Q.Can you suggest a method to remove oil (hydrocarbon) from seeds based on your understanding of rDNA technology and chemistry of oil?

Yes, you can use recombinant DNA technology to modify the oil composition in seeds so that the oil becomes easier to remove or is produced in a form that is more extractable. The key idea is to alter the genes responsible for oil synthesis in the seed.

First, identify the genes that code for enzymes involved in the biosynthesis of long-chain fatty acids or triglycerides. Using rDNA techniques, you can introduce a gene that either:

• Converts the oil into a less viscous or more polar form (e.g., by increasing short-chain or unsaturated fatty acids), or
• Produces an enzyme that breaks down the oil into smaller, water-soluble components within the seed.

For example, you could insert a gene for a lipase enzyme that is expressed only during seed maturation, so that the oil is partially hydrolysed into free fatty acids and glycerol. These products are more water-soluble and can be washed out with aqueous solvents rather than requiring organic solvents. …

The question asks for a method to remove oil from seeds using rDNA technology and chemistry of oil. This is a creative application that blends biotechnology with industrial processing. Let’s first understand the chemistry of oil in seeds. Oils are triglycerides—esters of glycerol and three fatty acids. They are stored in seed cells as energy reserves, often in structures called oil bodies, surrounded by a layer of proteins and phospholipids. To extract oil, we typically crush seeds and use solvents like hexane, which dissolve the oil. But the question hints at a more elegant, biotechnological approach.

Recombinant DNA technology allows us to modify organisms to produce specific enzymes. The key here is to target the chemical bonds in triglycerides. If we can break those bonds, the oil becomes water-soluble or easier to separate. One natural way is using lipases—enzymes that hydrolyze triglycerides into glycerol and free fatty acids. Glycerol is water-soluble, and fatty acids can be emulsified or removed with mild detergents. So, the idea is to engineer a microbe (like E. coli or yeast) to produce a lipase that works efficiently at the conditions needed for seed processing.

Here’s how it could work in practice. First, identify a lipase gene from a fungus or bacterium that naturally degrades oils. Using rDNA techniques, insert this gene into a host organism that can be grown in large quantities. The engineered microbe is then cultured, and the lipase enzyme is harvested and purified. Alternatively, the whole microbe could be applied directly to crushed seeds, but that might introduce contaminants. The purified lipase is then mixed with crushed, moistened seeds. The enzyme breaks the triglycerides into glycerol and fatty acids. Glycerol dissolves in water and can be washed away. The fatty acids can be separated by adjusting pH—they form soaps with alkali, which are water-soluble and can be removed. The remaining seed meal is now oil-free and can be used for protein extraction or animal feed.

Method — reverse-engineer from the goal

Goal: get oil OUT of the seed more easily. Two rDNA levers achieve this:

• Change the oil's chemistry (introduce a gene for enzymes that shorten/unsaturate fatty acid chains → less viscous, easier to extract). …