Effect of quercetin, L-ergothioneine and H89 on sperm motility and kinematic pattern, plasma membrane functionality and in vitro heterologous fertilizing capacity of cryopreserved equine semen.

Semen cryopreservation causes extensive chemical and physical damage to sperm structure, which generates premature aging and reduces viability and fertility of spermatozoa. The addition of antioxidants to freezing extenders can reduce the oxidative damage caused by excessive generation of reactive oxygen species (ROS), and the premature aging could be reduced by adding an enzyme inhibitor that prevents an anticipated capacitation. The aim of this study was to evaluate the in vitro effect of quercetin (Q), L-ergothioneine (E) and H89 addition to cryopreserved equine spermatozoa. Six experimental groups were stablished: control, Q, E, H89, H89Q and H89E. The analyzed parameters were sperm motility and kinematic using computer assisted sperm analysis (CASA), plasma membrane functionality with the hypoosmotic swelling test (HOST) and fertilizing capability with in vitro heterologous fertilization. Quercetin reduced curvilinear velocity (VCL) and increased beat-cross frequency (BCF), while its combination with H89 (H89Q) reduced total motility, progressive motility, VCL and hyperactive sperm (HA). Likewise, H89 and its combination with E (H89E) decreased VCL and amplitude of lateral head displacement (ALH). No significant differences were observed among treatments for membrane functionality and fertilizing capacity of sperm. In conclusion H89 in combination with Q and E reduced sperm motility or some kinematic parameters. However, they did not influence plasma membrane functionality and in vitro fertilizing capacity of frozen-thawed equine semen.

Optimization of the reproduction of Weissella cibaria in a fermentation substrate formulated with agroindustrial waste.

Agroindustrial wastes contain macronutrients and micronutrients essential for the reproduction of lactic acid bacteria. In this research, the reproduction of Weissella cibaria was experimentally optimized in a supplemented fermentation substrate (SFS) formulated from pineapple and sacha inchi wastes. Response surface methodology was used to evaluate the influence of the following independent variables: temperature (32-40 °C), pH (5.0-6.0), and stirring speed (SS) (100-150 rpm) on the following dependent variables: viability (Log10 CFU mL-1), biomass production (B Wc ), lactic acid production (LA), biomass yield (YBwc/S), biomass volumetric productivity (VP Wc ), LA volumetric productivity (VP LA ), carbon source consumption (CSC), N2 consumption (N2C), and specific growth rate (µ). The experimental optimization of multiple responses presented a desirability of 76.8%, thus defining the independent variables of the process: temperature = 35.1 °C, pH = 5.0, and SS = 139.3 rpm; and the dependent variables: viability = 10.01 Log10 CFU mL-1, B Wc  = 2.9 g L-1, LA = 19.4 g mL-1, YBwc/ S  = 43.9 g biomass/g CSC, VP Wc = 0.49 g L-1 h - 1, VP LA = 3.2 g L-1 h-1, CSC = 17.2%, N2C = 63.6% and µ = 0.28 h-1. From these, viability, YBwc/S, CSC, N2C, and LA presented significant statistical differences, while the independent variable with the least important effect on the process was pH. Under optimal conditions of temperature, pH and SS; SFS favors the reproduction and viability of W. cibaria. This provides evidence of a sustainable alternative for the production of probiotics in the context of circular economy.