Bacterial diversity in Icelandic cold spring sources and in relation to the groundwater amphipod Crangonyx islandicus

Abstract

Crangonyx islandicus is a groundwater amphipod endemic to Iceland, considered to have survived the Ice Ages in subglacial refugia. Currently the species is found in spring sources in lava fields along the tectonic plate boundary of the country. The discovery of a groundwater species in this inaccessible habitat indicates a hidden ecosystem possibly based on chemoautotrophic microorganisms as primary producers. To explore this spring ecosystem, we assessed its microbial diversity and analysed whether and how the diversity varied between the amphipods and the spring water, and if was dependent on environmental factors and geological settings. Isolated DNA from spring water and from amphipods was analysed using metabarcoding methods, targeting the 16S rRNA gene. Two genera of bacteria, Halomonas and Shewanella were dominating in the amphipod samples in terms of relative abundance, but not in the groundwater samples where Flavobacterium, Pseudomonas and Alkanindiges among others were dominating. The richness of the bacteria taxa in the microbial community of the groundwater spring sources was shaped by pH level and the beta diversity was shaped by geographic locations.

Epidemiology of Fusarium oxysporum causing root and crown rot of cannabis (Cannabis sativa L., marijuana) plants in commercial greenhouse production

“…Sphingobium spp. have been previously detected from biofilms in public water municipal systems (Koskinen et al 2000;Gulati and Ghosh 2017), in tap water (Yun et al 2016) and in natural spring water (Guðmundsdóttir et al 2019). Interestingly, some samples of dried harvested flowers (buds) of cannabis were found to be contaminated with a Sphingobium sp.…”

Bacterial communities at a groundwater‐surface water ecotone: gradual change or abrupt transition points along a contamination gradient?

“…Bacteria were extracted from a 250‐ml water sample taken into a sterile plastic bottle at each site. Such a sample likely represents unattached allochthonous groundwater bacteria that are largely independent of aquifer biofilm communities, and should therefore represent optimal microbial indicators for contamination of groundwater‐dependent ecosystems (Scharping and Garey 2021; see also Guðmundsdottir et al ., 2019). Samples were filtered with sterilized 0.2 μm MicroFunnel™ Disposable Filter Funnels and extracted with Qiagen's Dnase PowerWater DNA Isolation Kit following the manufacturer's recommendations.…”

A deep continental aquifer downhole sampler for microbiological studies

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