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.     

Nano zinc vis‐à‐vis inorganic Zinc as feed additives: Effects on growth,activity of hepatic enzymes and non‐specific immunity in rohu,Labeo rohita (Hamilton) fingerlings

The effects of dietary administration of inorganic zinc (zinc sulphate, ZnSO₄) and nano zinc (zinc oxide nanoparticles, ZnO‐NP) were evaluated in rohu, Labeo rohita fingerlings. Fish were fed with a basal diet (Control) supplemented with ZnSO₄ (T1, T2 and T3) and ZnO‐NP (T4, T5 and T6) at 10, 20 and 30 mg/kg, respectively, for a duration of 45 days. The results revealed that fish fed diet containing 20 mg ZnO‐NP per kg (T5) had the highest weight gain and specific growth rate (SGR, % per day), which was significantly different (p < .05) from the other experimental diets. Significantly (p < .05), higher activities of the digestive and metabolic enzymes were recorded in the fish fed ZnO‐NP containing diets as compared to the diets containing inorganic Zn or control diet. The maximum serum glucose and protein levels were noted in fish reared on diet T5. Both SGOT and SGPT activities were significantly increased in fish fed Zn‐supplemented diets (T1 to T6), as compared to the control group. Similarly, innate immune parameters were improved with feeding Zn incorporated diets. The highest phagocytic (40.74 ± 0.65%) and respiratory burst (0.33 ± 0.001, OD 630nm) activities were recorded in the fish fed diet containing ZnO‐NPs at 20 mg/kg (T5). The maximum superoxide production and serum peroxidase activity were detected in the fish fed T5 and T6 diets. Overall, results indicated that short‐duration feeding (≤45 days) of dietary ZnO‐NP (20 mg/kg) improved growth, enzyme activity, serum biochemical parameters and immune function in rohu fingerlings.     

Fabrication and in-pond operation of a low-cost,semiautomated portable carp hatchery with a temperature-adjustability feature

The present study describes a simple, portable, and inexpensive in-pond hatchery model assembled from locally available materials for seed production of small and medium-sized carp at high efficiency. This light-weight hatchery requires minimal engineering skills for assembly and operation. Further, the hatchery water supply mechanism has built-in components to filter out sediments and zooplankton from the pond water besides maintaining the water temperature 5°C–7°C lower than the pond surface water by drawing water from a metalimnion layer without additional energy requirements. Spontaneous spawning, automatic transfer of eggs to the incubation tank, and 80% hatching rates at an egg-holding capacity of 2,000 eggs/L was recorded for Barbonymus gonionotus, Labeo bata, and Labeo rohita with minimal human intervention. The production capacity of 0.06 million fry per cycle and estimated benefit-cost ratio of 2.48 demonstrated the high efficiency and economic feasibility of this portable hatchery.     

Protective immune responses of recombinant VP2 subunit antigen of infectious bursal disease virus in chickens

Infectious bursal disease virus (IBDV) is the causative agent of Gumboro disease and poses a huge threat to poultry industry. The risks associated with conventional attenuated viral vaccines make it indispensable to probe into the development of novel and rationally designed subunit vaccines which are safer as well as effective. VP2 is the major host-protective antigen found in IBDV capsid. It encompasses different independent epitopes responsible for the induction of neutralizing antibody. Here, we report the efficacy of the immunodominant fragment of VP2 which induces both humoral and cellular immunity against infectious bursal disease. A 366bp fragment (52-417bp) of the VP2 gene from an IBDV field isolate was amplified and expressed in Escherichia coli as a 21kDa recombinant protein. The efficacy of rVP2(52-417) antigen was compared with two commercial IBDV whole virus vaccine strains. The rVP2(52-417) induced significantly high antibody titres in chicken compared to commercial vaccines and the anti-rVP2(52-417) sera showed reactivity with viral antigens from both commercial strains (P<0.0001) and field isolates. Also, the chicken splenocytes from rVP2(52-417) immunized group showed a significantly high proliferation (P<0.01) compared to other groups, which implies that the rVP2(52-417) fragment contains immunogenic epitopes capable of eliciting both B and T cell responses. Further, rVP2(52-417) conferred 100% protection against vIBDV challenge in the immunized chickens which was significantly higher (P<0.001) compared to 55-60% protection by commercial vaccine strains. Hence, the study confirms the efficacy of the immunodominant VP2 fragment that could be used as a potent vaccine against IBDV infection in chicken.     

Identification and characterization of fowlpox virus strains using monoclonal antibodies.

The use of 2 monoclonal antibodies (MAbs), P1D9 and P2D4, which recognize different fowlpox virus (FPV) antigens, for the identification and characterization of FPV strains was evaluated. Initially, the MAbs were used in conjunction with a dot blot assay that enabled FPV to be differentiated from the avian herpesvirus, infectious laryngotracheitis virus. Confirmation of the specificity of these MAbs was provided by the demonstration that only FPV antigens were recognized by a combination of both antibodies when used for immunoblotting proteins contained in various avipoxviruses. Later, an antigenic characterization of 11 FPV field isolates, 6 FPV vaccine strains, and 3 pigeonpox virus vaccines was performed by Western blotting with the individual MAbs. Whereas MAb P2D4 consistently recognized a protein with an apparent molecular weight of 60 kD, there was variability in the size of the antigen that was immunoreactive with the other MAb. For example, MAb P1D9 recognized an antigen of apparent molecular weight of 46 kD in all vaccine strains except 2 of FPV origin. In these exceptions, either only a 39-kD or both a 42- and 46-kD protein were immunoreactive. As for the field isolates, a 39-kD antigen was recognized in 8 of them, whereas a 42-kD antigen was detected in the remaining 3. Therefore, the more extensive immunoblotting technique may facilitate FPV strain differentiation, whereas routine diagnosis of fowlpox could be accomplished by using the MAb-based dot blot assay.     

Management strategies for sustainable yield of potato crop under high temperature

High temperature has a deleterious effect in productivity of cool season crops like potato. This study was conducted to assess the efficacy of soil management practices to high-temperature tolerance in potato. Two popularly grown potato cultivars of northeast India, Kufri megha and Rangpuria, were sown under optimal and high-temperature conditions with soil application of inorganic nutrients (N, P, K, Ca, Zn), organic amendment, i.e. farm yard manure (FYM), and straw mulch. This integrative soil management practice showed significant positive influence on membrane integrity, chlorophyll content, total soluble sugars and superoxide dismutase activity of potato plant. Higher tuber bulking rate and tuber yield in both optimal and high-temperature situation was recorded under these soil applications. Kufri megha performed better with the application of Ca and Zn along with straw mulch, while Ca with farm yard manure substantially improved restore yield in Rangpuria. Application of CaSO₄ and ZnSO₄ (20 and 60 kg ha^?1, respectively) with FYM and straw mulch (10 and 6 t ha^?1, respectively) can mitigate the high-temperature stress in potato grown in acidic soil (deficient of Ca and Zn) of northeast India.     

Toxicity ameliorative effect of vitamin E against super-paramagnetic iron oxide nanoparticles on haemato-immunological responses,antioxidant capacity,oxidative stress,and metabolic enzymes activity during exposure and recovery in Labeo rohita fingerlings

Aquaculture International - The present study assessed the toxic effect of super-paramagnetic iron oxide nanoparticles (SPIONs) on haemato-immunological responses, antioxidant capacity, oxidative...     

Indole acetic acid and ACC deaminase-producing <Emphasis Type="BoldItalic">Rhizobium leguminosarum</Emphasis> bv. <Emphasis Type="BoldItalic">trifolii</Emphasis> SN10 promote rice growth,and in the process undergo colonization and chemotaxis

This study focuses on the chemotaxis, colonization and rice growth promoting ability of indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing rhizobacteria Rhizobium leguminosarum bv. trifolii SN10, previously isolated from root nodules of Trifolium alexandrium L. We show here that R. leguminosarum bv. trifolii SN10 promote the growth of four different rice varieties grown in India in terms of biomass, root branching and N content. In addition, using scanning electron microscopy and viable cell counts, we provide evidence that the bacteria successfully colonize the root surface of the rice variety which showed maximum growth promotion upon inoculation. Not only this, R. leguminosarum bv. trifolii SN10 exhibit a strong chemotaxis response towards the rice seed and root exudates despite the presence of a bacteriostatic phenolic compound, 7-hydroxycoumarin (umbelliferone). Further, R. leguminosarum bv. trifolii SN10 secretion of phytohormones such as IAA and ACC deaminase suggest the potential of the plant growth promoting rhizobacteria to be used as biofertilizer to enhance rice crop production in the subcontinent.