Volatile Nitrogenous Compounds from Bacteria: Source of Novel Bioactive Compounds

Bacteria can produce nitrogenous compounds via both primary and secondary metabolic processes. Many bacterial volatile nitrogenous compounds produced during the secondary metabolism have been identified and reported for their antioxidant, antibacterial, antifungal, algicidal and antitumor activities. The production of these nitrogenous compounds depends on several factors, including the composition of culture media, growth conditions, and even the organic solvent used for their extraction, thus requiring their identification in specific conditions. In this review, we describe the volatile nitrogenous compounds produced by bacteria especially focusing on their antimicrobial activity. We concentrate on azo-compounds mainly pyrazines and pyrrolo-pyridines reported for their activity against several microorganisms. Whenever significant, extraction and identification methods of these compounds are also mentioned and discussed. To the best of our knowledge, this is first review describing volatile nitrogenous compounds from bacteria focusing on their biological activity.     

Predation by the tayra on the common marmoset and the pale-throated three-toed sloth

Predation on arboreal mammals is rarely observed in the wild. Here we describe the first confirmed observations of predation on a juvenile wild common marmoset (Callithrix jacchus) and on a neonate wild pale-throated three-toed sloth (Bradypus tridactylus) by the mustelid carnivore Eira barbara, the tayra. We discuss predation on both of the prey species and review the nature of predation by the tayra.     

Infectious clones of cotton leafroll dwarf virus strains used for genotype evaluation in cotton

Cotton blue disease (CBD) and atypical-CBD are the most important viral diseases of cotton plants in the southern region of South America. Common and atypical strains of cotton leafroll dwarf virus (CLRDV and CLRDV-at, respectively) are thought to be causative agents of CBD and atypical-CBD, respectively. Inoculation of test plants via aphid vectors is difficult, as is determining strains via molecular diagnosis; accordingly, it is difficult for breeders to evaluate the effects of blue disease-associated virus infections in cotton lineages. In the present study, we attempted to circumvent these difficulties by producing six full-length cDNA infectious clones from CLRDV and CLRDV-at strains using the Gibson Assembly protocol. For inoculation of the infectious clones, a vacuum chamber-mediated agroinfiltration protocol was adapted and applied. Using this protocol, 90%–100% of cotton plants became infected with the clones, which was not possible via syringe-based agroinfiltration. A genotyping protocol based on RT-qPCR targeting a specific region of the virus P0 protein was also developed, allowing rapid differentiation of CLRDV and CLRDV-at. Applying this protocol to 68 field samples revealed that CLRDV-at was dominant (50%) over CLRDV (5.8%) in single virus infections. These preliminary results imply that CLRDV-at might occupy the ecological niche of CLRDV in the cotton fields of Brazil.