| Quote: |
It has now been found according to this invention that substances having antibiotic activity can be obtained by reacting with a suitable chemical reagent, the fermentation, liquor obtained ‘by growing a penicilline producing mould preferably in the absence of an added precursor...The present invention therefore provides 6aminopenicillanic acid having a structural formula: [img]  [/img]which is capable of reacting with phenylacetyl chloride to produce benzylpenicillin, and which gives a negative Bratten-Marshall test and a negative ninhydrin test, and its šalts |
Quote: Originally posted by peach  |
| It is still alive. Today, it's genetics and subatomic physics. A hundred years from now, everyone will be laughing it up at how silly people were when they didn't eat their cornflakes with added stem cells. And those would be the same people who'd be throwing shit storm grenades into the research labs now. Science is fundamentally and factually beyond the written law, because it is not based on society. Society needs to adapt to what science says. People don't like being told what to do with their own lives and opinions at such a deep, controversial level. And scientists are the human shield between it and the general public. ***If you're talking about Gordon Brown, he wasn't ever actually elected into the role of prime minister by the public. GO DEMOCRACY, YAY! ----------------------------------------------------------------------- To the topic at hand! I think the easiest way would be to follow one of the methods for science projects online, which is to simply sterilise some glass and leave some bread in there, in the dark - waiting for it to go mouldy. The citrus peel method is likely suggested because the spectrum of mould growth changes based on pH, as some are not fond of low pH's at all, whereas others prefer slightly alkaline conditions. I would then produce some plates, cut out bits of filter paper, dip them in the broth and breath all over the plates to get them nicely contaminated, then incubate and watch for clear spots. These plates would be easy due to them needing to be contaminated. If you see an exclusion spot around the filter paper, you have likely have the antibiotic. If you want to scale up production, you would then inoculate a sample of the culture onto some sterile plates. A good method for this is to only spot certain zones of the plates, or the centre. You then incubate the plate until it's well colonised with mould. You can now look through the plates for those showing zoning of the moulds. For instance, some areas of the plate will be pristine white and fully, others will be dirty green and so on, showing boarders between them where they appear to change in a small space. These is a board between a different culture or network. Penicillium tends to be greeny colours, and these can sometimes only appear once the mycelium has had a chance to colonise a decent amount of plate space and age, as it is the network going into spore production - these networks release spores from the 'roots' of the mould, whereas button mushrooms you have for dinner have a more advanced fruiting stage that involves gills and a cap to protect them. You then cut a sample out of that zone and put it on a sterile plate - you should do this with a couple of samples, each on their own plate. Then watch again. Now, you don't want to see any zoning, you want a pure culture. You may need to repeat this two or three times to get the sample away from the other forms on there. This process is much like re-crystallisation in chemistry, you are attempting to 'crystallise' a pure sample away from contaminants. And it does work, surprisingly well for the amount of effort and cost involved. It is the method by which mycologists culture fungi that they've collected outdoors. When they take spore prints or tissue samples, they will inevitably be covered in bacteria, contaminating spores, doggy piddle and various other gems of life*. The samples go onto plates and, hopefully, on one of those plates, a small, clean spot of mould will appear amongst the rubbish; where the mould has managed to established a little home for it's self in the short term. A small chunk of the clean spot is cut out with a sterile scalpel, moved to a new sterile plate and re-incubated. This time, the plate should have a much larger or full colonisation of that mould alone. Once you have a pure culture, you redo the broth test and check you have the antibiotic activity. If it's green for go, you can proceed to do a big batch. As the mould will tend to float on the surface, you may be best off choosing something with a large surface area to grow it in; rather than tall and thin. You will likely only be able to do batches and have to empty it all out to extract the cake. One would need to be aware that in biology labs, the cultured dishes are usually of inert strains of bacteria. If you breath and cough all over the plates to inoculate yours, then incubate them at body temperature, you have a potential pathogen risk and could get very sick if not careful. Also, when growing commercial broths, there are often many species and strains of an organism that will produce the desired product, the goal is to find one that produces a lot of it and that is easy to maintain. Numerous forms of penecillium are added to cheeses and meats with the specific aim being to prevent colonisation by other moulds or bacteria. The bacteria part means potential antibiotic activity and the colonisation part means the genus is a strong competitor, meaning it will be easier to swamp a plate with it as opposed to contaminations - where as some other moulds, bacteria and yeasts are weak competitors, and need constant care and maintenance or they'll get bullied to death by the others. *Fly Agaric mushrooms, Amanita Muscaria, are often full of maggots eggs or the grown up version. Yum yum sez the hippy! **John setup and ran a HEPA filtered mycology lab, bunny suits, laminar bench, autoclaves and all. [Edited on 20-1-2011 by peach] |
| Quote: Originally posted by Oppenheimer |