Aztreonam, sold under the brand name Azactam among others, is an antibiotic used primarily to treat infections caused by gram-negative bacteria such as Pseudomonas aeruginosa. This may include bone infections, endometritis, intra abdominal infections, pneumonia, urinary tract infections, and sepsis. It is given by intravenous or intramuscular injection or by inhalation.
Streptomyces is the largest genus of Actinomycetota, and the type genus of the family Streptomycetaceae. Over 700 species of Streptomyces bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positive, and have very large genomes with high GC content. Found predominantly in soil and decaying vegetation, most streptomycetes produce spores, and are noted for their distinct "earthy" odor that results from production of a volatile metabolite, geosmin. Different strains of the same species may colonize very diverse environments.
In organic chemistry, polyketides are a class of natural products derived from a precursor molecule consisting of a chain of alternating ketone and methylene groups: [−C(=O)−CH2−]n. First studied in the early 20th century, discovery, biosynthesis, and application of polyketides has evolved. It is a large and diverse group of secondary metabolites caused by its complex biosynthesis which resembles that of fatty acid synthesis. Because of this diversity, polyketides can have various medicinal, agricultural, and industrial applications. Many polyketides are medicinal or exhibit acute toxicity. Biotechnology has enabled discovery of more naturally-occurring polyketides and evolution of new polyketides with novel or improved bioactivity.
Sphingomonas was defined in 1990 as a group of Gram-negative, rod-shaped, chemoheterotrophic, strictly aerobic bacteria. They possess ubiquinone 10 as their major respiratory quinone, contain glycosphingolipids (GSLs), specifically ceramide, instead of lipopolysaccharide (LPS) in their cell envelopes, and typically produce yellow-pigmented colonies. The GSL serves to protect the bacteria from antibacterial substances. Unlike most Gram-negative bacteria, Sphingomonas cannot carry endotoxins due to the lack of lipopolysaccharides, and has a hydrophobic surface characterized by the short nature of the GSL's carbohydrate portion.
A halohydrin dehalogenase is an enzyme involved in the bacterial degradation of vicinal halohydrins. In several species of bacteria, it catalyses the dehalogenation of halohydrins to produce the corresponding epoxides. Different isoforms of the enzyme fall into one of three groups, A, B or C. Halogenases of the same class are genetically similar, but differ greatly from halogenases from a different group. Currently the most well-studied isoform is HheC which is purified from the bacterial species Agrobacterium radiobacter. The ability to dehalogenate organic compounds as well as form enantiomeric selective epoxides have generated interest in the potential of this enzyme in the biochemical field.
Antimicrobial peptides (AMPs), also called host defence peptides (HDPs) are part of the innate immune response found among all classes of life. Fundamental differences exist between prokaryotic and eukaryotic cells that may represent targets for antimicrobial peptides. These peptides are potent, broad spectrum antimicrobials which demonstrate potential as novel therapeutic agents. Antimicrobial peptides have been demonstrated to kill Gram negative and Gram positive bacteria, enveloped viruses, fungi and even transformed or cancerous cells. Unlike the majority of conventional antibiotics it appears that antimicrobial peptides frequently destabilize biological membranes, can form transmembrane channels, and may also have the ability to enhance immunity by functioning as immunomodulators.
Paenibacillus is a genus of facultative anaerobic, endospore-forming bacteria, originally included within the genus Bacillus and then reclassified as a separate genus in 1993. Bacteria belonging to this genus have been detected in a variety of environments, such as: soil, water, rhizosphere, vegetable matter, forage and insect larvae, as well as clinical samples. The name reflects: Latin paene means almost, so the paenibacilli are literally "almost bacilli". The genus includes P. larvae, which causes American foulbrood in honeybees, P. polymyxa, which is capable of fixing nitrogen, so is used in agriculture and horticulture, the Paenibacillus sp. JDR-2 which is a rich source of chemical agents for biotechnology applications, and pattern-forming strains such as P. vortex and P. dendritiformis discovered in the early 90s, which develop complex colonies with intricate architectures as shown in the pictures:
Halobacterium is a genus in the family Halobacteriaceae.
Chromobacterium violaceum is a Gram-negative, facultative anaerobic, non-sporing coccobacillus. It is motile with the help of a single flagellum which is located at the pole of the coccobacillus. Usually, there are one or two more lateral flagella as well. It is part of the normal flora of water and soil of tropical and sub-tropical regions of the world. It produces a natural antibiotic called violacein, which may be useful for the treatment of colon and other cancers. It grows readily on nutrient agar, producing distinctive smooth low convex colonies with a characteristic striking dark violet metallic sheen. Some strains of the bacteria which do not produce this pigment have also been reported. It has the ability to break down tarballs.
A depsipeptide is a peptide in which one or more of its amide, -C(O)NHR-, groups are replaced by the corresponding ester, -C(O)OR-. Many depsipeptides have both peptide and ester linkages. Elimination of the N–H group in a peptide structure results in a decrease of H-bonding capability, which is responsible for secondary structure and folding patterns of peptides, thus inducing structural deformation of the helix and β-sheet structures. Because of decreased resonance delocalization in esters relative to amides, depsipeptides have lower rotational barriers for cis-trans isomerization and therefore they have more flexible structures than their native analogs. They are mainly found in marine and microbial natural products.
Bacteria are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised and there are many species that cannot be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology.
Janthinobacterium lividum is an aerobic, Gram-negative, soil-dwelling bacterium that has a distinctive dark-violet color, due to a compound called violacein, which is produced when glycerol is metabolized as a carbon source. Violacein has antibacterial, antiviral, and antifungal properties. Its antifungal properties are of particular interest, since J. lividum is found on the skin of certain amphibians, including the red-backed salamander, where it prevents infection by the devastating chytrid fungus.
Staphylococcus is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. Staphylococcus species are facultative anaerobic organisms.
The genus Massilia belongs to the family Oxalobacteriaceae, and describes a group of gram-negative, motile, rod-shaped cells. They may contain either peritrichous or polar flagella. This genus was first described in 1998, after the type species, Massilia timonae, was isolated from the blood of an immunocompromised patient. The genus was named after the old Greek and Roman name for the city of Marseille, France, where the organism was first isolated. The Massilia genus is a diverse group that resides in many different environments, has many heterotrophic means of gathering energy, and is commonly found in association with plants.
Romidepsin, sold under the brand name Istodax, is an anticancer agent used in cutaneous T-cell lymphoma (CTCL) and other peripheral T-cell lymphomas (PTCLs). Romidepsin is a natural product obtained from the bacterium Chromobacterium violaceum, and works by blocking enzymes known as histone deacetylases, thus inducing apoptosis. It is sometimes referred to as depsipeptide, after the class of molecules to which it belongs. Romidepsin is branded and owned by Gloucester Pharmaceuticals, a part of Celgene.
Dokdonia donghaensis is a strictly aerobic, gram-negative, phototrophic bacterium that thrives in marine environments. The organism can grow at a broad range of temperatures on seawater media. It has the ability to form biofilms, which increases the organism's resistance to antimicrobial agents, such as tetracycline.
Massilia eurypsychrophila is a Gram-negative, aerobic, rod-shaped and facultatively psychrophilic bacterium from the genus Massilia with a polar flagella which has been isolated from the ice core of the Muztagh Glacier in Xinjiang in China.
Polaribacter is a genus in the family Flavobacteriaceae. They are gram-negative, aerobic bacteria that can be heterotrophic, psychrophilic or mesophilic. Most species are non-motile and species range from ovoid to rod-shaped. Polaribacter forms yellow- to orange-pigmented colonies. They have been mostly adapted to cool marine ecosystems, and their optimal growth range is at a temperature between 10 and 32 °C and at a pH of 7.0 to 8.0. They are oxidase and catalase-positive and are able to grow using carbohydrates, amino acids, and organic acids.
Kibdelosporangium is a Gram-positive genus from the family of Pseudonocardiaceae. Kibdelosporangium bacteria produce substances with antibacterial, anticancer, and antiviral activities.
Hymenobacter coccineus is a Gram-negative and rod-shaped bacterium from the genus Hymenobacter which has been isolated from a rock from the James Ross Island in the Antarctica.
