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J Nat Prod 67:811–816īérdy J (2005) Bioactive microbial metabolites. J Environ Sci Health B 42:441–451īassarello C, Lazzaroni S, Bifulco G, Lo CP, Iacobellis NS, Riccio R, Gomez-Paloma L, Evidente A (2004) Tolaasins A−E, five new lipodepsipeptides produced by Pseudomonas tolaasii. Org Lett 10:1167–1169īalba H (2007) Review of strobilurin fungicide chemicals. KeywordsĪhn JW, Jang KH, Chung SC, Oh KB, Shin J (2008) Sorangiadenosine, a new sesquiterpene Adenoside from the Myxobacterium Sorangium cellulosum. The development of drug-resistant bacteria has resulted in the search for novel antimicrobials from hitherto untapped microbial sources such as uncultured bacteria. Myxobacteria and filamentous fungi are also producers of important antimicrobials among other prokaryotes. Bacteria that belong to the genus Streptomyces, Bacillus and Pseudomonas are prolific producers of antimicrobials. Microorganisms differ in their potential to produce antimicrobial substances. The antimicrobials produced by microorganisms fall under chemical classes like Polyketides, terpenes, shikimates, peptides and alkaloids. Most of the antimicrobials produced by microorganisms are secondary metabolites. When favourable conditions arrive, spores reactivate into new bacteria.Microorganisms are potential sources of antimicrobial substances, including antiseptics, disinfectants and antibiotics, used to prevent the growth and spread of harmful microbes. Spore coat is formed by the formation of peptidoglycan layer between 2 layers.

Calcium dipicolinate is present in Forespore. It leaves a double membrane around the DNA. Forespore is formed by pinching the membrane into the cell. DNA replicates and septum form between genetic material and the rest of the cell. A membrane between the DNA and cortex is present that is called as septum. When favourable conditions arrive, spores germinate into bacteria which is called sporulation.

Some spores are present sub-terminally that are present between the two extremes of the cell.Terminal spores are those that are present in the terminal of the cell.Some spores are present in the centre of the cell.Calcium dipicolinate is present in high concentration that stabilizes the DNA molecule present in spore.ĭipicolinaic acid helps the spore to resist the heat fluctuations in the environment and calcium helps the spore from oxidizing agents. They also contain ribosomes and enzymes that are metabolically inactive. SASPs help in the protection of the DNA from UV radiation and heat. The core contains the bacterial DNA that is enclosed into Small acid-soluble spore protein (SASPs). Peptidoglycan is needed for the synthesis of the cell wall. Cortex:Ĭortex lies beneath the coat and it mainly composed of peptidoglycan. It is composed of keratin that has the enzymes that allow the germination of spore. It excludes large molecules such as lysozyme and toxins from the spore. It is a thin covering around the spore that acts as a sieve. Resistance to temperature and pH change.depletion of nutrient, high in temperature and pH and dehydration, bacteria forms spores. The bacteria that germinate from spore can grow and start a new progeny.Ĭlostridium botulinum, Bacillus anthracis Why bacteria produce spores?īacteria grow moderately in favourable condition. When favourable conditions arrive, these spores germinate into a new bacterium that has all the properties of the parent bacteria. Spores have the least metabolic activity. Spores are the dormant form of bacteria that can tolerate all the fluctuations in the environment. Spore-forming bacteria are those bacteria that can form spores under unfavourable conditions.

Bacterial spores examples