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Bacterial symbionts are essential components of healthy biological systems. They are increasingly recognized as important factors in the study and management of threatened species and ecosystems. Despite management shifts at the ecosystem level, microbial communities are often neglected in discussions of holobiont conservation in favor of the primary members of a symbiosis. In this study, we addressed the bacterial community knowledge gap for one of two federally endangered lichen species in the United States, Cetradonia linearis (Cladoniaceae). We collected 28 samples of the endangered rock gnome lichen (Cetradonia linearis) from 13 sites and characterized bacterial communities in thalli using 16S rRNA metabarcoding to investigate the factors influencing the microbiome composition and diversity within the thallus. We found that Proteobacteria (37.8% ± 10.3) and Acidobacteria (25.9% ± 6.0) were the most abundant phyla recovered. Cyanobacteria were a major component of the microbiome in some individuals, despite this species associating with a green algal symbiont. Habitat, climate, and geography were all found to have significant influences on bacterial community composition. An analysis of the core microbiome at a 90% threshold revealed shared amplicon sequence variants in the microbiomes of other lichens in the family Cladoniaceae. We concluded that the bacterial microbiome of Cetradonia linearis is influenced by environmental factors and that some bacterial taxa may be core to this group. Further exploration into the microbiomes of rare lichen species is needed to understand the importance of bacterial symbionts to lichen diversity and distributions. 

Western palearctic salamander susceptibility to the skin disease caused by the amphibian chytrid fungusBatrachochytrium salamandrivorans(Bsal) was recognized in 2014, eliciting concerns for a potential novel wave of amphibian declines following theB. dendrobatidis(Bd) chytridiomycosis global pandemic. Although Bsal had not been detected in North America, initial experimental trials supported the heightened susceptibility of caudate amphibians to Bsal chytridiomycosis, recognizing the critical threat this pathogen poses to the North American salamander biodiversity hotspot. Here, we take stock of 10 years of research, collaboration, engagement, and outreach by the North American Bsal Task Force. We summarize main knowledge and conservation actions to both forestall and respond to Bsal invasion into North America. We address the questions: what have we learned; what are current challenges; and are we ready for a more effective reaction to Bsal’s eventual detection? We expect that the many contributions to preemptive planning accrued over the past decade will pay dividends in amphibian conservation effectiveness and can inform future responses to other novel wildlife diseases and extreme threats. 

Abstract Lactobacillaceae are an important family of lactic acid bacteria that play key roles in the gut microbiome of many animal species. In the honey bee (Apis mellifera) gut microbiome, many species of Lactobacillaceae are found, and there is functionally important strain-level variation in the bacteria. In this study, we completed whole-genome sequencing of 3 unique Lactobacillaceae isolates collected from hives in Virginia, USA. Using 107 genomes of known bee-associated Lactobacillaceae and Limosilactobacillus reuteri as an outgroup, the phylogenetics of the 3 isolates was assessed, and these isolates were identified as novel strains of Apilactobacillus kunkeei, Lactobacillus kullabergensis, and Bombilactobacillus mellis. Genome rearrangements, conserved orthologous genes (COG) categories and potential prophage regions were identified across the 3 novel strains. The new A. kunkeei strain was enriched in genes related to replication, recombination and repair, the L. kullabergensis strain was enriched for carbohydrate transport, and the B. mellis strain was enriched in transcription or transcriptional regulation and in some genes with unknown functions. Prophage regions were identified in the A. kunkeei and L. kullabergensis isolates. These new bee-associated strains add to our growing knowledge of the honey bee gut microbiome, and to Lactobacillaceae genomics more broadly.