Xanthan gum is a microbial polysaccharide of great commercial importance as it has unusual rheological properties in solution and consequent range of applications. In this study, a series of mutants were isolated from Xanthomonas campestris PTCC 1473 by ethyl methanesulfonate mutagenesis. The polysaccharide yield of one mutant, XC1473E2, was 30% better than that of the parent strain. It also sh...

Staphylococcus aureus is a major causative pathogen of clinical and subclinical mastitis of dairy domestic ruminants. This agent produces a variety of extracellular toxins and virulence factors including Toxic Shock Syndrome Toxin-1 (TSST-1) which is the major cause of Toxic Shock Syndrome (TSS). In this study 58 S. aureus isolates obtained from 9 dairy herds in East and West Azerbaijan provinc...

OBJECTIVE In Australia, Salmonella serovar Typhimurium (S. Typhimurium) is the predominant zoonotic serovar in humans and is frequently isolated from layer hens. Vaccination against this serovar has been previously shown to be effective in broilers and the aim of this current study was to assess and determine the best vaccination strategy (live or inactivated) to minimise caecal colonisation by...

conclusions results of this study could be used to find suitable targets for inverse metabolic engineering and site-directed mutagenesis to achieve stable and high-level extracellular lipase production in y. lipolytica and other yeasts. results two nucleotide substitutions were found in the extracellular lipase lip2 orfs of y. lipolytica u6 mutant strain compared to the wild-type strain. in thi...

background : salmonella actively stimulates its own uptake into the epithelial cells by inducing cytoskeleton rearrangements and membrane ruffling triggered by some proteins secreted by salmonella into the cytosol of the epithelial cells via a type iii secretion system (ttss) encoded by genes of the salmonella pathogenicity island 1 (spi-1). hila is a transcriptional activator encoded on salmon...

reproductive parameters and ovipositional preference of plutella xylostella were assessed on some mutant genotypes of canola (rgs 8-1, rgs 10-2, rgs 8-13, zar 9-9 and talaye 8-3) and their cultivars (rgs, zar, talaye) under greenhouse condition (21 ± 6 °c, 65 ± 10 rh and a photoperiod of 16l: 8d h). comparison of the reproductive parameters on rgs and its mutant genotypes revealed that mutant g...

background: cholera toxin b subunit (ctb) has been extensively considered as an immunogenic and adjuvant protein, but its yield of expression is not satisfactory in many studies. the aim of this study was to compare the expression of native and mutant recombinant ctb (rctb) in pqe vector. methods: ctxb fragment from vibrio cholerae o1 atcc14035 containing the substitution of mutant ctxb for ami...