Article
Microbiology
David Sanz, Eduardo Diaz
Summary: In this study, it was found that the alicyclic compound cyclohexane carboxylate (CHC) is degraded through a different pathway in denitrifying bacteria compared to Rhodopseudomonas palustris. The bad-ali genes are involved in both anaerobic and aerobic degradation of CHC and are present in the genomes of various bacteria. A synthetic catabolic module was engineered to confer CHC degradation abilities to different bacterial hosts.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Polymer Science
Federico Di Bisceglie, Felice Quartinello, Robert Vielnascher, Georg M. Guebitz, Alessandro Pellis
Summary: Polyurethanes are widely used synthetic polymers in Europe, and their recycling poses a major challenge for the industry. This study investigated the enzymatic hydrolysis of a polyurethane-polyester copolymer to achieve decomposition under milder conditions. The results showed that the enzyme effectively hydrolysed the polymer and reduced its molecular weight, indicating the potential for environmentally friendly recycling strategies.
Article
Engineering, Environmental
Xueping Li, Zhansheng Wu, Xiyang Tao, Runze Li, Duoduo Tian, Xiaochen Liu
Summary: In this study, a synergistic system using immobilized laccase was constructed to improve stability and recyclability. The synthesized Lac@CoCu-MOF material exhibited good protection for the enzyme in various interfering environments and achieved high removal rates of the pollutant Congo red.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Gerlis von Haugwitz, Kian Donnelly, Mara Di Filippo, Daniel Breite, Max Phippard, Agnes Schulze, Ren Wei, Marcus Baumann, Uwe T. Bornscheuer
Summary: Poly(vinyl alcohol) (PVA) is a water-soluble synthetic vinyl polymer with remarkable physical properties. However, its biodegradability is low and existing degradation methods have disadvantages. In this study, a modified PVA film and a PQQ-independent enzymatic cascade for the degradation of PVA are presented, which can be suitable for industrial applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Hua Zhao, Caden J. Martin, Nathaniel E. Larm, Gary A. Baker, Tyler C. Trujillo
Summary: The study designed sixteen dual-functionalized ionic liquids containing glycol ether and tert-alcohol groups to mimic the aqueous environment for enzyme activation, enabling high transesterification activities. Several water-like ILs significantly increased the CALB activity and subtilisin activation. Fluorescence emission spectra suggested that characteristic emission maximum peaks were maintained in water-like ILs in most cases.
MOLECULAR CATALYSIS
(2021)
Review
Agricultural Engineering
Wei Wang, Jo-Shu Chang, Kuan-Yeow Show, Duu-Jong Lee
Summary: This review focuses on the application of anaerobic treatment for degrading recalcitrant compounds in wastewaters. It summarizes the recalcitrant compounds commonly found in wastewaters and their removal performance under anaerobic conditions. The study also highlights the limitation of using BOD/COD ratio to evaluate the anaerobic degradability of wastewater and calls for the development of a novel indicator to characterize the anaerobic recalcitrance of wastewater.
BIORESOURCE TECHNOLOGY
(2022)
Review
Environmental Sciences
Kuan-Yeow Show, Jo-Shu Chang, Duu-Jong Lee
Summary: This mini-review discusses the recalcitrance of acrylic acid and its biological degradation pathways, as well as the full-scale practices using anaerobic granulation technology for treating acrylic acid wastewater. It proposes that the granules can provide barriers for high-concentration acrylic acid, maintaining its high degradation rate without substrate inhibition. The potential of anaerobic granulation technology in handling high-strength recalcitrant wastewaters and improving process performances is highlighted.
ENVIRONMENTAL POLLUTION
(2023)
Review
Biotechnology & Applied Microbiology
Lijie Wang, Yan Sun
Summary: The enzymatic degradation of organophosphorus compounds is an efficient and clean approach for detoxification and bioremediation, but further improvement in catalytic efficiency and resistance is needed. Research has focused on enhancing enzyme performance through molecular mutations and engineering methods, as well as expanding substrate spectrum and designing artificial enzymes for extended applications.
BIOCHEMICAL ENGINEERING JOURNAL
(2021)
Article
Biotechnology & Applied Microbiology
Xiaoyan Qi, Xiaoxiao Li, Wenlong Yue, Chao-Fan Yin, Ying Xu, Nan Hui, Ning-Yi Zhou
Summary: This study aimed to investigate the degradation of PET microplastics (MPs) in high-temperature composting and explored the enhanced degradation by adding thermophilic PET hydrolase. The results showed that after 20 days of composting, the weight of PET MPs significantly reduced by 21.1%, and the addition of PET hydrolase resulted in a further reduction of 32.8%. The surface of PET MPs exhibited noticeable corrosion and oxidation after composting. These findings suggest that composting can effectively degrade PET MPs, and enzyme-assisted composting can enhance the degradation, providing a new approach for addressing environmental microplastics pollution.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2023)
Article
Biochemistry & Molecular Biology
Jenny Arnling Baath, Kim Borch, Kenneth Jensen, Jesper Brask, Peter Westh
Summary: Research on enzymatic degradation of synthetic polymers, particularly PET, has been stimulated by the potential of bioprocessing in a circular plastic economy. A kinetic framework for comparisons of PET hydrolases acting on insoluble substrate has been proposed and tested, revealing that a variant of the PET hydrolase from Ideonella sakaiensis is the most efficient enzyme at ambient conditions. Additionally, both soluble and insoluble PET fragments were hydrolyzed faster than intact PET, suggesting that interactions between polymer strands play a role in slowing down PET degradation.
Review
Polymer Science
Amber N. Johnson, Daniel E. Barlow, Abigail L. Kelly, Vanessa A. Varaljay, Wendy J. Crookes-Goodson, Justin C. Biffinger
Summary: Natural and synthetic polymers degrade over time due to changes in bonding, with microorganisms using chemical processes to release carbon sources. Polyesters and polyurethanes, making up 35% of global polymer production, are susceptible to degradation by enzymes released by microorganisms. This review focuses on recent research on biodegradation of these polymers.
POLYMER INTERNATIONAL
(2021)
Article
Engineering, Chemical
Lixian Wang, Lizhi Zhao, Didi Si, Zhixin Li, Huiqin An, Hui Ye, Qingping Xin, Hong Li, Yuzhong Zhang
Summary: Metalloporphyrin-based nanozymes integrated with poly (vinylidene fluoride) membrane show high catalytic activity and reusability for the decolorization of Congo Red dye in continuous flow process.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Environmental
Huan Du, Rui-Wen Hu, Hai-Ming Zhao, He-Biao Huang, Lei Xiang, Bai-Lin Liu, Nai-Xian Feng, Hui Li, Yan-Wen Li, Quan-Ying Cai, Ce-Hui Mo
Summary: The novel Hyd esterase has high activity and stability under a broad pH and temperature range, and it interacts with dibutyl phthalate (DBP) through a static quenching mechanism. The binding of DBP to Hyd induces conformational and micro-environmental changes, characterized by alterations in amino acid structure and secondary structure.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Engineering, Chemical
Renwen Tian, Yan Sun
Summary: The use of α-synuclein as a fusion chaperone resulted in improved enzymatic performance of PETase, with the fusion enzymes exhibiting higher activity and stability compared to PETase alone. The fusion proteins showed significantly enhanced PET degradation capability, possibly due to the binding affinity of the fused α-synuclein domain for PET.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Environmental
Siyuan Zhai, Min Ji, Yingxin Zhao, Spyros G. Pavlostathis
Summary: This study systematically assessed the biotransformation of 4-Hydroxybenzoic acid (HBA) in a microbial electrolysis cell (MEC) for the production of renewable H-2. The findings showed that in the absence of nitrate, most HBA was converted to phenol, while under nitrate-reducing conditions, complete degradation of HBA to H-2 was achieved. The predominant bacteria involved in this process were Magnetospirillum and Geobacter, contributing to the successful bioelectrochemical conversion of HBA.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Inorganic & Nuclear
Pedro D. Sarmiento-Pavia, Marcos Flores-Alamo, Alejandro Solano-Peralta, Peter M. H. Kroneck, Martha E. Sosa-Torres
INORGANICA CHIMICA ACTA
(2018)
Article
Biotechnology & Applied Microbiology
Edinson Puentes-Cala, Jens Harder
Article
Biotechnology & Applied Microbiology
Tanja Fischer, Martin Schorb, Greta Reintjes, Androniki Kolovou, Rachel Santarella-Mellwig, Stephanie Markert, Erhard Rhiel, Sten Littmann, Dorte Becher, Thomas Schweder, Jens Harder
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2019)
Article
Biotechnology & Applied Microbiology
Carlota Alejandre-Colomo, Jens Harder, Bernhard M. Fuchs, Ramon Rossello-Mora, Rudolf Amann
SYSTEMATIC AND APPLIED MICROBIOLOGY
(2020)
Article
Biotechnology & Applied Microbiology
Carlota Alejandre-Colomo, Tomeu Viver, Mercedes Urdiain, Ben Francis, Jens Harder, Peter Kaempfer, Rudolf Amann, Ramon Rossello-Mora
SYSTEMATIC AND APPLIED MICROBIOLOGY
(2020)
Article
Multidisciplinary Sciences
Yustian Rovi Alfiansah, Sonja Peters, Jens Harder, Christiane Hassenrueck, Astrid Gaerdes
SCIENTIFIC REPORTS
(2020)
Article
Limnology
Marit R. van Erk, Dimitri Meier, Timothy Ferdelman, Jens Harder, Ingeborg Bussmann, Dirk de Beer
LIMNOLOGY AND OCEANOGRAPHY
(2020)
Article
Chemistry, Multidisciplinary
Lin Zhang, Eckhard Bill, Peter M. H. Kroneck, Oliver Einsle
Summary: Copper-containing nitrous oxide reductase (N2OR) is the only known enzyme capable of converting nitrous oxide to dinitrogen, with unique Cu-Z and CUA sites. Systematic mutagenesis of histidine and surrounding H-bonding residues revealed that only variants with protonable side chains like His, Asp, and Glu can mediate electron transfer at physiological pH.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Microbiology
Anneke Heins, Greta Reintjes, Rudolf I. Amann, Jens Harder
Summary: Marine heterotrophic microorganisms play a significant role in remineralizing about half of the annual primary production, with microbiomes on and around algae and particles making a major contribution. Collecting particles in Imhoff sedimentation cones enriches microbiomes containing free-living chemotactic bacteria, different from those obtained by filtration or centrifugation. This method provides novel insights into the diversity, structure, and function of particle-associated microbiomes, including phycosphere members, by simultaneously enriching particle-attached and chemotactic free-living bacteria.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Ecology
Taylor Priest, Anneke Heins, Jens Harder, Rudolf Amann, Bernhard M. Fuchs
Summary: In this study, we investigate the species-level niche partitioning within the NS5 Marine Group by combining spatiotemporal dynamics and predicted substrate utilization. We identify depth as a key influencing factor in the distribution dynamics of NS5 species, and observe successional dynamics in relation to specialized substrate adaptations. Additionally, we provide a complete genome sequence and morphological insights for Arcticimaribacter forsetii AHE01FL, a candidate species within the NS5 group.
Review
Biochemistry & Molecular Biology
Peter M. H. Kroneck
Summary: Pentaheme cytochrome c nitrite reductase, also known as NrfA, is an enzyme that catalyzes the reduction of NO2- to NH4+ using multiple heme structures for electron transfer. It plays a role in nitrogen retention by generating NH4+ for assimilatory purposes and forms homodimers with distinct electron transfer systems. In different bacteria, NrfA interacts with different electron carriers to optimize electron transfer efficiency in a membrane-associated respiratory complex.
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY
(2022)
Article
Biotechnology & Applied Microbiology
Jana Kizina, Sebastian F. A. Jordan, Gerrit Alexander Martens, Almud Lonsing, Christina Probian, Androniki Kolovou, Rachel Santarella-Mellwig, Erhard Rhiel, Sten Littmann, Stephanie Markert, Kurt Stueber, Michael Richter, Thomas Schweder, Jens Harder
Summary: In this study, the ultramicrobacterial anaerobic epibiont OP3 LiM living on Archaea and Bacteria was described. The study revealed the predatory metabolism of OP3 LiM cells through cell-to-cell contact and genomic analysis. The findings highlight the important role of OP3 LiM in the recycling and remineralization of microbial biomass.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Biology
Yustian Rovi Alfiansah, Jens Harder, Matthew James Slater, Astrid Gardes
Summary: This study investigated the formation of bio-flocs in shrimp pond water by adding molasses, and found that molasses increased the number of beneficial bacteria and the content of macro-molecules in bio-flocs, while reducing the abundance of potential pathogens. The results suggest that molasses is suitable for shrimp farming to improve water quality.
TROPICAL LIFE SCIENCES RESEARCH
(2022)
Article
Microbiology
Anneke Heins, Jens Harder
Summary: Marine bacteria cultivable on plates are dominated by a minor population of planktonic bacteria that lives preferentially close to or on phytoplankton and particles. Planktonic particle-associated bacteria comprise particle-attached and motile free-living cells. These groups were obtained by settlement in Imhoff cones. Dilution plating on marine agar 2216 (ZoBell marine agar) and microscopic counts indicated a cultivability of 0.7% (0.4%-1.2%) of bacteria in coastal seawater collected at Helgoland Roads, North Sea. Particle-associated bacteria presented a minority population in seawater, but had a larger cultivability of 25% (0.9%-100%) for populations collected by settlement of particles and 5.7% (0.9%-24%) for populations collected by filtration. Partial 16S rRNA gene sequences indicated that 84% of the cultured taxa were either enriched in particle-associated microbiomes or only found in these microbiomes, including Sulfitobacter and other Rhodobacteraceae, Pseudoalteromonas, Psychromonas, Arcobacter and many Flavobacteriaceae. Illumina-based 16S rRNA V3V4 amplicon sequences of plate communities revealed that nearly all operational taxonomic units had a cultivated and described strain in close phylogenetic proximity. This suggested that decades of strain isolation from seawater on ZoBell marine agar had achieved a very good coverage of cultivable genera abundant in nature. The majority belonged to particle-associated bacteria, complementing observations that abundant free-living seawater bacteria often require cultivation conditions closer to their natural habitat like liquid cultivation in oligotrophic medium.
FEMS MICROBIOLOGY ECOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Lin Zhang, Eckhard Bill, Peter M. H. Kroneck, Oliver Einsle
Summary: This study investigated the assembly process of the Cu-Z cluster of N2OR enzyme through mutagenesis, revealing that the H382A variant carried a catalytically inactive [3Cu:2S] center with a sulfur ligand, S-Z2, forming a weak hydrogen bond to the nearby lysine residue K454. This relocation of the sulfide ligand changes the metal coordination in Cu-Z, providing insights into the mechanism of N2O reduction.