A Pseudomonas aeruginosa mutant derived by random mutagenesis with N-methyl-N¢-nitro-N-nitrosoguanidine, producing high levels of the rhamnolipid biosurfactants was selected on Siegmund-Wagner (SW) plates. The mutant designated P. aeruginosa PTCC1637 produces rhamnolipids at concentrations 10 time more than parent strain. NMR analysis and surface tension measurement showed that the biosurfactan...

In order to assess the responses of Hashemi rice genotype and its advanced mutant line under salinity stress of 100 mM Sodium chloride (NaCl) for three and six days the shoot samples were taken for biochemical analysis. This experiment was performed in split plot based on randomized complete block design with three replications. The main factor was factorial combination of saline treatmen...

A one kb portion of the rpoS gene from Flexibacter chinensis was isolated by PCR, sequenced and compared to the rpoS gene of a variety of other organisms. The gene was found to be 98% similar to previously sequenced genes. Mutation of the rpoS gene with tri-parental mating produced strain JR101 and the growth rate of the mutant was compared with that of the wild-type. The mutant grew slower, an...

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...

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...