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Aspergillus: A genus of mitosporic fungi containing about 100 species and eleven different teleomorphs in the family Trichocomaceae.Aspergillus fumigatus: A species of imperfect fungi from which the antibiotic fumigatin is obtained. Its spores may cause respiratory infection in birds and mammals.Aspergillus nidulans: A species of imperfect fungi from which the antibiotic nidulin is obtained. Its teleomorph is Emericella nidulans.Aspergillus niger: An imperfect fungus causing smut or black mold of several fruits, vegetables, etc.Aspergillus flavus: A species of imperfect fungi which grows on peanuts and other plants and produces the carcinogenic substance aflatoxin. It is also used in the production of the antibiotic flavicin.Aspergillosis: Infections with fungi of the genus ASPERGILLUS.Spores, Fungal: Reproductive bodies produced by fungi.Aflatoxins: Furano-furano-benzopyrans that are produced by ASPERGILLUS from STERIGMATOCYSTIN. They are structurally related to COUMARINS and easily oxidized to an epoxide form to become ALKYLATING AGENTS. Members of the group include AFLATOXIN B1; aflatoxin B2, aflatoxin G1, aflatoxin G2; AFLATOXIN M1; and aflatoxin M2.Aspergillus ochraceus: An imperfect fungus that produces ochratoxins and contaminates EDIBLE GRAIN and coffee beans.Antifungal Agents: Substances that destroy fungi by suppressing their ability to grow or reproduce. They differ from FUNGICIDES, INDUSTRIAL because they defend against fungi present in human or animal tissues.Fungal Proteins: Proteins found in any species of fungus.Pulmonary Aspergillosis: Infections of the respiratory tract with fungi of the genus ASPERGILLUS. Infections may result in allergic reaction (ALLERGIC BRONCHOPULMONARY ASPERGILLOSIS), colonization in pulmonary cavities as fungus balls (MYCETOMA), or lead to invasion of the lung parenchyma (INVASIVE PULMONARY ASPERGILLOSIS).Sterigmatocystin: A carcinogenic mycotoxin produced in high yields by strains of the common molds, Aspergillus versicolor, A. nidulans, and an unidentified species of Bipolaris. It causes necrosis of the liver and kidney and has an inhibitory effect on orotic acid incorporation into nuclear RNA.Aspergillosis, Allergic Bronchopulmonary: Hypersensitivity reaction (ALLERGIC REACTION) to fungus ASPERGILLUS in an individual with long-standing BRONCHIAL ASTHMA. It is characterized by pulmonary infiltrates, EOSINOPHILIA, elevated serum IMMUNOGLOBULIN E, and skin reactivity to Aspergillus antigen.DNA, Fungal: Deoxyribonucleic acid that makes up the genetic material of fungi.Glucan 1,4-alpha-Glucosidase: An enzyme that catalyzes the hydrolysis of terminal 1,4-linked alpha-D-glucose residues successively from non-reducing ends of polysaccharide chains with the release of beta-glucose. It is also able to hydrolyze 1,6-alpha-glucosidic bonds when the next bond in sequence is 1,4.Hyphae: Microscopic threadlike filaments in FUNGI that are filled with a layer of protoplasm. Collectively, the hyphae make up the MYCELIUM.Lung Diseases, Fungal: Pulmonary diseases caused by fungal infections, usually through hematogenous spread.Genes, Fungal: The functional hereditary units of FUNGI.Fungi: A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.Itraconazole: A triazole antifungal agent that inhibits cytochrome P-450-dependent enzymes required for ERGOSTEROL synthesis.Invasive Pulmonary Aspergillosis: Lung infections with the invasive forms of ASPERGILLUS, usually after surgery, transplantation, prolonged NEUTROPENIA or treatment with high-doses of CORTICOSTEROIDS. Invasive pulmonary aspergillosis can progress to CHRONIC NECROTIZING PULMONARY ASPERGILLOSIS or hematogenous spread to other organs.Gene Expression Regulation, Fungal: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in fungi.Penicillium: A mitosporic Trichocomaceae fungal genus that develops fruiting organs resembling a broom. When identified, teleomorphs include EUPENICILLIUM and TALAROMYCES. Several species (but especially PENICILLIUM CHRYSOGENUM) are sources of the antibiotic penicillin.TriazolesAntigens, Fungal: Substances of fungal origin that have antigenic activity.Ochratoxins: Isocoumarins found in ASPERGILLUS OCHRACEUS and other FUNGI. Ochratoxin contaminated FOOD has been responsible for cases of FOODBORNE DISEASES.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Drug Resistance, Fungal: The ability of fungi to resist or to become tolerant to chemotherapeutic agents, antifungal agents, or antibiotics. This resistance may be acquired through gene mutation.Amphotericin B: Macrolide antifungal antibiotic produced by Streptomyces nodosus obtained from soil of the Orinoco river region of Venezuela.Gliotoxin: A fungal toxin produced by various species of Trichoderma, Gladiocladium fimbriatum, Aspergillus fumigatus, and Penicillium. It is used as an immunosuppressive agent.Mycotoxins: Toxic compounds produced by FUNGI.Mannans: Polysaccharides consisting of mannose units.Echinocandins: Cyclic hexapeptides of proline-ornithine-threonine-proline-threonine-serine. The cyclization with a single non-peptide bond can lead them to be incorrectly called DEPSIPEPTIDES, but the echinocandins lack ester links. Antifungal activity is via inhibition of 1,3-beta-glucan synthase production of BETA-GLUCANS.Germinal Center: The activated center of a lymphoid follicle in secondary lymphoid tissue where B-LYMPHOCYTES are stimulated by antigens and helper T cells (T-LYMPHOCYTES, HELPER-INDUCER) are stimulated to generate memory cells.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Mycology: The study of the structure, growth, function, genetics, and reproduction of fungi, and MYCOSES.Child Day Care Centers: Facilities which provide care for pre-school and school-age children.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).MycosesMycelium: The body of a fungus which is made up of HYPHAE.Neuroaspergillosis: Infections of the nervous system caused by fungi of the genus ASPERGILLUS, most commonly ASPERGILLUS FUMIGATUS. Aspergillus infections may occur in immunocompetent hosts, but are more prevalent in individuals with IMMUNOLOGIC DEFICIENCY SYNDROMES. The organism may spread to the nervous system from focal infections in the lung, mastoid region, sinuses, inner ear, bones, eyes, gastrointestinal tract, and heart. Sinus infections may be locally invasive and enter the intracranial compartment, producing MENINGITIS, FUNGAL; cranial neuropathies; and abscesses in the frontal lobes of the brain. (From Joynt, Clinical Neurology, 1998, Ch 27, pp62-3)Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Fusarium: A mitosporic Hypocreales fungal genus, various species of which are important parasitic pathogens of plants and a variety of vertebrates. Teleomorphs include GIBBERELLA.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Antibodies, Fungal: Immunoglobulins produced in a response to FUNGAL ANTIGENS.Air Microbiology: The presence of bacteria, viruses, and fungi in the air. This term is not restricted to pathogenic organisms.Mycological Typing Techniques: Procedures for identifying types and strains of fungi.Arachis hypogaea: A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.Mitosporic Fungi: A large and heterogenous group of fungi whose common characteristic is the absence of a sexual state. Many of the pathogenic fungi in humans belong to this group.Fermentation: Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Benomyl: A systemic agricultural fungicide used for control of certain fungal diseases of stone fruit.Eye Infections, Fungal: Infection by a variety of fungi, usually through four possible mechanisms: superficial infection producing conjunctivitis, keratitis, or lacrimal obstruction; extension of infection from neighboring structures - skin, paranasal sinuses, nasopharynx; direct introduction during surgery or accidental penetrating trauma; or via the blood or lymphatic routes in patients with underlying mycoses.Reproduction, Asexual: Reproduction without fusion of two types of cells, mostly found in ALGAE; FUNGI; and PLANTS. Asexual reproduction occurs in several ways, such as budding, fission, or splitting from "parent" cells. Only few groups of ANIMALS reproduce asexually or unisexually (PARTHENOGENESIS).Community Health Centers: Facilities which administer the delivery of health care services to people living in a community or neighborhood.Transformation, Genetic: Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.Azoles: Five membered rings containing a NITROGEN atom.6-Phytase: An enzyme that catalyzes the conversion of myo-inositol hexakisphosphate and water to 1L-myo-inositol 1,2,3,4,5-pentakisphosphate and orthophosphate. EC 3.1.3.26.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Trauma Centers: Specialized hospital facilities which provide diagnostic and therapeutic services for trauma patients.Tertiary Care Centers: A medical facility which provides a high degree of subspecialty expertise for patients from centers where they received SECONDARY CARE.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Pyrimidines: A family of 6-membered heterocyclic compounds occurring in nature in a wide variety of forms. They include several nucleic acid constituents (CYTOSINE; THYMINE; and URACIL) and form the basic structure of the barbiturates.Genome, Fungal: The complete gene complement contained in a set of chromosomes in a fungus.Immunocompromised Host: A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation.Anthraquinones: Compounds based on ANTHRACENES which contain two KETONES in any position. Substitutions can be in any position except on the ketone groups.Polygalacturonase: A cell wall-degrading enzyme found in microorganisms and higher plants. It catalyzes the random hydrolysis of 1,4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. EC 3.2.1.15.Glycoside HydrolasesSequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Peptides, Cyclic: Peptides whose amino and carboxy ends are linked together with a peptide bond forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS. Some of them are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Xylosidases: A group of enzymes that catalyze the hydrolysis of alpha- or beta-xylosidic linkages. EC 3.2.1.8 catalyzes the endo-hydrolysis of 1,4-beta-D-xylosidic linkages; EC 3.2.1.32 catalyzes the endo-hydrolysis of 1,3-beta-D-xylosidic linkages; EC 3.2.1.37 catalyzes the exo-hydrolysis of 1,4-beta-D-linkages from the non-reducing termini of xylans; and EC 3.2.1.72 catalyzes the exo-hydrolysis of 1,3-beta-D-linkages from the non-reducing termini of xylans. Other xylosidases have been identified that catalyze the hydrolysis of alpha-xylosidic bonds.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Opportunistic Infections: An infection caused by an organism which becomes pathogenic under certain conditions, e.g., during immunosuppression.Rhizopus: A genus of zygomycetous fungi of the family Mucoraceae, order MUCORALES, a common saprophyte and facultative parasite of mature fruits and vegetables. It may cause cerebral mycoses in diabetes and cutaneous infection in severely burned patients.Drug Resistance, Multiple, Fungal: The ability of fungi to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance phenotype may be attributed to multiple gene mutations.Centers for Disease Control and Prevention (U.S.): An agency of the UNITED STATES PUBLIC HEALTH SERVICE that conducts and supports programs for the prevention and control of disease and provides consultation and assistance to health departments and other countries.Candida: A genus of yeast-like mitosporic Saccharomycetales fungi characterized by producing yeast cells, mycelia, pseudomycelia, and blastophores. It is commonly part of the normal flora of the skin, mouth, intestinal tract, and vagina, but can cause a variety of infections, including CANDIDIASIS; ONYCHOMYCOSIS; vulvovaginal candidiasis (CANDIDIASIS, VULVOVAGINAL), and thrush (see CANDIDIASIS, ORAL). (From Dorland, 28th ed)Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.beta-Glucans: Glucose polymers consisting of a backbone of beta(1->3)-linked beta-D-glucopyranosyl units with beta(1->6) linked side chains of various lengths. They are a major component of the CELL WALL of organisms and of soluble DIETARY FIBER.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Eurotiales: An order of fungi in the phylum ASCOMYCOTA characterized by the presence of well defined peridia and cleistothecial asci. Notable anamorphs (mitosporic forms) of Eurotiales include PENICILLIUM and ASPERGILLUS.Neosartorya: A genus of ascomycetous fungi in the family Trichocomaceae, order EUROTIALES. Some species can cause opportunistic infections in humans, similar to its anamorph ASPERGILLUS.Emericella: A genus in the family Trichocomaceae, order EUROTIALES. The anamorph is ASPERGILLUS.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Food Microbiology: The presence of bacteria, viruses, and fungi in food and food products. This term is not restricted to pathogenic organisms: the presence of various non-pathogenic bacteria and fungi in cheeses and wines, for example, is included in this concept.Aflatoxin B1: A potent hepatotoxic and hepatocarcinogenic mycotoxin produced by the Aspergillus flavus group of fungi. It is also mutagenic, teratogenic, and causes immunosuppression in animals. It is found as a contaminant in peanuts, cottonseed meal, corn, and other grains. The mycotoxin requires epoxidation to aflatoxin B1 2,3-oxide for activation. Microsomal monooxygenases biotransform the toxin to the less toxic metabolites aflatoxin M1 and Q1.Lipopeptides: Compounds consisting of a short peptide chain conjugated with an acyl chain.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Xylans: Polysaccharides consisting of xylose units.Chromatography, Thin Layer: Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Time Factors: Elements of limited time intervals, contributing to particular results or situations.DNA, Ribosomal Spacer: The intergenic DNA segments that are between the ribosomal RNA genes (internal transcribed spacers) and between the tandemly repeated units of rDNA (external transcribed spacers and nontranscribed spacers).Industrial Microbiology: The study, utilization, and manipulation of those microorganisms capable of economically producing desirable substances or changes in substances, and the control of undesirable microorganisms.Isomaltose: A disaccharide consisting of two glucose units in an alpha (1-6) glycosidic linkage.Kinetics: The rate dynamics in chemical or physical systems.Poison Control Centers: Facilities which provide information concerning poisons and treatment of poisoning in emergencies.Chitin: A linear polysaccharide of beta-1->4 linked units of ACETYLGLUCOSAMINE. It is the second most abundant biopolymer on earth, found especially in INSECTS and FUNGI. When deacetylated it is called CHITOSAN.Biosynthetic Pathways: Sets of enzymatic reactions occurring in organisms and that form biochemicals by making new covalent bonds.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.alpha-Amylases: Enzymes that catalyze the endohydrolysis of 1,4-alpha-glycosidic linkages in STARCH; GLYCOGEN; and related POLYSACCHARIDES and OLIGOSACCHARIDES containing 3 or more 1,4-alpha-linked D-glucose units.RNA, Fungal: Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.Ergot Alkaloids: Alkaloids originally isolated from the ergot fungus Claviceps purpurea (Hypocreaceae). They include compounds that are structurally related to ergoline (ERGOLINES) and ergotamine (ERGOTAMINES). Many of the ergot alkaloids act as alpha-adrenergic antagonists.Photosynthetic Reaction Center Complex Proteins: Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.Enzyme Stability: The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.beta-Glucosidase: An exocellulase with specificity for a variety of beta-D-glycoside substrates. It catalyzes the hydrolysis of terminal non-reducing residues in beta-D-glucosides with release of GLUCOSE.Penicillium chrysogenum: A mitosporic fungal species used in the production of penicillin.XyloseMultigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Cladosporium: A mitosporic Loculoascomycetes fungal genus including some economically important plant parasites. Teleomorphs include Mycosphaerella and Venturia.Information Centers: Facilities for collecting and organizing information. They may be specialized by subject field, type of source material, persons served, location, or type of services.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Granulomatous Disease, Chronic: A defect of leukocyte function in which phagocytic cells ingest but fail to digest bacteria, resulting in recurring bacterial infections with granuloma formation. When chronic granulomatous disease is caused by mutations in the CYBB gene, the condition is inherited in an X-linked recessive pattern. When chronic granulomatous disease is caused by CYBA, NCF1, NCF2, or NCF4 gene mutations, the condition is inherited in an autosomal recessive pattern.Cellulase: An endocellulase with specificity for the hydrolysis of 1,4-beta-glucosidic linkages in CELLULOSE, lichenin, and cereal beta-glucans.Food Contamination: The presence in food of harmful, unpalatable, or otherwise objectionable foreign substances, e.g. chemicals, microorganisms or diluents, before, during, or after processing or storage.Microtubule-Organizing Center: An amorphous region of electron dense material in the cytoplasm from which the MICROTUBULES polymerization is nucleated. The pericentriolar region of the CENTROSOME which surrounds the CENTRIOLES is an example.Fusariosis: OPPORTUNISTIC INFECTIONS with the soil fungus FUSARIUM. Typically the infection is limited to the nail plate (ONYCHOMYCOSIS). The infection can however become systemic especially in an IMMUNOCOMPROMISED HOST (e.g., NEUTROPENIA) and results in cutaneous and subcutaneous lesions, fever, KERATITIS, and pulmonary infections.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Carboxylic Ester Hydrolases: Enzymes which catalyze the hydrolysis of carboxylic acid esters with the formation of an alcohol and a carboxylic acid anion.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.RNA, Ribosomal, 28S: Constituent of the 60S subunit of eukaryotic ribosomes. 28S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.Scedosporium: A mitosporic fungal genus previously called Monosporium. Teleomorphs include PSEUDALLESCHERIA.PolysaccharidesPhenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Ascomycota: A phylum of fungi which have cross-walls or septa in the mycelium. The perfect state is characterized by the formation of a saclike cell (ascus) containing ascospores. Most pathogenic fungi with a known perfect state belong to this phylum.Candidiasis: Infection with a fungus of the genus CANDIDA. It is usually a superficial infection of the moist areas of the body and is generally caused by CANDIDA ALBICANS. (Dorland, 27th ed)Chitin Synthase: An enzyme that converts UDP glucosamine into chitin and UDP. EC 2.4.1.16.