What are auxotrophic strains?

In genetics, a strain is said to be auxotrophic if it carries a mutation that renders it unable to synthesize an essential compound. Such a strain is unable to synthesize uracil and will only be able to grow if uracil can be taken up from the environment.

How are auxotrophic mutants detected?

Auxotrophic mutants were screened by a replica plating method. After exposure to UV, colonies grown on YPD medium plates (200 to 500 per plate) were replica plated on MM and YPD medium plates, and cells that failed to grow on MM were selected.

What are yeast auxotrophic mutants?

A wild-type yeast cell that has the ability to synthesize its own nutritional requirement is called a prototroph. Its mutant counterpart that loses the ability to synthesize an essential nutrient due to a DNA mutation somewhere in the biosynthetic pathway is called an auxotroph.

What do you need to know about auxotrophic mutants?

Auxotrophic mutants are strains that require a growth supplement that the organism isolated from nature (the wild-type strain) does not require. The auxotrophic lipid metabolic mutants are those that require the addition of fatty acids or other lipid precursors (for example, glycerol-P) to the growth medium.

How many auxotrophic mutants are there in yeast?

Auxotrophic mutants have been described for six of the eight enzymes in this pathway (Loppes and Heindricks, 1986), which resembles the pathway used in yeast and Neurospora. Many of the B. subtilis derivatives are auxotrophic mutants and require nutrient supplements for optimal growth on minimal medium.

How is auxotrophy used in biosynthetic pathway mapping?

This then allows for biosynthetic or biochemical pathway mapping that can help determine which enzyme or enzymes are mutated and dysfunctional in the auxotrophic strains of bacteria being studied. Researchers have used strains of E. coli auxotrophic for specific amino acids to introduce non-natural amino acid analogues into proteins.

How is Aspergillus used to study auxotrophy?

Aspergillus strains were studied for development of multiple gene deletion auxotrophic mutants. Collective mutations in genes intricated in color pigmentation (fwnA and olvA) with selected auxotrophic markers (pyrG, nicB, argB, and adeA) were used by targeted deletion, omitting UV mutagenesis of the strains ( Niu et al., 2016 ).