A major 30.5-kb cluster of nif and associated genes of Acetobacter diazotrophicus (syn. Gluconacetobacter diazotrophicus), a nitrogen-fixing endophyte of sugarcane, was sequenced and analyzed. This cluster represents the largest assembly of contiguous nif-fix and associated genes so far characterized in any diazotrophic bacterial species. Northern blots and promoter sequence analysis indicated ...

Although a variety of bacterial species have been reported to use the interspecies communication signal autoinducer-2 (AI-2) to regulate multiple behaviors, the molecular mechanisms of AI-2 recognition and signal transduction remain poorly understood. To date, two types of AI-2 receptors have been identified: LuxP, present in Vibrio spp., and LsrB, first identified in Salmonella enterica serova...

We compute the large scale (macroscopic) correlations in ensembles of normal random matrices with a general non-Gaussian measure and in ensembles of general non-Hermition matrices with a class of non-Gaussian measures. In both cases the eigenvalues are complex and in the large N limit they occupy a domain in the complex plane. For the case when the support of eigenvalues is a connected compact ...

Rhizobium tropici, a member of the Rhizobiaceae family, has the ability to synthesize and secrete extracellular polysaccharides (EPS). Rhizobial EPS have attracted much attention from the scientific and industrial communities. Rhizobial isolates and R. tropici mutants that produced higher levels of EPS than the wild-type strain SEMIA4080 were used in the present study. The results suggested a h...

Polyuronides are an acidic class of polysaccharides with interesting rheological and biological properties. However, except pectin and alginate, the structural variability of this class of polysaccharides is poor and low described in literature. In this context, a new generation of polyuronides has been isolated from two sources in the middle of the 90’s. Firstly, a bacterial -(1,4) polyglucuro...