Labels: BIOSAFETY AND BIOETHICS
Labels: BIOSAFETY AND BIOETHICS
Labels: PHARMACEUTICALS
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Labels: ENZYME BIOTECHNOLOGY
Microbes useful in metal recovery
The microbes that are suitable and useful for metal recovery differ depending upon the temperature of the metal recovery process. At 40°C, the most important microbes are Gram negative bacteria belonging to genera Acidithiobacillus and Lactospirillum, which include
(i) iron and sulphur oxidizing At. ferrooxidans,
(ii) sulphur oxidizing At. thiooxidans and At. caldus, and
(iii) iron oxidizing L. ferrooxidans and L. ferriphilum.
At 50°C, the suitable biornining microbes include At. caldus, some species of the genus Leptospirillum, and some Gram negative bacteria including the members of the genera Sulphobacillus and Acidimicrobium, and at 70°C, the useful biomining microbes are members of the group archaea (Sulphobolus and Metallophaera). Improvement of bacterial strains for enhanced rate of leaching of metals is also being attempted for several of these bacteria.
Labels: ENVIRONMENTAL BT
A deoxyribonuclease (DNase, for short) is any enzyme that catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone. Deoxyribonucleases are thus one type of nuclease. A wide variety of deoxyribonucleases are known, which differ in their substrate specificities, chemical mechanisms, and biological functions.
Modes of action
Some DNases cleave only residues at the ends of DNA molecules (exodeoxyribonucleases, a type of exonuclease). Others cleave anywhere along the chain (endodeoxyribonucleases, a subset of endonucleases).
Some are fairly indiscriminate about the DNA sequence at which they cut, while others, including restriction enzymes, are very sequence-specific.Some cleave only double-stranded DNA, others are specific for single-stranded molecules, and still others are active toward both.DNase enzymes can be inhaled using a nebuliser by cystic fibrosis sufferers. DNase enzymes help because white blood cells accumulate in the mucus and when they breakdown they release DNA which adds to the 'stickiness' of the mucus. DNase enzymes breakdown the DNA and the mucus is much easier to clear from the lungs.
Types of deoxyribonucleases
The two main types of DNase found in metazoans are known as deoxyribonuclease I and deoxyribonuclease II.
Other types of DNase include Micrococcal nuclease
Labels: ENZYME BIOTECHNOLOGY
Labels: ENZYME BIOTECHNOLOGY
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Energy Recovery
The energy content of waste products can be harnessed directly by using them as a direct combustion fuel, or indirectly by processing them into another type of fuel. Recycling through thermal treatment ranges from using waste as a fuel source for cooking or heating, to anaerobic digestion and the use of the gas fuel to fuel for boilers to generate steam and electricity in a turbine. Pyrolysis and gasification are two related forms of thermal treatment where waste materials are heated to high temperatures with limited oxygen availability. The process usually occurs in a sealed vessel under high pressure. Pyrolysis of solid waste converts the material into solid, liquid and gas products. The liquid and gas can be burnt to produce energy or refined into other chenmical products (chemical refinery). The solid residue (char) can be further refined into products such as activated carbon. Gasification and advanced Plasma arc gasification are used to convert organic materials directly into a synthetic gas (syngas) composed of carbon monoxide and hydrogen. The gas is then burnt to produce electricity and steam. An alternative to pyrolisis is high temperature and pressure supercritical water decomposition (hydrothermal monophasic oxidation).
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Labels: ENVIRONMENTAL BT
Wind power is growing at the rate of 30% annually, with a worldwide installed capacity of 157,900 megawatts (MW) in 2009, and is widely used in Europe, Asia, and the United States. At the end of 2009, cumulative global photovoltaic (PV) installations surpassed 21,000 MW and PV power stations are popular in Germany and Spain. Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 MW SEGS power plant in the Mojave Desert. The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18% of the country's automotive fuel. Ethanol fuel is also widely available in the USA.
Labels: ENVIRONMENTAL BT