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

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.

Protease production by the keratinolytic Bacillus sp. CL18 through feather bioprocessing.

Bacillus sp. CL18 was investigated to propose a bioprocess for protease production using feathers as organic substrate. In feather broth (FB), containing feathers as sole organic substrate (1-100 g l-1), maximal protease production was observed at 30 g l-1 (FB30) after 6 days of cultivation, whereas increased feather concentrations negatively affected protease production and feather degradation. Protease production peaks were always observed earlier during cultivations than maximal feather degradation. In FB30, 80% of initial feathers mass were degraded after 7 days. Addition of glucose, sucrose, starch, yeast extract (2 g l-1), CaCl2, or MgCl2 (10 mmol l-1) to FB30 decreased protease production and feather degradation. FB30 supplementation with NH4Cl (1 g l-1) resulted in less apparent negative effects on protease production, whereas peptone (2 g l-1) increased protease yields earlier during cultivations (3 days). Through a central composite design employed to investigate the effects of peptone and NH4Cl (0.5-4.5 g l-1) on protease production and feather degradation, FB30 supplementation with peptone and NH4Cl (0.5-1.1 g l-1) increased protease production within a shorter cultivation time (5 days) and hastened complete feather degradation (6 days). Feather bioconversion concurs with sustainable production of value-added products.