Wednesday, February 1, 2012

Pseudomonas aeruginosa, Aspergillus: Natural way of dealing effectively with oil spills

Syed Akbar
Hyderabad: Oil spills is a major environmental problem and
researchers from Visakhapatnam have found a natural way to clean up
petrol, diesel and oil released during ship accidents on high seas,
and by ship-breaking units on the coast.

They have identified five strains of bacteria and three strains of
fungi that eat away hydrocarbons like petrol, diesel and oil.
Incidentally, these bacterial and fungal strains are opportunistic
parasites and cause severe health problems in human beings and
animals. But from the point of environment, these bacteria feed on oil
pollutants, clean up the area without leaving any residue, and serve
as natural scavengers in case of major oil spills.

“The methods now adopted the world over to clean up oil spills involve
use of chemicals, which though help in removing oil, cause damage to
the local ecology. The bacterial and fungal strains we have found do
their job naturally without harming the environment,” said Dr Ch
Pavana Jyothi, assistant professor of microbiology, Gitam University,

The team led by Dr Joythi collected four oil contaminated soil samples
from different locations in Visakhapatnam, mainly iron ore dump yards
and Hindustan Petroleum Corporation Limited (HPCL). The researchers
found strains of bacteria like Proteus vulgaris, E coli, Enterobacter
species, Pseudomonas species and Staphylococcus species and three
fungal strains of Aspergillus species. Of them Pseudomonas and
Aspergillus were studied for oil spill cleaning capabilities.

“We have selected Pseudomonas aeruginosa and one Aspergillus species
for hydrocarbon degradation. The degradation efficiency of petrol was
57 per cent, diesel 28 per cent and engine oil 10 per cent in case of
Pseudomonas aeruginosa at 37 degrees C for 7 days. In case of
Aspergillus species, the degradation efficiency of petrol was 56.6 per
cent, diesel
28 per cent and engine oil 10 per cent,” she said.

If both the organism were used for degradation, the efficiency
increased to 81 per cent in case of petrol, 41 per cent in case of
diesel  at 37 degrees C for six days.

She said as many as 60 organisms were found from the oil-contaminated
soil and further studies are on to find out if other species of
bacteria and fungi are useful in cleaning oil spills. The efficiency
of cleaning oil spills increased as the temperature increased. At 42
degrees C the efficiency was the highest, though the organism started
converting hydrocarbons at 37 degrees C. For tropical areas like India
and countries in the Indian Ocean, these organisms could be used to
clean up oil spills on the high seas and in ship breaking units, Dr
Jyothi added.

No comments: