Agricultural Development and Environmental Research American and Czechoslovak Perspectives: Proceedings of a Bilateral Workshop (1987) / Chapter Skim
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'BIOTECHNOLOGY AND THE DEVELOPMENT OF MICROBIAL PRODUCTS FOR AGRICULTURE'
'BIOTECHNOLOGY AND THE DEVELOPMENT OF MICROBIAL PRODUCTS FOR AGRICULTURE'
Pages 184-197
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From page 184... ...
Recognition at the molecular level is a fundamental characteristic of biological systems which is highly evolved in the genetic material to promote accurate replication through generations, and in the animal immune system to recognize foreign and potentially dangerous antigens. Understanding the biochemical aspects of these recognition systems has now also provided more precise tools to study cells and molecules.
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From page 185... ...
. Microbial inoculants for agriculture have attracted the attention of researchers and companies throughout the world because they hold the promise of providing lower cost, ecologically sound alternatives to many chemical applications.
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From page 186... ...
These other products include cyanobacterial fertilizers, frost protectants, Bacillus thuringiensisand virus-based insecticides, improved rhizobium inoculants, plant growth regulators, waste processing treatments, and fungicides. INCONSISTENT PERFORMANCE OF INOCULANTS: THE NEED FOR AUTECOLOGICAL DATA There are an estimated 10,000 to 20,000 strains of any given bacterial species.
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From page 187... ...
is currently funding 17 extramural research programs on related problems of environmental effects and on development of a methodology for estimating the fate of introduced organisms. Until now, methods for identification of specific strains of bacteria among large populations of similar strains of the same species have lacked adequate precision or have been prohibitively difficult.
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From page 188... ...
As suggested above, identification methods that rely on first culturing the organisms have many sources of error. In an adaptation which is not yet understood, sporulated gram positive organisms as well as some gram negative organisms can enter a resting state in soil where they cannot be cultured onto laboratory media.
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From page 189... ...
These include the nitrogen-fixation enzymes, symbiotic determinants, and probably competitiveness in rhizobia; the Ti and Hi plasmids of Agrobacterium which cause disease by incorporating into plant chromosomes and have become important vectors for plant genetic engineering; and the insecticidal crystal proteins of Bacillus thuringienesis. Many of the bacteriocin and antibiotic factors selected in typical screening for biological control agents are probably also plasmidassociated.
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From page 190... ...
plantarum strains isolated from 32-day-old uninoculated high moisture corn silage. The pH had been stable at about 4.0 for at least 3 weeks, and overall lactic acid bacteria numbers were continuing to slowly decrease from an initial peak reached in the first week.
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From page 191... ...
coli V517 lanes 14 and 28; MGD inoculant product (MGD286) lane 27; Chr, contaminating chromosomal DNA (Hill and Hill 1986)
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From page 192... ...
However, among the common soil microorganisms, the gram negative pseudomonads are widely regarded as active plant root colonizers and candidates for protective inoculants, while bacilli are thought to be saprophytes that do not selectively live in association with roots. The experiment was conducted to determine whether a particular organism with known beneficial effects might in fact persist in the rhizosphere and, if so, for how much of the growing season.
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From page 193... ...
1.4* 26 FIGURE 2 Plasmid profiles of Lactobactiliu plantamm isolates from silage inoculated with MGD286 (reference lane 15)
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From page 194... ...
Research on microbial ecology at the level of specific strains should be encouraged in all agroecosystems -- host/pathogen interactions, saprophytic life stages of pathogens, legume/rhizobium interactions, colonization of plant roots by nonpathogenic bacteria and fungi, fermentation of silage, decomposition of wastes, and colonization of the rumen and gut. In some cases, plasmid profiles are suitable for tracking individual strains in these environments.
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From page 195... ...
195 80 -I CONTROL PLOT MAY1 SO1L MAY 25 ROOT JUNE 26 ROOT AUG 1 ROOT SEPT 9 ROOT FIGURE 3 Recovery of organisms cross-reacting with polyclonal antibody to seed inoculant MGD311. Bacterial isolates from roots or soil with similar colony morphology to MGD311 were rated for strong positive reaction to anti-MGD311 by immunoblot assay (Brown and Hendricks, unpublished)
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From page 196... ...
•«»>* • FIGURE 4 Hindlll restriction fragments of plasmid DNA from MGD311 and cross-reacting field isolates from the treated plot as shown in Figure 3.
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From page 197... ...
1988. DNA probe method for the detection of specific microorganisms in the soil bacterial community.
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