Microorganism indicator

The salinity of seas, oceans, hypersadine lakes and the Dead Sea is represented mostly by chlorides inland waters contain mostly carbonates and hydrocarbonates. Salts present in industrial wastewaters can influence the quality of underground and surface water. A variety of microorganisms indicate the presence of salts in water. For example, the diatom Thalassiosire fluviatilis is an indicator of potassium salts in wastewaters. 

The intracellular PHA depolymerase system can act very efficiently in MCL PHA producers. Carbon limitation often leads to extremely rapid depolymerization. The diversity of metabolic machinery among PHA-accumulating microorganisms indicates that unusual and potentially valuable PHA copolymers await discovery. 

Compounds of class (iii) are either totally synthetic (a few steroids) or derivatives of natural products isolated from plants or microorganisms. They are discussed within the indicated sections. We will briefly describe published syntheses of the most common compounds... 

Toxicity to fish is included in the data Hsted in Table 4. Marine life, particularly fish, may suffer damage from spills in lakes and streams. The chlorobenzenes, because they are denser than water, tend to sink to the bottom and may persist in the area for a long time. However, some data indicate that dissolved 1,2,4-trichlorobenzene can be biodegraded by microorganisms from wastewater treatment plants and also has a tendency to slowly dissipate from water by volatilization (34). 

Cumene is expected to exist almost entirely in the vapor phase in the atmosphere (13). In water, mixed cultures of microorganisms collected from various locations and depths in the Atiantic Ocean were all found to be capable of degrading cumene (14). A number of studies have examined the aerobic degradation of cumene in seawater and in groundwater (15,16). The results indicate that cumene would normally be naturally degraded to below detectable limits within a week to ten days. Cumene is tightly adsorbed by soil and is not significantly mobile in soil (17). 

One aspect of the basic equation describing biological treatment of waste that has not been referred to previously is that biomass appears on both sides of the equation. As was indicated above, the only reason that microorganisms function in waste-treatment systems is because it enables them to reproduce. Thus, the quantity of biomass in a waste-treatment system is higher after the treatment process than before it. 

Heterotrophic plate count n/a TT3 HPC has no health effects, but can indicate how effective treatment is at controlling microorganisms. HPC measures a range of bacteria that are naturally present in the environment... 

Turbidity n/a Tt3 Turbidity, a measure of water cloudiness, is used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present). Higher turbidity is associated with higher levels of microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. Soil runoff... 

MLVSS Mixed Liquor Volatile Suspended Solids - the volume of organic solids that can evaporate at relatively low temperatures (550 C) from the mixed liquor of an aeration tank. This volatile portion is used as a measure or indication of microorganisms present. Volatile substances can also be partially removed by air stripping. 

Estimates indicate that 10 tons of carbon dioxide are fixed globally per year, of which one-third is fixed in the oceans, primarily by photosynthetic marine microorganisms. 

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. 

Topical antibiotics exert a direct local effect on specific microorganisms and may be bactericidal or bacteriostatic. Bacitracin (Baciguent) inhibits the cell wall synthesis. Bacitracin, gentamicin (G-myticin), erythromycin (Emgel), and neomycin are examples of topical antibiotics. These drugp are used to prevent superficial infections in minor cuts, wounds, skin abrasions, and minor burns. Erythromycin is also indicated for treatment of acne vulgaris. 

---