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MICROBIAL BIOTECHNOLOGY: SCOPE, TECHNIQUES CONTD

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ENVIRONMENTAL APPLICATIONS OF MICROORGANISMS:

Microorganisms mitigate a multitude of impacts that result from human
use of the natural resources of the planet. First and foremost, the essential
role of microorganisms in the treatment of waste water is critical to the well being of life on Earth. Bio-remediation, bio-mining, and microbial desulfurization of coal are other large-scale processes in which important positive environmental outcomes are achieved by directly exploiting the combined metabolic capabilities of naturally occurring communities of microorganisms. In such applications, the functioning of a particular microbial community can be influenced through the manipulation of conditions (e.g., nutrients, oxygen tension, temperature, agitation).
1) WASTE WATER TREATMENT:
Living organisms consist of about 70% water. A human being, for instance,
has to consume an average of 1.5 L/day to survive.Freshwater represents only
about 2.5% of the water on the planet  and is now a scarce resourc…

MICROBIAL BIOTECHNOLOGY: SCOPE, TECHNIQUES CONTD

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SINGLE CELL PROTEIN:
The term single-cell protein, or SCP, describes the protein-rich cell mass derived from microorganisms grown on a large scale for either animal or human consumption. SCP has a high content of protein containing all the essential amino acids. Microorganisms are an excellent source of SCP because of their rapid growth rate, their ability to use very inexpensive raw materials as carbon sources, and the uniquely high efficiency, expressed as grams of protein produced per kilogram of raw material, with which they transform these carbon sources to protein. In spite of these advantages,only one SCP product approved for human consumption has reached the market. This product is “mycoprotein,” the processed cell mass preparation from the filamentous fungus Fusarium venenatum. We  consider here the positive nutritional properties of this product and examine the many concerns that needed to be examined and addressed before this product gained regulatory approvals. The source o…

MICROBIAL BIOTECHNOLOGY: SCOPE, TECHNIQUES CONTD

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FOOD TECHNOLOGY: 

MONENSIN
                Monensin is the most widely used compound fed to cattle to increase feed
efficiency. In feedlot cattle, a dosage of 350 mg/day led to an improvement
in feed efficiency of approximately 6%. In grazing cattle, the average daily
gain increased by 15%. Monensin produces these outcomes by changing the
makeup of the bacterial population in the rumen, thereby influencing the
balance of the end products of ruminal fermentation metabolism. 
Monensin is produced by the bacterium Streptomyces cinnamonensis. It is a member of a large and important class of polyketides, the poly ether ionophores. The compound is toxic to many bacteria, fungi, protozoa, and higher organisms. The pKa of the carboxyl group in monensin is 7.95, so at the acidic pH of the rumen, the uncharged lipophilic molecule accumulates in cell membranes of bacteria sensitive to this ionophore. Monensin forms cyclic complexes with alkali metal cations (Na ion, K ion, Rb ion) with a preference for …

MICROBIAL BIOTECHNOLOGY: SCOPE, TECHNIQUES CONTD

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FOOD TECHNOLOGY:
PREPARATION OF FERMENTED FOODS:
The use of microorganisms to produce fermented foods has a very long history. Microbial fermentation is essential to production of wine,beer,bologna, buttermilk, cheeses, kefir, olives, salami, sauerkraut, and many more . The metabolic end products produced by the microorganisms flavor fermented foods. For example, mold-ripened cheeses owe their distinctive flavors to the mixture of aldehydes, ketones, and short-chain fatty acids produced by the fungi. Lactic acid bacteria are widely used to produce fermented foods. These organisms are also of particular importance in the food fermentation industry because they produce peptides and proteins(bacteriocins) that inhibit the growth of undesirable organisms that cause food spoilage and the multiplication of food borne pathogens. The latter include Clostridium botulinum(the cause of botulism) and Listeriamonocytogenes (which produces meningoencephalitis, meningitis, perinatal septicemia, and ot…

MICROBIAL BIOTECHNOLOGY: SCOPE, TECHNIQUES CONTD.

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AGRICULTURE: 
CONTROL OF PATHOGENIC BACTERIA, FUNGI,AND PARASITIC NEMATODES  

The cell walls of many plant pests, such as insects and fungi, contain chitin
(poly-N-acetylglucosamine) as a major structural component. Many bacteria (e.g., species of Serratia, Streptomyces, and Vibrio) produce chitin degrading enzymes (chitinases). The control of some fungal diseases by such bacteria has been correlated with the production of chitinases. Genes
encoding chitinases from several different soil bacteria have been cloned 
into Pseudomonas fluorescens,an efficient colonizer of plant roots.The effectiveness of these recombinant strains in controlling fungal disease is not yet known.


BACILLUS SUBTILIS STRAINS AS BROAD-SPECTRUM  MICROBIAL PESTICIDES

Selected B. subtilis strains are widely accepted as broad-spectrum microbial pesticides. Strains of the common soil bacterium B.subtilis secrete a formidable array of compounds, which together display antifungal, antibacterial, and even insecticidalactivitie…

MICROBIAL BIOTECHNOLOGY: SCOPE, TECHNIQUES CONTD.

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TAXOL:

Microbial endophytes (bacteria and fungi) are an enormous, highly diverse
component of the microbial world. Plant endophytes live in plant tissues
between living plant cells but generally can be isolated and cultured independent of the host. For some endophytes, there is evidence that genetic
exchange takes place in both directions between the plant and the endophyte. Such exchange raises the possibility that higher plant pathways for
the synthesis of complex organic molecules that have desirable biological activities might be transferred to their endophytes.
The story of the highly effective anticancer drug taxol provides proof of
the validity of this notion. Taxol, a highly substituted diterpenoid with multiple asymmetric centers was isolated in 1965 from the Pacific yew (Taxus brevifolia). In human cells, taxol prevents the depolymerization of microtubules during cell division. It has the same effect in fungi. Consequently, in nature, taxol is a fungicide.
Taxol proved to be an exce…