Microorganism growth

Inorganic Acids. Strong inorganic acids have little antimicrobial activity in themselves but inhibit microorganism growth by lowering the pH. Disinfectant toilet bowl cleaners that contain 9.5% HCl or more are antimicrobial. Carbonic acid [463-79-6] in soft drinks provides some antibacterial preservation. Sulfurous acid [7782-99-2] is an effective preservative used to preserve wines (see Wine), fmit juices (qv), and dried fmits. 

Measure the optical cell density of S. cerevisiae at a wavelength of 520 nm. Try to collect data based on information required in Table 10.1. Draw a growth curve based on incubation time and cell dry weight. The cell concentration is an indication of microorganism growth. A standard calibration curve is needed before any actual experiment. 

Activity improvement via co-expression or supplementation of the fourth enzyme DszD, the flavoprotein which provided reduced co-factor to DszC and DszA, was found to be successful [297,298], [126,299], Additionally, providing nutrient broth to favor the microorganism growth was also successful in activity improvement [300],... 

Liver tissue B12 is assayed by suspending 50 mg of lyophilized human liver in 100 ml of aconitate buffer to which 100 mg sodium metabisulfite is added. The suspension is autoclaved for 30 minutes at 16 psi to liberate the bound forms of the vitamin. Aliquots are diluted 1 10 after autoclaving to reduce metabisulfite toxicity on microorganism growth. Each milliliter now contains 50 pg of liver (w/v) 1.0, 1.5, and 2.0 ml of this hydrolyzate is added. After dilution to a volume of 5 ml, this represents an assay of 10, 15, and 20 ig of liver per milliliter of final solution. Normal liver contains between 2-14 mpg of vitamin B /mg liver powder. 

The increasing popularity of biodegradable materials, which are more susceptible to microbial attack, has boosted the demand for preservation. If the product does not already contain ingredients that are themselves preservatives, such as cationic surfactants, acids, or bases, preservatives may need to be added. The required level of preservatives can be related to water availability (AW), which is defined as the ratio between the water vapor pressure over a substance and the water vapor pressure over pure water at the same temperature [17], In general, an A W of below 70% should be targeted to prohibit microorganism growth [18],... 

One concern about biological treatment is the potential toxicity of pesticides, which could inhibit microorganism growth. Results from bench-scale treatability studies performed by one pesticide plant showed that a pesticide in concentrations up to 3000 mg/L did not inhibit aerobic degradation of sewage at typical aerator food-to-microorganism ratios [7]. 

Microbial sensors usually possess long lifetimes, yet proper maintenance is mandatory. Thus, the overall activity of immobilized microorganisms should be kept as constant as possible. For this purpose, sensors should be stored in phosphate buffer containing no nutrients at 4°C in order to avoid microorganism growth in the membrane. If the sensor activity diminishes for some reason, then the sensor should be dipped into a nutrient medium... 

The vendor claims that the addition of oxygen during air sparging enhances the aerobic microorganism growth, accelerating breakdown of contaminants in the aquifer. 

A plethora of lactase-treated products are described in the literature (Zadow 1984 Holsinger 1978). The use of hydrolyzed lactose syrups has been proposed as an alternative sweetener to corn syrup solids. Storage of syrups as concentrated liquids can be a problem due to microorganism growth or to extensive precipitation of residual lactose or galactose. Generally, both problems can be controlled by storage at -10 to -20°C if syrup total solids were around 70%. Guy (1979) has reported on the sweetness of hydrolyzed, demineralized syrups. 

Typical response times are of the order 15-30 minutes (i), days (ii), and several days (iii). The net microorganism growth rate is a key design parameter and its reciprocal is termed sludge age or mean cell residence time. An adequate control has to take into consideration, that the growth rate is time-varying (5). 

The glucose was determined enzymatically (Yellow Springs Instruments). The response time of the complete analyzer system was ca. 37 min, of which 5 min are due to the transfer distance of 3 m between the reactor, filtration module and analyzer system. The continuous air segmented flow analyzers have the disadvantage that after 3-4 days operation, microorganisms growth was detected in the non aseptic analyzer system. 

Spontaneous combustion can arise from exothermic chemical reactions of some materials, e.g., with water, or through the action of microorganisms. Microorganism growth can heat a medium to about 70°C where, although the heat is sufficient to kill the microorganisms, the increased temperature may be sufficient to rapidly increase the rate of some other chemical reaction which subsequently raises the temperature of the medium to the combustion point (Cross and Farrer, 1982). 

There are several acids that are widely used in industries. For example, synthetic carboxylic acid esters are used in the perfume industry. Benzoic acids are used as sodium salts in the food industry as inhibitors of microorganism growth. ... 

Preservatives Prevent microorganisms growth Hydrogen peroxide u J ... 

---