Characterization and Biolubricant Performance of Marinobacter alanticus Lipid Extract

Area of Science:

• Tribology and materials science.
• Biotechnology and sustainable chemistry.

Background:

• Petroleum-based lubricants face increasing demand for sustainable alternatives in tribology and energy sectors.
• Marine microorganisms are a potential source of novel biomaterials for lubrication applications.

Purpose of the Study:

• To evaluate the chemical and tribological properties of intracellular lipids extracted from Marinobacter atlanticus.
• To assess the potential of these bacterial lipids as renewable lubricants or lubricant additives.

Main Methods:

• Marinobacter atlanticus cells were cultured and intracellular lipids extracted.
• Lipid composition was analyzed using mass spectrometry.
• Thermal properties were determined by differential scanning calorimetry and thermogravimetric analysis.
• Tribological performance was evaluated using pin-on-disk tribometry.
• Bacterial lipids were blended with poly-α-olefin (PAO) and polyol ester (POE) base stocks.

Main Results:

• The lipid extract was primarily composed of wax ester palmityl palmitoleate, indicating suitability for boundary lubrication.
• The material exhibited a workable thermal window with a glass transition at 0°C, melting at 40°C, and degradation onset at 220°C.
• Neat bacterial extract showed a low friction coefficient (0.117) and wear rate (1.1 x 10^-8 mm^2/N), comparable to plant oils.
• Low-level additions (<5 wt.%) of bacterial lipids to PAO reduced friction and wear.
• The bacterial extract showed limited solubility in POE base stocks.

Conclusions:

• Lipids from Marinobacter atlanticus are a promising renewable resource for tribological applications.
• These lipids can function as effective standalone biolubricants or as drop-in additives for industrial formulations.
• The findings support the development of sustainable materials for the lubrication industry.