J/13 July 2012

From 2012.igem.org


July
MTWTFSS
            [http://2012.igem.org/J/1_July_2012 1]
[http://2012.igem.org/J/2_July_2012 2] [http://2012.igem.org/J/3_July_2012 3] [http://2012.igem.org/J/4_July_2012 4] [http://2012.igem.org/J/5_July_2012 5] [http://2012.igem.org/J/6_July_2012 6] [http://2012.igem.org/J/7_July_2012 7] [http://2012.igem.org/J/8_July_2012 8]
[http://2012.igem.org/J/9_July_2012 9] [http://2012.igem.org/J/10_July_2012 10] [http://2012.igem.org/J/11_July_2012 11] [http://2012.igem.org/J/12_July_2012 12] [http://2012.igem.org/J/13_July_2012 13] [http://2012.igem.org/J/14_July_2012 14] [http://2012.igem.org/J/15_July_2012 15]
[http://2012.igem.org/J/16_July_2012 16] [http://2012.igem.org/J/17_July_2012 17] [http://2012.igem.org/J/18_July_2012 18] [http://2012.igem.org/J/19_July_2012 19] [http://2012.igem.org/J/20_July_2012 20] [http://2012.igem.org/J/21_July_2012 21] [http://2012.igem.org/J/22_July_2012 22]
[http://2012.igem.org/J/23_July_2012 23] [http://2012.igem.org/J/24_July_2012 24] [http://2012.igem.org/J/25_July_2012 25] [http://2012.igem.org/J/26_July_2012 26] [http://2012.igem.org/J/27_July_2012 27] [http://2012.igem.org/J/28_July_2012 28] [http://2012.igem.org/J/29_July_2012 29]
[http://2012.igem.org/J/30_July_2012 30] [http://2012.igem.org/J/31_July_2012 31]


Day Thirteen

(10:00 am) The polystyrene test dish is ready and has solidified so it can be plated up when there is some bacteria to see if it works as a medium.

(12:00 pm) On further analysis the original plan of a agar and layer of polystyrene covering it has proved ineffective as the polystyrene just formed a thick solid in the centre. However, the team had another idea yesterday. The idea is to attempt to crush the Polystyrene 'sugar' (unexpanded polystyrene beads) using either a pestle and mortar or crushing them with toughened glass beads. Then the crushed 'sugar' can be suspended in minimal medium, thus creating cloudy media, where hopefully halos around specific colonies will form when polystyrene degrading bacteria are present. Its important to only use a low concentration of the the crushed 'sugar' as too much will mean that the halos won't form due to the slow degradation by these bacteria.

(15:00 pm) The grinding of polystyrene begins, but the process is very slow. The pestle and mortar was producing minimal results so the team switched to the grinder machine mixing our 'sugar' with glass beads to, by sheer force, crush the polystyrene down to an even finer grain.

(4:45) The grinding machine couldn't grind the polystyrene 'sugar' down, so the group has been seeing whether just adding the 'sugar' into agar may work on its own. Through experimenting with varying amounts of 'sugar' to agar (2.5% and 5% polystyrene), and varying the amount of agar used, the amount decided on is between 10 and 15 grams of agar/'sugar' mix at 5% 'sugar'. 20g of agar/'sugar' mix was just too deep as the 'sugar' just settled at the bottom or sides. At 10g agar/'sugar' mix, the 'sugar' is just below the agar's surface making it easier for bacterial colonies to access the polystyrene as a carbon source.

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