Related Experiment Video
Updated: Jul 19, 2026
12:37
Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Optimum melanin production using recombinant Escherichia coli
V H Lagunas-Muñoz1, N Cabrera-Valladares, F Bolívar
1Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico.
Journal of Applied Microbiology
|October 17, 2006
Summary
Researchers optimized conditions for converting tyrosine to eumelanin (EuMel) using recombinant E. coli. They achieved 100% tyrosine conversion and a record 6 g/L EuMel yield by controlling temperature, pH, and inducer concentration.
Area of Science:
- Biotechnology
- Biochemistry
- Microbial Engineering
Background:
- Eumelanin (EuMel) production from tyrosine is a valuable process.
- Recombinant Escherichia coli offers a potential platform for efficient EuMel synthesis.
- Optimizing fermentation conditions is crucial for maximizing EuMel yield.
Purpose of the Study:
- To determine optimal conditions for high-yield eumelanin production from tyrosine using recombinant E. coli.
- To investigate the effects of temperature, pH, and inducer concentration on melanin synthesis.
Main Methods:
- Utilized recombinant E. coli W3110 (pTrcMutmelA) expressing Rhizobium etli tyrosinase gene.
- Employed batch aerobic fermentor cultures with glucose-mineral media.
- Systematically varied temperature, pH, and isopropyl-D-thio-galactopyranoside concentration.
Main Results:
- Achieved 100% conversion of tyrosine to EuMel under optimized conditions.
- Identified optimal parameters: 0.1 mmol/L inducer, 30°C, and pH shift from 7.0 to 7.5.
- Reached a record yield of 6 g/L EuMel through tyrosine feeding strategies.
Conclusions:
- Temperature and pH are critical factors influencing tyrosine to EuMel conversion efficiency.
- This recombinant E. coli system provides a cost-effective and efficient alternative to traditional melanin production methods.
- The study demonstrates a scalable and high-yield bioprocess for producing valuable eumelanin.
Related Concept Videos
01:19Pigmentation
The color of the skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis. The melanin is transferred to the keratinocytes via melanosomes.
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
01:30Production of Pharmaceuticals
Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under sterile, tightly...