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Summer 2012 Blog - Joanna Ji

Joanna Ji is spending ten weeks at the University of Sao Paulo.


July 1, 2012

I am working with Professor Marcos Buckeridge and his lab professionals on a project accessing sugarcane’s response to elevated CO­­­­­­­­­2 levels and its potential as alternative energy source biofuel. The project is studying how sugarcane reacts to various amounts of CO2. Sugarcane is grown in controlled open-top chambers to be used as samples. My project is to determine the amount of monosaccharaides in various parts of the sugarcane and analyze the relationship between these data and the independent variable.

Currently I have performed a complete extraction process on a set of samples. The process involves grinding of samples, extracting glucose and other sugars from the sample, then subsequently prepare the extracted sugar sample for the measuring of amount of sugars.

One of the biggest difficulties I've encountered is the language barrier. Although English is a mandatory preparatory school course here it is rare to find people that speak fluent English, especially in the older generation. Fortunately my lab environment consists of English speakers. They have all been extremely accommodating and helpful, translating all the protocols for me. However other communications can be difficult. Everything from ordering cheese bread to taking the bus can have unforeseen complications. Usually they are resolved by smiling nodding and saying “Eu não falo português,” (I don’t speak Portuguese) the first and most useful phrase I learned.


August 2, 2012

The extraction process has been streamlined with practice. The limiting factor is the need to dry and freeze the extracted samples in ovens and desiccators. Another challenge is the limit of the machines. Sugarcane is well-known for harboring very high levels of glucose. The HPLC machine, which measures the amount of various sugars in a sample, might not be able to measure such high levels and the readings will max out its range, meaning the ‘spike’ on the graph will be cut off at the top of the graph, leading to unreliable results. This means that if such extreme levels are unforeseen then the samples must be diluted and ran through again, or in some cases re-extracted from the very beginning, which can be very time consuming. Each part of the sugarcane contains different levels of glucose or starch. Familiarity is needed with the samples to predict what and when samples should be diluted.

I now have five sets of data corresponding to the leaves, stems and roots of the sugarcane harvested at various stages of growth under exposure to different levels of carbon dioxide, also with factors such as wet or dry raised. I also have a set of data corresponding to Miscanthus leaves and stems from another lab. Next I will complete the compilation of these data and begin analysis on them. The specific programs and data adjustments will be taught to me by my lab supervisor. The analyses of the data began by cleaning it up. The data must be corresponded with its original sample numbers and assembled sequentially.  The majority of the analysis is done with excel.

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