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In this study therapeutic potential of fucoidan fraction-2 (Fu-F2) isolated from Sargassum polycystum was evaluated for the development of antibacterial agent against the human and animal pathogenic bacteria by in vitro and in vivo analysis. The Fu-F2 contained 51.12 ± 0.86% of total sugar and 20.41 ± 0.91% of sulfate. The structural characterization of Fu-F2 was performed by HPLC, FTIR and NMR analysis and reported in our earlier study. The in vitro antibacterial assays such as MIC, MBC, killing kinetics, disk diffusion, protein leakage, ROS and confocal laser scanning microscopy demonstrate that Fu-F2 possesses the highest antibacterial activity against the tested pathogens. Among the tested pathogens, the highest antibacterial activity (21 ± 1.0 mm) was recorded at the concentration of 50 μg/ml against Pseudomonas aeruginosa and the lowest activity (16 ± 0.53 mm) was registered against Staphylococcus aureus. In the in vivo analysis, the pre-treatment group with Fu-F2 at the concentration of 15 mg/0.1 kg through feed exhibited the highest survival (83.4%) and antioxidant activities (p 0.05) than the fish infected with pathogen. Thus, the present findings suggest that the Fu-F2 of S. polycystum encompasses significant antibacterial properties and that can be used as a therapeutic agent for controlling the bacterial disease.

We surveyed 130 shrimp farms located on the eastern coast of India to determine the prevalence of emerging diseases in Litopenaeus vannamei and Penaeus monodon. Live shrimps were collected from the farms based on external symptoms. The biochemical, molecular, and histopathology results confirmed infection with Enterocytozoon hepatopenaei (32.4%), Vibrio parahaemolyticus (27.7%), White Spot Syndrome Virus (25.4%), Vibrio alginolyticus (16.1%), Vibrio harveyi (13.1%), Monodon-type baculovirus (4.61%), and infectious Hematopoietic Necrosis Virus (2.3%) in the collected shrimps. Enterocytozoon hepatopenaei (EHP) occurred more frequently in L. vannamei than P. monodon, with the microsporidian spores in the hepatopancreas. In P. monodon, Monodon-type Baculovirus infection (33.3%) was dominant and small percentages of WSSV, IHHNV, V. alginolyticus, and V. harveyi were observed. A few ponds were observed with co-infection of EHP and WSSV (7.6%), V. parahaemolyticus and WSSV (4.6%) and also V. parahaemolyticus and EHP (6.1%). Among the Vibrio spp, V. parahaemolyticus showed the highest percentage of infection in L. vannamei. Overall, we found that shrimp were chiefly infected with EHP and V. parahaemolyticus. The impact of water quality parameters on shrimp diseases was not addressed in this study. In an antibiotic susceptibility study, V. parahaemolyticus isolated from L. vannamei ponds was susceptible to nitrofurantoin, chloramphenicol, oxytetracycline and tetracycline, but resistant to erythromycin and nalidixic acid. In a preliminary in vitro antibacterial activity assay, probiotics against V. parahaemolyticus showed high inhibitory activity and the results encourage further in-depth studies on the efficacy of probiotics for disease control and prevention in shrimp farms.

In this study, the biosynthesis of platinum nanoparticles (Hd-PtNPs) from red algae Halymenia dilatata and its broad spectrum of bioactivities were explored. The synthesized Hd-PtNPs were characterized by UV–visible spectroscopy, X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), high-resolution transmission electron microscope (HR-TEM), and dynamic light scattering (DLS) analysis. The XRD results showed that the synthesized particles were pure crystalline while the FE-SEM and HR-TEM analysis demonstrated that the Hd-PtNPs were spherical and well-dispersed with an average size of 15 ± 1.7 nm. The zeta potential of Hd-PtNPs was found to be −19.9 mV, which indicates that the synthesized particles were highly stable and well-dispersed. The presence of phytochemical constituents in the H. dilatata aqueous extract performs a capping and reducing process in the Hd-PtNPs formation, which was confirmed by FT-IR analysis. The synthesized Hd-PtNPs showed excellent antioxidant properties in DPPH radical scavenging, reducing power, and total antioxidant assays. Furthermore, Hd-PtNPs exhibit a strong cytotoxic effect against MDA-MB-231 cancer cell lines (IC50 = 50 μg/mL). Moreover, the Hd-PtNPs showed notable inhibitory activity against Gram-positive (Streptococcus pneumonia) and Gram-negative bacteria (Aeromonas hydrophila). In addition, Hd-PtNPs display less toxicity effect on Artemia nauplii even at a higher concentration corroborating the fact that the synthesized Hd-PtNPs are eco-friendly. Thus, Hd-PtNPs can be used as an alternative source in pharmaceutical and biomedical applications.

Hepatopancreatic microsporidiosis in cultivated Litopenaeus vannamei and Penaeus monodon is caused by the newly emerged pathogen Enterocytozoon hepatopenaei (EHP). It has been detected in shrimp cultured in China, Vietnam and Thailand and is suspected to have occurred in Malaysia and Indonesia and to be associated with severely retarded growth. Due to retarded shrimp growth being reported at farms in the major grow-out states of Tamilnadu, Andhra Pradesh and Odisha in India, shrimp were sampled from a total of 235 affected ponds between March 2014 and April 2015 to identify the presence of EHP. PCR and histology detected a high prevalence of EHP in both P. monodon and L. vannamei, and infection was confirmed by in situ hybridization using an EHP-specific DNA probe. Histology revealed basophilic inclusions in hepatopancreas tubule epithelial cells in which EHP was observed at various developmental stages ranging from plasmodia to mature spores. The sequence of a region of the small subunit rDNA gene amplified by PCR was found to be identical to EHP sequences deposited in GenBank. Bioassays confirmed that EHP infection could be transmitted orally to healthy shrimp. Histology also identified bacterial co-infections in EHP-infected shrimp sampled from slow-growth ponds with low-level mortality. The data confirm that hepatopancreatic microsporidiosis caused by EHP is prevalent in shrimp being cultivated in India. EHP infection control measures thus need to be implemented urgently to limit impacts of slowed shrimp growth.

The present study investigated the sources for remediation of heavy metals and salts from tannery effluent using salt marsh halophyte Sesuvium portulacastrum. From the results observed, in tannery effluent treated soil from 1 kg dry weight of plant sample, Sesuvium portulacastrum accumulated 49.82 mg Cr, 22.10 mg Cd, 35.10 mg Cu and 70.10 mg Zn and from 1 g dry weight of the plant sample, 246.21 mg Na Cl. Cultivation of Sesuvium portulacastrum significantly reduced the EC, pH and SAR levels in tannery effluent and salt treated soil and correspondingly increased in plant sample after 125 days of cultivation. In conclusion, Sesuvium portulacastrum was an efficient in accumulating heavy metals such as Chromium, Cadmium, Copper and Zinc, sodium and chloride maximum through its leaves when compared to stem and root. The finding of these bioacccumulation studies indicates that Sesuvium portulacastrum could be used for phytoremediation of tannery effluent contaminated field.

Present study perceives that textile dye effluents of Erode, Pallipalayam and Bhavani region have substantial volume of EC, pH, TDS, COD, BOD, Sodium Chloride, Calcium, Magnesium, Potassium and heavy metals. Results point out that irrespective of the source, effluent properties exceeded permissible limits by WHO/ FAO/Federal Environmental Protection Agency for irrigation. The textile industry consumes a mixture of chemicals and huge amount of water during the production process. About 200 L of water are used to produce 1 kg of textile. The textile effluent can cause several health infections like haemorrhage, ulceration of skin, nausea, skin irritation and dermatitis.

We assessed the arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal associations in 57 ferns and 3 lycophytes (belonging to 15 families in 39 genera) of different life forms (epiphytic, saxicolous and terricolous) occurring in Palni Hills of Western Ghats. Fungal symbiosis was absent in all the three lycophytes examined. Fifty-five of the 57 ferns (91.66 %) examined had AM and 37 (64.91 %) had DSE fungal association. This is the first report on AM and DSE fungal association for 22 and 30 species, respectively. In addition, AM morphology was evaluated for the first time in 34 species. Sixty-five percentage of the mycorrhizal ferns had intermediate-type AM and 19.30 % had typical Paris-type AM morphology. Both Paris- and intermediate-type AM morphologies were observed in 10.53 % of ferns. The root length colonized by AM and DSE fungal structures significantly varied among species, and a significant negative relation existed between the root length colonized by AM and DSE fungi.

Numerous studies have focused on the medicinal properties of angiosperms; however, only limited amount of studies have explored the medicinal potentials of fern and fern allies. The present study focuses on the ethnomedicinal values of fern and fern allies that are traditionally used by the tribal people of Palani hills in South India through a survey of the area. In the present study, information on 50 species belonging to 35 genera in 19 families were recorded for their medicinal values with their botanical name, family, habitat, and manner of using recipes have been recorded.