Distribution and diversity of eukaryotic microalgae in Kuwait waters assessed using 18S rRNA gene sequencing

Abstract

The microbial communities play a crucial role in ecosystem functioning through interactions among individuals and taxonomic groups in a highly dynamic marine ecosystem. The structure and functioning of the microbial communities are often influenced by the changes in the surrounding environment. Monitoring the microbial diversity of the marine ecosystem helps to understand spatial patterns of microbial community and changes due to season, climate, and various drivers of biological diversity. Kuwait is characterized by an arid environment with a high degree of temperature variation during summer and winter. Our understanding of spatial distribution patterns of microbial communities, their diversity, and the influence of human activities on the degree of changes in the diversity of the microbial community in Kuwait territorial waters remain unclear. In this study, we employed 18S rRNA sequencing to explore marine microalgal community composition and dynamics in seawater samples collected from Kuwait waters over two seasonal cycles across six locations. A total of 448,184 sequences across 36 replicates corresponding to 12 samples from six stations were obtained. The quality-filtered sequences were clustered into 1,293 representative sequences, which were then classified into different eukaryotic taxa. This study reveals that the phytoplankton community in Kuwait waters is diverse and shows significant variations among different taxa during summer and winter. Dinoflagellates and diatoms were the most abundant season-dependent microalgae taxa in Kuwait waters. Alexandrium and Pyrophacus were abundant in summer, whereas Gonyaulax was abundant during the winter. The abundance of Coscinodiscus and Navicula, of the diatom genera, were also dependent upon both seasonal and possible anthropogenic factors. Our results demonstrate the effectiveness of a sequencing-based approach, which could be used to improve the accuracy of quantitative eukaryotic microbial community profiles.

Diversity and spatiotemporal variations in bacterial and archaeal communities within Kuwaiti territorial waters of the Northwest Arabian Gulf

“…members of Rhodobacteraceae has also been linked with algal biofilms, which are commonly found in Kuwaiti waters [45,57]. This is further corroborated by the presence of Synechococcus, a genus of cyanobacterial origin [58].…”

“…Despite the demonstrated significance of shotgun metagenomic approaches, there have been very limited studies in the past involving community-level profiling of microbial communities within the Kuwaiti environment. Previous studies on the marine environment in Kuwait involved the use of DNA fingerprinting to examine the spatiotemporal diversity of bacterioplankton [42], sequencing of 16S rRNA to identify resident bacteria [43,44], sequencing of 18S rRNA to assess distribution and diversity of eukaryotic microalgae [45] and resistome profiling of polluted marine sediments [46]. Importantly, marine bioprospecting efforts in the…”

Does the microbial community play a role in the different colour morphs of the breadcrumb sponge Halichondria panicea?

“…To study the whole eukaryotic microorganisms in sponge samples, the V4 hypervariable region of the 18S rRNA gene was chosen for sequencing. The best primer set was selected by comparing primers used in different studies (Choi et al 2020;Fadeev et al 2018;Ferreira and Cleary 2022;Konstantinou et al 2020a;Kumar et al 2021) using the PR2 primer database (https://app.pr2-primers.org/pr2-primers/) and choosing the set with the higher percentage of amplified sequences of most of the chlorophyll-containing eukaryotes. Therefore, the general eukaryotic primers TAReuk454FWD1 (5′-CCAGCASCYGCGGTAATTCC-3′) and TAReu-kREV3 (5′-ACTTTCGTTCTTGATYRA-3′) (Stoeck et al 2010) were chosen for this study.…”

Unlocking the richness of microalgae biodiversity for potential applications

“…Metagenomics involves the direct study of genomes in their natural habitat without isolation, and this is made possible due to the development of next-generation sequencing. Samples can be either directly used for DNA extraction, such as soil samples or water samples can be filtered with the appropriate filter paper followed by DNA extraction, and samples can be sequenced using Illumina MiSeq™ and HiSeq™ platform [186,[196][197][198]. Next-generation sequencing provides the best tool to identify the highest microalgal diversity from environmental samples; however, similar to any DNA-based tool, it depends on the sequences available in the database and is not usually combined with single species isolation.…”