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Microorganisms, Industrial

Microorganisms, Industrial microorganisms that have been exploited by man in important industrial processes. Such microorganisms are natural isolates, but many are also modified through application of the modern techniques of molecular genetics in order to maximise their utility. Microorganisms are integral components of Earth's biota and are essential for the maintenance of biotic balance. These tiny microscopic organisms are present everywhere: air, water, soil, deep under the ocean, in extremely hot conditions such as undersea hot water vents, in geysers, and in extreme nutrient depleted habitats. They possess special abilities that render them as useful to nature as to man for specific attributes that are exploited for useful products.

Work on industrial microorganisms in Bangladesh has yet to be an active area of scientific research. Nevertheless, in some areas modest scientific research has been carried out over the past decades. One area that drew interest was based on possible utilisation of industrial wastes of the country's sugar mills in the northern part of the country. Thus, use of sugarcane molasses for production of citric acid by growing Aspergillus niger in media containing molasses was one such area. Production of citric acid was studied in the laboratory using high-yielding strains of Aspergillus niger developed by mutagenic treatment. Sugarcane bagasse is also a waste product of the sugar mills. It is rich in cellulose, a complex carbohydrate. Enzymatic conversion of the cellulose to simpler sugars for other uses was thought to be possible if the conversion could be carried out economically using microorganisms that produced the enzyme cellulase. This process, called saccharification was studied in the laboratory using standard cellulase-producing strains such as Cellulomonas sp. and Trichoderma reesei. Similarly, material used in paper and pulp industry where the complex sugar is xylan has been tested for production of simpler sugars with Thermomyces lanuginosus and Rhizomucor pusillus strains. Extra-cellular cellulase production by Thermoascus aurantiacus and extra-cellular-glucanase production by Saccharomyces cerevisiae have also been studied. Also, production of baker's yeast using sugarcane molasses has been studied on a semi-pilot scale in the laboratories of the Bangladesh Council for Scientific and Industrial Research (BCSIR).

Tannery industry represents an important economic sector in Bangladesh. For the processing of hides and skin it is frequently useful to degrade the protein and fat components of the skin to facilitate subsequent steps of processing. Enzymes such as alkaline protease and lipase are useful for this purpose. Some bacteria such as Bacillus species are known to produce these enzymes and excrete from the cell. In this area also some strains of Bacillus have been isolated and studied in the laboratory for extra-cellular protease production.

Many soil microorganisms such as actinobacteria make secondary metabolites with useful antibacterial properties. These substances are called antibiotics. Many soil isolates of actinobacteria have been studied in different university laboratories and research institutions of the country for useful antibacterial substances. A large number of isolates have indeed been found, and in some cases the active substance identified. However, no new antibiotic substances with good commercial potential has yet been found.

Most work on industrial microorganisms have been carried out at a small number of research institutions in the country. Among these are included the Atomic Energy Research Establishment (AERE) of Bangladesh Atomic Energy Commission (BAEC), Bangladesh Council for Scientific and Industrial Research (BCSIR), departments of Microbiology, and Biochemistry of the University of Dhaka and to a lesser extent, Microbiology departments in some of the relatively new universities of the country. Many research reports have been published by scientists of Bangladesh both in national and international journals describing laboratory work on industrial microorganisms isolated from Bangladesh. Application of any of these microorganisms to actual industrial product making has not, however, been possible.

The major microbial industrial process in the country at present is production of ethanol from sugarcane molasses using yeast by distilleries located in northern Bangladesh. Production of the nitrogen fixing bacterium Rhizobium for use as biofertiliser has been undertaken on a semi-pilot scale by the bangladesh institute of nuclear agriculture located in Mymensingh. The process is now under study by entrepreneurs for possible industrialisation. [Zia Uddin Ahmed]