Grape Winery Waste as Feedstock for Bioconversions: Applying the Biorefinery Concept

Abstract

Grape wine is among the most important alcoholic beverages in the globe, with a continuously rising world demand, currently sizing at 25 billion litres. Such a large and heavily industrialised market calls for the maintenance of a steady production of raw materials to end products. Consequently, intensive cultivation of land, harvesting of the goods and manufacturing for the production of commercially available products are being implemented. Wine making is a timed, multistage process producing a large amount of organic and inorganic waste. It has been calculated that during cultivation and harvesting about 5 tonnes of solid waste are generated per hectare per year, while the winery wastewater varies according to the production size from 650,000 m 3 (Greece) to over 18,000,000 m 3 (Spain) per year. Conventional treatments of winery waste are becoming increasingly expensive, demanding significant amounts of effort, resources and energy for safe waste discharge. Therefore, the need to recycle, reuse and recover energy and valuable chemicals from winery waste and wastewater becomes apparent. Valorisation of winery waste is possible when introducing the concept of biorefinery, i.e. the use of winery waste as bioconversions feedstock in order to produce platform chemicals, biofuels, heat and energy.

Pleurotus spp. Cultivation on Different Agri-Food By-Products: Example of Biotechnological Application

“…Grape wine is one of the most important alcoholic beverages in the world, with a continuously increasing demand. It has been calculated that the wine industry produces wastes at about 5 tons per hectare of land per year [74], generating both solid and liquid wastes. Solid winery waste is composed of grape stalks, grape seeds, and grape marc.…”

“…Grape seeds are very rich in linoleic acid and omega-6 fatty acids, and phenolic compounds [76], and therefore can be used for the extraction of these bioactive molecules. Grape pomace is generally used as feed additive due to its high fiber content (up to 40%), but it also contains sugars, pigments and phenolic compounds [74]. Thanks to their high lignocellulose contents, solid winery wastes could be good candidates as growth substrates for mushrooms cultivation.…”

Intensive Production of Carboxylic Acids Using <em>Cl. butyricum</em> in a Membrane Bioreactor (MBR)

“…Collected samples which had been clarified by centrifugation were then filtered (0.2 μm pore size filter). [3] valve [4] Feed pump [5] Magnetic stirrer plate [6] stirring bar [7] pH probe [8] (Fig.3) was developed equipped with a ceramic membrane to process the nutrient media. The unit comprised of a pressure gauge, a 5 L of 76 cm depth and 12 cm diameter, conical fermentation vessel, equipped with stainless steel coils, gas inlet and outlet, feed/inoculation port, sampling port, and drain port at the bottom.…”

“…The carbon based economy, in the developed Western world is challenged due to fossil fuel scarcity and socioeconomic changes, constituting the formation of petroleum distillates, such as acetic and butyric acid from alternative sources an attractive option [2]. The production of carboxylic acids by fermentation, within the biorefinery concept ergo the biobased conversion of waste, plant biomass and other materials is becoming an effective choice applied to bench, pilot and industrial scale [3][4][5][6]. Acetic and butyric acid have numerous uses in the industry, as aroma enhances in food applications, components in cosmetics or precusors in bioplastics, their intensive production in large volumes is necessary.…”

Aerobic L-tartrate Utilization by Bacillus Isolates

“…Of the stereoisomers known, L-tartaric acid is most abundant in nature, found as chief component of grapes, bananas and tamarind. L-Tartrate also accumulates as a major by-product in wine industry and like other components in the winery waste it could be useful as potential feedstock for bioconversions to produce variety of industrially relevant platform compounds 9 . Therefore, microbial utilization of tartaric acid stereoisomers, specifically L-tartrate could be explored to develop industrially and pharmaceutically relevant bioprocesses like conversion of L-tartrate in winery waste to lactic and succinic acids 6,9 as well as biocatalysts like tartrate decarboxylase or TDH (in conjunction with decarboxylating oxaloglycolate reductase) capable of converting L-tartrate into chiral synthon D-glycerate 10 .…”