It is well known that eutrophication occurs when excess nutrients are added to a body of water and primary productivity is increased. However, the scientific paper, Aquatic eutrophication promotes pathogenic infection in amphibians, puts a direct focus on a specific parasite, Ribeiroia ondatra, and seeks to give evidence that the onset of eutrophication is the driving factor allowing the parasite to disrupt amphibian development. The authors set-out with the goal to provide evidence that eutrophication leads to an increase in the number of snails as intermediate hosts for the parasite, while also increasing the snail size and reducing snail mortality; providing more candidates to pass the parasite onto amphibians to inhibit their development. This research, as stated in the paper, looks to identify eutrophication as the factor promoting this pathogenic infection in the amphibians. Although some have tried to pinpoint this already, no evidence prior had been provided to
Discovery and description of Aeromonas species: From the discovery of genus Aeromonas in 1943 till mid - 1970s, aeromonads are initially divided into two major groups; based upon growth characteristics and other biochemical features (Janda, and Duffey, 1988). This mesophilic group, typified by A. hydrophila, consisted of motile isolates that grew well at 35 °C to 37 °C and are associated with a variety of human infections (Ref ). In the second group, referred to as psychrophilic strains, caused diseases in fish that are nonmotile, and had optimal growth temperatures of 22 °C to 25°C. This group represent with isolates that currently reside within the species A. salmonicida (Ref ). Ten year following mid-1970s, several other groups were interested in the work that include Institute Pasteur, Paris, Centers for Disease Control and Prevention, Atlanta, USA, and Walter Reed Institute of Research, Washington USA.
and Pseudomonas fluorescens are part of a heterogenous group of microorganisms from the Pseudomonadacae group containing pervasive amounts of Gram-negative, Gram-positive, aerobic, non fermentative, catalase and oxidase positive, mesophilic and psychrotolerant, non-spore forming rods (Janda and Abbott, 2007). Pseudomonas micro-organisms are able to adapt to different environments due to their complex enzyme systems. This is the primary reason why psychrotrophic bacteria are associated with the spoilage of milk products (L.Caldera, L. Franzetti et. al. 2015).
Azotobacter is a free-living diastrophic bacteria which are aerobic soil microbes and play an important role in the nitrogen cycle. Azotobacter is non-pathogenic. It is mostly found in neutral soils, in aquatic environments and on some plants. It is used by humans in bio fertilizers, food additives and some biopolymers. Although Azotobacter has many metabolic functions it’s most well known in nitrogen fixing.
One example is eutrophication which causes a dense growth of plant life leading to the death of marine life from lack of oxygen. This is significant because it has serious, long-term effects. The most remarkable effect of eutrophication is blocking light from reaching the water. Smith and Schindler (2009) investigated that eutrophication prevents the aquatic plants from photosynthesizing and that would lead to reductions in fishes and in the food chain in general. In addition, when fishes die from lack of oxygen, they sink to the bottom, and the microbes that break down the organisms need oxygen to continue this process.
Genetic analysis of species which are polymorphic for flowering time has been useful in revealing the action of some of the genes involved in the control of flower initiation (Murfet IC et al., 1967). However, theinterpretation of the effects of these genes has been complicated by the lack of isogenic lines and the lack of a method for identifying the genes or the gene products affected by the mutations. In these respects, Arabidopsis is an attractive model species for a genetic analysis of flowering because the rapid development of the molecular genetics of Arabidopsis (Chang C et al., 1988; Finkelstein et al., 1988) may allow the cloning of genes which are otherwise evident only on the basis of a mutant phenotype. Arabidopsis thaliana is a quantitative long day plant. Long photoperiods promote flowering in all Arabidopsis ecotypes.
Eg: bacteria, viruses OBLIGATORY PARASITES Cannot survive without host FACULTATIVE PARASITES Can survive without host MICROPARASITES Small size, small life cycle, reproduces inside the host MACROPARASITES Large size, do not need reproduce inside the host Example: Lichens, which is the association between fungi and algae. Fungal partner is mycobiont and the algal is phycobiont. Being a phycobiont, algae provides the fungi with the food in exchange of the protection from the high light intensities, water and minerals from the fungi. Lamprey, a vertebrate parasite which obtains its food by attaching to other fishes. It has a circular toothfilled mouth, thus sucks blood and other bodily fluids.
They are rod shaped, non sporing, predominantly motile enterobacteria. They are 2-5μm in length and around 0.7-1.5μm diameter. They have peritrichous flagella (flagella covering the whole body), with exception of Salmonella serotypes pullorum and gallinarum being nonmotile. They are facultative anaerobes and are chemoorganotrophs, ie. obtain their energy by oxidation and reduction of organic sources.
The region of accumulation of pesticides within fish varies with the route of uptake. Their potential use as bio monitors is therefore significant in the assessment of bioaccumulation and bio magnifications of contaminants within the ecosystem .Many dangerous chemical elements, if released into the environment, accumulate in the soil and sediments of water bodies. The lower aquatic organisms absorb and transfer them through the food chain to higher trophic levels, including fish. Under acidic conditions, the free divalent ions of many metals may be absorbed by fish gills directly from the water . Hence, concentrations of pesticides in the organs of fish are determined primarily by the level of
The farmers of Dharwad (Karnataka) use acepahte and imidacloprid for control of leafhoppers and this present study also proved the occurrence of high number of bacterial diversity from Dharward population, which indicates that these bacteria were associated with imparting resistance to the insects. Based on the available literature and occurrence across the locations, the two most commonly recorded bacteria, Enterobacter cloacae and Bacillus pumilus were taken to further studies for their role in insecticide resistance, thereby establishing their role as endosymbionts. Maximum growth of Enterobacter cloacae and Bacillus pumilus was recorded when these organisms were observed growing in media amended with acephate and imidacloprid in minimal broth media. Liquid chromatography–mass spectrometry (LCMS) analysis indicated the ability of E. cloacae and B. pumilus recorded from insecticide resistant population of A. biguttula biguttula degraded acephate (183.78) into methamidophos (143.04). The occurrence of common gut bacterial genera Enterococcus, Serratia, Enterobacter, Staphylococcus, Paenibacillus, Pantoea and Bacillus has been reported in many insects on various crops and their role in the host fitness attributes including insecticide resistance was reported by various people.