cane molasses as a source of precursors in the bioproduction of tryptophan by bacillus subtilis.

background and objectives: the essential amino acid l-tryptophan can be produced by a condensation reaction between indole and l-serine, catalyzed by b. subtilis with tryptophan synthase activity. application of the tryptophan is widespread in the biotechnology domain and is sometimes added to feed products as a food fortifier. materials and methods: the optimum concentration of the iranian cane molasses was determined by measuring the amount of biomass after growth in 1 to 30 g/ml of molasses. the maximum amount of biomass was obtained in 10 g/ml molasses. chromatographic methods, tlc and hplc, were used to assay the amount of tryptophan produced in the presence of precursors of tryptophan production (indole and serine) and/or molasses. results: our results indicate the importance of the iranian cane molasses not only as carbon source, but also as a source of precursors for tryptophan production. conclusion: this report evaluates the potential of cane molasses as an economical source for tryptophan production by b. subtilis, hence eliminating the requirement for additional serine and indole as precursors.