Abundance, diversity and plant‐specific adaptations of plant‐associated lactic acid bacteria

Abstract

Summary Lactic acid bacteria (LAB) are essential for many fruit, vegetable and grain food and beverage fermentations. However, the numbers, diversity and plant‐specific adaptions of LAB found on plant tissues prior to the start of those fermentations are not well understood. When measured, these bacteria have been recovered from the aerial surfaces of plants in a range from <10 CFU g−1 to over 108.5 CFU g−1 of plant tissue and in lower quantities from the soil and rhizosphere. Plant‐associated LAB include well‐known generalist taxa such as Lactobacillus plantarum and Leuconostoc mesenteroides, which are essential for numerous food and beverage fermentations. Other plant‐associated LAB encompass specialist taxa such as Lactobacillus florum and Fructobacillus, many of which were discovered relatively recently and their significance on plants and in foods is not yet recognized. LAB recovered from plants possess the capacity to consume plant sugars, detoxify phenolic compounds and tolerate the numerous biotic and abiotic stresses common to plant surfaces. Although most generalist and some specialist LAB grow rapidly in food and beverages fermentations and can cause spoilage of fresh and fermented fruits and vegetables, the importance of living plants as habitats for these bacteria and LAB contributions to plant microbiomes remain to be shown.

Identification of Nitrogen Fixation Genes in Lactococcus Isolated from Maize Using Population Genomics and Machine Learning

“…These findings were corroborated by comprehensive genomic comparisons of L. lactis isolates that revealed lactococci adapted for use in dairy fermentations exhibited a loss of functions likely necessary for survival in plant environments [22]. Moreover, recent studies demonstrated that strains of L. lactis are found in numerous plants as integral members of the microbiome and are likely to exhibit distinct genomes with uncharacterized metabolic capabilities [23][24][25][26].…”

Effects of Ensiling Oxytropis glabra with Whole-Plant Corn at Different Proportions on Fermentation Quality, Alkaloid Swainsonine Content, and Lactic Acid Bacteria Populations

“…Microorganisms naturally present on forage are responsible for silage fermentation, but can be affected by many factors and vary widely [ 34 ]. Only 4.00 log 10 cfu/g FM of LAB was present in the raw OG ( Table 1 ), which was inadequate for natural fermentation during ensiling [ 35 ].…”

Valorization of Vegetable Food Waste and By-Products Through Fermentation Processes

“…Additionally, directed and controlled fermentations can also be driven in order to obtain valorized final products; in spite of the low predominance of LAB in plant autochthonous microbiota, they can also be key players in plant and plant-derived waste fermentations (Filannino et al, 2018). The reason behind this is the high adaptation of LAB to inhabit different plant niches of fruits and vegetables, which include flowers, grains, leaves, and/or grasses (Yu et al, 2020). In addition, Yu et al (2020) have reported the distinction between generalist-and specialist-LAB in plant ecosystems; the first ones occupy a wide range of habitats but with a variable degree of performance, whilst the specialists are present in a narrow range of habitats and they are highly adapted to them.…”

“…The reason behind this is the high adaptation of LAB to inhabit different plant niches of fruits and vegetables, which include flowers, grains, leaves, and/or grasses (Yu et al, 2020). In addition, Yu et al (2020) have reported the distinction between generalist-and specialist-LAB in plant ecosystems; the first ones occupy a wide range of habitats but with a variable degree of performance, whilst the specialists are present in a narrow range of habitats and they are highly adapted to them. The generalist-LAB have genomes of bigger size than the specialized once since they harbor a wide enzymatic machinery; an example of the first case is Lactiplantibacillus plantarum, widely isolated from plant and animal sources, meanwhile Fructilactobacillus sanfranciscensis is mainly associated with cereal (sourdough) fermentations.…”