Optimization of bacterial cellulose production by Komagataeibacter sucrofermentans in synthetic media and agrifood side streams supplemented with organic acids and vitamins.

The effect of thiamine (TA), ascorbic acid (AA), citric acid, and gallic acid (GA) on bacterial cellulose (BC) production by Komagataeibacter sucrofermentans, in synthetic (Hestrin and Schramm, HS) and natural substrates (industrial raisins finishing side stream extract, FSSE; orange juice, OJ; green tea extract, GTE), was investigated. The Response Surface Methodology was found reliable for BC yield prediction and optimization. Higher yields were achieved in the FSSE substrates, especially those supplemented with AA, TA, and GA (up to 19.4 g BC/L). The yield in the non-fortified substrates was 1.1-5.4 and 11.6-15.7 g/L, in HS and FSSE, respectively. The best yield in the natural non-fortified substrate FSSE-OJ-GTE (50-20-30 %), was 5.9 g/L. The porosity, crystallinity, and antioxidant properties of the produced BC films were affected by both the substrate and the drying method (freeze- or oven-drying). The natural substrates and the process wastewaters can be further exploited towards added value and sustainability. Take Home Message Sentence: Raisin and citrus side-streams can be efficiently combined for bacterial cellulose production, enhanced by other vitamin- and phenolic-rich substrates such as green tea.

Mineral Montmorillonite Valorization by Developing Ni and Mo-Ni Catalysts for Third-Generation Green Diesel Production.

Four Ni catalysts and one Mo-Ni catalyst supported on montmorillonite were synthesized, characterized by various techniques and evaluated, under solvent-free conditions, for the production of green diesel from waste cooking oil. The optimum Ni content was found to be 20 wt.%. The addition of 2 wt.% Mo to the catalyst resulted in a considerable increase in the amount of green diesel hydrocarbons. The Mo species, moreover, led to a decrease in the (C15 + C17)/(C16 + C18) ratio, which is beneficial from the viewpoint of carbon atom economy. The promoting action of Mo was mainly attributed to the synergy between the oxygen vacancies on the surface of the well-dispersed Mo(V) and Mo(VI) oxides and the neighboring Ni0 sites. The optimum reaction conditions, for achieving a proportion of liquid product in the green diesel hydrocarbons (C15-18) equal to 96 wt.%, were found to be 350 °C, 3 g of catalyst per 100 mL of waste cooking oil and 13 h reaction time. These conditions correspond to an LHSV of 2.5 h-1, a value that is considered quite reliable from the viewpoint of industrial applications. Thus, the cheap and abundant mineral montmorillonite is proved a promising support for developing efficient Ni-Mo catalysts for green diesel production.