Neocallimastix
Chytridiomycota
Rumen
Fungi
Neocallimastigales
Endo-1,3(4)-beta-Glucanase
Cellulase
Anaerobiosis
Xylan Endo-1,3-beta-Xylosidase
Cellobiose
Cellulose
Glycoside Hydrolases
Molecular Sequence Data
Identification and characterization of anaerobic gut fungi using molecular methodologies based on ribosomal ITS1 and 185 rRNA. (1/8)
The gut fungi are an unusual group of zoosporic fungi occupying a unique ecological niche, the anaerobic environment of the rumen. They exhibit two basic forms, with nuclear migration throughout the hyphal mass for polycentric species and with concentration of nuclear material in a zoosporangium for monocentric species. Differentiation between isolates of these fungi is difficult using conventional techniques. In this study, DNA-based methodologies were used to examine the relationships within and between two genera of monocentric gut fungi gathered from various geographical locations and host animals. The ribosomal ITS1 sequence from 16 mono- and 4 polycentric isolates was PCR-amplified and sequenced; the sequences obtained were aligned with published sequences and phylogenetic analyses were performed. These analyses clearly differentiate between the two genera and reflect the previously published physiological conclusions that Neocallimastix spp. constitute a more closely related genus than the relatively divergent genus Piromyces. The analyses place two type species N. frontalis and N. hurleyensis together but, contrary to a recent suggestion in the literature, place them apart from the other agreed species N. patriciarum. In situ hybridization and slot-blotting were investigated as potential methods for detection of and differentiation between monocentric gut fungi. DNA slot-blot analysis using ribosomal sequences is able to differentiate between gut fungal genera and thus has considerable potential for use in ecological studies of these organisms. (+info)Clostridium beijerinckii cells expressing Neocallimastix patriciarum glycoside hydrolases show enhanced lichenan utilization and solvent production. (2/8)
Growth and the production of acetone, butanol, and ethanol by Clostridium beijerinckii NCIMB 8052 on several polysaccharides and sugars were analyzed. On crystalline cellulose, growth and solvent production were observed only when a mixture of fungal cellulases was added to the medium. On lichenan growth and solvent production occurred, but this polymer was only partially utilized. To increase utilization of these polymers and subsequent solvent production, the genes for two new glycoside hydrolases, celA and celD from the fungus Neocallimastix patriciarum, were cloned separately into C. beijerinckii. To do this, a secretion vector based on the pMTL500E shuttle vector and containing the promoter and signal sequence coding region of the Clostridium saccharobutylicum NCP262 eglA gene was constructed and fused either to the celA gene or the celD gene. Stable C. beijerinckii transformants were obtained with the resulting plasmids, pWUR3 (celA) and pWUR4 (celD). The recombinant strains showed clear halos on agar plates containing carboxymethyl cellulose upon staining with Congo red. In addition, their culture supernatants had significant endoglucanase activities (123 U/mg of protein for transformants harboring celA and 78 U/mg of protein for transformants harboring celD). Although C. beijerinckii harboring either celA or celD was not able to grow, separately or in mixed culture, on carboxymethyl cellulose or microcrystalline cellulose, both transformants showed a significant increase in solvent production during growth on lichenan and more extensive degradation of this polymer than that exhibited by the wild-type strain. (+info)Stable linker peptides for a cellulose-binding domain-lipase fusion protein expressed in Pichia pastoris. (3/8)
Fusion proteins composed of a cellulose-binding domain from Neocallimastix patriciarum cellulase A and Candida antarctica lipase B were constructed using different linker peptides. The aim was to create proteolytically stable linkers that were able to join the functional modules without disrupting their function. Six fusion variants containing linkers of 4-44 residues were expressed in Pichia pastoris and analysed. Three variants were found to be stable throughout 7-day cultivations. The cellulose-binding capacities of fusion proteins containing short linkers were slightly lower compared with those containing long linkers. The lipase-specific activities of all variants, in solution or immobilized on to cellulose, were equal to that of the wild-type lipase. (+info)Characterisation of the DNA-binding profile of barley HvCBF1 using an enzymatic method for rapid, quantitative and high-throughput analysis of the DNA-binding activity. (4/8)
A rapid and quantitative DNA-binding assay was developed based on the translational fusion of a DNA-binding protein (DBP) with a Neocallimastix patriciarum beta-1,4-D-glucanase, CelD. CelD releases a fluorescent 4-methylumbelliferyl product from 4-methylumbelliferyl cellobioside. This hydrolysis activity was used to quantify the amount of DBP-CelD bound to an immobilised biotin-labelled target sequence. The DNA-binding assay can be performed in a 96-well plate format for high- throughput analysis of putative DBPs. This method was applied to analysis of the binding properties and sequence selectivity of a cold-inducible transcription factor HvCBF1 from barley containing an AP2 DNA-binding domain. A base-scanning approach using degenerate oligonucleotide probes was employed for rapid identification of the conserved core motif of the HvCBF1 binding site. Quantitative analysis of the binding site of HvCBF1 using systematic base substitution revealed that a (G/a) (C/t)CGAC sequence was sufficient to constitute a functional motif, where the lower-case letters represent less efficient bases. The method enables us to provide accurate and quantitative data on a comprehensive DNA-binding profile for a cold-inducible AP2 transcription factor as well as information on environmental parameters potentially influencing the DNA-binding activity. The accurate binding sequence data facilitate identification of candidate genes regulated by HvCBF1 from genome sequence databases. (+info)Fungal hydrogenosomes contain mitochondrial heat-shock proteins. (5/8)
At least three groups of anaerobic eukaryotes lack mitochondria and instead contain hydrogenosomes, peculiar organelles that make energy and excrete hydrogen. Published data indicate that ciliate and trichomonad hydrogenosomes share common ancestry with mitochondria, but the evolutionary origins of fungal hydrogenosomes have been controversial. We have now isolated full-length genes for heat shock proteins 60 and 70 from the anaerobic fungus Neocallimastix patriciarum, which phylogenetic analyses reveal share common ancestry with mitochondrial orthologues. In aerobic organisms these proteins function in mitochondrial import and protein folding. Homologous antibodies demonstrated the localization of both proteins to fungal hydrogenosomes. Moreover, both sequences contain amino-terminal extensions that in heterologous targeting experiments were shown to be necessary and sufficient to locate both proteins and green fluorescent protein to the mitochondria of mammalian cells. This finding, that fungal hydrogenosomes use mitochondrial targeting signals to import two proteins of mitochondrial ancestry that play key roles in aerobic mitochondria, provides further strong evidence that the fungal organelle is also of mitochondrial ancestry. The extraordinary capacity of eukaryotes to repeatedly evolve hydrogen-producing organelles apparently reflects a general ability to modify the biochemistry of the mitochondrial compartment. (+info)Expression of rumen microbial fibrolytic enzyme genes in probiotic Lactobacillus reuteri. (6/8)
This study was aimed at evaluating the cloning and expression of three rumen microbial fibrolytic enzyme genes in a strain of Lactobacillus reuteri and investigating the probiotic characteristics of these genetically modified lactobacilli. The Neocallimastix patriciarum xylanase gene xynCDBFV, the Fibrobacter succinogenes beta-glucanase (1,3-1,4-beta-D-glucan 4-glucanohydrolase [EC 3.2.1.73]) gene, and the Piromyces rhizinflata cellulase gene eglA were cloned in a strain of L. reuteri isolated from the gastrointestinal tract of broilers. The enzymes were expressed and secreted under the control of the Lactococcus lactis lacA promoter and its secretion signal. The L. reuteri transformed strains not only acquired the capacity to break down soluble carboxymethyl cellulose, beta-glucan, or xylan but also showed high adhesion efficiency to mucin and mucus and resistance to bile salt and acid. (+info)Incorporation of fungal cellulases in bacterial minicellulosomes yields viable, synergistically acting cellulolytic complexes. (7/8)
Artificial designer minicellulosomes comprise a chimeric scaffoldin that displays an optional cellulose-binding module (CBM) and bacterial cohesins from divergent species which bind strongly to enzymes engineered to bear complementary dockerins. Incorporation of cellulosomal cellulases from Clostridium cellulolyticum into minicellulosomes leads to artificial complexes with enhanced activity on crystalline cellulose, due to enzyme proximity and substrate targeting induced by the scaffoldin-borne CBM. In the present study, a bacterial dockerin was appended to the family 6 fungal cellulase Cel6A, produced by Neocallimastix patriciarum, for subsequent incorporation into minicellulosomes in combination with various cellulosomal cellulases from C. cellulolyticum. The binding of the fungal Cel6A with a bacterial family 5 endoglucanase onto chimeric miniscaffoldins had no impact on their activity toward crystalline cellulose. Replacement of the bacterial family 5 enzyme with homologous endoglucanase Cel5D from N. patriciarum bearing a clostridial dockerin gave similar results. In contrast, enzyme pairs comprising the fungal Cel6A and bacterial family 9 endoglucanases were substantially stimulated (up to 2.6-fold) by complexation on chimeric scaffoldins, compared to the free-enzyme system. Incorporation of enzyme pairs including Cel6A and a processive bacterial cellulase generally induced lower stimulation levels. Enhanced activity on crystalline cellulose appeared to result from either proximity or CBM effects alone but never from both simultaneously, unlike minicellulosomes composed exclusively of bacterial cellulases. The present study is the first demonstration that viable designer minicellulosomes can be produced that include (i) free (noncellulosomal) enzymes, (ii) fungal enzymes combined with bacterial enzymes, and (iii) a type (family 6) of cellulase never known to occur in natural cellulosomes. (+info)Catalytic efficiency diversification of duplicate beta-1,3-1,4-glucanases from Neocallimastix patriciarum J11. (8/8)
(+info)Neocallimastix is a genus of anaerobic fungi that are commonly found in the digestive tracts of herbivorous mammals and birds, where they play a crucial role in breaking down complex plant material into simpler compounds that can be absorbed and utilized by their hosts. These fungi are characterized by their ability to produce enzymes that can break down cellulose, hemicellulose, and lignin, the major structural components of plant cell walls. Under a microscope, Neocallimastix species appear as branching, septate hyphae with rounded or pointed ends, and they reproduce by forming spores within specialized structures called sporangia.
Chytridiomycota is a phylum that includes various species of fungi known as chytrids. These fungi are characterized by having a unique life cycle that involves a motile, flagellated stage in their reproductive process. Chytridiomycota fungi can be found in a wide range of environments, including freshwater and terrestrial habitats. Some species of chytrids are parasites that infect various organisms, such as algae, plants, and animals, while others are saprophytes that obtain nutrients by decomposing organic matter.
One notable species of Chytridiomycota is Batrachochytrium dendrobatidis (Bd), which is a pathogenic fungus that infects the skin of amphibians. This fungus has been implicated in declines and extinctions of amphibian populations worldwide, making it a significant concern for global biodiversity conservation efforts.
The rumen is the largest compartment of the stomach in ruminant animals, such as cows, goats, and sheep. It is a specialized fermentation chamber where microbes break down tough plant material into nutrients that the animal can absorb and use for energy and growth. The rumen contains billions of microorganisms, including bacteria, protozoa, and fungi, which help to break down cellulose and other complex carbohydrates in the plant material through fermentation.
The rumen is characterized by its large size, muscular walls, and the presence of a thick mat of partially digested food and microbes called the rumen mat or cud. The animal regurgitates the rumen contents periodically to chew it again, which helps to break down the plant material further and mix it with saliva, creating a more favorable environment for fermentation.
The rumen plays an essential role in the digestion and nutrition of ruminant animals, allowing them to thrive on a diet of low-quality plant material that would be difficult for other animals to digest.
Fungi, in the context of medical definitions, are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as the more familiar mushrooms. The study of fungi is known as mycology.
Fungi can exist as unicellular organisms or as multicellular filamentous structures called hyphae. They are heterotrophs, which means they obtain their nutrients by decomposing organic matter or by living as parasites on other organisms. Some fungi can cause various diseases in humans, animals, and plants, known as mycoses. These infections range from superficial, localized skin infections to systemic, life-threatening invasive diseases.
Examples of fungal infections include athlete's foot (tinea pedis), ringworm (dermatophytosis), candidiasis (yeast infection), histoplasmosis, coccidioidomycosis, and aspergillosis. Fungal infections can be challenging to treat due to the limited number of antifungal drugs available and the potential for drug resistance.
Neocallimastigales is an order of anaerobic fungi that are commonly found in the digestive tracts of herbivorous mammals, such as cattle, sheep, and horses. These fungi play a crucial role in breaking down complex plant material into simpler compounds that can be absorbed and utilized by their hosts for energy and growth. Neocallimastigales fungi are characterized by their unique morphology and life cycle, which include the ability to form motile zoospores that can swim through liquid environments. They are also capable of producing a variety of enzymes that enable them to break down cellulose, hemicellulose, and lignin, making them important players in the global carbon cycle.
Cellulase is a type of enzyme that breaks down cellulose, which is a complex carbohydrate and the main structural component of plant cell walls. Cellulases are produced by certain bacteria, fungi, and protozoans, and are used in various industrial applications such as biofuel production, food processing, and textile manufacturing. In the human body, there are no known physiological roles for cellulases, as humans do not produce these enzymes and cannot digest cellulose.
Anaerobiosis is a state in which an organism or a portion of an organism is able to live and grow in the absence of molecular oxygen (O2). In biological contexts, "anaerobe" refers to any organism that does not require oxygen for growth, and "aerobe" refers to an organism that does require oxygen for growth.
There are two types of anaerobes: obligate anaerobes, which cannot tolerate the presence of oxygen and will die if exposed to it; and facultative anaerobes, which can grow with or without oxygen but prefer to grow in its absence. Some organisms are able to switch between aerobic and anaerobic metabolism depending on the availability of oxygen, a process known as "facultative anaerobiosis."
Anaerobic respiration is a type of metabolic process that occurs in the absence of molecular oxygen. In this process, organisms use alternative electron acceptors other than oxygen to generate energy through the transfer of electrons during cellular respiration. Examples of alternative electron acceptors include nitrate, sulfate, and carbon dioxide.
Anaerobic metabolism is less efficient than aerobic metabolism in terms of energy production, but it allows organisms to survive in environments where oxygen is not available or is toxic. Anaerobic bacteria are important decomposers in many ecosystems, breaking down organic matter and releasing nutrients back into the environment. In the human body, anaerobic bacteria can cause infections and other health problems if they proliferate in areas with low oxygen levels, such as the mouth, intestines, or deep tissue wounds.
Xylan Endo-1,3-beta-Xylosidase is an enzyme that breaks down xylan, which is a major component of hemicellulose in plant cell walls. This enzyme specifically catalyzes the hydrolysis of 1,3-beta-D-xylosidic linkages in xylans, resulting in the release of xylose units from the xylan backbone. It is involved in the process of breaking down plant material for various industrial applications and in the natural decomposition of plants by microorganisms.
Cellobiose is a disaccharide made up of two molecules of glucose joined by a β-1,4-glycosidic bond. It is formed when cellulose or beta-glucans are hydrolyzed, and it can be further broken down into its component glucose molecules by the action of the enzyme beta-glucosidase. Cellobiose has a sweet taste, but it is not as sweet as sucrose (table sugar). It is used in some industrial processes and may have potential applications in the food industry.
Xylans are a type of complex carbohydrate, specifically a hemicellulose, that are found in the cell walls of many plants. They are made up of a backbone of beta-1,4-linked xylose sugar molecules and can be substituted with various side groups such as arabinose, glucuronic acid, and acetyl groups. Xylans are indigestible by humans, but they can be broken down by certain microorganisms in the gut through a process called fermentation, which can produce short-chain fatty acids that have beneficial effects on health.
Cellulose is a complex carbohydrate that is the main structural component of the cell walls of green plants, many algae, and some fungi. It is a polysaccharide consisting of long chains of beta-glucose molecules linked together by beta-1,4 glycosidic bonds. Cellulose is insoluble in water and most organic solvents, and it is resistant to digestion by humans and non-ruminant animals due to the lack of cellulase enzymes in their digestive systems. However, ruminants such as cows and sheep can digest cellulose with the help of microbes in their rumen that produce cellulase.
Cellulose has many industrial applications, including the production of paper, textiles, and building materials. It is also used as a source of dietary fiber in human food and animal feed. Cellulose-based materials are being explored for use in biomedical applications such as tissue engineering and drug delivery due to their biocompatibility and mechanical properties.
Glycoside hydrolases are a class of enzymes that catalyze the hydrolysis of glycosidic bonds found in various substrates such as polysaccharides, oligosaccharides, and glycoproteins. These enzymes break down complex carbohydrates into simpler sugars by cleaving the glycosidic linkages that connect monosaccharide units.
Glycoside hydrolases are classified based on their mechanism of action and the type of glycosidic bond they hydrolyze. The classification system is maintained by the International Union of Biochemistry and Molecular Biology (IUBMB). Each enzyme in this class is assigned a unique Enzyme Commission (EC) number, which reflects its specificity towards the substrate and the type of reaction it catalyzes.
These enzymes have various applications in different industries, including food processing, biofuel production, pulp and paper manufacturing, and biomedical research. In medicine, glycoside hydrolases are used to diagnose and monitor certain medical conditions, such as carbohydrate-deficient glycoprotein syndrome, a rare inherited disorder affecting the structure of glycoproteins.
Fungal DNA refers to the genetic material present in fungi, which are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The DNA of fungi, like that of all living organisms, is made up of nucleotides that are arranged in a double helix structure.
Fungal DNA contains the genetic information necessary for the growth, development, and reproduction of fungi. This includes the instructions for making proteins, which are essential for the structure and function of cells, as well as other important molecules such as enzymes and nucleic acids.
Studying fungal DNA can provide valuable insights into the biology and evolution of fungi, as well as their potential uses in medicine, agriculture, and industry. For example, researchers have used genetic engineering techniques to modify the DNA of fungi to produce drugs, biofuels, and other useful products. Additionally, understanding the genetic makeup of pathogenic fungi can help scientists develop new strategies for preventing and treating fungal infections.
Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.