Toxin production

Optimum toxin production was found in a stirred, aerated culture medium consisting of potato infusion and sucrose after 3 to 5 days growth. The toxin was adsorbed on charcoal from the culture filtrate and eluted with chloroform. The red-brown residue remaining after evaporation showed little or no absorption in the carbonyl region of the infrared and only weak absorption in the ultraviolet. However, on mild treatment with acid, base, or heat two carbonyl peaks appeared at 1715 and 1685 cm.-1 in the infrared and at 266 mft in the ultraviolet (3). 

By utilizing the HPLC method, it is possible to determine the level of each individual toxin in sample solutions. This provides a "toxin profile" that can be very useful in PSP toxin research studies. The ability to examine relative changes in toxin concentration and profile has greatly facilitated studies relating to toxin production by dinoflagellates, metabolism of toxins in shellfish, and movement of toxins up the food chain. Since the HPLC method is easily automated and requires only very small sample sizes (< 1 g tissue), it has clear advantages over other analytical procedures for the toxins in many research situations. Two examples of the utilization of HPLC for the study of the PSP toxins follow. 

Some chemical modification studies on the sea anemone toxins have unfortunately been less than rigorous in analyzing the reaction products. Consequently, results from many of these studies can only provide suggestions, rather than firm conclusions, regarding the importance of particular sidechains. Many such studies also have failed to determine if the secondary and tertiary structures of the toxin products were affected by chemical modification. 

Community-acquired methicillin-resistant S. aureus (CA-MRSA) is becoming an increasingly common pathogen in cellulitis. CA-MRSA can be distinguished from health care-associated MRSA (HA-MRSA) by its genetic dissimilarity, host population, drug susceptibility patterns, and toxin production. 

Proper understanding of allelopathic crop and weed plants including their growth stages at which toxin production occurs and characterization of allelopathic agents frcm these plants provide new avenues for developing technologies in weed control, crop efficiency, pest control and plant diseases. 

Rationale. Microorganisms were isolated from soil and screened for toxin production according to the scheme in Figure 1. Some of the organisms causing strong inhibition on solid medium were tested for toxin production in liquid medium. Liquid culture will be required to obtain large amounts of material for commercial production of herbicides, however, the ability to produce toxins on solid medium does not necessarily imply toxin production in broth (34). Cyclo-heximide, a phytotoxic but relatively nonspecific antibiotic with little value as a herbicide, is produced by many actinomycetes. Liquid cultures were tested for cycloheximide to determine whether it caused the observed toxicity. 

Ophel, K.M., Bird, A.F. and Kerr, A. (1993) Association of bacteriophage particles with toxin production by Clavibacter toxicus, the causal agent of annual ryegrass toxicity. Phytopathology 83, 676-681. 

Mohamed ZA (2002) Allelopathic activity of Spirogyra sp. stimulating bloom formation and toxin production by Oscillatoria agardhii in some irrigation canals, Egypt. J Plankton Res 24 137-141... 

Pasteels JM, Daloze D, de Biseau JC, Termonia A, Windsor DM (2004) Patterns in host-plant association and defensive toxin production by neotropical Chrysomelines. In Jolivet E, Santiago-Blay JA, Scmitt M (eds) New developments on the biology of Chrysomelidae. Academic Publishing, The Hague (in press)... 

Microbial Cell Lines Species, strain, genotype, phenotype, pathogenicity, toxin production, and other biohazard information... 

The outgrowth of C. botulinum requires a suitable medium, temperature, atmosphere, pH, Eh potential, and water activity. Toxin is usually only produced in optimal or close-to-optimal conditions. Nutrient demands of C. botulinum are complex, and include amino acids, B vitamins, and minerals. In broth, non-proteolytic strains of type B and F grow and produce toxin at 4°C, but in crab meat the outgrowth and toxin production occurs solely at 26°C (Alberto et al., 2003). 

A low water activity a ), which for C. botulinum ranges from 0.94 (type B) to 0.97 (type E), enables the outgrowth and toxin production in packaged... 

Staphylococcus aureus is known for its ability to produce a variety of toxins and many disease syndromes. One of the most frequently observed diseases is staphylococcal tonsillitis. These bacteria are frequently present on tonsils of healthy carriers. Patients that are affected by tonsillitis swallow staphylococci hidden in tonsil crypts. However, in this case staphylococci do not cause any gastrointestinal symptoms in the host organism, even if they enter the gastrointestinal tract. The barrier of gastric juice and conditions in a small intestine inhibit the outgrowth of staphylococci and toxin production -gastroenteritis is caused solely by a toxin produced outside the host organism. 

Odlaug, T.E. and Pflug, I.J., Clostridium botulinum growth and toxin production in tomato juice containing Aspergillus gracilis, Appl. Environ. Microbiol., 37, 496-504, 1979. 

Tabita, K., Sakaguchi, S., Kozaki, S. and Sakaguchi, G., Distinction between Clostridium botulinum type A strains associated with food-bome botulism and those with infant botulism in Japan in intraintestinal toxin production in infant mice and some other properties, FEMS Microbiol. Lett., 63, 2-3, 251-256,1999. 

---