Microbial checks

Part of the company s quality control system should involve inspection of raw materials prior to use. Obviously contaminated products exhibiting one or more signs of microbial infection should not be used and any doubtful materials should be checked by the user, the supplier or a third party. 

Deodorants are also targeted to the skin surface to keep microbial growth in check. They slow or prevent rancidification of the secretions of apocrine glands found in and around the axillae (armpits) and the anogenital regions. Medicated soaps also belong in this family. 

After all the answers from the interviews had been uploaded, an expert analysed each supply chain for each of the seven defined criteria for quality and safety microbial toxins and abiotic contaminants potential pathogens natural plant toxicants freshness and taste nutrient content and food additives fraud social and ethical aspects. For example, an expert on freshness and taste would check each major step in a supply chain for tomatoes to determine if it fulfilled the definition of a CCP (HACCP, Principle 2) in relation to freshness and taste for this commodity. If the step was considered to be a CCP, the answers in the questionnaire that related to relevant substeps at this step would be reviewed, to assess the control procedures that were in use for this CCP. The expert would then fill in the text field, structuring the input to consist of the following points ... 

Food additives such as preservatives, sweetening agents, flavours, antioxidants, edible colours and nutritional supplements are added to the food to make It attractive, palatable and add nutritive value. Preservatives are added to the food to prevent spoilage due to microbial growth. Artificial sweeteners are used by those who need to check the calorie Intake or are diabetic and want to avoid taking sucrose. 

The hrefly Inciferin system is very sensitive and can be conpled to any enzymatic reaction that prodnces or nses ATP. For example, creatine phosphokinase can be determined by this method and hence be nsed in the diagnosis of myocardial infarction and mnscle disorders. The creatine phosphokinase converts AMP into ATP which then nndergoes the reaction with Inciferin as shown in Fignre 3.25. ATP pro-dnction is essential for every known life form and the firefly Inciferin system can be nsed to check for microbial life. Hence systems have been developed that use a portable luminescence workstation to monitor sanitation in food manufacturing and to check for sterile environments in technological workplaces. The system can also be applied in checking cell viability, for instance in cell cultures and to measure the toxic effects of chemicals on cells. 

Check fuel-water interface for microbial growth. 

Microbial (using L leichmanii, O, malhamensis, E. gracilis, etc.) bioassay methods are used, as are checking the effects of curative doses 011 experimental animals (chick, rat, etc.). Physicochemical methods used include spectrophotometry, polarography, and isotope dilution. 

Drugs such as tetracycline and chloramphenicol affect a wide variety of microbial species and are referred to as broad spectrum antibiotics (Figure 28.6C). Administration of broad spectrum antibiotics can drastically alter the nature of the normal bacterial flora and can precipitate a superinfection of an organism, such as Candida whose growth is normally kept in check by the presence of other microorganisms. 

To study and quantify microbial diversity one has to define what a species is. This is not a trivial objective since bacteria reproduce asexually and interbreeding cannot be applied for traditional species definition. While individual species of higher organisms may differ by as little as 1 % in their respective DNA, bacterial strains differ by up to 30%. Beside the so called species problem in microbiology, it is a widely accepted concept that bacteria with 16S rRNA gene sequences with similarity more than 98.7% (checked by DNA DNA hybridisation) belong to the same species. 

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