Applications of Biotechnology in the Environment: Arguments from Spanish Secondary School Students

Abstract

The widespread use of bacteria in bioremediation led us to consider what Compulsory Secondary Education (ESO) and Baccalaureate students know about prokaryotes and what their attitudes towards them are. This study focuses on the analysis of the arguments made by secondary school students from several Spanish schools regarding the application of bioremediation to eliminate polluting plastics from the environment. Semi-structured interviews were used to obtain information on descriptive aspects regarding the application of biotechnology to bioremediation. This instrument allows for a better understanding of what students know about biotechnology and what they value when adopting a particular attitude towards improving the environment through systematic observations and recording spontaneously occurring events. The arguments used by these students were analyzed from the perspective of the knowledge and values they consider when making their justifications. It was observed that the students viewed the use of microorganisms to treat waste positively and valued the environmental impact and scientific progress, although they had doubts about certain technical aspects. A teaching approach based on the biodegradation of plastics encourages critical thinking and can be integrated transversally into teaching, promoting debates and reflections on science and values. It is recommended that these types of activities continue to be developed to improve science education.

1. Introduction

Biotechnology offers vast benefits to the environment, animals, and human health and contributes to improving socioeconomic conditions for the public. However, innovations in biotechnology continue to trigger public concern and opposition over their potential social, health, and ecological risks. There is an opportunity to increase the knowledge and acceptance of biotechnology through engagement, education, and community participation [1].

1.1. Waste Management

As of 2015, approximately 6300 Mt of plastic waste was generated, around 9% of which was recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050. The packaging sector is the largest consumer of virgin plastic, followed by the construction and automotive industries [2].

If we consider plastic debris in the marine environment, which is widely documented, Jambeck et al. estimated the mass of land-based plastic waste entering the ocean and stated that it is the result of the intersection of high volumes of plastic production and consumption, population density in coastal areas, and poor or nonexistent waste management systems [3].

Regarding the pharmaceutical field, there are studies that highlight the fact that expired, unused, or unwanted medicines generated in households also represent a significant environmental pollution problem. This waste often contains potentially hazardous active substances (cytotoxic, genotoxic, mutagenic, etc.) and is not adequately regulated for disposal by consumers [4].

On the other hand, despite the fact that, traditionally, attention has focused on single-use plastics such as packaging, there are works which reveal that fast fashion and the dominance of synthetic fibers in clothing represent a massive source of plastic waste. The production and disposal of clothing, mostly made from plastic materials such as polyester, nylon, and acrylic, generates millions of tons of plastic waste annually. This waste comes not only from garments discarded at the end of their short lifespan (driven by the “fast fashion” model) but also from the plastics used in packaging and the industry’s supply chain [5].

1.2. Bioremediation as an Example of a Sustainable and Eco-Friendly Practice for the Disposal of Plastics

In 2023, global plastic production reached 413.8 Mt, with 90.4% of this amount being fossil fuel-derived plastics (6.2% being polyethylene terephthalate (PET)). In Europe, 54 Mt of plastic was produced, with 79.4% derived from fossil fuels (4.7% PET) [6].

Nowadays, plastics are mass-produced, accommodating new needs and promoting their constant consumption. Most of the plastic materials produced are used in the manufacture of single-use products such as containers or bottles [7]. At the end of their useful life, these plastics are deposited in landfills or burned to produce energy, with negative environmental effects for both. Alternatively, they can be recycled, but despite being an abundant waste with high recoverable value, their recycling rate is low due to factors such as the lack of return of containers, the high cost of transportation due to their low density, and the difficulty of separating the different types of plastics [8].

The final destination of other types of plastic that do not follow any of the options described above and whose useful life has ended is nature, where their degradation begins. This can be thermal, radiation-induced, mechanical, chemical, biological, or biodegradation. Biodegradation refers to the breakdown and assimilation of polymers by living organisms, primarily microorganisms. In general, and with a few exceptional cases, there are no microorganisms capable of attacking synthetic plastics [9].

PET is a fossil-fuel-derived plastic widely used worldwide, and its accumulation in the environment has become a global concern. The ability to enzymatically degrade PET is limited to a few fungal species, so biodegradation is not yet a viable remediation or recycling strategy. However, a bacterium that is capable of utilizing PET as its primary energy and carbon source, Ideonella Sakaiensis, has recently been isolated. When cultured on PET, this strain produces two enzymes capable of hydrolyzing both PET and the reaction intermediate, mono(2-hydroxyethyl)terephthalic acid. Both enzymes are required to efficiently enzymatically convert PET into its two environmentally benign monomers, terephthalic acid and ethylene glycol [10].

1.3. Biotechnological Approaches in the Specific Context of Spain

In France’s review [11] on the place of biotechnology in the curriculum, one of the aspects studied is the role of science and technology. In the 1990s, technology was included in the curriculum of many countries with the aim of uniting academic science with practical technology, so that students could contribute to debates with informed opinions. In Spain, the current curriculum for Biology and Geology includes the need to promote the development of curiosity and a critical attitude, as well as the reinforcement of the foundations of scientific literacy, which would allow students to understand their environment in order to cultivate attitudes such as responsible consumption or environmental care [12]. The last two years of secondary school constitute the so-called Baccalaureate (between 16 and 18 years of age, the educational stage prior to university). The curriculum for this stage includes several basic units related to the impact of biotechnology on society and the role of microorganisms within the subject of Biology [13] (p. 45):

“The importance and impact of biotechnology: applications in health, agriculture, the environment, new materials, the food industry, etc., and the prominent role of microorganisms”.

There are also other topics that have to do with the degradation of plastic within the subject Biology, Geology and Environmental Sciences [13] (p. 51), such as

“The problem of waste, such as xenobiotic compounds: plastics and their effects on nature and on human health and other living beings, prevention and proper management of waste”.

Finally, other topics that have to do with applications and repercussions of biotechnology for the environment appear in the subject General Sciences [13] (p. 57):

“Agriculture, livestock, medicine or environmental restoration, biotechnological importance of microorganisms, the relationship between environmental conservation, human health and the economic development of society, One Health concept”.

Therefore, everything mentioned above is related to the curriculum established for teaching at this stage and justifies the importance of addressing these aspects in the classroom. Biotechnology is proposed as an ideal area to satisfy the educational needs presented in the theoretical framework because it is a field of science with a multitude of different applications, based on basic concepts of genetics and of interest to students. With it, in addition to learning concepts and techniques, socio-scientific issues (SSIs) can be explored to encourage argumentation in the classroom, as indicated by Fritz et al. [14].

Controversial issues linking science and society (stem cell research, genetic engineering, cloning, and environmental issues) have been termed socio-scientific problems or controversies [15]. SSIs focus on issues or dilemmas with social relevance and with conceptual links to science in areas such as environmental sustainability, health, security, or technological development, among others, which are oriented towards personal or social decision-making and which have an open and complex response [16,17]. Therefore, there is a certain consensus in science education that their use should be extended to the classroom to generate communicative situations that require critical analysis, reasoning, and argumentation—skills that should be promoted in the education of our students [17].

In this sense, the applications of biotechnology occupy a prominent place in decision-making in relation to SSIs [14] because biotechnology is an area undergoing constant growth that motivates students not only to know its biological principles but also to be aware of the values that are related to it, as well as the possible benefits and risks of a political, social, legal, and ethical nature that derive from its development [18]. The manipulation of an organism’s DNA, one of biotechnology’s main fields of application (from medicine to agriculture), and the procedures this uses (such as genetic engineering or the cultivation of microorganisms) are part of what we know as modern biotechnology [19]. Despite its multiple applications, biotechnology raises social controversies about the possible effects on human health, the environment, or even the economy, posing threats to natural crop varieties or provoking ethical debates [20].

1.4. Development of Scientific Reasoning and Argumentation Skills Among Secondary and High School Students, Particularly in Relation to Environmental Education and Sustainability

It is precisely the increasing use of SSIs in the classroom that leads us to highlight the need to evaluate how students justify their statements when discussing these topics. According to Christenson [21], science teaching should not only focus on subject-specific content but also on implementing teaching strategies that include the discourse on and social use of science, such as argumentation about socio-scientific controversies. Scientific practices such as argumentation, inquiry, and modeling contribute to expressing ideas, obtaining relevant evidence, designing experiments, and contrasting initial ideas to draw conclusions. Furthermore, solving a real-life problem allows students to integrate content learning and scientific practices in science teaching [22].

Regarding the work of argumentation in science class, in recent years, it has become indispensable, since it can play a prominent role in promoting socio-scientific decision-making and the development of communicative skills and critical thinking, as well as in fostering scientific literacy, the development of epistemic criteria for the evaluation of knowledge, and the development of reasoning among our students [23,24]. Argumentation helps students to develop the ability to reason about the criteria that allow them to choose between different explanations [25]. López-Banet et al. [26] highlighted instructional sequences to explain the greenhouse effect and its climatic implications through the scientific practice of argumentation. This type of activities intends to facilitate the understanding of scientific concepts in the context of a socio-scientific controversy related to the use of hydrocarbons and global warming.

Therefore, it is relevant to analyze how students justify their positions on aspects related to biotechnological applications, with the aim of developing strategies that could be used by teachers to evaluate the quality of arguments. One way to approach argument analysis is to code the statements made using the qualitative analysis program Atlas.ti [27]. Much research on argument evaluation uses the framework proposed by Toulmin [28], known as the “Argumentation Pattern” (TAP), as a reference to analyze the quality of an argument based on the presence or absence of its structural components (claims, data, warrants, support, qualifiers, and refutations). Several studies describe different adaptations of the TAP to facilitate analysis [29]. Some contributions have considered that the argument analysis model should take into account both the content of the argument, that is, the adequacy or accuracy of the components in the argument from a scientific perspective, and its structure or components [30]. Other studies have considered a quality argument to be one that manages to simultaneously achieve high levels of coherence and structural complexity [31].

From another perspective, some works have investigated student argumentation regarding biotechnological applications, not so much to provide criteria to evaluate the quality of the argumentation but to analyze the values on which the arguments are based, according to the relative importance they attribute to them, and how these values affect decision-making regarding the crucial problems that these applications pose for society [32]. Furthermore, works such as that of [17] propose a four-stage didactic framework that includes the presentation of the dilemma, a reading of a text on the topic, a debate by the students, and, finally, the writing of an essay, with the aim of improving students’ argumentative capacity in the classroom.

Having said that, the main objective of this research is to analyze the arguments related to bioremediation made by Spanish secondary and high school students. This topic is of interest in our educational context due to the lack of studies about bioremediation specifically and the way in which it is connected with microorganisms, the degradation of plastics, or the question of how to solve the current environmental problems. Furthermore, this topic can be useful in the educational context in order to improve critical thinking and the ability to make arguments; at the same time, students learn about an interesting application of the biotechnology field. This analysis has two main aspects:

-

Determining students’ general knowledge related to microorganisms, plastic degradation, and bioremediation.

-

Determining students’ different ideas toward bioremediation and what they take into account when accepting or rejecting it.

2. Materials and Methods

2.1. Context and Participants

The results presented here correspond to interviews conducted with 15 secondary school students (

Table 1. List of students participating in the study.

	4th Year ESO	2nd Year Baccalaureate
Students	S1, S2, S3, S4, S5	S6, S7, S8, S9, S10, S11, S12, S13, S14, S15

): 5 students in their 4th year of Compulsory Secondary Education (15–16 years old) and 10 students in their 2nd year of Baccalaureate (17–18 years old). Of this total of 15 students, 13 attended two public schools located in a rural area, while the remaining 2 attended a public school in an urban setting. Students in the 4th year of ESO (15–16 years old) were taking Biology and Geology, optional subjects for this course, and had not previously studied biotechnology-related or bioremediation content in the classroom but had studied example bacteria and their characteristics. Students in the 2nd year of Baccalaureate (17–18 years old) were taking Biology and had studied biotechnology-related and microorganism-related content in the classroom.

2.2. Information Collection

In social sciences, qualitative interviews are increasingly used as a research method to understand how students reason. The interaction between the interviewer and the interviewee goes beyond the spontaneous exchange of views and transforms into a careful questioning and listening approach aimed at obtaining fully tested knowledge [33]. Among the possible types of interviews, including individual or group interviews, and within the former, closed or open interviews, semi-structured interviews are characterized by a lack of options from which the interviewee can choose their answer; instead, the questions are written to allow for individual responses. Thus, these are guided interviews, in which the topics are chosen beforehand; however, the researcher decides on the order and the expression of the questions during the interview, making it more likely that the interviewees will express their points of view [34], which is why in this work we proposed to collect data by conducting interviews. This instrument is considered suitable for obtaining information on knowledge and opinions.

On the other hand, the selected biotechnological application corresponds to bioremediation because the field of biotechnology and the environment generates interest in students, as indicated by previous studies on high school students [35]. First, we searched for popular science texts and articles related to bioremediation, aimed at the general public, but with rigorous vocabulary and information processing, which, in turn, could be easy to understand. A semi-structured script was developed, including questions that initially inquired about the knowledge of this technology and their opinions on its use. This script was validated by experienced teachers, who suggested eliminating or changing the wording of some questions and adding some more clarifying images. A pilot test was carried out on another two students belonging to two different high schools, which led to the final interviews after verifying that the texts and the questions posed were well understood; at the same time, with the final questions, different aspects could be evaluated, such as knowledge plus opinions. This interview had not been tested on these students before.

The interviews were conducted at the end of the academic year at the students’ schools; they were recorded and lasted approximately 5–10 min. They were conducted individually between the first author of the paper, the teacher responsible for the subject in the 4th year of ESO (4E from here on out), and each of the students. For the 2nd year of Baccalaureate (2B from here on out), the interviews were also conducted individually by the three authors of the paper, none of whom taught the students. So, the sample was chosen taking into account students at these educational levels who belong to the high school at which the researchers worked; these students could represent the ideas of students at this academic level in Spain. During the interviews, the researcher guided the students to obtain information on the issues raised, allowing them to explain their views and express their concerns as they saw fit.

In the interviews, a background text was included, as shown below, along with various drawings representing plastics, bacteria, and the chemical compounds in plastic, which explained how PET is degraded by the bacterium Ideonella Sakaiensis.

The bacteria that eats plastics.

Read the text we present to you about bacteria that can degrade plastic.

A scientific team from the Kyoto Institute of Technology (Japan) has recently discovered a previously unknown bacteria that can survive by feeding on PET (polyethylene terephthalate), one of the most widely used plastics in the food industry for packaging mineral water, soft drinks, oils, and pharmaceutical products, among others.

“The assimilation of PET by the bacterium Ideonella sakaiensis can be very useful for eliminating this petroleum-derived material from the environment,” writes researcher Uwe T. Borns-cheuer in an article accompanying the research.

“This work is very interesting and adds to others in this field. Several microorganisms capable of degrading plastic materials have been found, but much remains to be done to translate these findings into large-scale bioremediation,” María José López, a researcher in the Microbiology Department at the University of Almería, told this newspaper.

El Mundo—Ciencia—10 March 2016. http://www.elmundo.es/ciencia/2016/03/10/56e1c141e2704e7a6a8b4629.html (accessed on 5 June 2018).

• Do you think bacteria are good or bad for humans?
• What does the expression “The assimilation of PET by the bacterium Ideonella sakaiensis can be very useful for eliminating this petroleum-derived material from the environment” mean?
• Could you explain the image that represents the process?
• Why is it interesting that bacteria degrade plastic? What is special about this material?
• Do you think this could have applications in the not too distant future?
• Would this process have negative consequences for the environment?

2.3. Analysis of Results

To analyze the results, the following procedure was followed: First, each interview was transcribed, and then, following the model proposed by other researchers in our educational context [27], the qualitative data analysis program Atlas.ti version 8 was used to perform an initial provisional coding collected from each interview, assigning different codes to the different responses of the students based on the expressions they used.

Secondly, the authors of this study, acting independently, grouped the codes they had provisionally obtained from each interview by similarity. This led to the emergence of broader and more representative categories of the students’ justifications for the biotechnology applications presented in the interviews. After completing this process, we adapted the emerging categories and the aspects considered. The methodology proposed by Christenson and Chang [36], inspired by those of Chang and Rundgren [37] and Chang and Chiu [30], was considered, although it was adapted to the requirements of students at this educational stage for use in the classroom. The authors of this study employed two main components related to structural aspects of the argument: the statement (decision) and the justifications declared in favor (pros) and in opposition (cons) of the statements themselves. The categories finally used to analyze the interviews arose from the codes that emerged in the first stage and the mentioned elements of the justification of the students’ opinions on biotechnology.

In the third and final stage, the authors of this work independently grouped the students’ responses according to the criteria of the previously discussed SSI justification model in biotechnology, obtaining an initial consensus of 71.3% in assigning them to the proposed categories. The discussion, clarification of discrepancies, and final consensus on the definitions of each of the categories led to complete agreement.

The codes used were as follows: affirmation, referring to what the student mentions in relation to a question posed by the interviewer, which can be in favor of the proposed approach (pro) or contrary to it (contra).

The justification can consist of knowledge statements, when the arguers use discipline-specific content to support their claims, and/or value statements, when they express their moral or ethical awareness of the topic. Within justification with knowledge, there are three possible modalities: A (for incorrect content; this also includes those who did not answer anything), B (general information given; content that is not specific enough), or C (correct and relevant scientific content).

In turn, according to the previously mentioned model of Christenson and Chang [36], the value category can be subdivided into two possibilities: value-unfounded (a simple answer that does not go beyond the personal) or value-based (when the interviewee expresses a judgment and shows a broad understanding of the long-term and large-scale consequences of the chosen point of view). This paper includes a specification of the category of value-based assessment based on the area on which the assessment is based: “health”, “utilitarian”, or “environmental”.

The qualitative data analysis program Atlas.ti was used to perform the coding collected in each interview, following the model proposed by other researchers in our area [27].

3. Results

The arguments presented by the students, explaining their views on bioremediation, are analyzed below, examining the quality of the scientific knowledge used, the values underlying their opinion, and whether the rationale provides justifications for and/or against its use. The presentation of results is accompanied by excerpts from the interview transcripts, indicating the assigned codes.

3.1. Relationship Between Bacteria and Humans

First, the widespread use of bacteria in bioremediation has led us to consider what students know about prokaryotes and what their attitude toward them is. We found that, for most of the 2B students interviewed, there are both bacteria that are beneficial to humans and other harmful ones that can cause disease. They mentioned examples of the actions produced by both types of bacteria (8 out of 10 cases) and based their justification on health aspects (

Table 2. Transcriptions and example coding of different questions.

Question	Transcription	Coding
Q1 Do you think bacteria are good or bad for humans?	Well, there are good ones and bad ones. I don’t know about good ones, but bad ones, yes, for example, those that cause pneumonia	Pro/Against-B-Health
	Depending on what those bacteria do. Good bacteria, for example, are good bacteria for food, like yeast and such. Medicine uses bacteria to create drugs that can prevent certain diseases, and harmful bacteria are harmful bacteria that enter the body, like those that cause a cold (S8)	Pro/Against-C-Health
	I think they can be good for some things and bad for others. A good bacteria would be one that… I think there are bacteria that form symbiosis with humans and can also be used for what we’re talking about, like the environment. Bad bacteria are those that cause disease (S15)	Pro/Against-C-Health
Q4 Why is it interesting that bacteria degrade plastic? What’s special about this material?	Because this way you can eliminate the materials that are more harmful, so to speak, to the environment (S1)	Pro-B-Environmental
	Because that bacteria would help eliminate plastics from the environment (S2)	Pro-C-Environmental
	Because plastic takes a long time to degrade. With bacteria, it will take less time because it increases degradation (S10)	Pro-C-Environmental
Q5 Do you think this could have applications in the not too distant future?	I don’t know… There’s a lot of plastic in the sea, and bacteria too…	Pro/Against-B-Environmental
	Yes, for example, on plastic bags (S5)	Pro-C-Environmental
	Yes, it can be useful in the future because it could be used to reduce plastic if we were in danger of contamination (S10)	Pro-C-Environmental
	Little by little it will be discovered but on a large scale it is still lacking (S13)	Pro-B-Scientific Development
Q6 Would this process have negative consequences for the environment?	Yes, it can be, because bacteria can also harm us (S2)	Against-B-Health
	Yes, because maybe it would also eat the plastic that we need (S3)	Contra-B-Utility
	At first glance, more positive than negative, maybe those bacteria then go to the sea and the fish feed and are bad for them (S12)	Pro/Against-B-Environmental

). Interaction with the students allowed us to identify other examples of bacteria they know of that are beneficial to humans, such as those that inhabit the body, and others of bacteria that are harmful, such as those that cause acne. However, some conceptual errors were detected in several definitions (confusing bacteria with yeast (they belong to different kingdoms of living beings), confusing the cold (a viral disease) with a disease of bacterial origin, or mentioning bacteria that “eat the bad things in the body”). Among 4E students, knowledge about bacteria and their relationship with humans was more superficial. Three out of five students knew that there are beneficial bacteria species and others that can be harmful, while two only mention that they are always harmful. Furthermore, no student provided an example of bacteria that are good for humans, and as an example of harmful bacteria, two mentioned that they can cause infections (without specifying which ones), and only one cited an example of a disease (pneumonia).

3.2. Explanation of the Case Presented: “The Bacteria That Eats Plastic”

The 2B students’ responses regarding the meaning of this expression and its title were generally adequate. When asked to explain the diagrams supporting the text, one student did not provide an adequate response and two did so incompletely, while the rest provided a valid description. For the 4E students, their responses regarding the meaning of the expression that referred to the article and interview title were generally adequate, although some had difficulty identifying the specific problem it addressed as the degradation of plastic.

Regarding why it is interesting for plastic to degrade, students recognized that plastic constitutes an environmental problem, and the vast majority responded that with this bacterium, the process for plastic’s elimination from the environment would be accelerated, so their answers were classified as correct and relevant knowledge and well-founded environmental value. When asked to explain the diagrams supporting the text, the students did not fully understand them, and although they did identify the plastic bottle and the bacterium, they did not know how to interpret the formulas appearing alongside them, which refer to the chemical degradation of PET by the bacterium. One student identified this with the bacterium itself, and three identified it with components of the bacterium. Some transcripts of these responses are found in Table 2.

3.3. Possible Future Applications and/or Drawbacks of This Example

Regarding the application of bioremediation processes, 2B students were optimistic (9 out of 10 cases) and believed that they can be used to reduce environmental pollution, but, at the same time, they believe—and this is another dominant value in the justifications—that putting it into practice would require further research. As for 4E students, they were unsure about the procedure by which the bacteria would degrade the plastic if it were applied; three students said it could have future applications, and two said they are unaware of them. Despite this, two students situated the action in marine ecosystems, and one student focused specifically on plastic bags (Table 2).

Virtually no students found any drawbacks to bioremediation (Table 2), but it is equally interesting to observe how they questioned whether there might be side effects after applying this technique, such as wondering what would happen to the bacteria used in the process and what effects their release would have on the environment. In the interviews with 2B students, we found very few students who justified their position with arguments both for and against (only two did so for this question). This aspect is important because it indicates the quality of the arguments, demonstrating the ability to contrast ideas even if the opinion later goes one way or the other. On the other hand, there was considerable heterogeneity in the quality of the knowledge used, and environmental values used to support the justifications predominated. When 4E students were asked about the negative aspects, only two justified any negative consequences using values based on health and utilitarian reasons.

In our interviews, we found very few students who justified their position with arguments both for and against. This aspect is important because it indicates the quality of the argument, demonstrating the ability to contrast ideas even if the opinion ultimately goes one way or the other. Furthermore, there was considerable heterogeneity in the quality of the knowledge used, and environmental values predominated in supporting the justifications.

4. Discussion

Some works link a deficient knowledge of non-university students in basic disciplines such as genetics, cell biology, or microbiology with a serious difficulty in understanding biotechnology and its applications [38,39,40]. Students’ knowledge of biotechnology has been described as insufficient and erroneous by different authors [38,41,42,43]. Hammann [18] also states that although more recent studies show a certain improvement in students’ knowledge, research clearly shows a significant lack of knowledge. However, citizens must understand most basic notions of biotechnology, so that they have the appropriate intellectual tools that allow them to make informed decisions regarding its applications in everyday life [44].

Some research shows that knowledge of biotechnology tends to be highest in the healthcare field, such as the production of biopharmaceuticals [45], or in the food field, such as genetically modified foods [46], but is lower in its environmental or industrial uses [47]. Studies such as Gardner and Troelstrup [47] described a very high acceptance of research in genetic technology for environmental sustainability among students, but they showed some concern towards the regulation of risks to the environment associated with biotechnology.

Considering the important role that bacteria play in numerous biotechnology research projects, studies on students’ knowledge of microorganisms are also of interest. Thus, authors such as Harms [19] have investigated the deficient understanding of their role in different parts of the human body, attributing to them, for example, a digestive function by absorbing “harmful agents” or processing unwanted substances in the liver, purifying the blood, or increasing the efficiency of bile.

It is also mentioned in Simonneaux’s work [32] that students emphasize that bacteria feed on waste matter and that the intestinal flora is composed of “good bacteria” that digest fiber. Harms [19] says that students are able to name foods that are prepared using bacteria, such as yogurt, but they also mention foods that are not prepared using them, such as wine or beer. In addition, the first biotechnological process that students connect to bacteria is water purification via the decomposition of chemicals (a scientifically correct idea). Simonneaux [32] points out that the industrial use of bacteria is practically unknown to students, since bacteria are often perceived as agents of decomposition and they can hardly conceive of using them to make food.

Regarding students’ level of awareness of the main biotechnology applications, it has been found that the diversity of applications explains their varying levels of knowledge about each one. Thus, research shows that students have more information about applications related to medicine or nutrition than those related to environmental issues or industry [40,44,46]. Few students are aware of the elimination of polluting oils using genetically modified bacteria [44].

For different authors, the attitudes that students show toward biotechnology vary widely depending on three factors: its pragmatic value, the safety of its use, and its moral acceptability [48]. Thus, studies suggest that students show favorable attitudes toward biotechnology applications aimed at improving human health or producing new drugs [39,42,49,50]. The type of living being involved in the experiments also influences students’ opinions, since the use of animals is generally not accepted, although there is less rejection if plants or microorganisms are involved [51].

On the other hand, the literature reviewed indicates that students accept genetically modified organisms to save human lives or prevent diseases, but not for our own pleasure or economic gain [40]. Thus, the production of transgenic Bt corn (Bacillus thuringiensis) is more acceptable than the breeding of genetically modified salmon. The application of gene therapy to somatic lines is also more acceptable than when it affects germ lines [19]. Finally, students are more affected by controversies related to the environment, but less by those related to health and industry, since they provide perceptible and positive results from the perspective of the patient or consumer [52].

In another sense, with respect to the use of microorganisms in biotechnology processes, other research has established that it has been accepted by students [51]; this is also the case for wastewater treatment [43]. Furthermore, de la Vega et al. [39] point out that there is a high level of opinions in favor of the use of microorganisms in biotechnology, as well as their use to prevent or treat diseases. Studies such as those of López-Fernández and Franco-Mariscal [53] show that working on the problem of plastics in the classroom through inquiry allows students to observe that plastics are difficult to degrade and helps them understand the environmental impact of these materials, with social awareness being crucial to promote recycling. Furthermore, the study of bioremediation could help students understand microorganisms from a different perspective, since, as Simonneaux indicates [32], many consider microorganisms to be harmful.

It has been generally found in this study that students have favorable attitudes toward bioremediation, one of the main applications of biotechnology, and that among the values on which they base their position, environmentalism predominates, as does the need to increase scientific development to enhance its effectiveness. However, although students do understand the most basic aspects they are asked about, such as the use of plastic by bacteria, there are still doubts, for example, about how it would be carried out in practice. We highlight here the novelty of the information obtained in the area of bioremediation, as its effects are often presented as examples in textbooks, and some studies on biotechnology also consider it. However, we have not found other studies that analyze what students know about it and what their attitudes toward it are in a detailed and comprehensive manner thanks to semi-structured interviews.

Moreover, the need for argumentation in the science classroom has been highlighted on numerous occasions. This work once again highlights the importance of including the scientific practice of argumentation in the classroom to discuss scientific topics, relate data, and offer explanations, especially considering that the ability to develop arguments is not a common element in our school system [54,55].

The main limitation of the study is the number of students who participated. However, the predominantly qualitative nature of the information collected provides novel and highly useful data for reflection. Thus, in general, it is observed that students from both secondary school stages interviewed (4E and 2B) showed a positive attitude toward the use of microorganisms for waste treatment and expressed interest in learning about the techniques and applications of biotechnology in this field. It is evident that the students have favorable attitudes toward this application of biotechnology and that, among the values on which they justify their position, environmental issues and the need to increase scientific development to enhance its effectiveness predominate. However, certain difficulties are detected in explaining what happens to the bacteria once the contaminant has been removed and whether its applicability is imminent.

5. Conclusions

Based on the results presented in this paper, types of SSI-based teaching activities in real-life situations, with the development of the proposed methodological framework, can facilitate student participation in debates in an appropriate and critical manner by having them reflect on the importance of using scientific knowledge, the variety of possible positions, and the values that support the arguments used. Although students have some knowledge about biotechnology applications, we believe it is necessary to use scientific and informative articles in the classroom, as well as to encourage role-playing activities and debates, so that students can learn more examples of these applications, express their opinions, and compare them with those of other classmates, thus increasing their interest in this topic.

Biotechnology is a field with a multitude of different applications; it is based on basic concepts of genetics and is of interest to students. It can also be used to explore the world of SSIs and classroom argumentation. Although this is a very specific example and is currently under investigation, the analysis of the case of the bacterium Ideonella sakaiensis can serve as a starting point for other activities related to the applications of biotechnology in the environment. Thus, due to its transversal nature, it would be ideal for beginning an educational proposal that subsequently expands students’ knowledge on bioremediation and different aspects of chemistry, such as their knowledge of microorganisms and the necessary environmental conditions, such as pH, temperature, concentration, types of contaminants, and genetically modified organisms, as well as other current examples of bioremediation, both in situ and ex situ. Finally, this proposal on biodegradation contributes to reflecting on the problem of plastic pollution and could contribute to the development of critical thinking.