Activated carbon has become a widely used tool to investigate root-mediated allelopathy of plants, especially in plant invasion biology, because it adsorbs and thereby neutralizes root exudates. Allelopathy has been a controversially debated phenomenon for years, which revived in plant invasion biology as one possible reason for the success of invasive plants. Noxious plant exudates may harm ot...

Plant growth-promoting bacteria –PGPB– are microorganisms that can grow in, on, or around plant tissues and stimulate plant growth by numerous mechanisms (Vessey 2003). Within this group, nitrogen-fixing bacteria play a remarkable role in plant nutritition. They can take N2 from atmosphere and make it available for plant uptake (Halbleib and Ludden 2000). Azotobacter, a nitrogen-fixing bacteria...

The enzyme which cleaves the benzene ring of 6-chlorohydroxyquinol was purified to apparent homogeneity from an extract of 2,4,6-trichlorophenol-grown cells of Streptomyces rochei 303. Like the analogous enzyme from Azotobacter sp. strain GP1, it exhibited a highly restricted substrate specificity and was able to cleave only 6-chlorohydroxyquinol and hydroxyquinol and not catechol, chlorinated ...

CooA is a heme-containing transcriptional activator that enables Rhodospirillum rubrum to sense and grow on CO as a sole energy source. We have identified a number of CooA homologs through database searches, expressed these heterologously in Escherichia coli, and monitored their ability to respond to CO in vivo. Further in vitro analysis of two CooA homologs from Azotobacter vinelandii and Carb...

Cyclopropane fatty acids constitute 25% of the phospholipid acyl groups in cysts of Azotobacter vinelandii. These are lost by dilution during germination when the synthesis of the fatty acids characteristic of vegetative cell phospholipids commences.

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Azotobacter synthesizes an extensive internal membranous nework when grown with air (N(2)), i.e., under conditions when these bacteria fix nitrogen. Very slight quantities of internal membrane, concentrated mainly about the cell periphery, are formed when Azotobacter grows with fixed nitrogen, i.e., ammonia and amino acids. Compared to cells growing with ammonia, cells utilizing atmospheric nit...

Ornithine decarboxylase (ODC), cyclin D1 (CCND1) and antizyme inhibitor (AZI) promote cell growth. ODC and CCND1 can be degraded through antizyme (AZ)-mediated 26S proteasomal degradation. This paper describes a mechanistic study of the molecular interactions between AZ and its interacting proteins. The dissociation constant (Kd) of the binary AZ-CCND1 complex and the respective binding sites o...