Human Practices

Inspiration

Indigo is a kind of reduction dye with a history of more than three thousand years. During the Warring States period, Xun Kuang's famous phrase, "Green out of blue is better than blue," originated from the blue dyeing technology of that time. The word "green" here refers to the color cyan, while "blue" refers to the blue grass used to make indigo. Before the Qin and Han dynasties, the application of indigo was already quite common. The ancient method of making indigo is as follows: first mow the blue upside down in the pit, add water and filter, put the filtrate in the urn, add lime in proportion, and then hit the water sharply with a wooden stick to speed up the contact between the indigo glycosides dissolved in the water and the oxygen in the air, so that the oxidation becomes indigo. After precipitation, the water will be removed, and when the water of indigo is completely evaporated, then it can be held into the container and made into indigo. This technique of making and dyeing indigo is exactly the same as the mechanism of modern synthetic indigo dyeing. Like safflower, bluegrass can also be made into solid dyes: indigo in mud form is first made, and when it is to be dyed, it is fermented with lees, and the hydrogen and carbon dioxide produced during the fermentation process can reduce indigo to leucoindigo. The white cloth dyed with leucoindigo can show blue color again by air oxidation. This fermentation reduction technology of indigo has been used in the Spring and Autumn and Warring States period, and the ancient method is still in use. Indigo was first made in India in about 100 B.C. Unlike the Chinese, they used the urine fermentation method to dye blue. In 1901, Pfleger in Germany improved the synthetic line by using aniline as the basic raw material to produce indigo, which was called the Heumann-Pfleger method, or HP method for short. After that, Swiss scientist have brought up new synthetic lines in 1907 and 1914 respectively, but both eventually failed due to safety problems. Now, 100 years later, the HP method is still the main method for synthesizing indigo widely used all over the world. Today, chemically synthesized indigo is very common. However, the environmental problems that come with it cannot be ignored. So, we hope we can produce it on a large scale through synthetic biology and specifically, indigoidine.

Finding the problem

Background

The study hopes to test the cognition and acceptance level of the public related to a biological dye. Currently chemical dyes are causing severe problems to their surrounding industry and also residential areas. Therefore, to look further into this phenomenon, questionnaires have been sent out and data are gathered.

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The overall situation of questionnaire data and the reliability and validity test of the questionnaire

A total of 297 valid questionnaires were collected online. The questionnaire data come from different gender, age, occupation and education level in many provinces and cities in China as the following picture shows, and have good universality and representativeness.

An overall evaluation of split-half coefficientis carried out by using the “reliability analysis” function of SPSS, and the α value is calculated. The results are shown in Table 1. Since only 2 of the questions involved in the questionnaire are considered to be scale questions, reliability test iscarried out with them with α value of 0.799, indicating a reliable source of statistics in Table 2.

Then the ‘factor’ option of SPSS is used to test the structural validity of each question data of the questionnaire, and the KMO value and significance level are calculated. The results are shown in Table 3. According to the data in Table 3, the KMO value is 0.603 and the significance level is much less than 0.01, which indicates that there is a significant correlation among the variables of each question of the questionnaire. And the questionnaire is suitable for factor analysis, which shows that the validity of the questionnaire is not bad.

Discussion on public cognition of biological dye

Since the study hopes to improve current situation and if possible, get funding from universities and professional agencies, this questionnaire hopes to understand a basic source of the cognition of biological dyes from the public. Results are shown in Table 4.

As shown above, the access of public in response to biological dye is not as significantly expected by the researcher, with 45.64% of the interviewees never heard of any approach to make biological dye. This may well be attributed to a lack of access to dye industry and a low level of attention to types of dyes when purchasing clothing. A chi-square test is carried out between question ‘Do you ask about the type of dye when you buy clothes?’ and ‘From what access have you learned about biological dyes ?’ as Table 5 shows.

As shown above, the proportion of ‘unknown’ is much higher in condition of ‘will not’ than in condition of ‘will’. Also, this table suggests a high proportion of cognition source from ‘newspaper of magazines’. Inspiration might be that the study can focus more on applying its achievements on newspaper and magazines in order to raise more attention.

The relation between cognition level and acceptance

The correlation between cognitive level and acceptance was tested by bivariate correlation analysis of SPSS. Because the cognitive score and acceptance score mentioned above are essentially ordered variables, the Kendall correlation coefficient and Spearman correlation coefficient are used to analyze the cognitive score and acceptance score. The results are shown in Table 6 and Table 7.

According to Table 6 and Table 7, the correlation coefficients between cognitive level and acceptance are 0.116 and 0.445, respectively, which indicates that there is a positive correlation between cognitive level and acceptance, but the correlation is not strong. That is, people who know more about dyes are more likely to appreciate indigoidine.

The results of scatter analysis in Figure 1 confirmed the results of correlation analysis. That is, there is a positive but not obvious correlation between acceptance and cognitive level.

Figure 2 and Figure 3 are two Histograms of Total Level Distribution in Samples of questions ‘How well do you know the dye industry?’ and ‘How much do you like the clothes made of indigoidine dyes?’. Figure 2 shows that a large proportion of questionnaire takers do not have an ample knowledge about dye industry, indicatinga necessity for a propaganda to the society. Figure 3 can be estimated as a standard normal distribution. Therefore, the product of this study-- indigoidine dye, is acceptable to the society and has a good market potentials.

Factors affecting cognition and acceptance level

I. The impact of gender

An overall chi-square test is carried out with ‘What is your gender?’ as X and ‘How well do you know the dye industry?’ ‘How much do you like the clothes made of indigoidine dyes?’ and ‘What is your willingness to buy clothes?’ as Y respectively. Results are shown in Table 8.

As table 8 shows, significance level is the highest between question ‘What is your gender?’ and ‘What is your willingness to buy clothes?’ than in other two pairs of questions. Next, scatter analysis is carried out with three different Xs. Results are shown in Figure 4, Figure 5 Figure 6. Mann-Whitney U test is carried out in Figure 7 and Table 9 between question‘What is your gender?’ and ‘How well do you know the dye industry?’, together with ‘How much do you like the clothes made of indigoidine dyes?’

The number of r square in Figure 4 and 6 are respectively 0.005, 0.014. It indicates that gender does not have much influence on these independent variables. The number of r square in Figure 5 is 0.026. The significance in Table 9 also shows that there is a positive correlation between gender and how well people know about dye industry.

II. The impact of age

In Table 10, the significance level of both variables are in the acceptable range. But with a p value of 0.000, a greater relation exists between‘What is your age group?’ and ‘How well do you know the dye industry?’. Next, scatter analysis is carried out with three different Xs. Results are shown in Figure 8, Figure 9 Figure 10. Mann-Whitney U test is carried out in Figure 7 and Table 9 between question‘What is your gender?’ and ‘How well do you know the dye industry?’, together with ‘How much do you like the clothes made of indigoidine dyes?’

The r square does not show great diversity from Figure 8-10, with the largest r square number of 0.049 in Figure 8. A further Kruskal-Wallis test is carried out to look deeper into the correlation in Table 11 and Figure 11.

According to Table 11 and Figure 11, in general, a stronger relation is present between question ‘What is your age group?’ and ‘How much do you like the clothes made of indigoidine dyes?’.

III. The impact of the level of education

An overall chi-square test is carried out with ‘What is your level of education?’ as X and ‘How well do you know the dye industry?’ ‘How much do you like the clothes made of indigoidine dyes?’ and as Y respectively. Results are shown in Table 12.

In Table 12, the significance level of both variables are in an optimal range, indicating a notable correlation. Next, a scatter analysis is carried out in Figure 12.

In Figure 12, all three lines do not show significant r square results. After that, a Kruskal-Wallis test is carried out as Table 13 and Figure 13 represents. All three items show an available level of significance.

Discussion and overall summary

Currently, most of the dyes on the market still come from chemical manufacturing methods. However, biological dyes have been proven through several experiments and studies to be an equally effective and more environmentally friendly method of dye production. Although public awareness and interest in this process has yet to increase, this study identifies the market potential for biological dyes. With the increasing emphasis on environmental protection, it is more likely that capital will be attracted to this industry in the near future. The market share of bio-dyes will also gradually increase. In Table 14, the questions 'What is your age group?' and 'How well do you know the dye industry?' and 'How much do you like the clothes made of indigoidine dyes?', the 50+ group shows the highest mean value of knowledge and relatively high mean value of indigoidine liking. Considering the lack of curriculum and knowledge in schools, those aged 12-18 years showed the lowest mean knowledge of dyes. Nevertheless, this group has the highest mean indigoidine liking, showing considerable potential for product promotion.

Seek a good solution

Knowing the main problems faced by the dye industry, we hoped that through the method of synthetic biology, the production and dyeing of Indigo dye can bring improvement to its stakeholders. There were many problems need to be solved, so we consulted relevant experts and stakeholders to answer our questions. After discussing with fellow teammates and instructors, we finally came up with a basic solution. Using C.glu to produce indigodine dyes, we can create environmental-friendly indigo dyes in an efficient way.

Contact with the public

After successfully producing indigo dyeswith C.glu, we made slides and presentations to spread our thoughts. Because of the pandemic, we chose to record videos of teammates’presenting the content. We divided ourselves into two groups, one for primary school presentation, and another for middle school presentation. Depending on which age range we were trying to reach, we differentiated the contents. For primary school presentation, we added more simple and fun cartoons in a light mood to show the importance of Biology. For middle school presentation, we added more about the history and making of Indigo dyes as well as the analysis of our experiments and results. In general, our integrated human practice connects with our project all the time. Through early questionnaire design and research, we understood the pollution problem of chemical dyes and the feasibility of using synthetic biology to produce Indigo dyes. Then we mainly communicated in environmental protection and product forms, conducting our own deep-dive experiments. We have also participated in a lot of meetings for communication between iGEMers, and tried our best to help them while improving our project.In terms of seeking social significance, we thought of intangible cultural heritage inheritance. Eventually, we help spread the key thought of environmental protection, creating a more efficient production of biological indigo dyes.

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