Cultivated bacterial diversity associated with the carnivorous plant Utricularia breviscapa (Lentibulariaceae) from floodplains in Brazil

Abstract

Carnivorous plant species, such as Utricularia spp., capture and digest prey. This digestion can occur through the secretion of plant digestive enzymes and/or by bacterial digestive enzymes. To comprehend the physiological mechanisms of carnivorous plants, it is essential to understand the microbial diversity related to these plants. Therefore, in the present study, we isolated and classified bacteria from different organs of Utricularia breviscapa (stolons and utricles) and from different geographic locations (São Paulo and Mato Grosso). We were able to build the first bacterium collection for U. breviscapa and study the diversity of cultivable bacteria. The results show that U. breviscapa bacterial diversity varied according to the geographic isolation site (São Paulo and Mato Grosso) but not the analyzed organs (utricle and stolon). We reported that six genera were common to both sample sites (São Paulo and Mato Grosso). These genera have previously been reported to be beneficial to plants, as well as related to the bioremediation process, showing that these isolates present great biotechnological and agricultural potential. This is the first report of an Acidobacteria isolated from U. breviscapa. The role of these bacteria inside the plant must be further investigated in order to understand their population dynamics within the host.

Keywords: Aquatic microbiota; Microbial communities; Microbial ecology; Utricularia breviscapa.

Fig. 1

Habit of Utricularia breviscapa with inflorescence (bar = 10 mm). The detail shows a stolon with utricles (arrow indicates an utricule; bar = 5 mm).

Fig. 2

Bacterial density in (A) utricles and (B) stolons of U. breviscapa from Mato Grosso (MT) and São Paulo (SP). Statistically different at p < 0.05.

Fig. 3

Dendrogram of bacterial communities associated to U. breviscapa.

Fig. 4

Phenetic trees representing the cultivable bacterial found in utricles and stolons from U. breviscapa were built using Neighbor Joining method in MEGA 5 software. (A) Isolates from Mato Grosso and (B) from São Paulo. The solid gray circles next to the tree branches correspond to bootstrap values higher than 50%. Brachyspira innocens (S000437178); Brachyspira hyodysenteriae (S000437188), Brachyspira hyodysenteriae (S000437188) and Brachyspira hyodysenteriae (S000437188) was used as outgroup.

Fig. 5

Venn diagram represented by shared UTO's of stolons (stol) and utricules (utric) of U. breviscapa from Mato Grosso (MT) and São Paulo (SP) (dissimilarity of 0.09). Therefore: utricMT: utricules from Mato Grosso, stolSP: stolons from São Paulo, utricSP: utricules from São Paulo and stolMT: stolons from Mato Grosso.

Fig. 6

Phenetic tree representing the cultivable Acidobacteria found in association with utricles of U. breviscapa from SP using Neighbor Joining method in MEGA 5 software. Numbers above the branches indicates bootstrap values. Brachyspira species were used as outgroup.