Microbial Analysis

Microbial Analysis

METHODS

Algae/Protozoa

1. Samples are observed as wet mounts to estimate numbers and types present
2. An appropriate aliquot is fixed and stained with Lugol's Iodine
3. Organisms are identified and enumerated using a Sedgewick-Rafter Counting Cell, or a settling chamber. A professional phycologist identifies the organisms using a large reference library, and culture collection.

Fungi

1. Samples for identification are prepared & dispensed onto a number of media for specific or general fungal isolation and/or enumeration. Agar plates are incubated at several temperatures and checked on a daily basis.
2. Organisms are enumerated (either from agar isolations or direct) using an appropriate microscope (with/without stains; epi-fluoresence, phase, DF, Nomarski, or dissection microscopy).
3. A professional mycologist identifies the organisms using a large reference library & culture collection.

Bacteria

A. Standard Methods for Coliforms (Total & Fecal) & Enterococci (Fecal Streptococcus)

1. Multiple tube fermentation (15 or 10 tube)
2. Membrane filter techniques
3. Modified MacConkey for Fecal Coliforms
4. Enzyme or antibody techniques

All media and components are pre-tested for sterility and ability to support the appropriate growth. Test results are checked with gram stains and alternative tests for confirmation.

B. Microbial Identification for Bacteria, & Yeast

1. Appropriate volume of sample is filtered through sterile 450nm membrane filter, or blended/diluted.
2. The filter contents are suspended in 2mL heart infusion broth.
3. Agar plates and liquid media are inoculated using appropriate volumes. Sample volumes are dispensed using calibrated loops (platinum APHA) & pipettes.
4. Inoculated plates and tubes are incubated at appropriate temperatures (such as 4, 20, 28, 35, 44.5, 55C) in aerobic, C02 enriched or anaerobic atmospheres -C02, H2 or N).
5. Colonies are enumerated and recorded.
6. Representative colonies are removed and identified using routine microbiological tests.
7. A professional microbiologist identifies the organisms using the tests, interactive identification programs and an extensive reference library and culture collection.

General Comments:

All filters are sterilized in individual filter holders to eliminate all cross-contamination between samples. All media are prepared in our laboratory and are pre-tested for sterility and ability to support the appropriate growth. Test results are checked with gram stains and alternative tests for confirmation.

Time Required for Microbial Identification:

Time will vary between a few days to several weeks. This is because the number and types of tests required and the organism(s)’s rate of growth will be dictated by the microbe not the laboratory.

Micro Identification Tests for Bacteria and Yeast

Typical Tests or determinations required to identify an organism

Notes:

• all tests adhere to internationally recognized methods. Where no ‘official’ methodology exists, all analysis are conducted with verifiable scientific practices
• all test media are pre-tested for ability to support appropriate growth
• positive and negative controls are used routinely
• temperatures are monitored electronically on a continuous basis
• shellfish are prepared as per Laboratory Procedures for the Examination of Seawater & Shellfish APHA 5th ed 1985. 6. 3-5 sub-samples are used throughout the protocols.

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