Defence of Agaricus bisporus against toxic secondary metabolites from Trichoderma aggressivum.

Trichoderma spp are effective competitors against other fungi because they are mycoparasitic and produce hydrolytic enzymes and secondary metabolites that inhibit the growth of their competitors. Inhibitory compounds produced by Trichoderma aggressivum, the causative agent of green mold disease, are more toxic to the hybrid off-white strains of Agaricus bisporus than the commercial brown strains, consistent with the commercial brown strain’s increased resistance to the disease. This project looked at the response of hybrid off-white and commercial brown strains of A. bisporus to the presence of T. aggressivum metabolites with regard to three A. bisporus genes: laccase 1, laccase 2, and manganese peroxidase. The addition of T. aggressivum toxic metabolites had no significant effect on MnP or lcc1 transcript abundance. Alternatively, laccase 2 appears to be involved in resistance to T. aggressivum because the presence of T. aggressivum metabolites results in higher lcc2 transcript abundance and laccase activity, especially in the commercial brown strain. The difference in laccase expression and activity between A. bisporus strains was not a result of regulatory or coding sequence differences. Alteration of laccase transcription by RNAi resulted in transformants with variable levels of laccase transcript abundance. Transformants with a low number of lcc transcripts were very sensitive to T. aggressivum toxins, while those with a high number of lcc transcripts had increased resistance. These results indicated that laccase activity, in particular that encoded by lcc2, serves as a defense response of A. bisporus to T. aggressivum toxins and contributes to green mold disease resistance in commercial brown strains.

Polycyclic aromatic hydrocarbons and toxic trace metals in seawater and sediments from the west coast of India and their bioaccumulation in some selected species of fishes

Polycyclic Aromatic Hydrocarbons and other toxic compounds from industrial effluents are noted for their high potency for skin, lung, bladder and gastrointestinal cancers. Increased industrialization, and population growth led to greater production of wastes, Pesticides and PAHs have received attention due to their carcinogenic effects. The main objectives of the study were; to collect base line data on the concentration of PAHs in seawater and sediment from the west coast of India, the concentration of PAHs in certain species of fishes, the comparative levels of PAHs in fish, the influence of sediment characteristics on the concentration of PAH in sediment, changes in PAH concentration in water, sediment and fish, to provide a base line concentration of trace metals in water, sediment and fish, the seasonal changes in content of selected trace metals in water, sediment and fish from the west coast of India. The present study revealed that a predominance of silt and clay at all stations in the off Cochin area. The study has provided comprehensive information available to date for PAHs in seawater, sediment and fishes from the west cost of India especially from the Quilon to Mangalore region.

Studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab Scylla serrata (Forskal)

This thesis Entitled studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab scylla serrata (Forskal). Evaluate the toxicity of three sub lethal concentrations of mercury, viz., 0.009 mg/l, 0.02 mg/1, and 0.04 mg/l on the mud crab, Scylla serrata through bioaccumulation, and depuration studies. To characterize the biochemical responses to the sub-lethal stress of mercury in chelate muscles, abdominal muscles, hepatopancreas and gills. To study the activity pattern of acid and alkaline phosphatases in mercury-exposed crabs. To evaluate the induced changes in these tissues through histopathological studies,The Cochin backwaters is one of the most productive and biologically active backwater systems, and is the habitat of varieties of fishes, mollusks, and crustaceans, though this water body also receives tons of effluents from factories located on the banks of the river, Periyar.To study the activity levels of acid and alkaline phosphatases in crabs, at three time periods, exposed to three sub lethal concentration of mercury,

Studies on the toxic effects of somepesticides on the fish etroplus maculatus

The present study involved investigation of the lethal and sublethal effects of three pesticides individually. The pesticides are the commercial formulations of DDT (organochlorine).Dime— cron (organophosphate) and Gramoxone (paraquat dichloride).Aspects like individual toxicity, modulations in the activities of some selected enzymes, consequent to exposure to sub lethal levels of pesticides, sub lethal effects onperipheral haematology and alterations caused on the tissue architecture of brain, gills and liver, have been documented. Attempts have been made to analyse the impact of pesticides, added at realistic Levels to the experimental media, on the life and activity of Etroplus maculatus

Combined toxic effects of oil and pesticides on selected marine invertebrates

In recent years, pollution in general and sea water pollution in particular, has become an important topic for national and international considerations. Because of its impact on society, marine pollution has attracted great attention from politicians, administrators, natural scientists and technologists all over the world. To save our environment from further deterioration, it is essential to have an assessment of this problem This thesis involves investigation of the lethal and sub lethal effects of four pesticides and two petroleum oil, individually and in combinations on two commercially important bivalves. Among the four pesticides used two are organophosphates and the other two are organochlorines. Synthetic Pesticides, especially organophosphates and organochlorines have become increasingly important additions to chemical wastes polluting natural aquatic Communities special attention is given in the present investigation to delineate the combined toxic effect of oil and pesticides. The results are presented under different sections to make the presentation meaningful.

Effect of some toxic metals on selected phytoplankton of Kerala water

The extraction and use of metals has been the mainstay for the sustained development and progress of a nation. Metals, though fairly stable in the natural environment are found in trace quantities in water bodies. Attention has therefore been focused to identify the metals that impair the water quality. In the last few decades the concern about the fate of these metals in the aquatic system has been gaining momentum, particularly in the industrial belts. The disasters caused by metal poisoning in recent times have prompted an indepth study of the interaction of metals with aquatic biota. Kerala, basically an agriculture oriented state has witnessed the upsurgence of various industries as a part of the nationwide economic development programme. Cochin has been identified as the industrial capital of the state.The present study is an attempt towards a better understanding of the metal-phytoplankton interactions with special reference to the physiological changes in the species. various parameters such as temperature, salinity, pH, nutrients, number of cells, photosynthetic pigments, carbohydrates, protein and lipid are studied to highlight the complexity of metal..phytoplankton interaction

Studies on the toxic effects of selected heavy metals in the freshwater mussel lamellidens corrianus (lea)

Industrialisation affects air, water, and soil. Industrial effluents which enter the aquatic environment either by direct disposal or through run off, affect living organisms at morphological and physiological levels. In any living tissue toxic materials exert their effects first at molecular and biochemical levels (Robbins and Angell, 1976). Most of the industrial effluents contain elevated concentrations of organic and inorganic chemicals capable of eliciting stimulatory or inhibitory effects on the metabolism of aquatic organisms. Heavy metals form an important group of environmental pollutants. Effects of pollution on the aquatic environment by heavy metals have received considerable attention in recent years due to their toxicity even at very low levels, persistence in the environment, and chances of getting biomagnified. A pollutant that does not affect a particular process under normal unstressed condition may affect the ability of the animal to adjust to changing environmental conditions which ultimately decrease its chances of survival (Thurberg et al., 1973

Investigations on Longline Fishing in Lakshadweep Sea with special reference to Bycatch Issues Bait and Hook Selectivity

The main objectives of the present study have been studies on the operational performance of tuna longline in Lakshadweep Sea studies on the efficiency of hooks in the longline operation studies on the efficiency of baits in the longline operation studies on bycatch in longline operation studies on predation on the longline catch and the hook loss encountered during the fishing operation

Toxic Metal Distribution in the Core Sediment of Cochin Estuarine System (CES)

This article present the result from a study of two sediment cores collected from the environmentally distinct zones of CES. Accumulation status of five toxic metals: Cadmium (Cd), Chromium (Cr), Cobalt (Co), Copper (Cu) and Lead (Pb) were analyzed. Besides texture and CHNS were determined to understand the composition of the sediment. Enrichment Factor (EF) and Anthropogenic Factor (AF) were used to differentiate the typical metal sources. Metal enrichment in the cores revealed heavy load at the northern (NS1 ) region compared with the southern zone (SS1). Elevation of metal content in core NS1 showed the industrial input. Statistical analyses were employed to understand the origin of metals in the sediment samples. Principal Component Analysis (PCA) distinguishes the two zones with different metal accumulation capacity: highest at NS1 and lowest at SS1. Correlation analysis revealed positive significant relation only in core NS1, adhering to the exposition of the intensified industrial pollution

An??lisis bibliom??trico sobre evaluaci??n de programas y comunidades terap??uticas para la rehabilitaci??n de toxic??manos

Analizar el estado de la cuesti??n sobre trabajos que se han realizado para evaluar programas y comunidades terap??uticas orientadas a la rehabilitaci??n de toxic??manos. Consulta de 7 bases de datos que facilitaron el acceso a 14 revistas, en su mayor??a estadounidenses. En total, se consultan 166 registros referidos al objeto de estudio. Se parte de una fundamentaci??n te??rica y metodol??gica sobre estudios bibliom??tricos y de una b??squeda de referencias bibliogr??ficas sobre evaluaci??n de programas y comunidades terap??uticas para la rehabilitaci??n de toxic??manos en las bases de datos pertinentes. Seguidamente se hace un an??lisis de documentos en el cual se identifican diversas variables: a) Referentes a los datos propios del documento (autor, a??o, t??tulo...); b) Referentes a la estructura interna del documento (tipo de evaluaci??n, finalidad, dise??o, muestra...); c) Referentes a los resultados y/o conclusiones obtenidas (puntos fuertes y d??biles, recomendaciones...). Adem??s de ello, se tienen en consideraci??n indicadores de productividad e indicadores de colaboraci??n. Se ha utilizado una parrilla de an??lisis construida 'ad-hoc' y tambi??n una serie de indicadores bibliom??tricos. Esta parrilla est?? estructurada en tres unidades de an??lisis compuestas por un n??mero determinado de variables. La codificaci??n de la informaci??n de tipo cuantitativo se hace a trav??s del programa inform??tico SPSS, el cual permite obtener estad??sticos de cada variable. El an??lisis cualitativo se realiza mediante el procedimeitno de an??lisis de contenido. Destacan, entre otras: a) La mayor??a de los trabajos analizados est??n realizados en colaboraci??n; b) La producci??n de trabajos desde 1984 hasta 1997 permanece uniforme, en 1998 se observa un punto de inflexi??n que corresponde con un aumento de los trabajos publicados y que dura hasta 2004; c) La mayor??a de los trabajos son realizados en USA debido a la mayor tradici??n evaluadora que existe en ese pa??s y el mayor n??mero de recursos existentes para financiar y publicar las evaluaciones realizadas; d) El tipo de documento m??s utilizado es el art??culo de revista; e) La mayor parte de los trabajos est??n realizados en contexto p??blico y con financiaci??n de la administraci??n; f) Todos los trabajos revisados contemplan una revisi??n bibliogr??fica; g) La mayor parte de los trabajos se refieren a la teor??a o modelo de evaluaci??n del que parten de un modo impl??cito; h) El tipo de evaluaci??n m??s empleada es la 'sumativa, expost, externa'; i) La finalidad de la mayor??a de los trabajos es 'verificar', tanto si se cumplen los objetivos planteados por el programa evaluado, como si se cumplen las hip??tesis de evaluaci??n planteadas que hacen referencia a alg??n resultado deseado; j) La metodolog??a empleada en los dise??os es en su mayor parte cuasiexperimental; k) El sistema de control m??s utilizado es el control reflexivo, es decir, menciones sobre un mismo grupo; l) Las t??cnicas e instrumentos de recogida de informaci??n m??s utilizados son los cuantitativos; m) El tama??o de la muestra elegido suele ser grande siendo el tipo de muestreo m??s com??n el 'no probabil??stico'; n) Las evaluaciones se dirigen a los usuarios de los programas y comunidades terap??uticas.