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Showing papers in "Advances in Applied Microbiology in 1992"


Book ChapterDOI
TL;DR: The fruit body and liquid-cultured mycelium of Ganoderma have been reported to contain polysaccharides which inhibit the growth of tumors, and the search for new uses for the traditional medicinal fungi continues.
Abstract: Publisher Summary This chapter discusses medicinal benefits of the Mushroom Ganoderma . Recently, the fruit body and liquid-cultured mycelium of Ganoderma have been reported to contain polysaccharides which inhibit the growth of tumors. Identified as glucans, one of the major constituents in the cell wall of fungi, they appear to increase bodily resistance against the growth of tumors, induce the production of interferon, enhance the immunity function, and kill tumor cells within the body. The role of medicinal mushrooms in metabolic regulation is gaining greater attention. Their use in the development and application of beneficial biological activities offers an advantage in that the active principle is safe and can be tolerated by humans. Cultivation of such mushrooms provides an adequate supply but is unnecessary if mycelial cultures grown in large-scale fermentations can produce the same active principle. Finally, the search for new uses for the traditional medicinal fungi continues and the public should be educated about their potential value.

234 citations


Book ChapterDOI
TL;DR: This chapter presents an overview of microbial degradation of nitroaromatic compounds, and has identified organisms capable of using TNT as the sole carbon and nitrogen source.
Abstract: Publisher Summary This chapter presents an overview of microbial degradation of nitroaromatic compounds. Nitroaromatics are produced on a massive scale in the manufacture of dyes, plastics, and explosives. Their discharge in wastewater and application as pesticides have broadened their environmental impact and called for solutions for remediation of these toxic compounds. The use of microorganisms to transform or eliminate nitroaromatics has been proposed in effluent treatment and land reclamation. While microbial strains utilizing nitrobenzoates or nitrophenols were isolated from contaminated sources several decades ago, microbial action on 2,4,6-trinitrotoluene (TNT) was largely limited to nitro group reduction and formation of azoxy derivatives which may complex with humus. However, recent work has identified organisms capable of using TNT as the sole carbon and nitrogen source. Finally, the versatile white rot fungus also merits further attention in nitroaromatic degradation.

104 citations


Book ChapterDOI
TL;DR: Research to optimize the breakdown of PCBs has been directed firstly at the isolation of species especially competent in the removal of a spectrum of Aroclor components, and secondly, at the bringing together of pathway segments with a view to constructing an organism that can use PCBs as sole carbon source.
Abstract: Publisher Summary The role of microorganisms in maintaining steady-state concentrations of environmental chemicals is well established and these activities constitute the basis for the cycle of carbon in nature However, the widespread, recalcitrant, and bioaccumulating nature of polychlorinated biphenyls (PCBs) presents a major environmental problem Research to optimize the breakdown of PCBs has been directed firstly at the isolation of species especially competent in the removal of a spectrum of Aroclor components, and secondly, at the bringing together of pathway segments with a view to constructing an organism that can use PCBs as sole carbon source Electron acceptors are usually limiting in anaerobic environments, so that a selection pressure is exerted by PCB contamination in river sediments The microbial population adapts to the Aroclor present and to achieve optimal dehalogenation, one should look at sites contaminated by this mixture for suitable experimental inocula Competition with existing microorganisms for space and nutrients is a limiting factor for all new inoculants, even for soil biphenyl degraders provided with biphenyl

57 citations


Book ChapterDOI
TL;DR: It can take the ingenuity of mankind, coupled with nature's mercy, to unravel the untapped potentialities of the basidiomacromycetes.
Abstract: Publisher Summary Basidiomacromycetes represent a circumscribed group of higher fungi of the class Basidiomycetes, wherein the basidia bearing the exogenously produced basidiospores represent the fertile layer (hymenium), which in turn is lined up, encroached, and covered by tufts of tissues to form distinct objects of the Earth's beauty, namely the basidiocarps. Genetic incompatibility factors (bipolarhetrapolar) allow these fungi fungi great diversity in their ability to grow over a range of conditions: fermented or unfermented; pasteurized or unpasteurized; sterilized or unsterilized; on soft woods or hardwoods; on cereal straws or oil crop residues, or plantation crop residues. Moreover, Basidiomacromycetes display an array of physiological properties that have a range of useful applications. Edible species represent the best examples: they grow over a range of lignocellulosic substrates to yield fruiting bodies, and the degarded substrates can in turn be used in a number of useful ways. The search for new species of basidiomacromycetes and research on new and different ways to use these fungi should be a matter of priority. It is a task that requires much intelligence and perseverance. Increasing the list of their applications depends on prolonged and continued research. It can take the ingenuity of mankind, coupled with nature's mercy, to unravel the untapped potentialities of the basidiomacromycetes.

53 citations


Book ChapterDOI
TL;DR: This chapter discusses the properties and use of haloperoxidases in organic synthesis, and suggests that once large-scale production of these enzymes is advanced, their applications in industrial organic synthesis can follow immediately.
Abstract: Publisher Summary This chapter discusses the properties and use of haloperoxidases in organic synthesis. Haloperoxidases are enzymes that are capable of halogenating a variety of organic compounds using hydrogen peroxide and halide ions as substrates. Haloperoxidases are known from almost 100 sources, including mammals, birds, plants, algae, molds, and bacteria. The main sources of haloperoxidases can be divided into two groups: algae and bacteria. Algae produce several heme-containing haloperoxidases. Although all the heme-containing haloperoxidases that have been isolated so far possess ferriprotoporphyrin IX as the prosthetic group, not all enzymes have the same halogenating abilities: some can chlorinate, while others can only brominate. Moreover, the prospects for haloperoxidase research are still good, particularly in the field of nonheme microbial chloroperoxidases, which are stable toward heat and oxidizing chemicals. It is suggested that once large-scale production of these enzymes is advanced, their applications in industrial organic synthesis can follow immediately.

53 citations


Book ChapterDOI
TL;DR: This chapter examines what is known about the sensitivity of enzymes and organisms to shear stress, the magnitude of the forces experienced by biocatalysts in various reactor types, and the implications for the design and operation of biochemical processes.
Abstract: Publisher Summary This chapter reviews the current status of shear sensitivity of microorganisms and other biocatalysts. The structural features of biocatalysts serve as a basis for rational explanation of effects of shear damage. One of the key parameters in the development of processes utilizing biocatalysts is their sensitivity to hydrodynamic shear stress. Bioreactors can generate strong forces in the region of the impeller, along the walls, and at air–liquid interfaces. The chapter examines what is known about the sensitivity of enzymes and organisms to shear stress, the magnitude of the forces experienced by biocatalysts in various reactor types, and the implications for the design and operation of biochemical processes It discusses physical and biological mechanisms of shear damage and outlines the ways of overcoming the adverse effects of shear.

30 citations


Book ChapterDOI
TL;DR: An evaluation study of bacterial standards and disinfection practices used for the assessment and treatment of stormwater finds that total coliform or fecal coliform indicators cannot be used to assess accurately the pathogenicity of recreational waters receiving stormwater from uncontaminated separate storm sewers or surface water runoff.
Abstract: Publisher Summary This chapter presents an evaluation study of bacterial standards and disinfection practices used for the assessment and treatment of stormwater. The Environment Protection Agency's (EPA's) current emphasis on water-use attainability and risk assessment warrants the reevaluation of existing disinfection requirements and bacteriological criteria. Water quality and disinfection criteria based on human disease contraction potentials of pathogenic microorganisms are needed for stormwater as well as combination with stormwater (CSO). The results of some epidemiological studies strongly suggest that total coliform (TC) or fecal coliform (FC) indicators cannot be used to assess accurately the pathogenicity of recreational waters receiving stormwater from uncontaminated separate storm sewers or surface water runoff. Carefully planned strategy should be adopted for storm sewers containing evidence of human-fecal contamination to indicate the presence of illicit or inappropriate cross-connections. In stormwater outfalls where cross-connections are too numerous or too costly to be corrected, it is advisable to deal with the separate storm sewer system as a combined sewer system.

9 citations