New bioantioxidants, biopreservers and bioantifungal obtained by fermentation of agroindustrial subproducts.

Description of the technology

A Spanish research group from the Department of Microbiology and Parasitology of Alcalá University has obtained new natural high value added products such as antioxidants, preservatives and anti-fungals, through the fermentation and/or digestion of agro-industrial sub-products, destined to feeding and control of phytopathogens using selected actinomycetes strains in pure or mixed culturing and/or enzymes. The group is looking for license agreements.

Specifications

The industries that use vegetables as raw materials obtain hundreds of thousands of tons of by-products per year. These agro-alimentary industries, where we might mention the sugar refinery and brewery industries, usually allocate these by-products to animal feeding. This research group is working to obtain greater advantages from these sub-products through fermentation processes, in order to obtain high value-added natural substances such as antioxidants, preservers and anti-fungals. Agro-industrial by-products generally contain high amounts of carbohydrates and phenolic compounds such as cyanic acid. An example of cyanic acid is the ferulic acid which is an intermediate substrate in the production of vanilla (very important in the food industry). It also can be used as a powerful antioxidant (cosmetics and food industries) and as an effective UV-protector (important in textile industries). Over the last ten years, several studies have described the enzymatic activity of releasing ferulic acid from several agro-materials by using different types of microorganisms. Very few studies have been carried out on the enzymatic ferulic-esterase activity of bacterias, and in particular of streptomycetes. This research is the first in this area. Streptomycetes belong to the group of actinomycetes, which are Gram positive soil bacteria and play an important role in the degradation of vegetable biomass in soil. The activity of ferulic esterases on insoluble substrates increases with the addition of different carbohydrolases, which are involved in the cell wall degradation, as it happens with pectinases in the sugar-beet pulp or xylanases in cereal bran. We are currently researching in these activities during the fermentation process of these substrates and so far we have managed to clone and overproduce a xylanase. These carbohydrolases make soluble different sizes of ferulated residues. These are subsequently a substrate for esterases, so this increases their efficiency. Moreover, these enzymes, when acting on plant material, produce oligosaccharides which may stimulate plant resistance against phytopathogens or inhibit their own hydrolytic enzymes produced by the phytopathogens in order to damage the plant cell and be able to invade the host. Other kind of hydrolytic enzymes, such as chitinases, are able to hydrolyse the cell wall of phytopathogenic fungi. Finally, we must stress the importance of enzymes like the esterases in the biological control mechanism, as they can release cinamic acid ester compounds with antifungal activity from vegetable substrate. Very few studies have been carried out on the ferulic-esterase activity of bacteria, and in particular in streptomycetes, being our research group one of the pioneers in this area.

Main advantages of its use

• - Involves an environmental improvement.
• - These products are obtained from secondary products thus increasing profits.
• - This technique is intended to add value to agricultural products in most cases are used as supplements in animal feed. Natural products obtained would therefore not subject to the regulation of synthesis products intended for human consumption as antioxidants and / or preservatives, or as antifungal agents for controlling plant pathogens.

Applications

• This research group is looking for companies from the agro-alimentary sector interested in profiting from agro-industrial sub-products. The products obtained could be used for human and animal consumption. They also look for companies that are interested in implementing this technology as an environmental improvement in their production plants of agricultural products. The interested company would have to install a lab for the fermentation of the sub-products.