Cumulative effects of tree-based intercropping on arbuscular mycorrhizal fungi

In tree-based intercropping system (agroforestry), the role of perennial trees in maintaining active populations and mycelial networks of arbuscular mycorrhizal fungi (AMF) is well documented. Agroforestry positively influences the AMF community, but complete studies regarding mycorrhization in such systems are scarce. The present study was conducted to assess the effect of tree introduction in agriculture fields on mycorrhization. In particular, we investigated the effect of trees on AMF colonization of intercrops and vice versa, the effect of canopy management of trees on their root colonization, and the cross-infectivity of AMF isolated from tree rhizosphere in intercrops and vice versa. The results of the field study suggest that in agroforestry systems, trees acted as AMF inoculum reservoir for intercrops, especially during the rainy season. Intercropping (Phaseolus mungo and Triticum aestivum in the rainy and winter seasons, respectively) increased mycorrhization, i.e., root colonization and spore population in the rhizosphere of Albizia procera and Eucalyptus tereticornis. Canopy management, i.e., shoot pruning, reduces root colonization in A. procera, Anogeissus pendula, Dalbergia sissoo, Hardwickia binata, and Tectona grandis, especially in April 2005 (late spring), but during subsequent periods, differences among the treatments were at par. Results from greenhouse suggest that AMF are nonspecific in their selection of host since species isolated from tree rhizosphere could colonize the roots of crops and vice versa.     

Quorum Sensing Inhibition by Asparagopsis taxiformis,a Marine Macro Alga: Separation of the Compound that Interrupts Bacterial Communication

The majority of the marine algal species, though completing their life cycle in seawater, are rarely susceptible to fouling, making them an important source of quorum sensing (QS) inhibitory substances. The separation and characterization of QS inhibitors are crucial for any potential application. Thirty marine macroalgae were tested for QS inhibition activity by using Chromobacterium violaceum CV026 as the reporter strain, and among them, Asparagopsis taxiformis showed antibacterial, as well as antiquorum, sensing activities. Cinnamaldehyde (75 mM) and methanol were used as positive and negative controls, respectively. The antiquorum sensing activity of A. taxiformis was further confirmed using the sensor strain, Serratia liquefaciens MG44, having green fluorescent protein (gfp). Methanolic extract of the alga was fractionated by solid phase extraction (SPE), and each fraction was tested for QS inhibition. Two types of activities were observed—zone of clearance (antibacterial activity) and zone of inhibition with or without finger-like projections (QS inhibition). Out of five SPE cartridges, Bond Elut PH showed clear separation of these two fractions. The Ion Cyclotron Resonance Fourier Transformation Mass Spectrometer (ICR-FT/MS) analysis of the fractions further supported the bioassay results. The presence of strong QS inhibitory compound in A. taxiformis indicates its potential use in antifouling preparations.     

Antimicrobial and pesticidal activity of partially purified flavonoids of Annona squamosa

Foliar extracts of Annona squamosa (Family: Annonaceae) were screened for antimicrobial and insecticidal activity against the common microbial infestants of pulses and the stored grain pest pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae). Flavonoids isolated from aqueous extracts of A squamosa showed antimicrobial activity against all the common microbial contaminants of pulses and 80% insecticidal activity against C chinensis at a concentration of 0.07 mg ml-1. Various physico-chemical tests, chromatographic and spectroscopic studies with partially purified aqueous extract indicated the presence of flavonol type flavonoids. This may provide a useful beginning for the development of botanical pesticides for post-harvest safeguard of pulses.     

REVIEW paper: pathophysiology of myocardial reperfusion injury: the role of genetically engineered mouse models

Coronary heart disease is the leading cause of death worldwide, affecting millions of men and women each year. Following an acute myocardial infarction, early and successful reperfusion therapy with thrombolytic therapy or primary percutaneous coronary intervention plays an important role in minimizing tissue injury associated with cessation of blood flow. The process of restoring blood flow to the ischemic myocardium, however, can induce additional injury. This phenomenon, termed myocardial ischemia-reperfusion (MI-R) injury, can paradoxically reduce the beneficial effects of myocardial reperfusion. MI-R injury is characterized by the formation of oxygen radicals upon reintroduction of molecular oxygen to the ischemic tissue, resulting in widespread lipid and protein oxidative modifications, mitochondrial injury, and cell death. In addition, studies have shown that MI-R is characterized by an inappropriate immune response in the microcirculation, resulting in leukocyte-endothelial cell interactions mediated by the upregulation of both leukocyte and endothelial cell adhesion molecules. Furthermore, MI-R ameliorates the production of certain cardioprotective factors such as nitric oxide. Advances in the generation of genetically modified mouse models enable researchers to identify the functional importance of genes involved in these processes.     

Strategies to modulate the intestinal microbiota and their effects on nutrient utilization,performance, and health of poultry

Poultry is widely produced and consumed meat global y. Its demand is expected to continue increasing to meet the animal protein requirement for ever-increasing human population. Thus, the chal enge that poultry scientists and industry face are to produce sufficient amount of poultry meat in the most efficient way. In the past, using antibiotics to promote the growth of poultry and manage gut microbiota was a norm. However, due to concerns over potential fatalistic impacts on food animals and indirectly to humans, their use as feed additives are banned or regulated in several jurisdictions. In this changed context, several alternative strategies have been proposed with some success that mimics the functions of antibiotics as growth promoters and modulate gut microbiota for their beneficial roles. These include the use of probiotics, prebiotics, organic acids, and exogenous enzyme, among others. Gut microbiota and their metabolic products improve nutrient digestion, absorption, metabolism, and overal health and growth performance of poultry. This paper reviews the available information on the effect of feed additives used to modulate intestinal microbiota of poultry and their effects on overal health and growth performance. Understanding these functions and interactions wil help to develop new dietary and managerial strategies that wil ultimately lead to enhanced feed utilization and improved growth performance of poultry. This review wil help future researchers and industry to identify alternative feed ingredients having properties like prebiotics, probiotics, organic acids, and exogenous enzymes.     

Antifungal activity of flavonoids and their mixtures against different fungi occurring on grain

The antifungal activity of three flavones and one flavanone and of different mixtures of these flavonoids was investigated on malt extract agar against four fungi usually occurring on grain. As pure substances the unsubstituted flavone and flavanone showed higher activity than the hydroxylated flavones. Mixtures containing flavone and 7-hydroxyflavon or flavone, flavanone and flavonol caused higher inhibition of fungal growth than the remaining ones.     

Antibacterial activity of Abies webbiana

The methanol extract of the dried leaves of Abies webbiana was evaluated for antimicrobial activity. The methanol extract showed a broad spectrum of antibacterial activity.     

Effects of natural dietary carotenoids on skin coloration of false Clownfish (Amphiprion ocellaris Cuvier, 1830)

This study was performed to evaluate the effect of dietary natural carotenoid sources on skin colour enhancement of false clownfish Amphiprion ocellaris. The juvenile fish (initial body wt. 0.30 g) were fed with four experimental diets including (a) commercial feed (reference diet), (b) moist feed, (c) sweet potato (potato diet) and (d) dried gut weed Enteromorpha sp. (gut weed diet). Sweet potato and gut weed were used to boost up β‐carotene levels in the diets. There was no significant difference in final weight (0.51 ± 0.02 – 0.61 ± 0.01 g) and length (2.80 ± 0.02 cm) of fishes among treatments (p > 0.05) after 8 weeks. The survival rate of the fish in all dietary treatment was greater than 89%. Principal component analysis results showed that fish fed potato and gut weed diets performed brighter colour in skin with more orangeness, body and accumulated β‐carotene levels were higher than those fish fed with reference diet. Indicator a* value for the redness of fish fed potato diet (16.18 ± 0.59) and gut weed (14.36 ± 2.14) was also higher than fish fed reference diet (10.92 ± 0.82). The result of this study provided key information for developing dietary colour enhancement of ornamental fish by using cost‐effective feed ingredients (potato and gut weed) as natural supplemental carotenoid sources.