Application of ESI FT-ICR MS to Study Kraft Lignin Modification by the Exoenzymes of the White Rot Basidiomycete Fungus TrametesHirsutaLE-BIN 072

Trameteshirsuta is a wood rotting fungus that possesses a vast array of lignin degrading enzymes, including7 laccases, 7 ligninolyticmanganese peroxidases, 9 lignin peroxidases and 2 versatile peroxidases. In this study,electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS)was used to examine kraft lignin modification by the enzymatic system of this fungus.The observed pattern of lignin modification suggested that before the 6th day of cultivation,the fungal enzymatic system tended to degrade more oxidized moleculesand, hence, less recalcitrant molecules, with the production of hard-to-modify reduced molecular species. At some point after the 6th day of cultivation,the fungal enzymatic system tended to degrade more oxidized moleculesand, hence, less recalcitrant molecules, with the production of hard-to-modify reduced molecular species. At some point after the 6th day of cultivation,the fungus started to degrade less oxidized, more recalcitrant, compounds, converting them into the more oxidized forms. The altered pattern of lignin modification enabled changes in the fungal enzymatic system. These changes were further attributed to the appearance of the particular ligninolyticmanganese peroxides enzyme(MnP7), which was added by the fungus to the mixture of enzymes that had already been secreted (VP2 and MnP5). Keywords: wood rotting fungi, kraft lignin, mass spectrometry, peroxidase

Analytical Characterization of the Widely Consumed Commercialized Fermented Beverages from Russia (Kefir and Ryazhenka) and South Africa (Amasi and Mahewu): Potential Functional Properties and Profiles of Volatile Organic Compounds

In this study, four commercialized indigenous fermented beverages most highly consumed in Russia (kefir and ryazhenka) and South Africa (amasi and mahewu) were analyzed for their potential health-promoting properties and flavor-forming volatile organic compounds (VOC). The analysis of antioxidant capacity demonstrated superiority of dairy-based beverages (kefir, ryazhenka and amasi) over the corn-based mahewu; however, mahewu outperformed dairy-based beverages in terms of its potential antihypertensive effect (i.e., the ability to inhibit angiotensin I converting enzyme). The fatty acid (FA) content of kefir and ryazhenka were more diverse compared to that of amasi, but included a lesser amount of branched chain FA. In terms of calculated FA nutritional indices (e.g., indices of atherogenicity and thrombogenicity), kefir and ryazhenka performed similarly and significantly better than amasi. The agreement between beverages theoretical flavor profiles, which was obtained based on the flavors of individual VOC, and consumers’ flavor perception allow hypothesizing about the contribution of detected VOC to the overall products’ flavor. The obtained data expand current knowledge regarding traditional fermented beverages and their values in terms of national dietary recommendations. Additionally, reported VOC profiles will promote the inclusion of traditional fermented beverages into the rations based on the flavor pairing concept (which is controversial but widely applied)

Functional Properties and Metabolic Profile of National Fermented Products of Russia and South Africa

. Both Russia and South Africa have a long-standing history of fermented milk product consumption. Along with the products widely distributed around the world, such as yoghurts, in each of these countries there are a number of national products. An example of a widely demanded fermented milk product in Russia is Kefir.This productis used not only as a food source in the diet of children and adults, but also in medical institutions, since ithasa positive effect onhuman health when consumed regularly. South Africa is characterized by the consumption of products such as Amasi,which is produced commercially. Its consumption has also been shown to have beneficial effects on the digestive system. In this research, the metabolic profiles(fatty acid composition and volatile compounds) of these fermented milk products were analyzed and these showed significant differences. The results indicated that this metabolite composition reflected the different production protocols and microbial complexity of these dairy products. The functional properties of the studied drinks were also considered.The average content of L-leucine equivalents in Amasi was slightly higher (6.5-8.9mMol×L −1) than in Kefir (4.9-6.7mMol×L −1). Antioxidant and antihypertensive activity of the fermented products correlated with the depth of hydrolysis of the milk proteins. Amasishowed higher antioxidant and antihypertensive activities (600- 796µМolТE/ml and 1.3-1.5mg/ml, respectively) than Kefir (246-574µМolТE/ml and 2.0-4.3mg/ml, respectively). Keywords: fermented products, Kefir, Amasi,metabolic profile, antioxidant potential, antihypertensive propertie

The 20S proteasome processes NF-κB1 p105 into p50 in a translation-independent manner

The NF-κB p50 is the N-terminal processed product of the precursor, p105. It has been suggested that p50 is generated not from full-length p105 but cotranslationally from incompletely synthesized molecules by the proteasome. We show that the 20S proteasome endoproteolytically cleaves the fully synthesized p105 and selectively degrades the C-terminus of p105, leading to p50 generation in a ubiquitin-independent manner. As small as 25 residues C-terminus to the site of processing are sufficient to promote processing in vivo. However, any p105 mutant that lacks complete ankyrin repeat domain (ARD) is processed aberrantly, suggesting that native processing must occur from a precursor, which extends beyond the ARD. Remarkably, the mutant p105 that lacks the internal region including the glycine-rich region (GRR) is completely degraded by 20S proteasome in vitro. This suggests that the GRR impedes the complete degradation of the p105 precursor, thus contributing to p50 generation