Biological activities of Sarcanthus pauciflorus.

Sarcanthus pauciflorus is a pendulous epiphytic orchid belonging to the family Orchidaceae. The present study was conducted to determine antimicrobial, antioxidant, anthelmintic and insecticidal efficacy of methanol extract of S. pauciflorus. Antimicrobial activity of methanol extract was determined against four bacteria and two fungi by Agar well diffusion method. Antioxidant activity was performed by DPPH free radical scavenging and Ferric reducing assay. Anthelmintic activity was studied on the basis of time taken for paralysis and death of adult Indian earthworms by the extract. Insecticidal activity, in terms of larvicidal effect, was evaluated using II instar larvae of Aedes aegypti. Total phenolic content of extract was estimated by Folin-Ciocalteau reagent assay. Phytoconstituents viz., tannins, saponins and glycosides were detected in methanol extract. Content of total phenolics was found to be 258.65 mg GAE/g of extract. All test bacteria and fungi were susceptible to extract of orchid. Bacillus subtilis and Cryptococcus neoformans were susceptible to high extent among bacteria and fungi respectively. Gram positive bacteria have shown greater susceptibility than Gram negative bacteria to extract. The extract exhibited marked dose dependent scavenging of DPPH free radicals. An increase in absorbance at 700nm revealed reducing power of the extract. The extract caused paralysis and death of adult Indian earthworms in a dose dependent manner. The lethal effect of extract on II instar larvae of Aedes aegypti was found to be dose dependent. The results of the present study shows that the methanol extract of S. pauciflorus is found to possess antimicrobial, antioxidant, anthelmintic and insecticidal activities which might be attributed to the presence of secondary metabolites. Further experimentations concerned with isolation of the bioactive components present in the orchid and determination of their biological activities are under progress.

Studies on Oecophylla smaragdina as a bio-control agent against pentatomid bug infesting on Pongamia tree.

Weaver ants, (Oecophylla smaragdina) have been found to predate on pentatomid bug (Cyclopelta siccifolia) infesting Pongamia pinnata tree in mid-western Ghat region of Shimoga district, Karnataka. The present study was undertaken to evaluate the potential of weaver ants, that are abundant on P. pinnata trees, to control the pentatomid bugs. Consistent and systematic field surveillance was carried out for a period of two months, March and July 2010. This showed that the number of pentatomid bugs colony found on branches of tree was significantly lower in tree with abundant weaver ants (11.21-16.84%) than in trees with fewer weaver ants (26.51-38.24%), or in trees without ants (61.42-75.47%) similarly, the branches damaged by pentatomid bug (9.42-11.43%) their in trees with abundant weaver ants which was significantly lower than in trees with fewer weaver ants (16.13-23.24%) and without ants (38.42-51.47%) in March and July. The pentatomid bug colony and their damage was significantly low on trees with abundant weaver ants than with fewer ants, or without the ants. Field observations regarding infestation of pentatomid bugs revealed that weaver ants are effective naturally occurring biological agents help in controlling damage caused by pentatomid bugs on Pongamia trees.

Avifaunal diversity of Anekere wetland, Karkala, Udupi district, Karnataka, India.

The avifaunal diversity and density in Anekere wetland, Karkala, Udupi district, Karnataka, India, was studied for a period of three years. Anekere pond inhabits several local and migratory bird species. Reduction in water retention in this pond in summer, weed infestation, variations in food availability in different seasons and threat of predation on the breeding activity of birds affected the avifauna diversity in the study area. This habitat attracted 44 bird species, which are local and migratory including aquatic birds, waders and others. Highest population of tree ducks (lesser whistling teal) was recorded in all the three years of study. Other prominent residents were Moorhens, Jacanas, Herons and Cormorants. The visitors include ringed plovers, wagtails and storks. It was evident that purple moorhen and tree ducks have developed high tolerance to this highly fluctuating habitat and human activity.

Phytotoxicity of cadmium on the physiological dynamics of Salvinia natans L. grown in macrophyte ponds.

The objective of this experiment is to study the potential ability of Salvinia natans L. to use in phytoassay for the cadmium toxicity in ecotoxicological studies. It is a simple and cost competitive method. The sensitivity of S. natans in terms of biochemical changes and enzyme activities to Cd2+ was remarkably noticeable. The catalase and protease activity was significantly decreased in the presence of cadmium, with increase of peroxidase and superoxide dismutase activity. The level of protein, carbohydrate and chlorophyll decreased and proline content increased in plants. The maximum permissible concentration of cadmium in different general water quality standards was evaluated and found that cadmium standard is not stringent enough.

Biodiversity of algae and protozoa in a natural waste stabilization pond: a field study.

A field study was carried out on the biodiversity of protozoa and algae from a natural waste stabilization pond during November, 1996 to April, 1997. The raw waste and pond samples were analysed for physico-chemical and biological parameters. High dissolved oxygen (DO) coinciding with phytoplankton peak was recorded. The algae--Chlorella vulgaris, Scenedesmus acuminatus, Oscillatoria brevis and Nostoc piscinale and Protozoa--Paramecium caudatum, Acanthamoeba sp., Bodo saltans and Oikomonas termo were obvious as dominant species, whereas algae Ochromonas pyriformis and Synura uvella and protozoa, Didinium masutum and Stentor coerulus were noted as rare species. Totally 71 species of algae and 13 species of protozoa were identified.

Combined treatment of chemical, pharmaceutical and cosmetic industrial effluents by waste stabilization ponds.

Influent and final effluent was collected from the CMM Ltd., Bethora, Ponda, Goa and were analysed for pH, DO, BOD, enzyme activity and chlorophyll content of the waste stabilization pond for over a period of two years of which the data for one year (pre monsoon, monsoon and post monsoon periods) is given. The study revealed that the DO was maximum during the pre-monsoon months and least during the monsoon. Maximum removal of BOD and phosphate was observed during the pre-monsoon periods. Enzymatic activity was at its peak during the monsoons than during the other months. Chlorophyll content was maximum during the pre-monsoon months due to increased growth of phytoplankton as the conditions were favourable for their growth. Also depending on the concentration of different chlorophyll pigments, one can come to know the different groups of algae inhabiting the stabilization ponds.

Indirect enzyme-linked immunosorbent assay (ELISA) for monitoring antibodies in rainbow trout Oncorhynchus mykiss.

An indirect enzyme-linked immunosorbent assay (ELISA) has been described to detect and measure the antibodies in O. mykiss against a lambda bacteriophage antigen (strain c1187 Sam7). Antibodies were first detected six days after the first intraperitoneal injection and by day 21 all fish were positive. Maximum mean titres were detected on day 30 (3 days after the second injection). The mean titre declined by day 33 which was 6 days after second injection and remained constant from day 39 to day 45. The results suggest that immune response in a rainbow trout occurred faster and the fish were able to mount a very good response to viruses.