UDP-α-D-galactofuranose (UDP-Galf): β-galactofuranoside β-(1→5)-galactofuranosyltransferase, known as GfsA, is essential in synthesizing β-(1→5)-galactofuranosyl oligosaccharides that are incorporated into the cell wall of pathogenic fungi. This study analyzed the structure and function of GfsA from . To provide crucial insights into the catalytic mechanism and substrate recognition, the complex structure was elucidated with manganese (Mn), a donor substrate product (UDP), and an acceptor sugar molecule (β-galactofuranose).
View Article and Find Full Text PDFGray mold, caused by , is a significant threat to tomato production. Traditional chemical control methods have become increasingly ineffective because of the development of resistance. This study aimed to isolate methanol-utilizing bacteria from tomato leaves and evaluate their biocontrol potential against gray mold.
View Article and Find Full Text PDFProkaryotes organize intracellular compartments with protein-based organelles called encapsulins. Encapsulins with icosahedral symmetry can encapsulate specific cargo proteins mediated by targeting peptides or encapsulation-mediating domains. Encapsulins have been used in eukaryotic cells for bioengineering, vaccine development, and nanoparticle alignment.
View Article and Find Full Text PDFThe cell surface of is covered by a thick capsular polysaccharide. The capsule is the most important virulence factor of ; however, the complete mechanism of its biosynthesis is unknown. The capsule is composed of glucuronoxylomannan (GXM) and glucuronoxylomannogalactan (GXMGal).
View Article and Find Full Text PDFUnlabelled: The cellular surface of the pathogenic filamentous fungus is enveloped in a mannose layer, featuring well-established fungal-type galactomannan and -mannose-type galactomannan. This study reports the discovery of cell wall component in mycelium, which resembles -glycan outer chains found in yeast. The glycosyltransferases involved in its biosynthesis in were identified, with a focus on two key α-(1→2)-mannosyltransferases, Mnn2 and Mnn5, and two α-(1→6)-mannosyltransferases, Mnn9 and Van1.
View Article and Find Full Text PDFMicrobiol Resour Announc
December 2023
We report the complete genome sequence of subsp. NARUSE, which has been traditionally employed for fermenting soybeans in Japan. The genome was sequenced using the PacBio system, yielding a sequence, yielding a sequence length of 4,148,793 nucleotides for the circular chromosome and 62,770 nucleotides for the plasmid.
View Article and Find Full Text PDFFilamentous fungi belonging to the genus are known to possess galactomannan in their cell walls. Galactomannan is highly antigenic to humans and has been reported to be involved in the pathogenicity of pathogenic filamentous fungi, such as , and in immune responses. In this study, we aimed to confirm the presence of D-galactofuranose-containing glycans and to clarify the biosynthesis of D-galactofuranose-containing glycans in , a yellow fungus.
View Article and Find Full Text PDFThe fungal cell wall is necessary for survival as it serves a barrier for physical protection. Therefore, glycosyltransferases responsible for the synthesis of cell wall polysaccharides may be suitable targets for drug development. Mannose is a monosaccharide that is commonly found in sugar chains in the walls of fungi.
View Article and Find Full Text PDFFungal cell walls and their biosynthetic enzymes are potential targets for novel antifungal agents. Recently, two mannosyltransferases, namely core-mannan synthases A (CmsA/Ktr4) and B (CmsB/Ktr7), were found to play roles in the core-mannan biosynthesis of fungal-type galactomannan. CmsA/Ktr4 is an α-(1→2)-mannosyltransferase responsible for α-(1→2)-mannan biosynthesis in fungal-type galactomannan, which covers the cell surface of Strains with disrupted / have been shown to exhibit strongly suppressed hyphal elongation and conidiation alongside reduced virulence in a mouse model of invasive aspergillosis, indicating that CmsA/Ktr4 is a potential novel antifungal candidate.
View Article and Find Full Text PDFAlogliptin is one of a new class of therapeutic agents for type 2 diabetes called dipeptidyl peptidase-4 inhibitors. Here, we used immunohistochemistry to investigate the pharmacokinetics of alogliptin at the cell and tissue levels in the rat kidney and liver. One hour after alogliptin administration, the most noticeable immunoreactivity in the kidney was a moderate-to-strong staining in proximal tubule S3 segment epithelial cells.
View Article and Find Full Text PDFBiochem Biophys Res Commun
June 2020
Anaerobic ammonium oxidation (anammox) and denitrification are two different microbial reactions that form nitrogen gas. The initial step in the anammox reaction-reduction of nitrite to nitric oxide-is thought to be catalyzed by homologs of dissimilatory nitrite reductase, which is known to be involved in denitrification. Here, we reveal the crystal structure of the copper-containing nitrite reductase (CuNIR) of strain KSU-1, an anammox bacterium.
View Article and Find Full Text PDFAerobic ammonia-oxidizing archaea (AOA) play a crucial role in the global nitrogen cycle by oxidizing ammonia to nitrite, and nitric oxide (NO) is a key intermediate in AOA for sustaining aerobic ammonia oxidation activity. We herein heterologously expressed the NO-forming, copper-containing, dissimilatory nitrite reductase (NirK) from Nitrososphaera viennensis and investigated its enzymatic properties. The recombinant protein catalyzed the reduction of NO to NO, the oxidation of hydroxylamine (NHOH) to NO, and the production of NO from NHOH and NO.
View Article and Find Full Text PDFAnammox is a bacterial energy metabolic process that forms N gas from nitrite and ammonium ions. The enzymatic mechanisms of anammox have been gradually revealed; however, the electron transport chain in anammox bacteria remains poorly understood. In the present study, we purified and characterized two low-molecular-weight c-type cytochromes from an enriched culture of the anammox bacterium strain, KSU-1.
View Article and Find Full Text PDFNitrogenous pollution of water is regarded as a global environmental problem, and nitrogen removal has become an important issue in wastewater treatment processes. Landfill leachate is a typical large source of nitrogenous wastewater. Although the characteristics of leachate vary according to the age of the landfill, leachates of mature landfill have high concentrations of nitrogenous compounds.
View Article and Find Full Text PDFTo date, six candidate genera of anaerobic ammonium-oxidizing (anammox) bacteria have been identified, and numerous studies have been conducted to understand their ecophysiology. In this study, we examined the physiological characteristics of an anammox bacterium in the genus 'Candidatus Jettenia'. Planctomycete KSU-1 was found to be a mesophilic (20-42.
View Article and Find Full Text PDFThe hydroxylamine oxidoreductase (HAO) from the anammox bacterium, Candidatus Kuenenia stuttgartiensis has been reported to catalyze the oxidation of hydroxylamine (NH2OH) to nitric oxide (NO) by using bovine cytochrome c as an oxidant. In contrast, we investigated whether the HAO from anammox bacterium strain KSU-1 could catalyze the reduction of NO with reduced benzyl viologen (BVred) and the NO-releasing reagent, NOC 7. The reduction proceeded, resulting in the formation of NH2OH as a product.
View Article and Find Full Text PDFAnaerobic ammonium oxidation (anammox) and denitrification are two distinct microbial reactions relevant to the global nitrogen cycle. The proposed initial step of the anammox reactions, reduction of nitrite to nitric oxide, has been postulated to be identical to that in denitrification catalyzed by the dissimilatory nitrite reductase of the cytochrome cd(1)-type. Here, we characterized the copper-containing nitrite reductase homolog encoded by nirK detected in the genome of an anammox bacterium strain KSU-1.
View Article and Find Full Text PDFCompletely autotrophic nitrogen removal over nitrite (CANON) is a cost-effective nitrogen removal process. Implementation of the CANON process relies on the cooperation of ammonium-oxidizing and Anammox bacteria, as well as the inhibition of nitrite-oxidizing bacteria. Strict limitations on dissolved oxygen (DO) concentration in the reactor, and the addition of sufficient inorganic carbon in the influent, were adopted as the main operational strategies.
View Article and Find Full Text PDFThe feasibility of treating low-strength wastewater with an up-flow anaerobic sludge blanket (UASB) reactor, using a poly(vinyl alcohol)-gel carrier, at various temperatures and hydraulic retention times (HRTs) was examined. The temperature was decreased from 35°C to 25°C and then to 15°C. The HRT was reduced from 2.
View Article and Find Full Text PDFThe anaerobic ammonium oxidation (anammox) process has attracted considerable attention in recent years as an alternative to conventional nitrogen removal technologies. In this study, an innovative hybrid reactor combining fluidized and fixed beds for anammox treatment was developed. The fluidized bed was mechanically stirred and the gaseous product could be rapidly released from the anammox sludge to prevent washout of the sludge caused by flotation.
View Article and Find Full Text PDFReject water treatment performance was investigated by whole cell anammox sludge entrapped polyvinyl alcohol/sodium alginate gel in the stirred tank reactor (STR). The whole experiment was conducted through Phase 1 and Phase 2 in which synthetic wastewater and modified reject water were used as feeding medium, respectively. The anammox reactor demonstrated quick start-up after 22 days as well as stable and relatively high nitrogen removal rate of more than 8.
View Article and Find Full Text PDFReject water from a municipal wastewater treatment plant was treated using a stirred tank anammox reactor after being treated by a partial nitrification reactor. The results indicated the variations in the influent NO(2)(-)-N to NH(4)(+)-N ratio had a negative effect on reactor performance, especially when the T-N concentrations were high. Influent total organic carbon concentrations greater than 50mg/L were proven to have a serious effect on the nitrogen removal efficiencies of the anammox reactor.
View Article and Find Full Text PDFIn this study, a lab-scale swim-bed partial nitrification reactor was developed to treat ammonium-rich reject water to achieve an appropriate NO(2)(-)-N/NH(4)(+)-N mixture that could serve as a pretreatment for anaerobic ammonium oxidation (anammox). Strictly controlling the DO concentration was adopted as the main operational strategy. In addition, the influent concentrations of inorganic carbon/ammonium (IC/NH(4)(+)) and alkalinity/ammonium (Alk/NH(4)(+)) that were approximately 0.
View Article and Find Full Text PDFHere, the stable performance of nitrogen removal from digester liquor after partial nitrification was experimentally demonstrated in an up-flow anammox reactor with polyethylene sponge (PE sponge) as a biomass carrier. A high nitrogen loading rate of 8.4 kg-N/m(3)/day with a TN removal rate of 7.
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