Copper and chromium exposure affect chironomid larval microbiota composition

Chironomus ramosus Larval Microbiome Composition Provides Evidence for the Presence of Detoxifying Enzymes

“…First, raw sequences were quality filtered, trimmed (maxN = 0, maxEE = 2, trimLeft = 15bp, truncLen = 150), and merged (min overlap = 8bp). Next, both runs were merged by sample (resulting in 31 fastq format files) and checked for chimeras using the DADA2 pipeline, as described in Laviad-Shitrit et al [ 8 ]. In total, for the 31 samples, 2,431,002 sequences (2423–177,570 per sample) were binned into 817 ASVs.…”

“…For DNA metagenomic sequencing, we used 100 ng genomic DNA. Sample preparation and sequencing procedures were described in Laviad-Shitrit et al [ 8 ]. Library preparation, quality control sequencing, and Nova-Seq 6000 sequencing were performed at the DNA Services Laboratory at the University of Illinois at Urbana-Champaign.…”

“…Halpern and Senderovich (2015) suggested that the diverse arsenal of bacteria that inhabit chironomids defend the insect under different stress conditions [1]. Recently, we showed that endogenous bacterial communities that inhabit C. transvaalensis support their host's survival in a toxic environment containing copper and chromium [8].…”

“…Chironomus larvae contain hemoglobin which enables them to survive at low oxygen concentrations [ 3 , 4 , 5 ]. The larvae exhibit tolerance to various toxic or stressful environmental conditions such as temperature, pH, salinity, dehydration, ultraviolet light (UV), toxic substances, and gamma radiation [ 1 , 6 , 7 , 8 , 9 , 10 ].…”

“…Here, we hypothesize that the microbial community of C. ramosus larvae plays a role in protecting its host under toxic conditions, as demonstrated for C. transvaalensis [ 6 , 8 ]. In the current study, we explored, for the first time, the microbiota composition of C. ramosus larval samples from a river and a laboratory culture from India.…”