lactobacillus
Microbial Ecology | SpotlightPhylotype-Level Characterization of Complex Communities of Lactobacilli Using a High-Throughput, High-Resolution Phenylalanyl-tRNA Synthetase (pheS) Gene Amplicon Sequencing ApproachSpecies formerly classified within the genera Lactobacillus and Pediococcus have been studied extensively at the genomic level. To accommodate their exceptional functional diversity, the over 270 species were recently reclassified into 26 distinct genera. Despite their relevance to both academia and industry, methods that allow detailed exploration of their ecology are still limited by low resolution, high cost, or...
Enzymology and Protein EngineeringAn 1,4-α-Glucosyltransferase Defines a New Maltodextrin Catabolism Scheme in Lactobacillus acidophilusThe degradation of starch in the small intestine generates short linear and branched α-glucans. The latter are poorly digestible by humans, rendering them available to the gut microbiota, e.g., lactobacilli adapted to the small intestine and considered beneficial to health. This study unveils a previously unknown scheme of maltooligosaccharide (MOS) catabolism via the concerted activity of an 1,4-α-glucosyltransferase together with a...
Food MicrobiologyAntibiofilm Activity of Lactobacillus plantarum 12 Exopolysaccharides against Shigella flexneriS. flexneri is a widespread foodborne pathogen causing food contamination and responsible for food poisoning outbreaks related to various foods in developing countries. Not only has biofilm formation by S. flexneri been difficult to eliminate, but it has also increased the drug resistance of the...
Microbial Ecology | SpotlightEcological Importance of Cross-Feeding of the Intermediate Metabolite 1,2-Propanediol between Bacterial Gut SymbiontsThrough experiments in gnotobiotic mice that employed isogenic mutants of bacterial strains that produce (Bifidobacterium breve) and utilize (Lactobacillus reuteri) 1,2-propanediol, this study provides mechanistic insight into the ecological ramifications of a trophic interaction between gut...
Invertebrate Microbiology | SpotlightGenetic Influences of the Microbiota on the Life Span of Drosophila melanogasterAssociated microorganisms (“microbiota”) are intimately connected to the behavior and physiology of their animal hosts, and defining the mechanisms of these interactions is an urgent imperative. This study focuses on how microorganisms influence the life span of a model host, the fruit fly Drosophila melanogaster. First, we performed a screen that suggested a strong...
Food Microbiology | SpotlightCompetitive Exclusion Is a Major Bioprotective Mechanism of Lactobacilli against Fungal Spoilage in Fermented Milk ProductsIn societies that have food choices, conscious consumers demand natural solutions to keep their food healthy and fresh during storage, simultaneously reducing food waste. The use of “good bacteria” to protect food against spoilage organisms has a long, successful history, even though the molecular mechanisms are not fully understood. In this study, we show that the depletion of free manganese is a major bioprotective mechanism of...
Food MicrobiologyGenetic Determinants of Hydroxycinnamic Acid Metabolism in Heterofermentative LactobacilliThe metabolism of secondary plant metabolites, including phenolic compounds, by food-fermenting lactobacilli is a significant contributor to the safety, quality, and nutritional quality of fermented foods. The enzymes mediating hydrolysis, reduction, and decarboxylation of phenolic acid esters and phenolic acids in lactobacilli, however, are not fully characterized. The genomic analyses presented here provide evidence for three novel...
Invertebrate MicrobiologyCadmium and Selenate Exposure Affects the Honey Bee Microbiome and Metabolome, and Bee-Associated Bacteria Show Potential for BioaccumulationBees are important insect pollinators that may encounter environmental pollution when foraging upon plants grown in contaminated areas. Despite the pervasiveness of pollution, little is known about the effects of these toxicants on honey bee metabolism and their symbiotic microbiomes. Here, we investigated the impact of selenate and cadmium exposure on the gut microbiome and metabolome of honey bees. We found that exposure to these...
Food Microbiology | SpotlightInterspecies Inhibition of Porphyromonas gingivalis by Yogurt-Derived Lactobacillus delbrueckii Requires Active Pyruvate OxidaseP. gingivalis is implicated in the onset and progression of periodontal disease and associated with some systemic diseases. Probiotic bacteria represent an attractive preventative therapy for periodontal disease. However, the efficacy of probiotic bacteria can be variable between studies. Our data support the known importance of selecting particular strains of...
Environmental MicrobiologyHoneybee-Specific Lactic Acid Bacterium Supplements Have No Effect on American Foulbrood-Infected Honeybee ColoniesThe previously demonstrated antagonistic effects of honeybee-derived bacterial microbiota on the infectivity and pathogenicity of P. larvae in laboratory bioassays have identified a possible new approach to AFB control. However, honeybee colonies are complex superorganisms where social immune defenses play a major role in resistance against disease at the colony level...