1.1 INTRODUCTION
Β-N-methylamino-L-alanine (BMAA) (figure 1) is an unusual amino acid produced by cyanobacteria and found in some species of cycads. C4H10N2O2 is the structural formula of this molecule with a molecular weight of 118,13. (NATIONAL TOXICOLOGY PROGRAM, 2008).
Figure 1: Graphical representation of the molecular structure (structural formula) of β-N-methylamino-L-alanine (BMAA).
BMAA is a neurotoxin found in the seeds of cycads such as Cycas circinalis. By consumption of these seeds originative of the cycad, BMAA made its way into the diets of humans by biomagnification. There was also found that fruit bats, which are a delicacy in the Chamorro, feed on the seed of the cycad, where after the toxin accumulates in their flesh and therefore also enters the human food chain in this manner. BMAA production by cyanobacteria, one of the most popular groups of organisms, raises concern of exposure of humans around the world to BMAA that can be very harmful. BMAA is produced by cyanobacteria of the genus Nostoc. Nostoc has a symbiotic relationship with the tissue of plants and supplies nitrogen to the plant with which they form a symbiotic relationship. Seeing that nitrogen is essential for the vitality and success of most plants this is an important symbiotic relationship because most plants are unable to utilize free nitrogen. The cyanobacteria supply the plant with fixed nitrogen that is essential for use. Cellular BMAA pools consist of both free and protein associated toxin. Presumable BMAA is produced on nitrogen starvation but the mechanisms of biosynthesis are not clear. Also it is believed that BMAA is modified on exposure to biologically available nitrogen and appears to be a longer delay in ...
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ESTERHUIZEN-LONDT, M., DOWNING, S. & DOWNING, T.G. 2011. Improved sensitivity using liquid chromatography mass spectrometry (LC-MS) for detection of propyl chloroformate derivatised β-N-methylamino-L-alanine (BMAA) in cyanobacteria. Water SA. 37:1-6
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NATIONAL TOXICOLOGY PROGRAM. 2008. Chemical Information Review Document for L-β-Methylaminoalanine. National Institute of Environmental Health Sciences. 1-40p
MILLER, S.R., MARTIN, M., TOUCHTON, J. & CASTENHOLZ, R.W. 2002. Effects of nitrogen availability on pigmentation and carbon assimilation in the cyanobacterium Synechococcus sp. strain SH-94–5. Arch Microbiology. 177:392–400
Ryazantseva, I. N., Saakov, V. S., Andreyeva, I. N., Ogorodnikova, T. I. and Zuev, Y. F. 2012. Response of pigmented Serratia marcescens to the illumination. Journal of Photochemistry and Photobiology B: Biology, 106 p. 18-23
It is shown that the black color or the strain STM 5480 is more efficient in nitrogen fixing than the white color or STM 5472 strain in the singe-inoculation assay. It is also seen that the biomass...
This prompted a lot of study and investigations to uncover the mystery and to establish possible remedies. Among the many reasons for the causes of the CCD was the use of harmful and dangerous pesticides. Timbrell (2002) provides a solid foundation on the effects of toxins in the body of animals with an aim of providing a scientific solution towards the problem. This paper focuses its study on these pesticides with an aim of establishing the effects of the toxins found in the insecticides that could be affecting the bees. In CCD, honey bee colonies lose their workers under unclear circumstances (Cox-Foster et al., 2007, p. 283).
When the aerobic organisms in the body consume all the oxygen present, anaerobic organisms from the digestive system begin to multiply. They consume macromolecules (proteins, carbohydrates, lipids) and form acids and gases in the p...
Pigments produced by microorganisms has been used to dye fabrics of different types. Talaromyces verruculosus produce a red colored pigment which is suitable to dye cotton and is harmless. Pigments from microorganisms give different types of shades of a color. For instance; Janthinobacterium lividum produce a pigment which gives purplish-blue shade to different types of fabrics. Thermomyces produce a yellow pigment used to dye number of fabrics specifically silk. NP2 and NP$ strains of Streptomyces produce dark blue and red colored pigments. Among retaining dye of microbial strains cotton fabric were stained comparatively weak while acrylic and polyamide fibers stained strongly.
...hemical energy from cyanobacteria (the only bacteria that can perform photosynthesis) 2.4 billion years ago (Wernergreen). The first chloroplast came into being about one billion years ago when a single-celled protist and a cyanobacterium came together through endosymbiosis, and this first photosynthesizing eukaryotic lineage was the ancestor of land plants, green algae, and red algae. Cyanobacteria and algae endosymbionts have spread photosynthetic capabilities in such a broad range (Wernergreen). In other words, heterotrophic prokaryote cells had taken in autotrophic photosynthetic bacteria cells. The ingested cell continued to provide glucose and oxygen by photosynthesis. The host cell protected as well as provided carbon dioxide and nitrogen for the engulfed cell and overtime both cells lost the aptitude to survive without each other (Weber and Osteryoung).
Stokes, W.S. “Animals and the 3 R’s on Toxicology Research and Testing.” Human and Experimental Toxicology December 2015: 7. Academic Search Premier. Web. 14 February
It is widely believed that this change was brought about by the emergence of cyanobacteria which had adapted to create energy from the sun by photosynthesis(probably due to a shortage of raw materials for energy), as a result they had began to poison the earlier anaerobic bacteria or archea with their waste product; oxygen.
The product was made from 4-methylcyclohexanol. The chemical, 4-methylcyclohexanol is used in industrial settings. In 2014, West Virginia was exposed to this chemical in drinking water. Since this chemical is used to wash coal of its impurities, it was unsafe to drink the water as well as take a shower (CNN). Similarly, 4-methylcyclohexanol has a strong smell which may cause people to have symptoms like vomiting, skin irritation, and trouble breathing. Diesel is also replaced by 4-methylcyclohexanol (National Geographic).
...and MEA. These chemicals are said to be linked with breast cancer, skin rashes, estrogenic, hormone disruptor, linked to liver and kidney cancer, and irritates the eye.
The first and best known example is the various sub-species of the bacterium ‘Bacillus thurnigenesis’. As mentioned earlier, these produce crystalline proteins otherwise known as ‘Δ-endotoxins’ or ‘cry proteins’ (Ellis et al, 2002). These endotoxins attack the digestive tract of the insect. The Bt spores then leaks from the gut and germinate in the insect causing death within few days. Bacillus thurnigenesis (Bt) Δ-endotoxins are well known for their ability to control a variety of insect pests, including members of Lepidoptera, Coleoptera, and Diptera
Many pesticides, that of which have many unanswered questions regarding the potential health risk have been authorized by the EPA Office of Pesticide ...
Temperature has a strong effect on nitrifying bacteria, as in the case of heterotrophic aerobic bacteria. The temperature dependence for the nitrification process corresponds to an Arrhenius equation, at least below 30 °C. At higher temperatures (30-35 ° C), the growth rate of nitrifying bacteria is constant and Begins to decrease between 35 and 40 °C. The two-stage biological nitrification process is a two-sludge system which is generally used when ammonia Disposal is subject to advanced treatment. The process is also used prior to biological denitrification systems where nitrate removal is required. The first step of the two-step process is typically a high-throughput activated sludge that is designed to achieve at least 75% to 85% elimination of carbonated BOD5. By realizing this Level of reduction of BOD5 in the first stage, conditions can be developed in the second step to improve nitrification. The nitrification of ammonia into nitrate occurs chiefly in the second stage. Nitrification is realized in a two-stage process by the biological activities of two specific groups of bacteria known as Nitrosomonas and
The energy extracted today by the burning of coal and petroleum products represents sunlight energy captured and stored by photosynthesis almost 200 million years ago. A third very interesting group of bacteria synthesize sugars, not by using sunlight’s energy, but by extracting energy from inorganic chemical compounds; In a (d) deep sea vent, chemoautotrophs, such as these (e) thermophilic bacteria, capture energy from inorganic compounds to produce organic compounds.
Nitrogen is essential for plants because it is an essential component of all proteins. A lack of nitrogen in a plant diet can result in slower growth, stunted growth, and even chlorosis (1). Plants affected by chlorosis produce insufficient amounts of chlorophyll, reducing its ability to make carbohydrates through photosynthesis. These plants become a yellowish or pale color and eventually die from the lack of chlorophyll. (2) All of the transformations that nitrogen goes under in and out of the soil are known as the nitrogen cycle. Plants lose nitrogen from their soil system through run-off, leaching, volatilization, and denitrification. Most of the nitrogen that plants uptake from the soil is in the forms of ammonium and nitrate. Proteins and amino acids can only be built from nitrate and ammonia and therefore must be reduced. Organic nitrogen, found in organic matter, is converted into ammonium in the process...