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Hagel S, Lüssenhop P, Walk S, Kirjoranta S, Ritter A, Bastidas Jurado CG, Mikkonen KS, Tenkanen M, Körner I, Saake B. Valorization of Urban Street Tree Pruning Residues in Biorefineries by Steam Refining: Conversion Into Fibers, Emulsifiers, and Biogas. Front Chem 2021; 9:779609. [PMID: 34869228 PMCID: PMC8634610 DOI: 10.3389/fchem.2021.779609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 10/12/2021] [Indexed: 11/13/2022] Open
Abstract
Street tree pruning residues are a widely available and currently undervalorized bioresource. Their utilization could help alleviate an increasing biomass shortage and offset costs of the pruning process for the municipalities. In this work, a holistic valorization pathway of pruning residues leading to fibers, oligosaccharides, biogas, and compost is presented. For this, representative mixtures of tree pruning materials from the most prevalent street tree genera (oak, linden, maple) found in Hamburg (Germany) were prepared by shredding and cleaning procedures. Collection of sample material was performed in summer and winter to account for seasonality. A steam-based fractionation was conducted using treatment severities ranging from log R0 = 2.5 to 4.0. At the highest severity, a fiber yield of around 66%, and liquor yield of 26-30% was determined. The fibers were evaluated with respect to their properties for paper product applications, with higher treatment severities leading to higher paper strengths. From the oligosaccharide-rich liquor, emulsions were created, which showed promising stability properties over 8 weeks of storage. The liquors and the rejects from the material preparation also displayed good potential for biomethane production. Overall, the differences between material collected in summer and winter were found to be small, indicating the possibility for a year-round utilization of pruning residues. For the presented utilization pathway, high severity treatments were the most promising, featuring a high liquor yield, good biomethane potential, and the highest paper strengths.
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Affiliation(s)
- Sebastian Hagel
- Institute of Wood Science, Chemical Wood Technology, Universität Hamburg, Hamburg, Germany
| | - Phillipp Lüssenhop
- Institute of Wastewater Management and Water Protection, Bioresource Management Group, Technische Universität Hamburg, Hamburg, Germany
| | - Steffen Walk
- Institute of Wastewater Management and Water Protection, Bioresource Management Group, Technische Universität Hamburg, Hamburg, Germany
| | - Satu Kirjoranta
- Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Annalena Ritter
- Institute of Wood Science, Chemical Wood Technology, Universität Hamburg, Hamburg, Germany
| | - Carla Gabriela Bastidas Jurado
- Institute of Wastewater Management and Water Protection, Bioresource Management Group, Technische Universität Hamburg, Hamburg, Germany
| | - Kirsi S Mikkonen
- Department of Food and Nutrition, University of Helsinki, Helsinki, Finland.,Helsinki Institute of Sustainability Science, University of Helsinki, Helsinki, Finland
| | - Maija Tenkanen
- Department of Food and Nutrition, University of Helsinki, Helsinki, Finland.,Helsinki Institute of Sustainability Science, University of Helsinki, Helsinki, Finland
| | - Ina Körner
- Institute of Wastewater Management and Water Protection, Bioresource Management Group, Technische Universität Hamburg, Hamburg, Germany
| | - Bodo Saake
- Institute of Wood Science, Chemical Wood Technology, Universität Hamburg, Hamburg, Germany
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Krafft MJ, Berger J, Saake B. Analytical Characterization and Inhibitor Detection in Liquid Phases Obtained After Steam Refining of Corn Stover and Maize Silage. Front Chem 2021; 9:760657. [PMID: 34722463 PMCID: PMC8551624 DOI: 10.3389/fchem.2021.760657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/29/2021] [Indexed: 11/21/2022] Open
Abstract
The utilization of agricultural products and residues for the production of value-added and biobased products is a highly relevant topic in present research. Due to the natural recalcitrance of lignocellulosic biomass against enzymatic degradation, pretreatments are important requirement for further processes. For the raw material in this study, corn stover (CS) as highly available agricultural residue and maize silage (MS) as model substrate for an ensiled agricultural product were pretreated by steam refining. However, after processing a liquid fraction and fibers are present. Subsequent to steaming the fiber fraction is well characterized. Nonetheless, in depth characterizations of the filtrates are also important for their subsequent utilization. Decreasing molar masses from 7,900 g/mol to 1,100 g/mol for CS filtrates and 100.000–12.900 g/mol for MS filtrates were determined with increasing severity. Due to their proven inhibitory effect on microorganisms weak acids, furans and phenolic compounds within the liquid phased were analyzed. Especially formic acid increases with increasing severity from 0.27 to 1.20% based on raw material for CS and from 0.07 to 0.23% based on raw material for MS. Further GC/MS measurements indicate, that up to 8.25% (CS filtrate) and 5.23% (MS filtrates) of the total peak area is related to inhibitory phenols. Considering the data, detoxification strategies are of non-negligible importance for filtrates after steam refining and should be considered for further research and process or parameter optimizations. An alternative may be the application of milder process conditions in order to prevent the formation of inhibitory degradation products or the dilution of the gained filtrates.
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Affiliation(s)
- Malte Jörn Krafft
- Chemical Wood Technology, University of Hamburg, Barsbüttel, Germany
| | - Jens Berger
- Chemical Wood Technology, University of Hamburg, Barsbüttel, Germany
| | - Bodo Saake
- Chemical Wood Technology, University of Hamburg, Barsbüttel, Germany
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Menyailo ME, Bokova UA, Ivanyuk EE, Khozyainova AA, Denisov EV. Metastasis Prevention: Focus on Metastatic Circulating Tumor Cells. Mol Diagn Ther 2021; 25:549-562. [PMID: 34287797 DOI: 10.1007/s40291-021-00543-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2021] [Indexed: 12/13/2022]
Abstract
Metastasis is the main cause of cancer death. Metastatic foci are derived from tumor cells that detach from the primary tumor and then enter the circulation. Circulating tumor cells (CTCs) are generally associated with a high probability of distant metastasis and a negative prognosis. Most CTCs die in the bloodstream, and only a few cells form metastases. Such metastatic CTCs have a stem-like and hybrid epithelial-mesenchymal phenotype, can avoid immune surveillance, and show increased therapy resistance. Targeting metastatic CTCs and their progenitors in primary tumors and their descendants, particularly disseminated tumor cells, represents an attractive strategy for metastasis prevention. However, current therapeutic strategies mainly target the primary tumor and only indirectly affect metastasis-initiating cells. Here, we consider potential methods for preventing metastasis based on targeting molecular and cellular features of metastatic CTCs, including CTC clusters. Also, we emphasize current knowledge gaps in CTC biology that should be addressed to develop highly effective therapeutics and strategies for metastasis suppression.
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Affiliation(s)
- Maxim E Menyailo
- Laboratory of Cancer Progression Biology, Cancer Research Institute, Tomsk National Research Medical Center, Kooperativny Str. 5, Tomsk, 634009, Russia
| | - Ustinia A Bokova
- Laboratory of Cancer Progression Biology, Cancer Research Institute, Tomsk National Research Medical Center, Kooperativny Str. 5, Tomsk, 634009, Russia
| | - Elena E Ivanyuk
- Laboratory of Molecular Oncology and Immunology, Cancer Research Institute, Tomsk National Research Medical Center, Kooperativny Str. 5, Tomsk, 634009, Russia
| | - Anna A Khozyainova
- Laboratory of Cancer Progression Biology, Cancer Research Institute, Tomsk National Research Medical Center, Kooperativny Str. 5, Tomsk, 634009, Russia
| | - Evgeny V Denisov
- Laboratory of Cancer Progression Biology, Cancer Research Institute, Tomsk National Research Medical Center, Kooperativny Str. 5, Tomsk, 634009, Russia.
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SPAD Leaf Greenness Index: Green Mass Yield Indicator of Maize ( Zea mays L.), Genetic and Agriculture Practice Relationship. PLANTS 2021; 10:plants10050830. [PMID: 33919413 PMCID: PMC8143313 DOI: 10.3390/plants10050830] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 11/16/2022]
Abstract
The study presents the results of two field studies (Experiment I, Experiment II), whose aim was to assess the impact of agriculture factors on maize green mass and leaf greenness index (Soil and Plant Analysis Development, SPAD) in critical growth stages, as well as to determine the relationship between the SPAD index and the yield of green maize for ensiling. It was shown that thermal and humidity conditions in maize growing seasons determined the value of the SPAD leaf greenness index and the yield of maize harvested for silage. Row application of mineral fertilizer (N, NP) and selection of "stay-green" varieties guarantee a higher yield of maize green mass. Growing maize in direct sowing reduces chlorophyll content expressed in SPAD units, thereby reducing plant nitrogen condition, which significantly decreases the yield of biomass intended for silage. The SPAD leaf greenness index determined in critical stages of maize growth can be considered as a yield predictor of green mass for ensiling. The examined maize cultivars were divided into two groups on the basis of hierarchically grouping using the unweighted pair group method of arithmetic means. The first group comprised cultivars SY Cooky and Drim "stay-green," while the second one included cultivars ES Paroli "stay-green" and ES Palazzo.
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