Starch-Derived Products for Detergents

Recent developments in the formulation of detergents have been driven by a strong consumer demand for natural and biodegradable products. Detergent manufacturers responded to this demand with corresponding products and advertising slogans such as “fully biodegradable”, “natural” or even “double natural” to oust their competitors. In a detergent formulation, starch- derived products can in principle be used for the following purposes: as the hydrophilic head group in surfactants, as the starting material for (poly)carboxylate co-builders and as the backbone of bleaching activators. Non-ionic classical surfactants can be replaced by alkylpolyglucosides (APGs), a class of products completely based on renewable resources such as glucose and fatty alcohols derived from natural fatty acids. Sodium tripolyphosphate (STPP), the product responsible for the eutrophication of surface waters, can be substituted by a combination of an inorganic zeolite and highly oxidised starch (dicarboxylic starch) or by citrate. Acetylated polyols derived from hydrogenated carbohydrates such as sorbitol can take over the function of the petrochemically-based tetraacetyl ethylene diamine (TAED) used as activator to allow perborate bleaching at lower washing temperatures.     

Erythritol,a New Raw Material for Food and Non-food Applications

In response to an increasing demand from consumers for healthier and calorie controlled foods, Cerestar has developed a new food ingredient, erythritol. Erythritol can be produced from starch by a full biotechnological process, combining enzymatic and fermentative conversions. The use of an osmophilic yeast allows the fermentation step to be performed at high dry substance, giving an economic advantage. An extremely pure end product is then easily obtained by final crystallisation. Erythritol is structurally a polyol and shares the health properties of other polyols such as being toothfriendly and safe for diabetics. However, it offers in addition two very important nutritional advantages: a lower calorific value (0.3 Kcal/g) and a good tolerance. This is due to its low molecular weight, which allows erythritol to be rapidly absorbed from the small intestine, with subsequent excretion in the urine. Fermentation in the colon is therefore excluded and any resulting gastro-intestinal discomfort avoided. The combination of these properties makes erythritol a unique low calorie bulk sweetener. From a functionality point of view, erythritol is a moderately sweet bulking agent with a cooling taste: workability is similar to other polyols. It has a taste profile close to that of sucrose and may therefore improve the taste quality of a blend with intense sweeteners. Its low solubility and ease of crystallisation, make erythritol very suitable for applications which require a crystalline sweetener, such as chocolate. Other potential application areas are bakery, table-top and confectionery. Presently erythritol is under evaluation to establish beyond any doubt its safety and to obtain food approval as a new, low calorie, bulk sweetener. Potential non-food applications of erythritol are in polymers, fine chemicals and pharmaceutical intermediates.     

Influence of growth conditions on biofilm development and mass transfer at the bulk/biofilm interface

In a long-term study on heterotrophic biofilms in tube reactors, this investigation focused on mass transfer at the bulk/biofilm interface, biofilm density and substrate conversion rates. Several biofilms were cultivated under different substrate and hydrodynamic conditions. Oxygen concentration profiles were measured with microelectrodes in the biofilm and in the boundary layer directly in the biofilm tube reactors. The thickness of the concentration boundary layer was found to depend on the surface structure of the biofilm. The hydrodynamic conditions and the substrate load during the growth phase of the biofilm in biofilm systems are two key parameters that influence the biofilm growth, particularly the structure, density and thickness. The measured substrate conversion rates, biofilm densities and the boundary layer thickness were used to formulate an equation for the mass transfer in biofilm tube reactors.     

Integrated energy in Germany–A critical look at the development and state of integrated energies in Germany

In the face of global warming and a scarcity of resources, future energy systems are urged to undergo a major and radical transformation. The recognition of the need to embrace renewable energy technologies and to move toward decarbonization has led to significant changes in the German energy generation, consumption and infrastructure. Ambitious German national plans to decrease carbon dioxide emissions on one side, and the unpredictable and volatile nature of renewable energy sources on the other side have elevated the importance of integrated energies in recent years. The deployment of integrated technologies as a solution to interlink various infrastructures creates opportunities for increasing the reliability of energy systems, minimizing environmental impacts and maximizing the share of renewable resources. This paper discusses the role of integrated energy systems in supporting of sustainable solutions for future energy transitions. Moreover, the reinforcement of this movement with the help of different technologies will be discussed and the development of integrated energy systems in Germany will be reviewed.     

Diamine oxidase supplementation improves symptoms in patients with histamine intolerance

Food Science and Biotechnology - Histamine intolerance (HIT) is thought to be caused by a disproportionate amount of histamine in the body. The enzyme diamine oxidase (DAO) is considered for the...     

Engineering of Saccharomyces cerevisiae for the production of (+)-ambrein

The triterpenoid (+)-ambrein is the major component of ambergris, a coprolite of the sperm whale that can only be rarely found on shores. Upon oxidative degradation of (+)-ambrein, several fragrance molecules are formed, amongst them (−)-ambrox, one of the highest valued compounds in the perfume industry. In order to generate a Saccharomyces cerevisiae whole-cell biocatalyst for the production of (+)-ambrein, intracellular supply of the squalene was enhanced by overexpression of two central enzymes in the mevalonate and sterol biosynthesis pathway, namely the N-terminally truncated 3-hydroxy-3-methylglutaryl-CoA reductase 1 (tHMG) and the squalene synthase (ERG9). In addition, another key enzyme in sterol biosynthesis, squalene epoxidase (ERG1) was inhibited by an experimentally defined amount of the inhibitor terbinafine in order to reduce flux of squalene towards ergosterol biosynthesis while retaining sufficient activity to maintain cell viability and growth. Heterologous expression of a promiscuous variant of Bacillus megaterium tetraprenyl-β-curcumene cyclase (BmeTC-D373C), which has been shown to be able to catalyse the conversion of squalene to 3-deoxyachillol and then further to (+)-ambrein resulted in production of these triterpenoids in S. cerevisiae for the first time. Triterpenoid yields are comparable with the best microbial production chassis described in literature so far, the methylotrophic yeast Pichia pastoris. Consequently, we discuss similarities and differences of these two yeast species when applied for whole-cell (+)-ambrein production.     

Solution Structure and Dynamics of the Small Protein HVO_2922 from Haloferax volcanii

Past sequencing campaigns overlooked small proteins as they seemed to be irrelevant due to their small size. However, their occurrence is widespread, and there is growing evidence that these small proteins are in fact functionally very important in organisms found in all kingdoms of life. Within a global proteome analysis for small proteins of the archaeal model organism Haloferax volcanii, the HVO_2922 protein has been identified. It is differentially expressed in response to changes in iron and salt concentrations, thus suggesting that its expression is stress-regulated. The protein is conserved among Haloarchaea and contains an uncharacterized domain of unknown function (DUF1508, UPF0339 family protein). We elucidated the NMR solution structure, which shows that the isolated protein forms a symmetrical dimer. The dimerization is found to be concentration-dependent and essential for protein stability and most likely for its functionality, as mutagenesis at the dimer interface leads to a decrease in stability and protein aggregation.