Utilization and biodegradation of starch stillage (distillery wastewater)

Abstract

Stillage (distillery wastewater) is the main by-product originating in distilleries, and its volume is approximately 10 times that of ethanol produced. It is not surprising that the utilization of the stillage raises serious problems, and that many attempts have been made all over the world to solve them. In Poland most of the ethanol (about 90%) is produced from starch-based feedstocks, i.e. grains and potatoes. Starch feedstocks are widely used for spirit production also in other European countries, as well as outside Europe. The manuscript provides an overview of global fuel ethanol production and information on methods used for starch-based stillage biodegradation and utilization. The methods presented in this paper have been classified into two major groups. One of these includes the mode of utilizing starch stillage, the other one comprises methods, both aerobic and anaerobic, by which the stillage can be biodegraded.Scarcely 5 per cent of world's ethanol production comes from chemical synthesis. More than 95 per cent of the *Corresponding author ethanol produced is obtained from agricultural or agriculture-related feedstocks. Of these, sugar-based feedstocks account for approximately 42%, and non-sugar feedstocks (mainly starch-based ones) for about 58% of the ethanol volume produced (Tolmasquim, 2007). It seems interesting to note that about 67% of the global ethanol volume (in 2006 this was a total of 39 billion litres (REN21, 2008)) is used for fuel production.

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

“…wastewater, has not been widely used as biotechnological conversion feedstock [109,119]. Limited studies have been conducted, with winery wastewater being used as substrate for Gluconacetobacter xylinus for the production of cellulose at a 6.26 g L -1 [110,111]. Other studies involve the use of fungi, Trichoderma viride, Aspergillus niger and Aspergillus oryzae for the production of SCP at a 5 g L -1 and a simultaneous reduction of COD to 90 % [112].…”

Optimization of biogas production from wheat straw stillage in UASB reactor

“…Stillage, also termed as distillery wastewater, distillery slops, distillery spent wash and thin stillage, is an aqueous by-product from the distillation of ethanol following fermentation of carbohydrates. Stillage production volume has been estimated to be 10-20 times that of ethanol produced and has a considerable pollution potential [2,3]. Depending upon the ethanol process and stillage treatment, the chemical oxygen demand (COD) load of the liquid phase of stillages can range from 10 to 100 g O 2 /l [see reviews e.g.…”

Astaxanthin synthesis by Xanthophyllomyces dendrorhous DSM 5626 and its astaxanthin overproducing mutants on xylose media under diferent illumination

“…vitamin B) are essential for the appropriate development of X. dendrorhous. Although vitamin B complex is present in the stillage [Krzywonos et al 2009], following enzymatic hydrolysis stillage was centrifuged and all solids were removed, including also residual yeast, being a source of nitrogen and vitamins B. Such prepared medium was most probably too defi cient in substrates other than carbon and in biostimulants in contrast to YM-K medium, which completely covered the nutritional requirements for yeast.…”

“…Liquid stillage may be a cheap and valuable source of nutrients required for microbial growth [Krzywonos et al 2009]. In turn, a problem is connected with the low content of dry matter and thus readily available carbon substrate.…”