Characterization and emended description of Lactobacillus kunkeei as a fructophilic lactic acid bacterium

Abstract

Lactobacillus kunkeei is an inhabitant of fructose-rich niches and is a potential member of the fructophilic lactic acid bacteria. In the present study, the phylogenetic and biochemical characteristics of the type strain and eight isolates of L. kunkeei, originating from wine, flowers and honey, were studied. The nine isolates, including the type strain, formed a well-defined phylogenetic subcluster based on the analysis of 16S rRNA gene sequences. The subcluster was not closely related to other subclusters in the Lactobacillus phylogenetic group. Biochemically, the eight new isolates showed typical fructophilic characteristics. The eight isolates grew poorly on glucose, but grew well on fructose. Good growth on glucose was only recorded in the presence of electron acceptors. The type strain of L. kunkeei differed from the other isolates only on the basis of poor growth on fructose. Although they belong to a group of obligately heterofermentative lactic acid bacteria, all nine isolates, including the type strain, produced almost equimolar amounts of lactic acid and acetic acid and very little ethanol from glucose. Eight of the isolates can thus be regarded as typical 'obligately' fructophilic lactic acid bacteria. Although the type strain of L. kunkeei was phenotypically slightly different from the other isolates, it possessed several important fructophilic characteristics. On the basis of the evidence gathered in this study, the type strain of L. kunkeei is recognized as a member of the 'obligately' fructophilic lactic acid bacteria.

Specificity between Lactobacilli and Hymenopteran Hosts Is the Exception Rather than the Rule

“…These M. smithiiassociated OTUs were found in both fungus-garden and worker samples (see Table S2 in the supplemental material). As already reported in McFrederick et al (16), halictids associated mainly with Lactobacillus OTUs that were related to flower-inhabiting, fructophilic lactobacilli (52) or to a clade that includes flower-inhabiting and fructophilic lactobacilli (53) and lactobacilli used in sourdough fermentation (54). Some of the halictidassociated OTUs formed monophyletic clades, but these clades did not exhibit the same level of divergence as the Firm3 and Firm4 clades (Fig.…”

Improvement of identification methods for honeybee specific Lactic Acid Bacteria; future approaches

“…kunkeei has been classified as an obligate fructophilic bacteria preferring fructose as sugar source and being able to grow well on glucose only in the presence of fructose and external electron acceptors [48,49,50]. Later, it was found that L .…”

Origin and Effect of Alpha 2.2 Acetobacteraceae in Honey Bee Larvae and Description of Parasaccharibacter apium gen. nov., sp. nov

“…The phylogenetic cutoffs that are commonly used in high-throughput studies to group taxa often do not align with phenotypic differences based on standard biochemical profiles or microscopy (47,48). For example, Endo et al (49) find that L. kunkeei bacteria, which are widespread in the pollination environment, in the honey bee gut, and the honey bee colony (10)(11)(12), can have nearly identical 16S rRNA gene sequences yet very different biochemical profiles. This phenotypic diversity could have great implications for the study of bacterium-bee interactions and also the use of bacteria for improving honey bee health.…”