prebiotic.     

Isolation and identification of anionic surfactant degrading bacteria from activated sludge

BACKGROUND: Linear alkylbenzene sulfonate (LABS) is an anionic surfactant widely used all over the world. They will eventually end-up and accumulate in household or industrial sewage. Due to their high foaming capabilities which can cause numerous problems in sewage treatment facilities as well as direct toxic effects on many different organisms in ecosystem; they are generally considered as serious pollutants. Many reports have indicated that common bacteria can readily degrade LABS. METHODS: In this survey, two different bacteria were isolated from Tehran municipal active sludge that showed the ability to degrade LABS rapidly and actively upon using it as their sole source of carbon. Biochemical tests as well as 16S rRNA gene sequencing performed. RESULTS: Results have indicated the two isolates to be Acinetobacter johnsoni and Pseudomonas beteli. After experiments to optimize the pH and temperature for growth of the two bacterial isolates, the extent of LABS, utilization was evaluated by HPLC method. The Pseudomonas beteli and Acinetobacter johnsoni isolates were able to degrade 96.4% and 97.2% of the original LABS levels after 10 days of growth, respectively. Mixed culture of the two isolates did not significantly increase LABS utilization (97.6%). CONCLUSION: Our study showed the ability of two isolated steains to rapidly biodegrade LABS under aerobic conditions.     

Isolation and characterization of potassium solubilizing bacteria in some Iranian soils

The ability of a few soil bacteria to transform unavailable forms of potassium (K) to an available form is an important feature in plant growth-promoting bacteria for increasing plant yields of high-K-demand crops. In this research, isolation, screening, and characterization of six isolates of K solubilizing bacteria (KSB) from some Iranian soils were carried out. The ability of all isolates were tested in three treatments including acid-leached soil, biotite, and muscovite by analyzing the soluble K content after 5 days of incubation at 28 ± 2°C. Identification and phylogenetic analyses were also carried out by morphological, biochemical, and 16S rDNA analyses. Among the six efficient isolates, five isolates belonged to Bacillus megaterium (JK3, JK4, JK5, JK6, and JK7), while isolate JK2 belonged to Arthrobacter sp. The soluble K contents in all isolated-treatments were significantly (p < 0.01) higher than the contents in nonbacteria treatment. Herein, isolate JK2 had lower potential for K solubilization (910 mg kg^?1) compared with other isolates in acid-leached soils. The six bacterial strains showed higher solubilized K in biotite treatment than other two treatments. Overall, it can be concluded that the isolates belong to B. megaterium are the most efficient KSB under in vitro condition.     

Effect of soil moisture on the release of alachlor from alginate-based controlled-release formulations

The release of alachlor from controlled-release formulations (CRFs) based on alginate-montmorillonite matrices into aqueous polyethylene glycol (PEG) solutions of different concentrations and into a soil at different moisture contents was studied. In distilled water and in PEG-containing solutions displaying -0.1 MPa potential and up, the beads imbibe water and swell. The ensuing increase in weight is about 5%, and the increase in the bead's diameter is about 10%. At water potentials of -0.5 MPa and lower, loss of weight and shrinkage of the beads were observed. The changes in weight and diameter of the alginate-clay beads incubated in a Hamra loamy sand soil at 26.5% moisture content (w/w; -0.18 MPa) were similar to those observed in PEG solutions of >-0.5 MPa moisture potential. The weight and diameter losses observed in the drier soils (12.0 and 7.1% water content; -0.49 and -1.11 MPa) were similar to those in the more concentrated PEG solutions. A decrease in the rate of release of the active ingredient from the beads into soil was observed as the water potential decreased (drier soils). The release of the active ingredient from the investigated CRFs displayed a linear relationship to the square root of time, suggesting a diffusion-controlled-release rate. Data extracted from this relationship enabled the formulation of a mathematical model that correlates rate of release to water content.     

Molecular mobility of fish flesh measured by low-field nuclear magnetic resonance (LF-NMR) relaxation: effects of freeze–thaw cycles

In this study, the molecular mobility of fish flesh was measured by low field nuclear magnetic resonance (LF-NMR) relaxation. Sardine, tuna and mackerel were frozen at ?40 °C and stored for 1 day (24 h); and then these samples were thawed at room temperature (20 °C). The relaxation of water protons in fish flesh was measured for fresh (i.e., before freezing) and multi-cycle freeze–thaw samples (i.e., up to 12 times). Three domains from different pools of protons (i.e., low-mobile, medium-mobile and high-mobile) were identified from the relaxation curve. The T _2b (low-mobile), T ₂₁ (medium-mobile) and T ₂₂ (high-mobile) indicated the proton populations in the protein molecules, strongly bound water molecules, and weakly bound water molecules, respectively. In all cases, the relaxation time (T _2b: sardine r = 0.736 and p < 0.01, tuna r = 0.857 and p < 0.001, mackerel r = 0.904 and p < 0.001; and T ₂₂: sardine r = 0.956 and p < 0.0001, tuna r = 0.927 and p < 0.0001, mackerel r = 0.890 and p < 0.0001) increased with the freeze–thaw cycles and it reached a nearly constant value after 6 freeze–thaw cycles. The increased relaxation time (i.e., higher mobility) up to 6 freeze–thaw cycles could be due to the increase in proton mobility. However, relaxation time (T ₂₁: sardine r = ?0.510 and p > 0.05, tuna r = 0.162 and p > 0.5, mackerel r = 0.513 and p > 0.01) showed insignificant change with the increase of freeze–thaw cycles, which indicated minimal change in the medium-mobile protons. The results in this study revealed that the changes in proton mobility in the fish flesh during freeze–thaw cycles could be identified using T _2b and T ₂₂ relaxation of LF-NMR.     

Stimulation of insulin and glucagon synthesis in rat Langerhans islets by malathion in vitro: Evidence for mitochondrial interaction and involvement of subcellular non-cholinergic mechanisms

We examined the effects of malathion, an organophosphorus (OP) insecticide, on glucagon, C-peptide, and insulin content or secretion from isolated rat Langerhans islets in vitro. Islets were isolated from the pancreas of rats by standard collagenase digestion, separation by centrifugation, and hand-picking technique. Then islets were cultured in medium and supplemented with various concentrations of malathion (25, 125, and 625 μg/ml) for 1, 3, and 5 h. In vitro exposure to malathion increased insulin and C-peptide contents at doses of 25, 125, and 625 μg/ml following 5 h incubation as compared to control. All doses of malathion increased glucagon content after 3 and 5 h as compared to control. Increase of the glucagon content at all doses in the fifth hour was higher than that of third hour. Malathion also decreased 2.8 and 16.7 mM glucose-stimulated insulin secretion at all doses after 30 min as compared to control.It is concluded that malathion reduce insulin exocytose in a short time (first hour) but after a long time (e.g., 5 h), the content of insulin is increased by compensating mechanisms such as resynthesize of insulin or aggregation of insulin. The present in vitro study for the first time proposes the involvement of subcellular non-cholinergic mechanisms in malathion-induced changes in Langerhans islets insulin and glucagon.     

Effect of flunixin meglumine and aspirin administration on conception rate and estrous cycle characteristics of Egyptian Baladi cows during hot season

The current investigation aims to evaluate the effects of flunixin meglumine (FM) and aspirin as non-steroid anti-inflammatory drug (NSAID) administration on estrous cycles characteristics and conception rate of Egyptian Baladi cows during hot season. In the first phase, 30 cows were divided into 3 groups, 10 cows for each treatment. The first group was treated with FM at the rate of 1.1 mg/kg body weight (BW) intramuscular, while the second group was administrated aspirin solution orally at the rate of 50 mg/kg BW. The third group was assigned as control (CG) that has no treatment. The FM group was administrated on day 14 after mating, while aspirin was given on day 14 and day 15 post-mating. All cows were mated naturally after showing estrus signs. Pregnancy diagnosis was carried 60 days after mating by rectal palpation. In the second phase, cows were monitored for estrus behavior by visual observation twice a day. The length of normal estrous cycles was 20, 23, and 22 days in cows treated with FM, aspirin, and control cows, respectively. There was no significant effect of treatment on the length of normal estrous cycles in Egyptian cows (P < 0.05). Proportions of long cycles in Egyptian cows that treated with FM or aspirin and control were 75, 67.7, and 57.1%, respectively. Short cycles were completely absent in cows that treated with FM or aspirin, but it was 29% in CG. Mounting behavior and tail rising were not detected in CG compared to 0 and 33% in FM or 25 and 33% in aspirin treated cows, respectively. Conception or pregnancy rate were 60, 40, and 30%, respectively, in FM, aspirin treated, and CG. Treatment cows whether FM or aspirin group did not influence (P < 0.05) progesterone concentration during the 14 days and 21 days from estrous cycle in pregnant and non-pregnant Egyptian Baladi cows than CG. In conclusion, the results of this study clearly indicated beneficial effect of FM and aspirin administration on intense of displayed estrous behavior and conception rate of Egyptian Baladi cows during the hot season.

     

Breeding strategy for resistance to Striga asiatica (L.) Kuntze based on genetic diversity and population structure of tropical maize (Zea mays L.) lines

Genetic Resources and Crop Evolution - Maize (Zea mays L.) is a major staple crop in southern Africa and is produced on millions of hectares. However, its yield is greatly reduced by Striga spp. a...