Saccharopolyspora spinosa
UNDER CONSTRUCTION
Classification
Domain: Bacteria
Phylum: Actinobacteria
Class: Actinobacteria
Order: Actinomycetales
Family: Pseudonocardiaceae
Genus: Saccharopolyspora
Species
Saccharopolyspora spinosa
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NCBI: [1] |
Saccharopolyspora hirsuta
Saccharopolyspora erythraea
Description and Significance
In 1982, researchers vacationing in the Virgin Islands discovered the actinomycete bacteria, Saccharopolyspora spinosa, in soil collected at an inoperative sugar mill rum still (Mertz and Yao 1990, Thompson et al. 2000). Similar to other species in the Saccharopolyspora genus, S. spinosa are aerobic, gram-positive, and have mycelium (Mertz and Yao 1990). The mycelium are made up of pale yellowish-pink aerial hyphae, and yellow to yellow-brown substrate hyphae (Mertz and Yao 1990). These hyphae are long bead-like spore chains that are surrounded by spiny(='spinosa') spore sheaths (Mertz and Yao 1990). These bacteria are most similar to S. erythraea in morphology, but have different physiological characteristics compared to other species in this genus (Mertz and Yao 1990). Furthermore, since the discovery of S. spinosa, many research cultures have developed distinct strains of S. spinosa (##refs). Strains of S. spinosa are convoluted in scientific literature, but a few including the type strain A83543.1 are listed on StrainInfo.net.
Saccharopolyspora spinosa produce metabolites named 'spinosyns' that are economically, ecologically, and agriculturally important. It has been found that spinosyns have pesticidal properties that are effective for many mites and insects (Salgado 1998, Bond et al. 2004, Cloyd 2009, Thompson et al. 2000, Watson 2001, Hertlein et al. 2011). Interestingly, the discovery of these properties led to a patent on S. spinosa and the byproducts produced by the organisms (Turner et al. 1995). Spinosyns are generated by S. spinosa in an aerobic fermentation broth that contains nutrients necessary for metabolism and the organisms. The spinosyns extracted from the broth make up a class of insecticides that are sold under trade names such as Conserve® and Entrust®. Because the active ingredients in these pesticides are biological byproducts, the pesticides are marketed as "natural," and less toxic compared to other available chemicals. Therefore, pesticides containing spinosyns are attractive options for pest management in agriculture.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
The genome of S. spinosa has been drafted by the Beijing Genomics Institute. It was produced using a genome shotgun strategy as well as pyrosequencing. The entire genome was found to be at 8,581,920 base pairs with 8,302 predicted coding sequences. G+C content was found to be 67.94%(ref #). This organism is still under study and its genome is in the process of being fully mapped.
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Cell Structure The cell wall of Saccharopolyspora spinosa is mainly composed of a thick layer of peptidoglycan, and lipoteichoic acids, that serve as chelating agents and also for adherence. The individual peptidoglycan molecules are cross-linked by pentaglycine chains using a DD-transpeptidase enzyme. Spores of S. spinosaare round to oval and covered by a sheath. The cell wall of this organism, just as with other members in its genus is characterized by the absence of mycolic acids (long-chain α-substituted Β-hydroxylated fatty acids) (Alexander et al., 2000)
Metabolism S. spinosa is a chemoorganoheterotroph that decomposes organic matter to produce energy. It may utilize a list of organic acids for carbon and energy. Some of those that it metabolizes are: acetate, butyrate, citrate, formate, lactate, malate, proprionate, pyruvate, and succinate. This species is also able to reduce nitrogen. Nitrogen is a limiting nutrient in most plants and the ability of S. spinosa to reduce nitrogen could make it a great symbiont to agricultural plants.
Life Cycle Many actinomycetes are soil dwelling decomposers (##ref). S. spinosa was discovered in soil and has been kept in culture... It has not been found in nature since its discovery (ref).
Ecology and Pathogenesis
Mode of Action of Spinosyns
Spinosyns have a unique mode of action involving the postsynaptic nicotinic acetylcholine and GABA receptors (Bond et al, 2004; Watson, 2001). Spinosyn A, the major active component of spinosad, causes involuntary muscle contractions and tremors by widespread excitation of neurons in the central nervous system of insects at low concentrations. Prolonged spinosyn-induced hyperexcitation results in paralysis associated with neuromuscular fatigue and death (Salgado, 1998).
Habitat
Saccharopolyspora spinosa is kept in culture. Culture medias that have demonstrated good growth conditions for S. spinosa include actinomycete isolation agar, Bennett agar, tomato paste-oatmeal agar (Waksman 1961 via Thompson et al. 1990, Thompson et al. 1990), and BHI (Brain Heart Infusion) agar (Waldon et al. 2001). The optimal temperature for growth in media are 15-37°C (Thompson et al. 1990). These organisms are also grown in fermentation broths (Waldon et al. 2001).
S spinosa is part of the family actinomycete. It is the only bacterium that produces a natural, low-risk insecticidal chemical called Spinosad. This natural pesticide consists of a mixture of tetracyclic macrolide neurotoxins,spinosyn A and D that kills most pests and has no known toxic effect on humans (Pan et al., 2011, Bond et al., 2004)
This chemical is already in use as a grain protect-ant in several countries. Spinosad protects against a large range of insects, predominantly moths and beetles. It is also being used as a larvicide for in the control of container breeding mosquitoes, an attractive option due to its highest ratings for safety, environmentally favourable toxicity profile and low persistence (Bond et al., 2004). This chemical compound is able to remain viable in dry grain storage bins and its length of virility has been measured to last from six months up to two years. The effectiveness of this compound is still being explored and it is reported that its strength is determinant upon several factors such as: insect species, pest life stage, grain type, and grain variety. Spinosad has also been marketed as a treatment for headlice under the pharmaceutical name Natroba.
Symbiosis
The interrelationships between S. spinosa and other organisms has not been thoroughly investigated. However in a study using potato cyst nematode, Globodera rostochiensis, bioagents obtained from S. spinosa caused significant inhibitory effect on multiplication of the nematode, suggesting a possible antagonistic relationship with this organism in nature (Trifona, 2010).
References
Alexander, M., Bloom R.B., Hopwood, D.A., Hull, R., and B.H., Iglewski (Ed). Encyclopedia of Microbiology. Second Edition. 2000. Elsevier Science.
Bond J.G., Marina, C.F., and Williams, T. "The naturally Derived Insecticide Spinosad is highly Toxic to Aedes and Anopheles Mosquito Larvae. Medical and Veterinary Entomology. 2004. Volume 18. p 50-56
Cloyd, R. "Western Flower Thrips Managment: Have We Reached An Impasse?". OFA Bulletin. 2009. Volume 918. p. 24-29.
Hertlein Mark B. et al. "Spinosad: A New Natural Product for Stored Grain Protection". Journal of Stored Products Research. 2011. Volume 47. p. 131-146.
Mertz, F.P., and Yao, R.C. "Saccharopolyspora spinosa sp. nov. Isolated from Soil Collected in a Sugar Mill Rum Still". International Journal of Systematic Bacteriology. 1990. Volume 40(1). p. 34-39.
Pan, Y., Yang, X., Li, J., Zhang, R., Hu, Y., Zhou., Y., Wang, and B Zhu . "Genome Sequencing of the Spinosyns-Producing Bacterium Saccharopolyspora Spinosa NRRL 18935". Journal of Bacteriology. 2011. Volume 193(12). p. 3150-3151.
Salgado, V.L. "Studies on the Mode of Action of Spinosad: Insect Symptoms and Physiological Correlates". Pesticide Biochemistry and Physiology. 1998. Volume 60. p 91–102.
Thompson, G.D., Dutton, R., and Sparks, T.C. "Spinosad - a case study: an example froma natural products discovery programme". Pest Management Science. 2000. Volume 56. p. 696-702.
Trifonova, Z.T. "Studies on the Efficacy of some Bacteria and Fungi for Control of Globedera restochiensis". Journal of Agricultural Sciences. 2010. Volume 55 (1). p. 37-44.
Turner, J.R., Huber, M.L.B., Broughton, M.C., Mynderse, J.S., Martin, J.W.
Waldon, C., Matsushima, P.,Rosteck, P.R.J., Broughtonb, M.C., Turnerb, J., Madduria, K., Crawforda, K.P., Merloa, D.J., and Baltz, R.H. "Cloning and analysis of the spinosad biosynthetic gene cluster of Saccharopolyspora spinosa". Chemistry & Biology. 2001. Volume 8(5). p. 487–499.
Watson, G.B. "Actions of Insecticidal Spinosyns on γ-aminobutyric Acid Receptors from Small Diameter Cockroach Neurones". Pesticide Biochemistry and Physiology. 2001. Volume 71. p. 20–28.
Author
Page authored by Emily Pochubay, Matt O'Grady, Placid Mpeketula, and Demetrious Parker students of Prof. Jay Lennon at Michigan State University.
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