IAS Gyan

Daily News Analysis


23rd August, 2023 Geography


The role of a specific type of bacteria called Alcanivorax borkumensis (Alca) in enhancing the biodegradation of oil.


  • The passage discusses the role of Alcanivorax borkumensis bacteria, also known as Alca, in enhancing the biodegradation of oil.
  • The researchers have discovered how these bacteria optimize oil consumption through the formation of dendritic biofilms around oil droplets.

Oil-Degrading Bacteria - Alcanivorax borkumensis

  • Alcanivorax borkumensis bacteria are categorized as obligately hydrocarbonoclastic bacteria (OHCB) due to their ability to consume hydrocarbons as their sole carbon and energy source.
  • OHCB, like Alca, play a crucial role in the bioremediation of petroleum spills worldwide.

Bloom During Oil Spills

  • Alca, a rod-shaped and aerobic OHCB, thrives on organic acids and alkanes present in crude oil.
  • During oil spills, Alca populations bloom to exploit the hydrocarbons within the spilled oil.

Role of Biofilm Formation

  • Alca bacteria form biofilms around oil droplets during the consumption of alkanes.
  • The function of biofilm formation in oil consumption by Alca remains unclear.

Microfluidic Device for Observation

  • Researchers developed a microfluidic device for real-time imaging of bacteria-covered oil droplets.
  • This device enabled the observation of biofilm development dynamics, from initial colonization to complete consumption of oil droplets.

Shift in Biofilm Morphology

  • Researchers noticed a change in biofilm morphology based on adaptations to oil consumption.
  • Newly exposed cultures formed thick spherical biofilms growing outward from the oil, while longer-exposed cultures developed thin biofilms with dendritic finger-like protrusions.

Dendritic Biofilms and Consumption Optimization

  • Dendritic biofilms altered oil-water interfacial tension, reshaping oil droplets as bacterial cells proliferated.
  • This reshaping increased the droplet's surface area, allowing more bacteria to feed simultaneously.
  • Alca's efficiency in oil consumption was optimized by expanding the interfacial properties of the droplets.

Multi-Species Microbial Community

  • The research emphasizes that Alca alone cannot degrade the numerous hydrocarbons in crude oil.
  • The degradation process requires a diverse microbial community that interacts and sometimes competes with each other.

Broader Implications and Future Directions

  • The findings provide insights into the mechanisms that drive oil biodegradation and transport in oceans.
  • Expanding the understanding from micro-scale interactions to macro-scaled multi-species processes can enhance our knowledge of oil spill mitigation.


Q) Explain the mechanism of dendritic biofilm formation and its role in optimizing oil consumption by Alca. Evaluate the broader implications of this research for environmental management and the sustainable mitigation of oil spills. (250 words)