Question

Berkley Pit​ lake

1. What types of microbes would one expect to be living in such polluted water?
2. Suggest some possible ways that microbes survive and even thrive under such conditions.
3. Identify an environment similar to the Berkeley Pit. Describe the environment, the pollutant and the possibility of environmental hazard, if you think it would cause one..

Answer 1

Berkeley Pit is an open pit located near the copper mining area in Butte, Montana, United States. It is filled with highly acidic water (2.5 pH level) rich in heavy metals such as Cu, As, Cd, Zn and sulfuric acid. The pit and its water is suppose to pose a serious environmental problem because the water is rich in pyrite, sulfide and high dissolved oxygen content which causes decay of minerals present in the ore and wall rocks releasing acid.

1.      In a polluted water like this we expect to find microbes such as certain species of fungi and bacteria that are adapted to survive in such extreme environmental conditions ( highly acidic waters). These microbes are called as extremophiles. Andrea A. Stierle, and Donald B. Stierle have reported the presence of a protozoan species named Euglena mutabilis inside the pit. The species have been found to well adapted to the harsh conditions of the water. The conditions such as competition for the limited resources lead to its evolution as species that produces highly toxic compounds, natural products such as Berkeleydione, Berkeleytrione, and Berkelic acid to improve its survivability. These substances have been found to possess anti-cancer and anti-inflammatory activity. Some of these species are also found to ingest metals and hence possess the potential for cleaning water. Besides this some antibiotic-resistant bacteria, species of fungi have also been found in the tailing pond that produce a new compound that kills multiple strains of methicillin-resistant Staphylococcus aureus (MRSA). Till date two species of algae, Euglena mutabilis Schmitz and Chlamydomonas acidiophila Negoro, and some protozoans, fungi, and bacterial species have been reported to be found in samples of Berkeley Pit but many remain yet to be identified.

1.      The microbes or the extermophiles that survive in extreme environments such as intense heat, highly acidity, high pressure and extreme cold possess the machinery that help them to sustain life. They develop certain features/adaptations that help them to overcome adverse environmental conditions. Thermophiles are the microbes that survive in high temperature conditions. Thermus aquaticus, bacteria has been discovered from the hot springs in Yellowstone National Park. It can survive temperatures of 70°C (160°F). Later some species were also found to surviving in hydrothermal vents found deep in the ocean under such high pressure with water boiling up to 340°C. In most of the species, chemolithoautotrophic mode of nutrition is seen. In this mode a inorganic redox reactions serve as energy sources (chemolithotrophic) and CO2 is the carbon source required to build up organic cell material (autotrophic). Membrane lipids of these species contain a novel glycerol ether lipid, 15,16-dimethyl-30-glyceryloxy-triacontanedioic acid and esterlipids which significantly increase the stability of membranes against hydrolysis at high temperatures.
                   Extremophiles known as psychrophiles survive at low temperatures of 2°C. The species adapt to low temperature conditions by developing substances such as glycerol or antifreeze proteins which lower the freezing point of water by several degrees. Some organisms also adapt to cold conditions by forming symbiotic relationships with other organisms.

2.      Lake Karachay is another such example. This water body is located in central Russia. One square mile of water found in the lake is dumped with nuclear waste. The lake shows the presence of highly radioactive waste. Radiation of around 6 Sv/hour, have been measured in the area near the lake. This dose has been found to be lethal for humans and other living beings.   A 21 percent increase in cancer incidence, a 25 percent increase in birth defects, and a 41 percent increase in leukemia has been noted in the surrounding region of Chelyabinsk in the last decade.