Biological control has been shown to be one of the possible biotechnological applications of fungi and their proteases. The objective of this study was to evaluate the nematicidal activity of the fungus Pleurotus ostreatus and its proteases on Panagrellus sp. larvae. Proteolytic activity of P. ostreatus (PLO 06) was measured and characterized at different pHs, temperatures and in the presence of a inhibitor (PMSF). Daily samples of culture medium were collected in order to determine the period of maximum enzyme production. A zymogram showed the profile of several proteases. Predatory activity of the fungus P. ostreatus (PLO 06) was evaluated on Panagrellus sp. larvae (assay A) as well as the nematicidal activity of PLO 06 proteases on the same larvae (assay B). At pH 9 and 60°C, the activity of the proteases reached the maximum. In the presence of inhibitor, there was no proteolytic activity. A sample collected on the fifth day of incubation showed the highest enzyme activity. P. ostreatus demonstrated capture activity on larvae Panagrellus sp. The values ​​of the reduction of the larvae (Assay A) were: day 1 (65.6%); day 2 (77.4%); day 3 (95.2%). The reduction of the larvae (Assay B) was 42%. P. ostreatus (PLO 06) and its proteases were very effective against Panagrellus sp. larvae, demonstrating great potential for use in integrated biological control. Key words: Pleurotus, protease, Panagrellus sp., biological control, nematicidal.

Protease production fromDuddingtonia flagrans(isolate AC001) was optimized and the larvicidal activity of the enzymatic extract was evaluated on infective horse cyathostomin larvae (L3).Duddingtonia flagranswas grown in liquid medium with eight different variables: glucose, casein, bibasic potassium phosphate (K₂HPO₄), magnesium sulphate (MgSO₄), zinc sulphate (ZnSO₄), ferrous sulphate (FeSO₄), copper sulphate (CuSO₄) and temperature. The Plackett–Burman analysis showed a significant influence of MgSO₄, CuSO₄and casein (P < 0.05) on protease production byD. flagransin liquid medium. Central composite design indicated that the highest proteolytic activity was 39.56 U/ml as a function of the concentrations of casein (18.409 g/l), MgSO₄(0.10 g/l) and CuSO₄(0.50 mg/l). A significant difference (P < 0.01) was found for the larval number between the treated and control groups at the end of the experiment. A reduction of 95.46% in the number of free-living larvae was found in the treated group compared with the control. The results of this study suggest that protease production byD. flagrans(AC001) in liquid medium was optimized by MgSO₄, CuSO₄and casein, showing that the optimized enzymatic extract exerted larvicidal activity on cyathostomins and therefore may contribute to large-scale industrial production.

Climate change is causing detrimental changes in living organisms, including pathogens. This review aimed to determine how climate change has impacted livestock system management, and consequently, what factors influenced the gastrointestinal nematodes epidemiology in small ruminants under tropical conditions. The latter is orientated to find out the possible solutions responding to climate change adverse effects. Climate factors that affect the patterns of transmission of gastrointestinal parasites of domesticated ruminants are reviewed. Climate change has modified the behavior of several animal species, including parasites. For this reason, new control methods are required for controlling parasitic infections in livestock animals. After a pertinent literature analysis, conclusions and perspectives of control are given.