The working group is composed by people coming from three organization units of the University of Pavia:

• Center for Health Technology (CHT)
• Department of Biology and Biotechonology "Lazzaro Spallanzani" (DBB)
• Consiglio Nazionale delle Ricerca - Instituto di Genetica Molecolare (CNR-IGM) 

Our project aims to valorize bio-wastes which will be used as feedstock for industrially relevant bacterial fermentation processes, in order to support the development of a green economy era in Italy.

Synthetic biology concepts will be adopted to rationally modify cellular metabolic pathways of the microorganisms considered and to optimize the conversion of waste streams in added-value products. Synthetic biology is an emerging field of bioengineering which aims at realizing novel biological functions by predictably programming DNA molecules from basic parts, like electronic components are assembled to form a circuit with desired behaviour. Such new research area represents an extension of molecular genetics, with additional key features from the engineering world, like abstraction, modularity and model-based design to enhance its potential and enable higher complexity.

Efforts will be focused on two different biomolecules that have raised high expectations in the biotech market industries:

• - Ethanol through Escherichia coli fermentation from dairy waste.

  Cheese whey is an abundant by-product of the cheese production process and it is considered a special waste under the Italian legislation due to its high nutritional load and hypertrophic potential. Technologies for whey valorization are available that convert such waste into high-value products, like whey proteins. However, the remaining liquid (permeate) is still considered a polluting special waste due to its high lactose concentration, and permeate downstream processing (e.g. lactose extraction) is not always economically convenient. Hence, the engineering of E. coli bacteria to improve fermentation of lactose into ethanol will simultaneously achieve two important goals: safe disposal of a pollutant waste and green energy production.

• - Poly gammaglutamic acid (γ-PGA) production through Bacillus subtilis fermentation of glycerol from biodiesel industry waste.

  Glycerol is generated as stoichiometric by-product with a 10% (w/w) ratio with respect to biodiesel produced. Beyond some well consolidated utilizations, there is a low cost surplus of crude glycerol that can be used as feedstock for bacterial fermentation, contributing to defray biodiesel production costs. The B. subtilis bacteria will be rationally modified in order to obtain γ-PGA from glycerol. γ-PGA is a biopolymer that has a large number of appealing biotechnological applications, ranging from the biomedical field to bioremediation.