Browsing by Subject "TANNINS"

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  • Jyske, Tuula; Brännström, Hanna; Sarjala, Tytti; Hellström, Jarkko; Halmemies, Eelis; Raitanen, Jan-Erik; Kaseva, Janne; Lagerquist, Lucas; Eklund, Patrik; Nurmi, Juha (2020)
    Softwood bark is an important by-product of forest industry. Currently, bark is under-utilized and mainly directed for energy production, although it can be extracted with hot water to obtain compounds for value-added use. In Norway spruce (Picea abies[L.] Karst.) bark, condensed tannins and stilbene glycosides are among the compounds that comprise majority of the antioxidative extractives. For developing feasible production chain for softwood bark extractives, knowledge on raw material quality is critical. This study examined the fate of spruce bark tannins and stilbenes during storage treatment with two seasonal replications (i.e., during winter and summer). In the experiment, mature logs were harvested and stored outside. During six-month-storage periods, samples were periodically collected for chemical analysis from both inner and outer bark layers. Additionally, bark extractives were analyzed for antioxidative activities by FRAP, ORAC, and H(2)O(2)scavenging assays. According to the results, stilbenes rapidly degraded during storage, whereas tannins were more stable: only 5-7% of the original stilbene amount and ca. 30-50% of the original amount of condensed tannins were found after 24-week-storage. Summer conditions led to the faster modification of bark chemistry than winter conditions. Changes in antioxidative activity were less pronounced than those of analyzed chemical compounds, indicating that the derivatives of the compounds contribute to the antioxidative activity. The results of the assays showed that, on average, ca. 27% of the original antioxidative capacity remained 24 weeks after the onset of the storage treatment, while a large variation (2-95% of the original capacity remaining) was found between assays, seasons, and bark layers. Inner bark preserved its activities longer than outer bark, and intact bark attached to timber is expected to maintain its activities longer than a debarked one. Thus, to ensure prolonged quality, no debarking before storage is suggested: outer bark protects the inner bark, and debarking enhances the degradation.
  • Silfver, Tarja; Kontro, Merja; Paaso, Ulla; Karvinen, Heini; Keski-Saari, Sarita; Keinanen, Markku; Rousi, Matti; Mikola, Juha (2018)
    Background and aims Differences among plant genotypes can influence ecosystem functioning such as the rate of litter decomposition. Little is known, however, of the strength of genotypic links between litter quality, microbial abundance and litter decomposition within plant populations, or the likelihood that these processes are driven by natural selection. Methods We used 19 Betula pendula genotypes randomly selected from a local population in south-eastern Finland to establish a long-term, 35-month litter decomposition trial on forest ground. We analysed the effect of litter quality (N, phenolics and triterpenoids) of senescent leaves and decomposed litter on microbial abundance and litter mass loss. Results We found that while litter quality and mass loss both had significant genotypic variation, the genotypic variation among silver birch trees in the quantity of bacterial and fungal DNA was marginal. In addition, although the quantity of bacterial DNA at individual tree level was negatively associated with most secondary metabolites of litter and positively with litter N, litter chemistry was not genotypically linked to litter mass loss. Conclusions Contrary to our expectations, these results suggest that natural selection may have limited influence on overall microbial DNA and litter decomposition rate in B. pendula populations by reworking the genetically controlled foliage chemistry of these populations.
  • Adamczyk, Bartosz; Heinonsalo, Jussi; Simon, Judy (2020)
    Abstract Organic matter decomposition plays a major role in the cycling of carbon (C) and nutrients in terrestrial ecosystems across the globe. Climate change accelerates the decomposition rate to potentially increase the release of greenhouse gases and further enhance global warming in the future. However, fractions of organic matter vary in turnover times and parts are stabilized in soils for longer time periods (C sequestration). Overall, a better understanding of the mechanisms underlying C sequestration is needed for the development of effective mitigation policies to reduce land-based production of greenhouse gases. Known mechanisms of C sequestration include the recalcitrance of C input, interactions with soil minerals, aggregate formation, as well as its regulation via abiotic factors. In this Minireview, we discuss the mechanisms behind C sequestration including the recently emerging significance of biochemical interactions between organic matter inputs that lead to C stabilization.
  • Kilpeläinen, Jouni; Barbero-López, Aitor; Adamczyk, Bartosz Wojciech; Aphalo, Pedro J.; Lehto, Tarja (2019)
    Background and aims The aim was to assess possible benefits or drawbacks of arbuscular-mycorrhizal (AM) and ectomycorrhizal (EM) colonisation compared to no mycorrhizas (NM) in seedlings of the same host species. Eight broadleaf species were tested for mycorrhiza formation. Grey alder (Alnus incana) and four fungal species were selected for further experiments. Methods Grey alder seedlings were inoculated with AM fungi Rhizophagus intraradices and Glomus hoi or EM fungi Paxillus involutus plus an ascomycete isolated from Alnus roots or mock-inoculated (NM). Results EM formed in 70% of root tips and AM in 30% of root length. AM plants were smaller than EM and NM, but their specific root length (SRL) and specific leaf area (SLA) were highest. Net photosynthesis, stomatal conductance and shoot water potential did not differ between treatments. Foliar Ca, K, Mg, Mn, N, P and S concentrations (mg g−1) were highest in AM plants. However, total foliar contents (mg per plant) were lowest in AM plants, except for P, K and Zn. Conclusions The larger SRL and SLA suggest more efficient resource usage in AM plants, even though these were smaller than EM and NM plants. Grey alder is proposed as a new model species for comparisons between mycorrhiza types in cold climates.
  • Adamczyk, Bartosz; Sietio, Outi-Maaria; Strakova, Petra; Prommer, Judith; Wild, Birgit; Hagner, Marleena; Pihlatie, Mari; Fritze, Hannu; Richter, Andreas; Heinonsalo, Jussi (2019)
    Boreal forests are ecosystems with low nitrogen (N) availability that store globally significant amounts of carbon (C), mainly in plant biomass and soil organic matter (SOM). Although crucial for future climate change predictions, the mechanisms controlling boreal C and N pools are not well understood. Here, using a three-year field experiment, we compare SOM decomposition and stabilization in the presence of roots, with exclusion of roots but presence of fungal hyphae and with exclusion of both roots and fungal hyphae. Roots accelerate SOM decomposition compared to the root exclusion treatments, but also promote a different soil N economy with higher concentrations of organic soil N compared to inorganic soil N accompanied with the build-up of stable SOM-N. In contrast, root exclusion leads to an inorganic soil N economy (i.e., high level of inorganic N) with reduced stable SOM-N buildup. Based on our findings, we provide a framework on how plant roots affect SOM decomposition and stabilization.
  • Salih, Enass Y. A.; Julkunen-Tiitto, Riitta; Luukkanen, Olavi; Sipi, Marketta; Fahmi, Mustafa K. M.; Fyhrquist, Pia Johanna (2020)
    In Sudanese traditional medicine, decoctions of the stem bark ofAnogeissus leiocarpaare used for the treatment of tuberculosis (TB). However, this plant has not been investigated before for its antimycobacterial effects. Our screening results show, for the first time, that many extracts of various parts ofA. leiocarpaexhibit growth inhibitory activity againstMycobacterium smegmatis. Minimum inhibitory concentration (MIC) values ranged between 625 and 5000 mu g/mL, with an ethyl acetate extract of the root showing the lowest MIC value. The good antimycobacterial effects of the root part could be due to its high concentration of ellagic acid derivatives, ellagitannins, and flavonoids. Thin layer chromatography (TLC) fractionation resulted in some fractions with better activity than the starting point crude methanol extract (MIC 2500 mu g/mL). Those fractions with the lowest MIC values contained a high number of antioxidant compounds. Fractions3and4(MIC 1500 and 1000 mu g/mL, respectively) contained high concentrations of di-methyl ellagic acid ([M-H](-)329.0318). Fraction6(MIC 2000 mu g/mL) contained a lower concentration of di-methyl ellagic acid and was not as growth inhibitory as fractions3and4. Moreover, in fraction3, an acetylated ellagic acid derivative ([M-H](-)343.0477) and di-methyl-ellagic acid xyloside ([M-H](-)461.0739) were tentatively characterized. Di-methyl ellagic acid xyloside was also present in fraction4and could strongly contribute to the antimycobacterial effect of this fraction. Additionally, protocatechuic acid ([M-H](-)at m/z 153.0196) was present in fraction4.Our antimycobacterial results obtained from this research justify the use ofA. leiocarpain Sudanese folk medicine against cough related to TB. Roots, stem bark, and leaves ofA. leiocarpaare sources for new potent anti-TB drug lead compounds.