Team:Stuttgart/Design
LIGHT UP THE PIPE - Four Parts for a better flow
RESEARCH
During the theroretical research and the brainstorming sessions we discovered many interesting projects: To filter fine dust with yeast flocculation, rose-scented Escherichia coli, and so on. In the end we decided to work on keratinases, esterases and lipases to develope a keranolytic Escherichia coli. The projects of past iGEM-teams were part of our investigation too and we are already co-working with iGEM-team OLS_Canmore 2015/2016 to exchange information. We would like to use the knowledge of these groundworks to develop a new type of enzymatic cleaning agent by complementing and combining ideas out of different scientific sources. To differ from other projects we are aiming to engineer Escherichia coli to express enzymes like proteases, keratinases, lipases, or esterases into the medium. Due to the extracellular expression expensive and time-consuming purification steps could be avoided and the enzymes could be secreted directly into the drain.
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PART I - EsterasesIn our project we used esterases for degrading the layer of grease and waxes on hair which increases the accessibility for the keratinases. We investigated two different esterases for their enzyme activity. One esterase from the registry (EstCS2 BBa_K1149002) and one esterase (LipB) supplied by Dr. Eggert from Evoxx were compared.
EstCS2EstCS2 from the iGEM Imperial College 2013 was proved to be active. In their project the cells expressing these construct were grown and lysed by sonication and were utilized in a colourimetric assay with the substrate analog para-Nitrophenyl butyrate. In our project we didn’t purify the esterases but used the supernatant for the enzyme activity assay. LipBEstCS2 from the iGEM Imperial College 2013 was proved to be active. LipB showed an enzyme activity of 2,8 U/mL in the supernatant. First, we repeated the enzyme activity assay from the iGEM TU Darmstadt 2012 to determine the esterase with the highest enzyme activity. |
PART II - LipasesBlablabla |
PART III - KeratinasesThe microbial synthesis of natural flavor compounds has become a very attractive alternative to the chemical production (1). In recent years microorganisms such as E.coli and Yeast have been metabolically engineered to produce different flavors like limonene, geraniol or rose (1,2,3). For our project we discussed different approaches and choose two different scents: rose and Limonene |
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PART IV - A lovely scent of ...The microbial synthesis of natural flavor compounds has become a very attractive alternative to the chemical production (1). In recent years microorganisms such as E.coli and Yeast have been metabolically engineered to produce different flavors like limonene, geraniol or rose (1,2,3). For our project we discussed different approaches and choose two different scents: rose and Limonene. |
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PART IV.1 - ... rose frangranceAs first special fragrance we want to install a lovely scent of rose in our microbial system. Hair are commonly made of Keratin (90%) and small amounts of amino acids, such as L-phenylalanine. This amino acid can be used as substrate for the production of 2-Phenylethylacetate (2-PEAc), which has a rose-like odor (1)
Therefor this odor can act as an indicator for keratin degradation. In recent studies from Guo et al the 2-PEAc biosynthetic pathway was successfully designed and expressed in E.coli (1). This pathway comprised four steps (Fig.1):
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PART IV.2 - ... limonene fragranceLimonene is a well-known cyclic monoterpene which can occur in two optical forms.2 (D)-Limonene is one of the most important and widespread terpenes in the flavor and fragrance industry, for example in citrus-flavored products such as soft drinks and candy.2 The (L)-Limonene form has a more harsh turpentine-like odor with a lemon-note.2 For our project we choose an enzyme-cascade, beginning with acetyl-coA and leading to the product (L)-limonene. This biosynthetic pathway was designed and inserted in E.coli. |
