Exploring the Diversity and Potential Use of Flower-Derived Lactic Acid Bacteria in Plant-Based Fermentation: Insights into Exo-Cellular Polysaccharide Production.

Isolation of new plant-derived lactic acid bacteria (LAB) is highly prioritized in developing novel starter cultures for plant-based fermentation. This study explores the diversity of LAB in Danish flowers and their potential use for plant-based food fermentation. A total of 46 flower samples under 34 genera were collected for LAB isolation. By introducing an enrichment step, a total of 61 LAB strains were isolated and identified using MALDI-TOF and 16S rRNA sequencing. These strains represent 24 species across 9 genera, predominantly Leuconostoc mesenteroides, Fructobacillus fructosus, Apilactobacillus ozensis, and Apilactobacillus kunkeei. Phenotypic screening for exo-cellular polysaccharide production revealed that 40 strains exhibited sliminess or ropiness on sucrose-containing agar plates. HPLC analysis confirmed that all isolates produced exo-cellular polysaccharides containing glucose, fructose, or galactose as sugar monomers. Therefore, the strains were glucan, fructan, and galactan producers. The suitability of these strains for plant-based fermentation was characterized by using almond, oat, and soy milk. The results showed successful acidification in all three types of plant-based matrices but only observed texture development in soy by Leuconostoc, Weissella, Lactococcus, Apilactobacillus, and Fructobacillus. The findings highlight the potential of flower-derived LAB strains for texture development in soy-based dairy alternatives.

Lactic acid bacteria as an adjunct starter culture in the development of metabiotic functional turmeric (Curcuma longa Linn.) beverage.

Turmeric (Curcuma longa) is a highly nutritious rhizomatous herbaceous plant with remarkable chemical composition and biologically active compounds. This study aimed to evaluate the turmeric, ginger and lemon blend as a fermentable substrate by lactic acid bacteria to develop a fermented nondairy beverage. Results showed that turmeric blend (turmeric 2%w/v, ginger 1.5% v/v, 5% v/v) was an excellent matrix for lactic acid bacteria growth and fermentation dramatically increased total phenolic, flavonoid content and antioxidants capacities impacting the color and sensory properties. Moreover, the formulated fermented turmeric blend was stable for more than 90 days at 4°C with a healthy bacterial population and nutraceutical stability. Turmeric beverage also inhibited the growth of Caco-2 and MOLT 4 cancerous cell lines in a dosage and time-reliant manner. This way, lactic acid fermentation can be considered as an appropriate tool for developing turmeric based novel bio-intervention with enhanced bioactivity and antagonistic efficacy against recurring food-borne pathogen in this post-antibiotic era.