Biosynthesis of γ-Polyglutamic Acid by Bacillus licheniformis Through Submerged Fermentation (SmF) and Solid-state Fermentation (SSF)

Gamma-Polyglutamic acid (γ-PGA) was produced from fermentation processes by inoculating the bacterium Bacillus licheniformis on different substrates. In submerged fermentation (SmF), glycerol and glucose were used as the main carbon substrates while ammonium sulfate served to provide nitrogen. In solid-state fermentation (SSF), soybean was used as the main substrate. Tests carried out in an airlift bioreactor with B. licheniformis showed a maximum productivity of 0.789 g L–1 h–1 and a yield of 0.4 g g–1. Different soybean cultivars from the 2015 and 2016 crops were used in the SSF. The BRS 1001IPRO cultivar, from the 2016 crop, showed the highest production, i.e., 1.2 g L–1 of γ-PGA. This cultivar was subjected to different levels of milling (fine, intermediate and coarse). Coarsely milled grains increased γ-PGA production to 2.7 g L–1. Moreover, coarse milling made the internal nutrients of the grains available for fermentation and this particle size did not compromise aeration during fermentation. This work is licensed under a Creative Commons Attribution 4.0 International License

Reproduction of Meloidogyne morocciensis (Tylenchida: Meloidogynidae) in weeds found in Brazil

Abstract Weeds can be hosts of root-knot nematodes of the genus Meloidogyne. The importance of the species Meloidogyne morocciensis parasitizing many crops is recognized, but their reproductive capacity in weeds is not known. The present study hypothesizes the ability of M. morocciensis to parasitize and reproduce in different weed species found in Brazil. The objective was to evaluate the reproduction of M. morocciensis in 36 weed species. The plants were individually inoculated with 5,000 eggs and second stage juveniles and kept in greenhouse for 60 days. The experimental design was completely randomized with twelve replications. The root system of each plant was evaluated for gall index (GI), final nematode population (PF), number of nematode/g of root (NNGR) and reproduction factor (RF). It was verified that M. morocciensis has the capacity to parasite 36 weed species belonging to 16 different botanical families, confirming the hypothesis proposed. From the 36 species evaluated, 77.8% (28) were susceptible (FR ≥ 1.0) to M. morocciensis. The present study is the first to identify different weeds as hosts of M. morocciensis, evidencing its polyphagous habit, indicating species of plants with high capacity to multiply this nematode and that need more attention during the integrated management of these pathogen

Efecto residual de los herbicidas utilizados en arroz Clearfield sobre la implantación de pastura en sucesión.

El sistema Clearfield posibilita el uso de la mezcla de herbicidas imazapir+imazapic sobre cultivares de arroz tolerantes, haciendo más sencillo y práctico el control de arroz maleza y otras malezas susceptibles. Apuntando a mejorar la implantación de pasturas en la sucesión de arroz, este artículo presenta resultados de los trabajos que INIA viene desarrollando para conocer la sensibilidad de diferentes especies forrajeras cultivadas a continuación de arroz que utiliza este sistema