bacillus subtilis: a rod shaped, nonpathogenic bacterium commonly found in the soil. This gram-positive microbe has had its genome studied in microbiology as well as in genetic engineering studies. Often, Bacillus subtilis is used as a host in recombinant DNA experiments because of its ability to secrete proteins. [Source: Biotechnology Industry Organization, www.bio.org]
bacillus thuringiensis (Bt): a bacterium naturally living in soil that generates an endotoxin lethal to insects (including genera Dipetera, Coleoptera, and Lepidoptera among others). The endotoxin released is deadly due to the increased pH and activation of peptides that create pores in the insect’s gut initiated by the toxin. This combination causes the destruction of cells inside the target, leading to the insect’s death. Currently, researchers are attempting to integrate the baterium’s insect toxins into plant DNA in order to create crops resistant to different insect species. [Source: Biotechnology Industry Organization, www.bio.org]
backcross: a cross between one animal type that is heterozygous for alleles obtained from two parental strains and a second animal type from one of those parental strains. The term is often used by itself to describe the two-generation breeding protocol of an outcross followed by abackcross used frequently in linkage analysis. [Source: NHBLI/NCBI Glossary]
bacteriophage: a virus that infects, replicates within, and often destroys bacteria. Bacteriophages consist of a protein coat (or capsid) that holds genetic information inside (either DNA or RNA). The bacteriophage binds to specific bacteria and then injects its genetic material inside. The host’s transcriptional and translational machinery then synthesizes new bacteriophages using the injected material. Often, phage lysozymes, compounds that can cause bacteria to rupture, are released so that the new bacteriophages can infect other bacteria. Currently, bacteriophages are utilized in recombinant DNA studies and have been used to examine structure and regulation of genes. [Source: Biotechnology Industry Organization, www.bio.org]
bacterium: a group of small, single-celled, prokaryotic microorganisms that can live as a parasite (survival depends on another organism) or as an independent life form. Bacteria can vary in size and shape (rod, sphere, spiral, etc.), reproduce by cellular division, and utilize different forms of motility. Their nutritional sources also vary widely, as bacteria can live off of organic or inorganic sources and can live with or without oxygen present. The ability for bacteria to adapt to different environments and food sources allow them to survive in practically any location. [Source: Biotechnology Industry Organization, www.bio.org]
base: one of the molecules – adenine, guanine, cytosine, thymine, or uracil – which form part of the structure of DNA and RNA molecules. The order of bases in a DNA molecule determines the structure of proteins encoded by that DNA. See nucleotide.
base pair (bp): two complementary nucleotide bases joined together by chemical bonds. The two strands of the DNA molecule are held together in the shape of a double helix by the bonds between base pairs. The base adenine pairs with thymine, and guanine pairs with cytosine.
base sequence: the order of nucleotide bases in a DNA molecule. [Source: DOE Primer on Molecular Genetics]
base sequence analysis: a method, sometimes automated, for determining the base sequence. [Source: DOE Primer on Molecular Genetics]
bioactive: having an effect on a biological system.
bioassay: determination of the effectiveness of a compound (i.e. a drug, hormone, etc.) by measuring its effect on animals, tissues or cultures in comparison with a standard preparation. [Source: Biotechnology Industry Organization, www.bio.org]
bioaugmentation: increasing the activity of bacteria that break down pollutants by adding more of their kind. A technique used in bioremediation, a technique used to remove or neutralize contaminants in a particular environment using biological agents (plants, bacteria, or other living organisms). [Source: Biotechnology Industry Organization, www.bio.org]
biocatalyst: in bioprocessing, a substance, usually an enzyme, that activates or increases the rate of a chemical reaction in a living organism. Biocatalysts are currently used in industry in the production of high fructose corn syrup, semi-synthetic penicillins and cancer drugs. [Source: Biotechnology Industry Organization, www.bio.org]
biochemical: a product by or involving a chemical reaction in a living organism. Biochemistry is the application of chemistry to living beings. A few general research areas of biochemistry include analysis of the physical properties of biological molecules, the chemical interactions used to regulate metabolism, and the chemistry of the immune system. [Source: Biotechnology Industry Organization, www.bio.org]
biochemical stock: a variety or strain known to possess desirable biochemical traits. [Source: Agricultural Genome Information System, USDA]
biochip: an electronic device that uses organic molecules to form a semiconductor instead of silicon or germanium. Examples of possible applications for such technology include genotyping, DNA sequencing, and even retinal implantation to serve as an artificial retina for those who suffer from macular degeneration of the eye. See DNA chip technology.
bioconversion: chemical restructuring of organic materials, like plants or waste products, into useable substances by using a biological agent. The biocatalyst used to modify the chemical could be an enzyme, bacteria, or some other microorganism. For example, paper residuals can be modified using bioconversion so that it creates a fertilizer or soil amendment.
bioinformatics: the science of informatics as applied to biological research. Informatics is the management and analysis of data using advanced computing techniques. Bioinformatics is particularly important as an adjunct to genomics research, because of the large amount of complex data this research generates.
biosensor technology: Biosensor technology couples knowledge of biology with advances in microelectronics. A biosensor is composed of a biological component, such as a cell or antibody, linked to a tiny transducer. Biosensors are detecting devices that rely on the specificity of cells and molecules to identify and measure substances at extremely low concentrations. When the substance of interest collides with the biological component, the transducer produces a digital electronic signal proportional to the concentration of the substance. Biosensors can measure the nutritional value, freshness and safety of food, provide emergency room physicians with bedside measures of vital blood components, and locate and measure environmental pollutants. [Source: Biotechnology Industry Organization, www.bio.org]
biotechnology: the application of biological research techniques to the development of products which improve human health, animal health, and agriculture.
blood cells: blood is a fluid body tissue responsible for the transport of food and waste. Blood contains two types of cells; red blood cells (erythrocytes) which transport oxygen and carbon dioxide and white blood cells (leukocytes), which are responsible for a wide range of immunological functions.
bone marrow: soft tissue contained within the large central cavity of a bone as well as within other internal spaces. Bone marrow is responsible for the formation of blood cells. Such marrow is called “red marrow”. As organisms mature, red marrow is replaced by a fatty tissue that does not produce blood cells. That fatty tissue is called “yellow marrow”.
Bovine Spongiform Encephalopathy (BSE): (a.k.a. Mad Cow Disease) a degenerative disease of brain tissue (“encephalopathy”). BSE is caused by prions and results in the deposition of amyloid tissue thatcauses a breakdown of brain tissue leaving the infected brain with a “spongy” (“spongiform”) appearance.
BRCA1 and BRCA2: two genes which normally help to restrain cell growth, but which can contain certain genetic mutations associated with the development of breast and ovarian cancer. Note, however, that inherited BRCA1 and BRCA2 mutations are thought to account for less than 10% of all breast and ovarian cancers. Recent evidence suggests that somatic cell genetic mutations (i.e., non-inherited genetic mutations) in these two genes may also play a role in the development of cancer.
breeding line: plant specimens of high quality that are kept to produce offspring. [Source: Agricultural Genome Information System, USDA]