18 research outputs found
Rearing the Cotton Bollworm, Helicoverpa armigera, on a Tapioca-Based Artificial Diet
The impact of a tapioca-based artificial diet on the developmental rate, life history parameters, and fertility was examined over five consecutive generations for the cotton bollworm, Helicoverpa armigera Hubner (Lepidoptera: Noctuidae), a highly polyphagous pest of many agricultural crops. The study showed that when fed the tapioca-based artificial diet during larval stage, larval and pupal developmental period, percent pupating, pupal weight, emergence rate of male and female, longevity, fecundity and hatching were non-significantly different than that of the control agar-based artificial diet. Moreover, the cost to rear on tapioca-based diet approached 2.13 times less than the cost of rearing on the agar-based artificial diet. These results demonstrate the effectiveness and potential cost savings of the tapioca-based artificial diet for rearing H. armigera
Establishment of an efficient callus induction and plant regeneration system in Pakistani wheat (Triticum aestivum) cultivars
Four commercially grown wheat varieties of Pakistan, namely Inqilab-91, Chakwal-97, Tatara and Manthar were used for this investigation. For callus induction different concentrations of 2,4-Dichlorophenoxyaceticacid (2,4-D) along with 0.1 mg/L of Kinetin were evaluated. For regeneration initially different concentrations of Indole-3-Acetic Acid (IAA) and 6-BenzylAminoPurine (BAP) were tested. Best hormone combinations were further subjected to Kinetin and 6-γ-γ-dimethylallylaminopurine (2iP). For Inqilab-91, Chakwal-97 and Manthar, 3 mg/L of 2,4-D was found optimum, which induced 83.25%, 77.75% and 95.20% of embryogenic calli, respectively. Maximum callus induction (97.18%) was observed in Tatara when 2 mg/L of 2,4-D was used. As regard to regeneration, Inqilab-91, Chakwal-97 and Manthar showed maximum regeneration on media containing 0.1 mg/L IAA, 0.4 mg/L Kinetin and 0.5 mg/L 2iP, regenerating 87.25%, 81.75% and 68.75% respectively. For Tatara maximum regeneration of 12.25% was obtained on 0.1 mg/L IAA and 2 mg/L of BAP. Presently optimized regeneration method holds promise for facilitating the deployment of agronomical important trait through genetic transformation for the improvement of this important food crop
Proizvodnja i karakterizacija α-galaktozidaze fermentacijom na čvrstoj podlozi s pomoću višestruko mutiranog soja Aspergillus niger
α-Galactosidase is applied in the sugar industry to enhance sugar recovery from sugar beet syrup and to improve nutritional value of the soymilk. In the present investigation, the influence of process variables on the production of this important enzyme has been explored in a newly isolated multiple mutant strain of Aspergillus niger in solid-state fermentation (SSF). Defined fermentation parameters include substrate type (pure lactose and by-products of rice and flour mills as prime substrates), nitrogen source, incubation time, initial pH of the medium and incubation temperature. Extracellular α-galactosidase reached the value of 135.4 IU/g of dry substrate (IU/g) after 96 h of fermentation. Supplementation with 2 g of glucose and 3 g of corn steep liquor significantly increased the enzyme production, and maximum value of product yield (318 IU/g) by the mutant strain was significantly higher than that reported by the wild type (this work), or other A. niger mutants, recombinants and yeasts reported in literature as producers of elevated levels of α-galactosidase. Among three α-galactosidases, one possessing high subunit molecular mass proteins (99 and 100 kDa) has been characterized in both wild and mutant organisms. Thermal properties of the purified enzymes indicate that the mutation decreased the values of activation energy for the formation of enzyme-substrate (ES) complex, enthalpy, Gibbs free energy demand for substrate binding, and transition state stabilization. A thermodynamic study of irreversible inactivation of enzymes suggests that the mutant–derived enzyme is more thermostable than the native enzyme, which is attributable to amino acids involved in active catalysis. Because of these properties, the mutant organism is a novel organism and may be exploited for bulk production of thermostable α-galactosidase for the above industrial and nutritional applications.U industriji se α-galaktozidaza primjenjuje radi povećanja prinosa šećera iz sirupa šećerne repe te poboljšanja hranjive vrijednosti sojinog mlijeka. U radu je ispitan utjecaj varijabli procesa na proizvodnju ovog važnog enzima fermentacijom na čvrstoj podlozi s pomoću novoizoliranog višestruko mutiranog soja Aspergillus niger. Procijenjeni su sljedeći parametri: supstrat (čista laktoza te nusprodukti meljave riže i brašna), izvor dušika, vrijeme inkubacije, početna pH-vrijednost podloge i temperatura inkubacije. Nakon 96 sati fermentacije dobiveno je 135,4 IU ekstracelularne galaktozidaze po g suhe podloge. Dodatak od 2 g glukoze i 3 g kukuruznog ekstrakta značajno je povećao proizvodnju enzima. S pomoću mutantnog soja postignut je kudikamo veći maksimalni prinos (318 IU/g) nego s divljim sojem (u ovom radu) ili drugim u literaturi navedenim mutantnim sojevima A. niger, rekombinantnim vrstama ili kvascima koji proizvode α-galaktozidazu. Ispitane su tri α-galaktozidaze, od kojih je ona što sadrži podjedinice proteina velike molekularne mase (99 i 100 kDa) karakterizirana i u divljem i u mutantnom soju. Toplinska svojstva pročišćenih enzima pokazuju da je mutacija smanjila energiju aktivacije potrebnu za nastajanje kompleksa enzim-supstrat, entalpiju, količinu Gibbsove slobodne energije utrošene za vezivanje supstrata i stabilizaciju prijelaznog stanja. Termodinamičkim ispitivanjem ireverzibilne inaktivacije enzima zaključeno je da enzim izoliran iz mutantnog soja ima veću termostabilnost od prirodnog enzima zbog aminokiselina u aktivnom katalitičkom procesu. Zbog toga bi se svojstva mutantni organizam mogao upotrijebiti u proizvodnji veće količine termostabilne α-galaktozidaze, za njezinu primjenu u industriji šećera, te radi poboljšanja hranjive vrijednosti proizvoda
Passive immunization using purified IgYs against infectious bursal disease of chickens in Pakistan
Infectious bursal disease (IBD) is an acute and highly contagious disease of young chickens caused by Birnavirus. Mortality of infected birds can be best prevented if injected with antibodies. The present study was an attempt to raise specific hyper-immune polyclonal antibodies against IBD virus in Pakistan. Commercial layers divided into four groups were injected with IBD vaccine subcutaneously according to four different treatment regimens. Eggs were collected daily and antibodies were purified from yolk with dextran sulphate. Titers of antibodies in serum and yolk were evaluated with enzyme linked immunosorbant assay and agar gel precipitation test. Antibody titers were significantly higher in yolk than serum. Eggs collected at 28 days post-vaccination had maximum antibody titers. Of treatment regimens, T3 was found to be most effective for hyperimmunization. Lyophilized antibodies stored at 4℃ did not lose their activity till the end of experiment. IBD virus infected birds were injected with purified antibodies which induced 92% recovery as compared to control birds. The study implicates that the purified antibodies may be useful as a therapeutic agent to cure IBD infected birds
Production of low cost <i>Bacillus thuringiensis</i> based-biopesticide for management of chickpea pod-borer <i>Helicoverpa armigera</i> (Huebn) in Pakistan
Effect of VAM on Drought Tolerance and Growth of Plant in Comparison with the Effect of Growth Regulators
Production and Characterization of α-Galactosidase by a Multiple Mutant of Aspergillus niger in Solid-State Fermentation
α-Galactosidase is applied in the sugar industry to enhance sugar recovery from sugar beet syrup and to improve nutritional value of the soymilk. In the present investigation, the influence of process variables on the production of this important enzyme has been explored in a newly isolated multiple mutant strain of Aspergillus niger in solid-state fermentation (SSF). Defined fermentation parameters include substrate type (pure lactose and by-products of rice and flour mills as prime substrates), nitrogen source, incubation time, initial pH of the medium and incubation temperature. Extracellular α-galactosidase reached the value of 135.4 IU/g of dry substrate (IU/g) after 96 h of fermentation. Supplementation with 2 g of glucose and 3 g of corn steep liquor significantly increased the enzyme production, and maximum value of product yield (318 IU/g) by the mutant strain was significantly higher than that reported by the wild type (this work), or other A. niger mutants, recombinants and yeasts reported in literature as producers of elevated levels of α-galactosidase. Among three α-galactosidases, one possessing high subunit molecular mass proteins (99 and 100 kDa) has been characterized in both wild and mutant organisms. Thermal properties of the purified enzymes indicate that the mutation decreased the values of activation energy for the formation of enzyme-substrate (ES) complex, enthalpy, Gibbs free energy demand for substrate binding, and transition state stabilization. A thermodynamic study of irreversible inactivation of enzymes suggests that the mutant–derived enzyme is more thermostable than the native enzyme, which is attributable to amino acids involved in active catalysis. Because of these properties, the mutant organism is a novel organism and may be exploited for bulk production of thermostable α-galactosidase for the above industrial and nutritional applications