Using hydrolyzed feather powder to replace tryptone for producing a novel bacterial medium

Abstract:

[Objective] In this study, since hydrolyzed feather powder is a kind of good nitrogen-containing material rich in a wide variety of amino acids, it is used to replace the tryptone, a common component in Luria-Bertani medium for cultivating bacteria, thus to develop a novel bacterial culture medium and recycle the waste resource. [Methods] Absorbance at 600 nm of the fermentation broths detected by turbidimetry and culture-dependent method were used to analyze the effect of media on cell growth. [Results] Compared to the LB medium, no significant difference or more abundance in the growth of the tested bacteria was observed when peptone was completely replaced by hydrolyzed feather powder and the biomass of type strains (Escherichia coli and Bacillus subtilis) tested, increased by 21.59% and 27.83%, respectively. Results of bacteria-growth curves showed that a bit delay at the initial phase and an extended logarithmic phase of the tested strains were observed in the novel medium. However, the biomasses of the strains tested at stable phase in the novel medium were higher than those in the control. Meanwhile, results from culture-dependent method also showed that no significant differences for the number of type strains were observed between the two media. [Conclusion] In conclusion, the hydrolyzed feather powder was able to replace tryptone to create a novel low-cost but high-quality medium.