Lactobacteria for fermentation of vegetable raw materials

The research relevance is determined by the need to select bacterial cultures capable of ensuring a stable and intensive course of plant biomass fermentation. A substantial criterion for the effectiveness of such cultures is their natural ecological adaptation to the substrate, which determines metabolic activity, tolerance to chemical components, and the ability to maintain key quality parameters of preservation. The study aimed to evaluate the morphological, physiological-biochemical, and fermentation properties of three lactic acid bacteria species isolated from different types of plant raw materials, as well as to determine their ability to grow and utilise carbohydrates in alfalfa juice, sugar beet tops juice, and their mixtures supplemented with sweet corn juice. The study was based on species identification methods based on determination of the fermentation profile, assessment of morphology, evaluation of growth characteristics under different temperature regimes, determination of the level of reducing sugar utilisation, and analysis of the dynamics of changes in substrate acidity during fermentation. The study established that isolates from plant raw materials exhibit a high adaptive capacity, manifested in an increase in cell numbers and active carbohydrate utilisation. The most intensive growth of heterofermentative cultures was observed in alfalfa juice and in the alfalfa-corn mixture, where their counts reached 8.68-8.77 log CFU/mL. Sugar beet tops supported enhanced sugar utilisation and pronounced changes in acidity but were less favourable for certain species. The addition of sweet corn juice improved the fermentation properties of all strains. The practical significance of the study is determined by identification of promising bacterial isolates suitable for the development of inoculants aimed at improving the fermentation of plant biomass, in particular for silage and haylage preservation