Most of us use both! We often store ground water in plastic containers (buckets). Sometimes we also observe a smooth, slippery layer that forms on the surface of plastic objects when ground water is kept in a plastic container for a few days.
Why does that happen?
Recently i read an article in THE HINDU regarding this. Let me quote it here:
| PROF. A. RAMACHANDRAIAH wrote: |
Microorganisms tend to survive everywhere. Unicellular, multicellular and strands-like algal and fungal species have their spores left abundantly in air, water and soil. Whenever suitable conditions emerge the spores germinate and the microorganisms grow their colonies.
A bucketful of water also may have such spores in their abundance if the water is dirty or from open source and not disinfected. However, these spores do not germinate vastly for want of contact ground or supporting surfaces.
Plastic objects or many solid objects may apparently look very smooth but their surfaces are rough and uneven at microscopic scale. Plastics, unlike metallic and clay objects, do not have ionic surfaces and are very benign for colonization of these microorganisms.
When plastic objects are in water for an extended duration, the algal spores or fungal hyphae find an appropriate contact surface for support and germinate to build their respective colonies on them by surviving from the suspended or available nutrients and dissolved oxygen in the aquatic surroundings.
It is these colonies of algal and/or fungal microorganisms that we feel as smooth, slippery and gel like layer formed on the surface of plastic objects kept in water for a few days. |
After reading it i was indeed mystified. I have often observed this phenomenon myself. But never really suspected that the ground water would contain many microbes. I therefore invested some time to explore on the Net. Soon I found a website that appeared to be quite authoritative. Its link is:
http://www.waterencyclopedia.com/La-Mi/Microbes-in-Groundwater.html
And to give an idea what info it contains, here's a bit of info it contains:
| Quote: |
Groundwater near the land surface usually teems with microbial life. Bacteria, which are microscopic single-celled organisms that lack a true nucleus and normally have a cell wall, are far more numerous than any other organism in the soil and groundwater. Near the surface where plant roots are abundant, there may be 100 million to 1 billion bacteria per gram of dry soil. These values decrease dramatically with soil depth below the root zone, with densities depending on the amount of nutrients (food) and water available. Although concentrations of microbes below the root zone are lower than in the root zone itself, as many as 10 to 100 million bacteria per gram of aquifer material may be present. Bacteria have been found in core samples from a depth of 2.8 kilometers (1.7 miles) below the Earth's surface, and at a depth of 3.2 kilometers in South African gold mines.
Protozoa, single-celled organisms that have a nucleus but lack a cell wall, also are common in groundwater. Protozoa typically are much larger than bacteria, and many types in groundwater feed on bacteria. Molds and other fungi also are common in groundwater near the land surface, where plenty of oxygen is present. These microbes are larger than bacteria and, unlike the protozoa, have a cell wall and often grow in long filaments. Most fungi feed on dead or decaying material. Algae may even be present despite the absence of sunlight. Similar to the bacteria, the numbers of protozoa, fungi, and algae decrease with depth.
A large variety of viruses probably are also common in groundwater. Viruses are much smaller than other microbes and cannot be seen with ordinary microscopes. They do not have a nucleus or cell wall, and can multiply only within the cells of larger organisms. The natural viruses in groundwater are able to reproduce only by infecting and usually killing the bacteria and other larger microbes present.
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