Página 14 dos resultados de 10906 itens digitais encontrados em 0.010 segundos

‣ Application of enzymes in leather processing: a comparison between chemical and coenzymatic processes

Souza,F. R. de; Gutterres,M.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2012 Português
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The use of biotechnology by tanneries has increased in recent years. Enzymes can be applied during different steps of the leather production process: soaking, dehairing, bating, dyeing, degreasing or in effluent and solid waste treatment. This study evaluated the performance of five commercial enzymes in soaking and unhairing/liming by comparing the chemical and coenzymatic processes. Tests were conducted in bench drums to evaluate the action of enzymes during each stage. Concentration, processing time and type of enzyme were varied. Total organic carbon and soluble protein were used to measure the efficiency of the processes. Enzymatic activity assays on collagen, keratin and lipid and scanning electron microscopic (SEM) analyses of hides were used to complement the study. Coenzymatic processes generally showed better results in comparison to chemical processes. The enzymes showed activity on all substrates, and the SEM analyses of the hides showed a clear difference between the chemical and coenzymatic processes.

‣ Biotechnology applied to salmoniculture

Isler,Iván Valdebenito
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2009 Português
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This work presents a conceptual analysis of the main biotechnologies used in Chilean salmoniculture, which is based on the production of Atlantic salmon (Salmo salar, 356.407 t),silver salmon or coho (Oncorhynchus kisutch, 116.481 t), (O. tshawytscha, 2.062 t) and rainbow trout (O. mykiss, 189.178 t).These activities are focused on the photoperiod artificial manipulation to obtain out-of-season spawning, in the use of hormonal therapies which allow synchronizing the final oocyte maturation (FOM) and sexual maturity acceleration or the increase in milt volume produced by males. Such actions are carried out using GnRHa in doses close to 10 µg/kg of fish. Once sexual maturity is reached, in vitro manipulation of gamets must often be done due to either the prolonged storage (particularly milt) they have to undergo in order to transport them where fertilization takes place, or awaiting for the ichtiopathological results, usually taken to broodstock. The production of "all female" populations is also common. Frequently, these populations in rainbow trout are triploided (through shock temperature close to 28º C or pressure close to 8.000 psi) to obtain sterile species which improve productive perfomance of cultured populations without sexual maturity signs. Besides...

‣ Scientific progress in the production of monogastric in the first decade of the twenty-first century

Costa,Fernando Guilherme Perazzo; Silva,José Humberto Vilar da; Lima,Raffaella Castro de; Oliveira,Cleber Franklin Santos de; Rodrigues,Valéria Pereira; Pinheiro,Sarah Gomes
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2010 Português
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Significant progress in the area of animal production is due to the development of researches on genetics, environment, health, management and nutrition. The search for better management conditions that benefit animal welfare resulted in changes to the installation. The genetic improvement more productive animals has encouraged the number of searches to reduce the incidence of diseases, mainly of metabolic origin. The incorporation in products with higher bioavailability as industrial amino acid and organic minerals, the inclusion of products modifiers enteric of microflora as probiotic, prebiotic, symbiotic, nucleotides and exogenous enzymes, has benefited the use of nutrients are not well absorbed and often unavailable in the diet. Biotechnology latest as nutrition in egg and molecular biology has been used for the benefit of the increase animal productivity.

‣ Date and their processing byproducts as substrates for bioactive compounds production

Tang,Zhen-Xing; Shi,Lu-E; Aleid,Salah Mohammed
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2014 Português
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Date is the most popular fruit in middle-east countries. However, the date production process is accompanied by a substantial increase of loss during picking, storage, commercialization and conditioning process. Date and their byproducts have many essential elements for the growth of microorganisms. Thus, they can be converted into value-added compounds through biotechnology. In this paper, date and their processing byproducts used as substrates for producing value-added products such as organic acids, exopolysaccharide, antibiotics, date flavored probiotic fermented dairy, bakery yeast, etc, were reviewed.

‣ Biotechnological approaches to the treatment of aspermatogenic men

Aponte,Pedro Manuel; Schlatt,Stefan; Franca,Luiz Renato de
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
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Aspermatogenesis is a severe impairment of spermatogenesis in which germ cells are completely lacking or present in an immature form, which results in sterility in approximately 25% of patients. Because assisted reproduction techniques require mature germ cells, biotechnology is a valuable tool for rescuing fertility while maintaining biological fatherhood. However, this process involves, for instance, the differentiation of preexisting immature germ cells or the production/derivation of sperm from somatic cells. This review critically addresses four potential techniques: sperm derivation in vitro, germ stem cell transplantation, xenologous systems, and haploidization. Sperm derivation in vitro is already feasible in fish and mammals through organ culture or 3D systems, and it is very useful in conditions of germ cell arrest or in type II Sertoli-cell-only syndrome. Patients afflicted by type I Sertoli-cell-only syndrome could also benefit from gamete derivation from induced pluripotent stem cells of somatic origin, and human haploid-like cells have already been obtained by using this novel methodology. In the absence of alternative strategies to generate sperm in vitro, in germ cells transplantation fertility is restored by placing donor cells in the recipient germ-cell-free seminiferous epithelium...

‣ Cultivar development of allogamous crops

Souza Jr.,Cláudio Lopes de
Fonte: Crop Breeding and Applied Biotechnology Publicador: Crop Breeding and Applied Biotechnology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
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Objectives of this review were to present the state of the art of the technologies used to develop cultivars in allogamous species, excluding the perennial and asexually propagated species. It was reviewed the genetic structure of these species and its relationship with the development of cultivars, the technologies used to develop hybrids and improved open-pollinated varieties and their F1´s, and the impact of the biotechnology and the mixed models on the development of cultivars. A summary of results from the researches developed in the maize breeding project at the Department of Genetics of the Agriculture College "Luiz de Queiroz" will be presented.

‣ Drugs obtained by biotechnology processing

Almeida,Hugo; Amaral,Maria Helena; Lobão,Paulo
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
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In recent years, the number of drugs of biotechnological origin available for many different diseases has increased exponentially, including different types of cancer, diabetes mellitus, infectious diseases (e.g. AIDS Virus / HIV) as well as cardiovascular, neurological, respiratory, and autoimmune diseases, among others. The pharmaceutical industry has used different technologies to obtain new and promising active ingredients, as exemplified by the fermentation technique, recombinant DNA technique and the hybridoma technique. The expiry of the patents of the first drugs of biotechnological origin and the consequent emergence of biosimilar products, have posed various questions to health authorities worldwide regarding the definition, framework, and requirements for authorization to market such products.

‣ Database resources of the National Center for Biotechnology Information

Wheeler, David L.; Church, Deanna M.; Lash, Alex E.; Leipe, Detlef D.; Madden, Thomas L.; Pontius, Joan U.; Schuler, Gregory D.; Schriml, Lynn M.; Tatusova, Tatiana A.; Wagner, Lukas; Rapp, Barbara A.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 01/01/2001 Português
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In addition to maintaining the GenBank® nucleic acid sequence database, the National Center for Biotechnology Information (NCBI) provides data analysis and retrieval resources that operate on the data in GenBank and a variety of other biological data made available through NCBI’s Web site. NCBI data retrieval resources include Entrez, PubMed, LocusLink and the Taxonomy Browser. Data analysis resources include BLAST, Electronic PCR, OrfFinder, RefSeq, UniGene, HomoloGene, Database of Single Nucleotide Polymorphisms (dbSNP), Human Genome Sequencing, Human MapViewer, GeneMap’99, Human–Mouse Homology Map, Cancer Chromosome Aberration Project (CCAP), Entrez Genomes, Clusters of Orthologous Groups (COGs) database, Retroviral Genotyping Tools, Cancer Genome Anatomy Project (CGAP), SAGEmap, Gene Expression Omnibus (GEO), Online Mendelian Inheri­tance in Man (OMIM), the Molecular Modeling Database (MMDB) and the Conserved Domain Database (CDD). Augmenting many of the Web applications are custom implementations of the BLAST program optimized to search specialized data sets. All of the resources can be accessed through the NCBI home page at: http://www.ncbi.nlm.nih.gov.

‣ Global and local implications of biotechnology and climate change for future food supplies

Evenson, Robert E.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 25/05/1999 Português
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The development of improved technology for agricultural production and its diffusion to farmers is a process requiring investment and time. A large number of studies of this process have been undertaken. The findings of these studies have been incorporated into a quantitative policy model projecting supplies of commodities (in terms of area and crop yields), equilibrium prices, and international trade volumes to the year 2020. These projections show that a “global food crisis,” as would be manifested in high commodity prices, is unlikely to occur. The same projections show, however, that in many countries, “local food crisis,” as manifested in low agricultural incomes and associated low food consumption in the presence of low food prices, will occur. Simulations show that delays in the diffusion of modern biotechnology research capabilities to developing countries will exacerbate local food crises. Similarly, global climate change will also exacerbate these crises, accentuating the importance of bringing strengthened research capabilities to developing countries.

‣ Database resources of the National Center for Biotechnology Information: 2002 update

Wheeler, David L.; Church, Deanna M.; Lash, Alex E.; Leipe, Detlef D.; Madden, Thomas L.; Pontius, Joan U.; Schuler, Gregory D.; Schriml, Lynn M.; Tatusova, Tatiana A.; Wagner, Lukas; Rapp, Barbara A.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 01/01/2002 Português
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In addition to maintaining the GenBank nucleic acid sequence database, the National Center for Biotechnology Information (NCBI) provides data analysis and retrieval resources that operate on the data in GenBank and a variety of other biological data made available through NCBI’s web site. NCBI data retrieval resources include Entrez, PubMed, LocusLink and the Taxonomy Browser. Data analysis resources include BLAST, Electronic PCR, OrfFinder, RefSeq, UniGene, HomoloGene, Database of Single Nucleotide Polymorphisms (dbSNP), Human Genome Sequencing, Human MapViewer, Human¡VMouse Homology Map, Cancer Chromosome Aberration Project (CCAP), Entrez Genomes, Clusters of Orthologous Groups (COGs) database, Retroviral Genotyping Tools, SAGEmap, Gene Expression Omnibus (GEO), Online Mendelian Inheritance in Man (OMIM), the Molecular Modeling Database (MMDB) and the Conserved Domain Database (CDD). Augmenting many of the web applications are custom implementations of the BLAST program optimized to search specialized data sets. All of the resources can be accessed through the NCBI home page at http://www.ncbi.nlm.nih.gov.

‣ Database resources of the National Center for Biotechnology Information

Wheeler, David L.; Chappey, Colombe; Lash, Alex E.; Leipe, Detlef D.; Madden, Thomas L.; Schuler, Gregory D.; Tatusova, Tatiana A.; Rapp, Barbara A.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 01/01/2000 Português
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26.299458%
In addition to maintaining the GenBank® nucleic acid sequence database, the National Center for Biotechnology Information (NCBI) provides data analysis and retrieval and resources that operate on the data in GenBank and a variety of other biological data made available through NCBI’s Web site. NCBI data retrieval resources include Entrez, PubMed, LocusLink and the Taxonomy Browser. Data analysis resources include BLAST, Electronic PCR, OrfFinder, RefSeq, UniGene, Database of Single Nucleotide Polymorphisms (dbSNP), Human Genome Sequencing pages, GeneMap’99, Davis Human–Mouse Homology Map, Cancer Chromosome Aberration Project (CCAP) pages, Entrez Genomes, Clusters of Orthologous Groups (COGs) database, Retroviral Genotyping Tools, Cancer Genome Anatomy Project (CGAP) pages, SAGEmap, Online Mendelian Inheritance in Man (OMIM) and the Molecular Modeling Database (MMDB). Augmenting many of the Web applications are custom implementations of the BLAST program optimized to search specialized data sets. All of the resources can be accessed through the NCBI home page at: http://www.ncbi.nlm.nih.gov

‣ High-pressure biotechnology in medicine and pharmaceutical science

Masson, Patrick; Tonello, Carole; Balny, Claude
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em //2001 Português
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High-pressure (HP) biotechnology is an emerging technique initially applied for food processing and more recently in pharmaceutical and medical sciences. Pressure can stabilize enzymes and modulate both their activity and specificity. HP engineering of proteins may be used for enzyme-catalyzed synthesis of fine chemicals, pharmaceuticals, and production of modified proteins of medical or pharmaceutical interest. HP inactivation of biological agents is expected to be applicable to sterilization of fragile biopharmaceuticals, or medical compounds. The enhanced immunogenicity of some pressure-killed bacteria and viruses could be applied for making new vaccines. Finally, storage at subzero temperatures without freezing is another potential application of HP for cells, animal tissues, blood cells, organs for transplant, and so forth.

‣ Transformation of Fatty Acids Catalyzed by Cytochrome P450 Monooxygenase Enzymes of Candida tropicalis

Eschenfeldt, William H.; Zhang, Yeyan; Samaha, Hend; Stols, Lucy; Eirich, L. Dudley; Wilson, C. Ronald; Donnelly, Mark I.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /10/2003 Português
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Candida tropicalis ATCC 20336 can grow on fatty acids or alkanes as its sole source of carbon and energy, but strains blocked in β-oxidation convert these substrates to long-chain α,ω-dicarboxylic acids (diacids), compounds of potential commercial value (Picataggio et al., Biotechnology 10:894-898, 1992). The initial step in the formation of these diacids, which is thought to be rate limiting, is ω-hydroxylation by a cytochrome P450 (CYP) monooxygenase. C. tropicalis ATCC 20336 contains a family of CYP genes, and when ATCC 20336 or its derivatives are exposed to oleic acid (C18:1), two cytochrome P450s, CYP52A13 and CYP52A17, are consistently strongly induced (Craft et al., this issue). To determine the relative activity of each of these enzymes and their contribution to diacid formation, both cytochrome P450s were expressed separately in insect cells in conjunction with the C. tropicalis cytochrome P450 reductase (NCP). Microsomes prepared from these cells were analyzed for their ability to oxidize fatty acids. CYP52A13 preferentially oxidized oleic acid and other unsaturated acids to ω-hydroxy acids. CYP52A17 also oxidized oleic acid efficiently but converted shorter, saturated fatty acids such as myristic acid (C14:0) much more effectively. Both enzymes...

‣ Information resources at the National Center for Biotechnology Information.

Woodsmall, R M; Benson, D A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1993 Português
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The National Center for Biotechnology Information (NCBI), part of the National Library of Medicine, was established in 1988 to perform basic research in the field of computational molecular biology as well as build and distribute molecular biology databases. The basic research has led to new algorithms and analysis tools for interpreting genomic data and has been instrumental in the discovery of human disease genes for neurofibromatosis and Kallmann syndrome. The principal database responsibility is the National Institutes of Health (NIH) genetic sequence database, GenBank. NCBI, in collaboration with international partners, builds, distributes, and provides online and CD-ROM access to over 112,000 DNA sequences. Another major program is the integration of multiple sequences databases and related bibliographic information and the development of network-based retrieval systems for Internet access.

‣ Database resources of the National Center for Biotechnology Information: update

Wheeler, David L.; Church, Deanna M.; Edgar, Ron; Federhen, Scott; Helmberg, Wolfgang; Madden, Thomas L.; Pontius, Joan U.; Schuler, Gregory D.; Schriml, Lynn M.; Sequeira, Edwin; Suzek, Tugba O.; Tatusova, Tatiana A.; Wagner, Lukas
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 01/01/2004 Português
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26.299458%
In addition to maintaining the GenBank(R) nucleic acid sequence database, the National Center for Biotechnology Information (NCBI) provides data analysis and retrieval resources for the data in GenBank and other biological data made available through NCBI’s website. NCBI resources include Entrez, PubMed, PubMed Central, LocusLink, the NCBI Taxonomy Browser, BLAST, BLAST Link (BLink), Electronic PCR, OrfFinder, Spidey, RefSeq, UniGene, HomoloGene, ProtEST, dbMHC, dbSNP, Cancer Chromosome Aberration Project (CCAP), Entrez Genomes and related tools, the Map Viewer, Model Maker, Evidence Viewer, Clusters of Orthologous Groups (COGs) database, Retroviral Genotyping Tools, SARS Coronavirus Resource, SAGEmap, Gene Expression Omnibus (GEO), Online Mendelian Inheritance in Man (OMIM), the Molecular Modeling Database (MMDB), the Conserved Domain Database (CDD) and the Conserved Domain Architecture Retrieval Tool (CDART). Augmenting many of the web applications are custom implementations of the BLAST program optimized to search specialized data sets. All of the resources can be accessed through the NCBI home page at: http://www.ncbi.nlm.nih.gov.

‣ Overproduction of Trehalose: Heterologous Expression of Escherichia coli Trehalose-6-Phosphate Synthase and Trehalose-6-Phosphate Phosphatase in Corynebacterium glutamicum

Padilla, Leandro; Krämer, Reinhard; Stephanopoulos, Gregory; Agosin, Eduardo
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /01/2004 Português
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Trehalose is a disaccharide with potential applications in the biotechnology and food industries. We propose a method for industrial production of trehalose, based on improved strains of Corynebacterium glutamicum. This paper describes the heterologous expression of Escherichia coli trehalose-synthesizing enzymes trehalose-6-phosphate synthase (OtsA) and trehalose-6-phosphate phosphatase (OtsB) in C. glutamicum, as well as its impact on the trehalose biosynthetic rate and metabolic-flux distributions, during growth in a defined culture medium. The new recombinant strain showed a five- to sixfold increase in the activity of OtsAB pathway enzymes, compared to a control strain, as well as an almost fourfold increase in the trehalose excretion rate during the exponential growth phase and a twofold increase in the final titer of trehalose. The heterologous expression described resulted in a reduced specific glucose uptake rate and Krebs cycle flux, as well as reduced pentose pathway flux, a consequence of downregulated glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. The results proved the suitability of using the heterologous expression of Ots proteins in C. glutamicum to increase the trehalose biosynthetic rate and yield and suggest critical points for further improvement of trehalose overproduction in C. glutamicum.

‣ Clinical and immunological reactions to Aspergillus niger among workers at a biotechnology plant.

Topping, M D; Scarisbrick, D A; Luczynska, C M; Clarke, E C; Seaton, A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1985 Português
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The workforce at a biotechnology plant producing citric acid by fermentation of molasses with a strain of Aspergillus niger was studied. A combination of a respiratory questionnaire and clinical assessment identified 18 subjects (4.9% of the workforce) with work related bronchospasm. In nine of these evidence of sensitisation to A niger was obtained by skin prick tests and radioallergosorbent test (RAST) using as an antigen an extract of the A niger culture fluid from the process. Of the 325 subjects without work related bronchospasm, only nine (2.7%) had a positive prick test. There were no subjects with symptoms of extrinsic allergic alveolitis. Investigation into the source of the antigen showed that whereas, in some areas of the plant, A niger spores were present, in others there were no detectable spores. In these areas, however, extracts of filters from air samplers were shown by RAST inhibition to contain A niger antigens, indicating that the culture fluid was generating airborne antigen. RAST inhibition studies showed that the A niger culture fluid used in the process contained antigens that were not present in a commercially available A niger extract, thus emphasising the importance in this type of investigation of using antigens prepared from material to which the workers are exposed.

‣ Twin-Arginine Translocation of Active Human Tissue Plasminogen Activator in Escherichia coli

Kim, Jae-Young; Fogarty, Elizabeth A.; Lu, Franklin J.; Zhu, Hui; Wheelock, Geoffrey D.; Henderson, Lee A.; DeLisa, Matthew P.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /12/2005 Português
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When eukaryotic proteins with multiple disulfide bonds are expressed at high levels in Escherichia coli, the efficiency of thiol oxidation and isomerization is typically not sufficient to yield soluble products with native structures. Even when such proteins are secreted into the oxidizing periplasm or expressed in the cytoplasm of cells carrying mutations in the major intracellular disulfide bond reduction systems (e.g., trxB gor mutants), correct folding can be problematic unless a folding modulator is simultaneously coexpressed. In the present study we explored whether the bacterial twin-arginine translocation (Tat) pathway could serve as an alternative expression system for obtaining appreciable levels of recombinant proteins which exhibit complex patterns of disulfide bond formation, such as full-length human tissue plasminogen activator (tPA) (17 disulfides) and a truncated but enzymatically active version of tPA containing nine disulfides (vtPA). Remarkably, targeting of both tPA and vtPA to the Tat pathway resulted in active protein in the periplasmic space. We show here that export by the Tat translocator is dependent upon oxidative protein folding in the cytoplasm of trxB gor cells prior to transport. Whereas previous efforts to produce high levels of active tPA or vtPA in E. coli required coexpression of the disulfide bond isomerase DsbC...

‣ White biotechnology

Frazzetto, Giovanni
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/2003 Português
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The application of biotechnology to industrial production holds many promises for sustainable development, but many products still have to pass the test of economic viability

‣ Metabolic Engineering of Corynebacterium glutamicum for Trehalose Overproduction: Role of the TreYZ Trehalose Biosynthetic Pathway

Carpinelli, Jorge; Krämer, Reinhard; Agosin, Eduardo
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2006 Português
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Trehalose has many potential applications in biotechnology and the food industry due to its protective effect against environmental stress. Our work explores microbiological production methods based on the capacity of Corynebacterium glutamicum to excrete trehalose. We address here raising trehalose productivity through homologous overexpression of maltooligosyltrehalose synthase and the maltooligosyltrehalose trehalohydrolase genes. In addition, heterologous expression of the UDP-glucose pyrophosphorylase gene from Escherichia coli improved the supply of glycogen. Gene expression effects were tested on enzymatic activities and intracellular glycogen content, as well as on accumulated and excreted trehalose. Overexpression of the treY gene and the treY/treZ synthetic operon significantly increased maltooligosyltrehalose synthase activity, the rate-limiting step, and improved the specific productivity and the final titer of trehalose. Furthermore, a strong decrease was noted in glycogen accumulation. Expression of galU/treY and galU/treYZ synthetic operons showed a partial recovery in the intracellular glycogen levels and a significant improvement in both intra- and extracellular trehalose content.