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

Abstract

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 (BWc), lactic acid production (LA), biomass yield (YBwc/S), biomass volumetric productivity (VPWc), LA volumetric productivity (VPLA), 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, BWc = 2.9 g L−1, LA = 19.4 g mL−1, YBwc/S = 43.9 g biomass/g CSC, VPWc = 0.49 g L−1h − 1, VPLA = 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.