Microbiology

Microbiology

Springborn Smithers Laboratories' resources include fully equipped microbiological facilities staffed by competent and experienced professional personnel.We routinely culture and propagate a bank of microbial organisms intended to assist in the elucidation of complex biological compounds and perform a battery of services including microbial metabolism, microbial toxicity, biotransformation and biosynthesis, microbiological assays, biomass determination, soil microflora analysis and cytotoxicity testing.

Microbial Metabolism

Biochemical and analytical identification of degradation products and intermediaries can be a time consuming and expensive process. Often microbial species can be cultured which synthesize these complex molecules in vivo that might be difficult or impossible to synthesize in vitro. Springborn Smithers has developed techniques to use these organisms to assist in the identification of transformation products. Starting with a radio-labeled precursor, these microorganisms transform the chemical into the radio-labeled metabolites and intermediaries. These "tagged" compounds can in turn be used as reference substances in metabolism studies.

Microbial Toxicity

Springborn Smithers has the staff and experience to evaluate or assess your product for antimicrobial properties. Environmental chambers and incubators with controlled temperature, lighting, and humidity are available. Laminar flow hoods and dedicated laboratories rated to biosafety level two (BSL-2) enable use of a wide variety of microorganisms.

Microbial Growth Inhibition (FDA 4.02) with five types of microorganisms (soil bacteria, nitrogen-fixing bacteria, ascomycetes, molds and blue-green algae) and activated sludge inhibition studies (OECD 209) are routinely performed by SSL to assess the potential for pharmaceutical and other products to disrupt wastewater treatment.

Efficacy testing under EPA-FIFRA, USP, FDA etc. guidelines can be used to establish minimum inhibitory concentration (MIC) and EC-50 concentration of antimicrobials, pharmaceuticals, and pesticides using a wide variety of target microorganisms or microbial consortia (activated sludge, soil, natural water, etc.). The assays may be customized depending on application, and include exposure of the particular microbial culture to the chemical of interest followed by growth comparison.

Plate counts using selective culture media or respirometry may be accompanied by analytical confirmation of exposure concentrations, if desired.

Microbial Biotransformation/Biosynthesis

Springborn Smithers has routinely used 19 fungal, actinomycete and bacterial species which contain the cytochrome P450 enzyme system or other degradative enzymes to metabolize a wide variety of complex molecules. Metabolite profiles may be similar to those observed formed in mammalian, avian, fish, plant, sediment and soil systems, and may be identified using SSL's state-of--the-art analytical capabilities (GC/MS, LC/MS, LC/MS/MS). These species can be used to quickly screen for potential metabolites which may be formed during long term mammalian or ecological studies, and may also be harnessed to synthesize desired metabolites in larger quantities, with or without radiolabel.

See our Species List for the pure cultures maintained at Springborn Smithers Laboratories.

Microbiological Assays

Springborn Smithers uses microbial assays to detect residues of antibiotics in animal tissues, foods, and environmental samples. Complex extraction techniques are used to remove and concentrate the antibiotic from the particular matrix. The extracts are applied to agar well plates containing strains of microorganisms with extreme sensitivity to the antibiotic of interest, and zones of inhibition are measured.

Springborn Smithers also has capabilities to assess potential mutagenic properties of chemicals using the Ames test (OECD 471, EPA OPPTS 870.5100). Five mutant bacterial strains (Salmonella typhimurium and/or E. coli) are tested with and without exogenous metabolic activation. The ability of the test substance to induce reverse mutation suggests mutagenic potential and the need for further testing in mammalian systems.

Biomass Determinations

Biomass determinations are important in assessing the microbial health of a particular ecosystem. Springborn Smithers routinely determines biomass concentrations in soil to support soil metabolism studies. We employ three methods to assess the microbial population in soil: plate counts on selective media, chloroform fumigation/extraction and substrate induced respirometry. Biomass is also determined to assess the stability of microbial pesticides.

Soil Microflora

Our research centers in both Switzerland and Massachusetts have many years of experience in the assessment of potential effects of chemicals on non-target organisms such as microorganisms living in soil. Springborn Smithers Laboratories in both Switzerland and in Massachusetts conduct soil microflora testing according to internationally accepted guidelines published by the European Plant Protection Organization (EPPO, Chapter 7) and by Germany's Federal Biological Institute for Agriculture and Forestry (BBA Part VI, 1990). The analytical procedures employed for these studies are used to monitor microbial processes such as carbon mineralization (through short-term substrate induced respirometry) and nitrogen transformation (using methods such as ion chromatography).

Cytotoxicity

Cytotoxicity by the agar diffusion test may be used as an in vitro screen for biological safety and is applicable to biomaterials, solutions, and extracts. Contact with murine cells in the presence of neutral red solution causes decolorization, and these zones of lysis are rated macroscopically.