Metagenomic analysis of lichen-associated bacterial community profiling in Roccella montagnei.

A lichen is a composite organism formed of algae or cyanobacteria that live in a mutually advantageous symbiotic relationship with the filaments (hyphae) of fungus. Three lichen samples were obtained from diverse sites at a terrestrial habitat located in Coimbatore and coastal habitats located in Kanyakumari and Nagapattinam districts of Tamil Nadu. Amplification and sequencing of 16S rRNA V3-V4 regions were used for metagenomic study. Aside from the Next-Generation Sequencing data (NGS), distinct types of lichen microbiome profiles were clearly revealed. The bacterial diversity in the lichen genera of Roccella montagnei growing in coastal and terrestrial environments was further investigated using common and unique operational taxonomic units (OTUs) and the QIIME pipeline (1.9.1). Using similarity clustering, the heat map analysis depicts the abundance information of chosen OTUs as well as the similarity and difference between OTUs and lichen samples. Using multiple methods, the alpha and beta diversity analysis revealed that there were differences in all of the samples. However, UPGMA tree inference of comparable bacterial community in coastal habitat lichen samples compared to terrestrial habitat validates their evolutionary lineage. As a result, the bacterial population associated with corticolous lichen is dependent on geographic locations, growth substrate, and climatic circumstances of similar lichen genera produced in different habitats and tree substrates.

In vitro study of trematodicidal action of Dicranopteris linearis (Burm.f.) Underw. extracts against Gastrothylax crumenifer.

The anthelmintic activity of column fractioned Dicranopteris linearis (Burm.f.) Underw. extracts was used for in vitro incubation study against adult Gastrothylax crumenifer. The qualitative analysis showed ethanol extract performed well to express 12 secondary metabolites studied except anthocyanin. Quantitative phytochemical analysis of terpenoids, phenols, flavonoids and tannins showed predominant amount of terpenoids (97.0±1.15)mg/g and tannins (30.8±0.44)mg tannic acid equivalents/gram. GC-MS analysis of fraction separated under column (Fraction V-79.5%) showed presence of QUERCETIN 7,3',4' TRIMETHOXY, a flavonoids (polyphenol derivative), PHYTOL, a diterpenoids, feren-8-ene, a triterpenoids, hexdecanoic acid, a fatty acid derivative shown to have potent anthelmintic property. 25ml of Hedon-Fleig (H-F) salt solution containing various concentrations (1, 2, 3, 4 and 5mg/ml) respectively as test extracts, Standard control Oxyclozanide @1(*)% (0.25g/25ml) and negative control H-F salt solution, distributed to 7-Petri plates in an incubator with 5% CO2 at 37°C. Twenty five amphistomes were incubated and the motility of control and drug treated flukes was observed under dissection microscope at a regular time interval of 0, 10, 15, 30min and 1hr respectively. The motility response of the parasites was categorized with specific score 3, 2, 1, 0 respectively. Relative Motility (RM) value based on mean mortality and drug concentration for analysis of Lethal Concentration (LC50) and were determined by Probit regression analysis. In vitro incubation study revealed death of all trematodes, lethal at 10min incubation time at 5mg/ml concentration, indicated RM value is 0, equivalent effective to Standard control Oxyclozanide, where RM value is 0 at 10min. Confirmative study on gross morphology, histopathology, and ultra-structural changes showed considerable effect on suckers, teguments and internal organs and were dose dependent. It is indicative that presence of terpenoids, flavonoids, tannins and phenolics which are contributing factors for anthelmintic activity, producing various degree of damage to suckers, teguments and internal organs. Hence D. linearis (Burm.f.) Underw. can be a lead for synthesis of a new trematodicidal drug as alternative for other drugs and overcome anthelmintic resistance and cost effective.