The phrase "a common competitor" is correct and usable in written English.
You can use it when referring to a competitor that is shared by two or more entities in a particular market or industry.
Example: "In the tech industry, both companies face a common competitor that dominates the market."
Alternatives: "a shared rival" or "a mutual competitor".
On the one hand, the two companies share an investor, the Japanese e-commerce giant Rakuten; and they also share a common competitor, the ridesharing behemoth Uber, and tying up their services, so that their loyal customers do not revert to using Uber when travelling, makes a lot of sense, since once they start they might simply jump to Uber when back home, too.
Second, since all aptamers are polyanions, another polyanion at high concentration, such as dextran sulfate, can serve as a common competitor that dramatically minimizes rebinding events in a multiplex assay.
The growth rates were determined against a common competitor in isolated cultures.
Similarly, two shops may be connected to one another through a mutual intermediary, but might be unaware that they are identifying a common competitor.
Fitness assays consisted of paired-growth experiments [ 22], which compared 24 hr growth on P. phaseolicola of a test genotype (or population) relative to a common competitor of φ6 bearing a genetic marker.
For completeness, we also determined whether the two groups of founding viruses differed in performance at high co-infection, by estimating the mean log10 W of each of the 24 strains relative to a common competitor, using repeated (n = 3) fitness assays.
In other assays the competitor was an engineered mutant bearing the alpha subunit of the Escherichia coli beta-galactosidase (β-gal) gene on the large RNA segment [ 21]; fitness comparisons among viruses were only conducted when the strains were competed against an identical common competitor.
Thus, for all 32 sequenced viruses we conducted fitness assays on PP against a genetically-marked common competitor that contained a host-range mutation on segment M, and an inserted X-gal mutation on segment L (see Methods).
When the common competitor was a host-range mutant, the ratios of competing genotypes in the starting mixture (R0) and in the harvested lysate (R1) were obtained by plating on mixed lawns of P. phaseolicola and P. pseudoalcaligenes (200 1 mixture), where ordinary and host-range genotypes form turbid and clear plaques, respectively.
The test strain and common competitor were mixed at a 1 1 volumetric ratio, and then a dilution of this mixture containing ~400 viruses was plated on a P. phaseolicola lawn.
"Our most common competitor is really a spreadsheet, or more likely, dozens of spreadsheets with customer names on them," he says.
