Current Issue : October - December Volume : 2011 Issue Number : 4 Articles : 8 Articles
Aflatoxin and T-2 toxin were produced from Aspergillus parasiticus and Fusarium sporotrichioides (F. tricinctum) respectively and quantified using TLC. The toxins were mixed with broiler feed to attain required concentrations. Four diets for broilers were prepared diet 1 – basal diet (control), diet 2-basal diet + aflatoxin (1 ppm) + T-2 toxin (1 ppm), diet 3 – basal diet + aflatoxin (1 ppm) + T-2 toxin (1 ppm) + activated charcoal (0.4%), diet 4 – basal diet + aflatoxin (1 ppm) + T-2 toxin (1 ppm) + activated charcoal (0.4%) + yeast culture (0.1%). These four diets were fed to 4 groups of day old broiler chicks with four replicates of eight birds in each replicate, in a completely randomized design for six weeks. Degenerative changes in liver, kidney and lymphoid depletion in bursa of Fabricius, disruption of cardiac muscle fibres, and disruption of intestinal villi were observed on histopathology in birds fed with aflatoxin and T-2 toxin supporting the biochemical study. Activated charcoal (0.4%) showed only partial ameliorative effect on combined toxicity in broilers. Histopathological studies of birds on diet 4 were comparable to those of control group fed on toxin free diet. These results indicate that aflatoxin and T-2 toxin in the diet caused damage to vital organs. The combination of activated charcoal and yeast culture was more effective in counteracting the combined toxicity of aflatoxin and T-2 toxin compared to the activated charcoal alone....
Background\r\nRecombinant antibody fragments have a wide range of applications in research, diagnostics and therapy. For many of these, small fragments like single chain fragment variables (scFv) function well and can be produced inexpensively in bacterial expression systems. Although Escherichia coli K-12 production systems are convenient, yields of different fragments, even those produced from codon-optimized expression systems, vary significantly. Where yields are inadequate, alternative production systems are needed. Pseudomonas putida strain KT2440 is a versatile biosafety strain known for good expression of heterologous genes, so we have explored its utility as a cell factory for production of scFvs.\r\nResults\r\nWe have generated new broad host range scFv expression constructs and assessed their production in the Pseudomonas putida KT2440 host. Two scFvs bind either to human C-reactive protein or to mucin1, proteins of significant medical diagnostic and therapeutic interest, whereas a third is a model anti-lysozyme scFv. The KT2440 antibody expression systems produce scFvs targeted to the periplasmic space that were processed precisely and were easily recovered and purified by single-step or tandem affinity chromatography. The influence of promoter system, codon optimization for P. putida, and medium on scFv yield was examined. Yields of up to 3.5 mg/l of pure, soluble, active scFv fragments were obtained from shake flask cultures of constructs based on the original codon usage and expressed from the Ptac expression system, yields that were 2.5-4 times higher than those from equivalent cultures of an E. coli K-12 expression host.\r\nConclusions\r\nPseudomonas putida KT2440 is a good cell factory for the production of scFvs, and the broad host range constructs we have produced allow yield assessment in a number of different expression hosts when yields in one initially selected are insufficient. High cell density cultivation and further optimization and refinement of the KT2440 cell factory will achieve additional increases in the yields of scFvs....
Extraction and enzyme analysis of six fungal strains including Aspergillus niger k32, A. niger mtc872, A. niger B42, Penicillium camembertii, Trichophyton terrestre, and Cladosporium cladosporoides were conducted. This experimentation was to evaluate absorbance and the reaction rate of an enzyme amylase in starh-iodine solution and by HCL methods. Testing the enzyme at different temperatures would determine at which temperature the enzyme worked the most efficiently. Analyzing absorbance of the solutions with spectrophotometery would determine the reaction rate. The dominating character of the enzyme amylase extracted from T. terrestre worked much efficiently at wide range of temperatures....
Lantana camara is a herb having antimicrobial, antidiabetic, hepatotoxic properties and is used in traditional system of medicine. Extract from root was prepared and different concentrations of this extract were examined for their activities against microbial agents and for their tolerance by specific cell culture. The cell culture was challenged with different doses of virus and the cultures were observed whether they can withstand or resist the challenge dose when treated with extract or whether the cell culture is capable of resisting the invasion or inhibiting the multiplication of the virus. Thereby, preventing the virus infection the different dilutions of extract did show a very low level of protection when challenged with a low dose of virus. The extract failed to protect the cell cultures with a high dose of virus challenge (100TCID50). In this investigation, the polio virus Type I, RNA virus was used as a challenge virus and the result indicated that the plant extract of root offered slight protection when the cells were treated with 100-200 µg/ml of the extract....
Aspergillus niger FETL FT3, a local extracellular tannase producer strain that was isolated from one of dumping sites of tannin-rich barks of Rhizophora apiculata in Perak, Malaysia. This fungus was cultivated in 250?mL Erlenmeyer flask under submerged fermentation system. Various physical parameters were studied in order to maximize the tannase production. Maximal yield of tannase production, that is, 2.81?U per mL was obtained on the fourth day of cultivation when the submerged fermentation was carried out using liquid Czapek-Dox medium containing (percent; weight per volume) 0.25% NaNO3, 0.1% KH2PO4, 0.05% MgSO4 Ã?·7H2O, 0.05% KCl, and 1.0% tannic acid. The physical parameters used initial medium pH of 6.0, incubation temperature of 3 0Ã?°C, agitation speed of 200?rpm and inoculums size of 6 Ã?â?? 1 06?\nores/ ml. This research has showed that physical parameters were influenced the tannase production by the fungus with 156.4 percent increment....
Marine Ircinia and Haliclona sponges (Porifera) associated bacteria were isolated and screened for antibacterial and antifungal activities against selected clinical isolates of bacteria, multidrug resistant strains and fungal strains. These isolated extracts were also screened for antitubercular activities by LJ media method. Methanolic and ethyl acetate extracts of three marine organisms demonstrated activity against one or more of microbes tested. NIO MAM 11.3, NIO MAM 4.2 and NIOMAM 4.1 strains were most active and exhibited a broad-spectrum antimicrobial activity against each of the microbe tested. Two of them were mass cultured with Zobells Marine Broth media .Ircinia sponge associated bacteria specifically showed activity against Vibrio cholera, MDR Acinetobacte and, Aspergillus fumigatus whereas the Haliclona sponge associated bacterial extract against Staph.aureus, S.Typhi, Shigella, Klebsiella species and Vibrio cholerae exhibited considerable antibacterial activity, respectively....
Being protein function a conformation-dependent issue, avoiding aggregation during production is a major challenge in biotechnological processes, what is often successfully addressed by convenient upstream, midstream or downstream approaches. Even when obtained in soluble forms, proteins tend to aggregate, especially if stored and manipulated at high concentrations, as is the case of protein drugs for human therapy. Post-production protein aggregation is then a major concern in the pharmaceutical industry, as protein stability, pharmacokinetics, bioavailability, immunogenicity and side effects are largely dependent on the extent of aggregates formation. Apart from acting at the formulation level, the recombinant nature of protein drugs allows intervening at upstream stages through protein engineering, to produce analogue protein versions with higher stability and enhanced therapeutic values....
A newly isolated fungus Aspergillus niger SOI017 was shown to be a good producer of �Ÿ-glucosidase from all isolated fungal strains. Fermentation condition (pH, cellobiose concentration, yeast extract concentration, and ammonium sulfate concentration) was optimized for producing the enzyme in shake flask cultures. Response surface methodology was used to investigate the effects of 4 fermentation parameters (yeast extract concentration, cellobiose concentration, ammonium sulfate concentration, and pH) on �Ÿ-glucosidase enzyme production. Production of �Ÿ-glucosidase was most sensitive to the culture medium, especially the nitrogen source yeast extract. The optimized medium for producing maximum �Ÿ-glucosidase specific activity consisted of 0.275% yeast extract, 1.125% cellobiose, and 2.6% ammonium sulfate at a pH value of 3....
Loading....