Symbionts of Ciliates and Ciliates as Symbionts.

Endosymbiotic relationships between ciliates and others are critical for their ecological roles, physiological adaptations, and evolutionary implications. These can be obligate and facultative. Symbionts often provide essential nutrients, contribute to the ciliate's metabolism, aid in digestion, and offer protection against predators or environmental stressors. In turn, ciliates provide a protected environment and resources for their symbionts, facilitating their survival and proliferation. Ultrastructural and full-cycle rRNA approaches are utilized to identify these endosymbionts. Fluorescence in situ hybridization using "species- and group-specific probes" which are complementary to the genetic material (DNA or RNA) of a particular species or group of interest represent convenient tools for their detection directly in the environment. A systematic survey of these endosymbionts has been conducted using both traditional and metagenomic approaches. Ciliophora and other protists have a wide range of prokaryotic symbionts, which may contain potentially pathogenic bacteria. Ciliates can establish symbiotic relationships with a variety of hosts also, ranging from protists to metazoans. Understanding ciliate symbiosis can provide useful insights into the complex relationships that drive microbial communities and ecosystems in general.

DNA barcoding, an effective tool for species identification: a review.

DNA barcoding is a powerful taxonomic tool to identify and discover species. DNA barcoding utilizes one or more standardized short DNA regions for taxon identification. With the emergence of new sequencing techniques, such as Next-generation sequencing (NGS), ONT MinION nanopore sequencing, and Pac Bio sequencing, DNA barcoding has become more accurate, fast, and reliable. Rapid species identification by DNA barcodes has been used in a variety of fields, including forensic science, control of the food supply chain, and disease understanding. The Consortium for Barcode of Life (CBOL) presents various working groups to identify the universal barcode gene, such as COI in metazoans; rbcL, matK, and ITS in plants; ITS in fungi; 16S rRNA gene in bacteria and archaea, and creating a reference DNA barcode library. In this article, an attempt has been made to analyze the various proposed DNA barcode for different organisms, strengths & limitations, recent advancements in DNA barcoding, and methods to speed up the DNA barcode reference library construction. This study concludes that constructing a reference library with high species coverage would be a major step toward identifying species by DNA barcodes. This can be achieved in a short period of time by using advanced sequencing and data analysis methods.

Soil ciliates of the Indian Delhi Region: Their community characteristics with emphasis on their ecological implications as sensitive bio-indicators for soil quality.

The present investigation aims to study the diversity of ciliates from different habitats in and around Delhi, India, and the correlation of this diversity with soil quality {agricultural lands (site 1 and 2), dump yards (site 3 and 4), sewage treatment plant (site 5), residential land (site 6), landfill (site 7) and barren land (site 8)}. Various physicochemical parameters of the different soil samples were studied and analysed for soil texture, interstitial water, pH, conductivity, total organic carbon, total organic matter, total nitrogen and phosphorous content, using standard protocols. Seventeen ciliate taxa belonging to four classes, seven orders, ten families, and 17 genera were recorded, with the maximum number of species (eleven) belonging to the class Spirotrichea. Ciliate diversity was highest at sites 5 and 6 and lowest at sites 1 and 2. Spathidium sp. was the dominant species in the conditioned land (site 8), while the ciliate Colpoda sp. was present in all the sites examined, showing the highest population density in the sewage treatment plant site (site 5). Statistical analysis showed that ciliate diversity was positively correlated to physicochemical parameters such as interstitial water, total organic matter and organic carbon, total nitrogen and total phosphorous content. Analyses of spirotrichs/colpodids (S/C) ratio and diversity indices implied that the habitat conditions of sites 1, 2, 3 and 8 are relatively unfavourable for soil ciliates to flourish; while sites 4, 5, 6 and 7 provided more favourable conditions. The ubiquity of ciliate distribution suggests their important role in the soil food webs and nutrient cycling, and their community structure and specific characteristics appear to be of major importance for soil formation. A full understanding of soil ciliate diversity and physicochemical parameters helps to inform best practice for improving soil quality as well as conservation practices for sustainable development and management of farms and cultivated lands. In conclusion, ciliate diversity serves as an important and sensitive bio-indicator for soil quality.