Nesting Biology and Fungiculture of the Fungus-Growing Ant, Mycetagroicus cerradensis: New Light on the Origin of Higher Attine Agriculture

The genus Mycetagroicus is perhaps the least known of all fungus-growing ant genera, having been first described in 2001 from museum specimens. A recent molecular phylogenetic analysis of the fungus-growing ants demonstrated that Mycetagroicus is the sister to all higher attine ants (Trachymyrmex, Sericomyrmex, Acromyrmex, Pseudoatta, and Atta), making it of extreme importance for understanding the transition between lower and higher attine agriculture. Four nests of Mycetagroicus cerradensis near Uberlândia, Minas Gerais, Brazil were excavated, and fungus chambers for one were located at a depth of 3.5 meters. Based on its lack of gongylidia (hyphal-tip swellings typical of higher attine cultivars), and a phylogenetic analysis of the ITS rDNA gene region, M. cerradensis cultivates a lower attine fungus in Clade 2 of lower attine (G3) fungi. This finding refines a previous estimate for the origin of higher attine agriculture, an event that can now be dated at approximately 21–25 mya in the ancestor of extant species of Trachymyrmex and Sericomyrmex

Cashew gum microencapsulation protects the aroma of coffee extracts

Microencapsulation of materials rich in volatile compounds by spray drying presents the challenge of removing water by vapourization without loss of odour and/or flavour components. Crioconcentrated coffee extracts rich in odour components were used as a substrate core to evaluate microencapsulation with cashew gum from Anacardium occidentale L. In Brazil, cashew gum is a low cost alternative to the traditional Arabic gum. A suspension containing coffee extract and the wall material was dissolved in water and then passed through a spray dryer. Core microcapsules were microwave-assisted extracted (MAE) and the aroma protection of the microcapsules produced was evaluated using gas chromatography and mass spectroscopy (GC/MS). The external morphology and size distribution of the microcapsules were obtained by scanning electron microscopy (SEM) and light scattering techniques, respectively. When comparing Arabic and cashew gum microencapsulation of coffee extracts both wall materials were observed to have similar aroma protection, external morphology and size distribution. Sensory analysis was employed to examine flavour protection and consumer preference with microencapsulation. These biochemical, sensory and structural data suggest that low cost cashew gum is a well suited alternative for odour microencapsulation to the more costly Arabic gum currently used in Brazil.251132

Protective immunity against Trypanosoma cruzi infection in a highly susceptible mouse strain after vaccination with genes encoding the amastigote surface protein-2 and trans-sialidase

Protective immunity against lethal infection is developed when BALB/c or C57BL/6 mice are immunized with plasmids containing genes from the protozoan parasite Trypanosoma cruzi. However, genetic vaccination of the highly susceptible mouse strain A/Sn promoted limited survival after challenge. This observation questioned whether this type of vaccination would be appropriate for highly susceptible individuals. Here, we compared the protective efficacy and the immune response after individual or combined genetic vaccination of A/Sn mice with genes encoding trans-sialidase (TS) or the amastigote surface protein-2 (ASP-2). After challenge, a significant proportion of A/Sn mice immunized with either the asp-2 gene or simultaneously with asp-2 and ts genes, survived infection. in contrast, the vast majority of mice immunized with the ts gene or the vector alone died. Parasitological and histological studies performed in the surviving mice revealed that these mice harbored parasites; however, minimal inflammatory responses were seen in heart and striated muscle. We used this model to search for an in vitro correlation for protection. We found that protective immunity correlated with a higher secretion of interferon-gamma by spleen cells on in vitro restimulation with ASP-2 and the presence of ASP-2-specific CD8 cells. Depletion of either CD4 or CD8 or both T-cell subpopulations prior to the challenge rendered the mice susceptible to infection demonstrating the critical contribution of both cell types in protective immunity. Our results reinforce the prophylactic potential of genetic vaccination with asp-2 and ts genes by describing protective immunity against lethal T. cruzi infection and chronic tissue pathology in a highly susceptible mouse strain.UNIFESP, Escola Paulista Med, CINTERGEN, BR-04044010 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04044010 São Paulo, BrazilUniv São Paulo, ICB, Dept Imunol, BR-05508900 São Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Bioquim & Imunol, BR-30190002 Belo Horizonte, MG, BrazilFiocruz MS, Ctr Pesquisas Rene Rachou, BR-30190002 Belo Horizonte, MG, BrazilUNIFESP, Escola Paulista Med, CINTERGEN, BR-04044010 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04044010 São Paulo, BrazilWeb of Scienc