Method for enhanced polystyrene waste decomposition by tenebrio molitor

Abstract

The present disclosure provides a method for decomposing polystyrene waste, and a method for enhancing polystyrene waste decomposition by yellow mealworms using specific amino acids. The method comprises: treating yellow mealworms or polystyrene waste with free amino acids before or simultaneously with the use of yellow mealworms to decompose polystyrene waste. The free amino acids are selected from essential amino acids and non-essential amino acids, wherein the essential amino acids are selected from phenylalanine, tryptophan, valine; and the non-essential amino acids are selected from cysteine, glutamine and glutamic acid.

Description

Technical Field

[0001] This disclosure relates to the field of biodegradation of plastics, and more specifically, to a method for decomposing polystyrene waste and a method for decomposing polystyrene waste using amino acids enhanced by mealworms. Background Technology

[0002] Plastic pollution is one of the most pressing environmental challenges facing the world today (see Nielsen et al., "Politics and the Plastic Crisis: A Review of the Plastic Life Cycle," Wiley Interdisciplinary Review: Energy and Environment, 2019, Vol. 9, No. 1). The persistence of plastic waste poses a unique challenge, leading to ecosystem disruption (Barnes, "Understanding Plastic Pollution: The Role of Economic Development and Technology Research," Environmental Pollution, 2019, 249(249), pp. 812–821). Current treatment methods are less than ideal, with problems such as waste accumulation, inefficient energy recovery, and the emission of harmful chemicals. Therefore, there is an urgent need for an alternative, environmentally friendly approach to address plastic waste (Mohan et al., "Degradation of Plastics Waste and Its Effects on Biological Ecosystems: A Scientific Analysis and Comprehensive Review," 2023).

[0003] Recent research has highlighted the enormous potential of the mealworm (Tenebrio molitor) to decompose plastic waste through ingestion, providing a biodegradation pathway that could significantly promote sustainable development in addressing plastic pollution (Bulak et al., "Biodegradation of Different Types of Plastics by Mealworms", Polymers, 2021, 13(20):3508). Although this method is a more environmentally friendly alternative, its decomposition process is time-consuming (Kuan, Chan, and Gan, "Insect Applications in the Circular Economy of Biowaste and Plastics: Hermetia illucens, Mealworm (Tenebrio molitor), and Super Mealworm (Zophobas morio)", Sustainability, 2022, 14(3):1594), thus limiting its feasibility for large-scale application. Several other groups have also reported increased rates of plastic consumption when natural food components, including sucrose, wheat bran, and soy protein, are added to the plastic matrix (Yang et al., Biodegradation and mineralization of polystyrene waste by plastic-eating mealworms: Part 1. Chemical and physical characterization and isotopic testing. Environmental Science & Technology, 2015, 49, 12080-12086; Gan et al., A method for achieving a zero-waste circular economy for plastics using worms: enhancing polystyrene waste consumption and plant growth, Methods and Protocols, 2021, 4, 43.). Conversely, cinnamon was found to have a negative impact on the rate of plastic consumption (Gan et al., 2021, ibid.). Therefore, there is substantial evidence that certain natural food components can accelerate the biodegradation process. The reason why adding certain feeds can increase the rate of plastic consumption is that when mealworms survive solely on plastic as a nutrient source, their reproduction is affected (Yang et al., 2015, ibid.).

[0004] There is a need to develop methods that can enhance the biodegradation capacity of mealworms for plastic waste (especially polystyrene waste) under environmentally friendly conditions. In other words, there is a need for methods that can increase the rate at which mealworms biodegrade plastic waste (especially polystyrene waste). Summary of the Invention

[0005] To address the aforementioned problems, this disclosure provides a method for decomposing polystyrene waste.

[0006] In a first aspect, this disclosure provides a method for decomposing polystyrene waste. The method includes:

[0007] a) Treatment of mealworms (Tenebrio molitor) with free amino acids;

[0008] b) Using treated mealworms to decompose the polystyrene waste.

[0009] Secondly, this disclosure provides a method for decomposing polystyrene waste. The method includes:

[0010] a) Contact the free amino acids with the polystyrene waste;

[0011] b) Using mealworms (Tenebrio molitor) to decompose polystyrene waste that has come into contact with the free amino acids.

[0012] In some embodiments of the method of the first or second aspect, the free amino acid is selected from essential amino acids, non-essential amino acids, and their salts.

[0013] In some embodiments of the method of the first or second aspect, the essential amino acid is selected from phenylalanine, tryptophan, valine and their salts.

[0014] In some embodiments of the method of the first or second aspect, the non-essential amino acid is selected from cysteine, glutamine, glutamic acid and their salts.

[0015] In some embodiments of the method of the first aspect, the free amino acids are pre-added to the mealworm feed in the form of a solid powder or solution.

[0016] In some embodiments of the method of the second aspect, the free amino acids are sprayed onto the polystyrene waste in the form of an aqueous solution with a concentration of 0.5 mol / L to 10 mol / L.

[0017] In some embodiments of the method of the second aspect, the free amino acids are sprayed onto the polystyrene waste in the form of an aqueous solution with a concentration of 1 mol / L to 5 mol / L.

[0018] According to this disclosure, pre-contamination of mealworms with specific amino acids or treatment of plastic waste with specific amino acids can enhance the decomposition effect of mealworms on plastic waste (especially polystyrene), thereby providing a more environmentally friendly and efficient biodecomposition method for plastic waste compared to the case without added amino acids. Attached Figure Description

[0019] Figure 1 The effects of different amino acids obtained according to Example 1 on the proportions of live, cannibalistic, and dead mealworms in a mealworm population are shown.

[0020] Figure 2 The mass of polystyrene waste remaining after different treatments over time, as obtained in Example 2, is shown. Detailed Implementation

[0021] The ability of mealworms (Tenebrio molitor) to effectively biodegrade plastic waste under environmentally friendly conditions has been demonstrated. However, the relatively slow rate of biodegradation makes it less feasible for large-scale implementation. To enhance the biodegradation of plastic waste by mealworms without increasing the environmental burden, certain types of free amino acids are used in this disclosure.

[0022] The inventors discovered that supplementing with three essential amino acids (phenylalanine, tryptophan, and valine) and three non-essential amino acids (cysteine, glutamine, and glutamic acid) not only increases the efficiency of mealworms in decomposing polystyrene, but also enhances the overall health, stability, and composition of the mealworm population, directly affecting their working capacity.

[0023] While amino acids contribute to the nutritional characteristics of mealworms, the data in Example 1 below indicate that their role extends beyond simply enhancing nutrient intake. The increased efficiency in polystyrene decomposition was observed not only to increased nutrition but also to the specific effects of amino acids on the physiology and behavior of mealworms, particularly their impact on mortality and cannibalistic behavior. This nutritional mechanism is not yet revealed in the prior art and goes beyond the basic nutritional role of amino acids.

[0024] Based on this discovery, the inventors proposed the following method to promote the decomposition of plastics by mealworms.

[0025] The first aspect of this disclosure relates to a method for decomposing plastic waste, comprising: first treating mealworms (Tenebrio molitor) with free amino acids, and then using the treated mealworms to decompose the plastic waste.

[0026] Secondly, this disclosure provides a method for decomposing plastic waste. The method involves first contacting the plastic waste with free amino acids, and then using mealworms (Tenebrio molitor) to decompose the plastic waste in contact with the free amino acids.

[0027] In some embodiments of the methods of the first or second aspect, the free amino acid is selected from essential amino acids, non-essential amino acids, and their salts. In some embodiments of this disclosure, the essential amino acid is selected from phenylalanine, tryptophan, valine, and their salts. In some embodiments of this disclosure, the non-essential amino acid is selected from cysteine, glutamine, glutamic acid, and their salts.

[0028] In some embodiments of this disclosure, the salt of the free amino acid is selected from the alkali metal salt of the amino acid, preferably the sodium salt of the free amino acid.

[0029] In some embodiments of the method of the first aspect, free amino acids are pre-added to the mealworm feed in the form of a solid powder or solution. In some embodiments of this disclosure, mealworms are fed a feed containing said amino acids for 1–30 days, or 2–25 days, or 3–20 days, or 4–18 days, or 5–15 days.

[0030] In some embodiments of the method in the second aspect, free amino acids are sprayed onto polystyrene waste in the form of an aqueous solution with a concentration of 0.5 mol / L to 10 mol / L, or 1 mol / L to 5 mol / L, or 2 mol / L, or 3 mol / L or 4 mol / L.

[0031] In some embodiments of this disclosure, the plastic waste is polystyrene waste.

[0032] In some embodiments of this disclosure, polystyrene waste may be generated by any industrial, agricultural, or manufacturing process. In some embodiments of this disclosure, polystyrene waste may have any degree of polymerization and molecular weight.

[0033] This disclosure is illustrated by the following exemplary embodiments, but is not limited to these embodiments.

[0034] Example

[0035]

Materials and Methods

[0036] 1. Sources of polystyrene waste and other chemicals

[0037] The polystyrene waste (PS) used in this study was purchased from Cainiao Limited, a subsidiary of Beijing Normal University (Zhuhai, China)-Hong Kong Baptist University United International College. To investigate the effects of different amino acids on the activity of mealworms, we selected a series of amino acids according to the classification criteria for essential and non-essential amino acids. These amino acids were provided by BASF Biotechnology (Hefei) Co., Ltd. The amino acids used in the experiment included: glutamic acid (CAS 56-86-0, purity ≥99.5%), phenylalanine (Phe, CAS 63-91-2, purity ≥99.0%), tryptophan (Trp, CAS 73-22-3, purity ≥99.0%), glutamine (Gln, CAS 56-85-9, purity ≥99.5%), cysteine ​​hydrochloride (Cys, CAS 52-90-4, purity ≥98%), and valine (Val, CAS 72-18-4, purity ≥99.5%). In addition, as a control experiment, we also purchased monosodium glutamate (MSG) with a purity of ≥99% from Jinjiang Xianzhiwei Food Co., Ltd.

[0038] 2. Sources and rearing of mealworms

[0039] Mealworms were sourced from Yangjiang City, Guangdong Province. According to the supplier, these mealworms were fed wheat bran prior to delivery. Upon arrival at the laboratory, they were first fed wheat bran for 72 hours, followed by a 48-hour fasting period to minimize the impact of pre-experimental feeding history on the research results (see "Biodegradation of polylactic acid through resource recovery: a sustainable waste management approach for Tenebriomolitor larvae" published by Peng et al. in the *Journal of Hazardous Materials* (2021, Vol. 416, p. 125803)). Each experimental group contained approximately 2,200 mealworms, with a total weight of approximately 110 g (±0.04 g), and were housed in rectangular stainless steel containers measuring 27 cm × 20 cm × 4.8 cm. The experiments were conducted under controlled environmental conditions of 25 °C (±2 °C) and 55% (±5%) humidity.

[0040] Example 1 investigates the role of amino acids in reducing cannibalism and improving decomposition efficiency.

[0041] Under the above conditions, mealworms were reared to investigate the effects of different amino acids on the composition of the insect population and the role of different amino acids in promoting the decomposition of polystyrene by the insect population.

[0042] Figure 1 The results show that both essential amino acids (EAAs) and non-essential amino acids (NEAAs) have a significant effect on reducing cannibalism within mealworm populations. High levels of cannibalism are typically triggered by environmental stress or resource scarcity, leading to population weakness and reduced overall polystyrene decomposition capacity. Supplementing with amino acids to reduce cannibalism creates a low-stress environment, thereby stabilizing population size and allowing more mealworms to focus on polystyrene decomposition. This not only maintained their health during the experiment but also extended the duration of their active plastic decomposition.

[0043] 1. Population stability and continuous decomposition:

[0044] Particularly in the EAA-supplemented experimental group, the reduction in cannibalism decreased intra-population conflict, thus maintaining a stable and efficient population size throughout the polystyrene decomposition process. This stability means that a larger proportion of the population can continuously participate in the polystyrene decomposition process over time, significantly increasing the overall rate of plastic consumption. When mealworms are not required to deal with aggressive interactions, their energy and activity can be more fully utilized for polystyrene decomposition, thereby improving decomposition efficiency.

[0045] 2. Health and work ability:

[0046] Amino acids such as phenylalanine and tryptophan significantly reduced the mortality rate and cannibalism in mealworms. Healthy mealworms, avoiding the damage and stress caused by cannibalism, exhibited improved metabolic function, thereby continuously promoting the decomposition of polystyrene. This improved health directly translates into higher working efficiency for the mealworms. A healthy population with low mortality and no damage can continuously and efficiently consume polystyrene, maximizing the utilization rate of each mealworm during the decomposition process.

[0047] 3. Mechanism Analysis: Amino Acids and Stress Relief:

[0048] The ability of specific amino acids to alleviate stress and reduce aggressive behavior may contribute to improving polystyrene degradation. Essential amino acids (EAAs), such as phenylalanine, may reduce cannibalistic triggers by influencing physiological pathways associated with stress responses in mealworms. This reduction in cannibalistic tendencies helps to foster more cooperative and productive groups, allowing more mealworms to focus on plastic degradation. While non-essential amino acids (NEAAs) are slightly less effective than essential amino acids (EAAs) in increasing polystyrene degradation rates, they still reduce stress responses and cannibalistic behavior to some extent.

[0049] like Figure 1 The results indicate that amino acids play a dual role in enhancing polystyrene decomposition by mealworms: they not only improve nutrient intake but also directly maintain the health, stability, and cooperative behavior of mealworm populations. This supporting role is confirmed by a significant reduction in cannibalism, enabling a larger proportion of mealworms to participate continuously and efficiently in the polystyrene decomposition process. Therefore, both essential amino acids (EAAs) and non-essential amino acids (NEAAs) promote polystyrene decomposition, with EAAs showing a particularly significant promoting effect.

[0050] The enhanced polystyrene decomposition effect observed through EAA and NEAA supplementation primarily stems from an overall improvement in individual and population health, rather than solely from the nutritional value of amino acids. This mechanism offers promising insights for optimizing mealworm-mediated plastic decomposition conditions.

[0051] Example 2

[0052] To investigate the effects of amino acids on the decomposition of plastics by mealworms, three essential amino acids (phenylalanine, tryptophan, and valine), three non-essential amino acids (cysteine, glutamine, and glutamic acid), and the ionic form of glutamic acid (monosodium glutamate, MSG) were selected. In addition, two control groups were established: a polystyrene control group and a polystyrene + water group. Since water is required to prepare the amino acid solution, water was chosen as the control group.

[0053] The initial polystyrene cubes fed to the mealworms in the polystyrene group were approximately 3cm × 4cm × 1cm in size, each weighing 0.4g (±0.003g). Amino acid solutions with a concentration of 2mol / L were prepared based on the molecular weight of each amino acid. In all experimental groups, the solutions were sprayed evenly onto the surface of the polystyrene cubes three times daily. The average volume of solution sprayed each time was approximately 0.3875±0.0166mL (values ​​represent mean ± SD).

[0054] During the first ten days of the experiment, residual polystyrene, surviving and dead mealworms, and feces were collected daily and weighed using electronic analytical balances (Sartorius BS2202S, Germany; and Zhejiang Jiming Technology Co., Ltd. JM-3002C, China). To prevent larvae from consuming the carcasses, dead insects and molted skins were removed from the incubator after recording (Ding et al., 2024). Insects were separated from feces using a 30-mesh sieve. After ten days, the recording and weighing intervals were extended to every five days until all experimental groups consumed 0.4 g of polystyrene, marking the end of the experiment. After the experiment, the remaining mealworms were subjected to 48 hours of starvation to ensure complete digestion and metabolism of the polystyrene (Ding et al., 2024). The mealworms were then euthanized by freezing, and after all experiments were completed, they were microwave-dried at 50–60°C, ground into powder, and sealed for storage. Before animal acid analysis, samples were stored at room temperature in sealed containers (Jin et al., 2022). All experiments were repeated three times.

[0055] result:

[0056] The effects of feed treatment and time on the decomposition of polystyrene waste by mealworms

[0057] The rate of plastic decomposition reflects, to some extent, the effectiveness of mealworms in decomposing plastic. To explore this, a linear mixed-effects model (LMM) was used to analyze the effects of different amino acids, time, and their interactions on polystyrene decomposition (Table 2). The analysis showed that the estimated initial polystyrene mass, expressed as an intercept, was 0.3509, which was highly significant (p < 0.001). The coefficient for the essential amino acid (EAA) treatment was –0.1527 (p < 0.001), indicating a significant reduction in residual polystyrene mass, suggesting that these amino acids significantly enhanced the mealworms' ability to decompose polystyrene. For the non-essential amino acid (NEAA) treatment group, the coefficient was -0.1039 (p < 0.001), which also promoted polystyrene decomposition, but its effect was weaker than that of the essential amino acid (EAA) treatment group. In the control group (NonAA), both the polystyrene-control group and the polystyrene-water treatment group showed a reduction in polystyrene mass, with a coefficient of –0.08142 (p < 0.005). This indicates that mealworms can still biodegrade polystyrene without amino acid treatment, but their decomposition effect is more limited than that of the group treated with added amino acids.

[0058] Besides the necessity of amino acids, the abundance of amino acids in mealworms also affects the decomposition rate of polystyrene. For example... Figure 2 As shown, glutamic acid (Glu), the most abundant amino acid in mealworm protein, significantly increased the decomposition rate. Conversely, cysteine ​​(Cys), the least abundant non-essential amino acid, did not significantly increase the decomposition rate when added to polystyrene.

[0059] Time (days) also had a significant effect on polystyrene decomposition, with a coefficient of –0.0157 (p<0.001), indicating that the quality of polystyrene in all treatment groups continued to decline over time.

[0060] However, subtle differences existed in the interaction between time and amino acid type. For the essential amino acid (EAA) group, the interaction with time was close to significant but not statistically significant (0.0035, p < 0.1), suggesting that the degradation rate of essential amino acids may slow down over time, although this change was not significant. The interaction between NEAA and the control group was not significant, indicating that time did not significantly alter the degradation rate of these treatments.

[0061] In this model, R²(R²m) equals R²(R²c) [R²(R²m) = R²(R²c) = 0.635], indicating that the fixed effects fully explain the variability of the data, while the random effects do not provide additional explanatory power. Effect size analysis showed that time had the greatest effect (0.57, 95% CI: [0.52, 1.00]), followed by amino acid type (0.12, 95% CI: [0.07, 1.00]), while the interaction between time and amino acid type had the smallest effect (0.01, 95% CI: [0.00, 1.00]).

[0062] In summary, Figure 2 The experimental results show that EAA significantly enhanced the ability of mealworms to decompose polystyrene, while NEAA also contributed, albeit to a weaker extent. Notably, the amino acid content in mealworms was strongly correlated with polystyrene decomposition; higher amino acid abundance indirectly promoted faster decomposition. Time was a key factor in the sustained promotion of polystyrene decomposition, although the interaction between time and amino acid type had a relatively small impact.

[0063] Table 1. Changes in polystyrene mass over time under different treatment conditions.

[0064]

[0065]

[0066] Table 2 Fixed effects and model statistics of the linear mixed effects model (LMM) based on day fitting.

[0067]

[0068] In Table 2, the intercept is the baseline estimate of the model, representing the mass estimate of polystyrene (PS) at the initial stage of the experiment without any treatment, and its value is 0.3509.

[0069] The significance of this value (p < 0.001) indicates that the model's prediction of the initial experimental quality is highly reliable and can be used as a benchmark for subsequent comparisons. The intercept is significant in providing a reference benchmark for quantifying the impact of different treatments (e.g., amino acid treatment) on PS quality.

[0070] The estimated values ​​are calculated using a statistical model (linear mixed-effects model, LMM), rather than being directly measured experimentally.

[0071] The reason for using estimated values ​​is that the experiment involved multiple variables (such as amino acid type, time, interaction effects, etc.), and direct measurement could not accurately distinguish the independent effects of each variable. This model can eliminate other confounding factors through data fitting and analysis, thereby accurately estimating the specific effects of variables. For example, the estimated value of EAA is -0.1527, indicating that after excluding other effects, EAA treatment reduced PS quality by an average of 0.1527. This makes the results more scientific and provides a reliable theoretical basis for existing techniques.

[0072] The Day value in the table represents the time variable, indicating the effect of time on PS decomposition. Taking EAA as an example, its estimated value is -0.0157, indicating that the mass of polystyrene decreases by an average of 0.0157 per day over time, and this effect is highly significant (p < 0.001). The experimental results show that time is a crucial factor promoting PS decomposition.

[0073] The data in Table 2 show that EAA is superior to NEAA, and NEAA is superior to nonAA. A comparative analysis of the estimated effects of EAA, NEAA, and nonAA treatments is provided below:

[0074] The estimated value for EAA (essential amino acids) was -0.1527 (p < 0.001), indicating that EAA treatment significantly promoted PS degradation. The estimated value for NEAA (non-essential amino acids) was -0.1039, which was weaker than that of EAA (p < 0.001). The estimated value for nonAA (control group) was -0.0814, which was the weakest (p < 0.05).

[0075] The above data clearly show that the addition of amino acids can significantly enhance PS decomposition, with EAA showing the best effect, which is consistent with the specific amino acid selection technology advantages emphasized in this application.

[0076] The items marked "Day" in the table (e.g., EAA:Day) represent the interaction between time and other variables, i.e., whether time significantly alters the decomposition rate of each treatment group. In this example, the estimated value of EAA:Day is 0.0035 (p = 0.0854). The decomposition rate of the EAA treatment may slow down slightly over time (close to significant but not reaching the statistical significance criterion), but this change is not significant, and the overall effect remains good.

[0077] Estimated values ​​for NEAA: Day and nonAA: Day values ​​were close to 0 (p > 0.05), indicating that time had almost no significant effect on the degradation rate of NEAA and the control group. This suggests that time itself is an important driver of PS degradation, but its interaction with treatment type is weak, indicating that the choice of amino acid type plays a dominant role in the degradation effect.

[0078] The results showed that the addition of amino acids, especially the essential amino acid EAA, significantly promoted the decomposition of polystyrene, and the decomposition effect further increased over time. The data in the table provide strong quantitative support for the technology presented in this application, confirming the superiority of specific amino acids and the scientific effectiveness of the treatment method.

[0079] Table 3: Overall performance and confidence intervals of the statistical model

[0080] <![CDATA[R 2 Value <![CDATA[Marginal R 2 (R 2 m)]]> 0.6364 - <![CDATA[Condition R 2 (R 2 c)]]> 0.6364 - <![CDATA[Effect size (Eta 2 )]]> Feed type 0.12 [0.07,1.00] sky 0.54 [0.49,1.00] type 0.01 [0.00,1.00]

[0081] The inventors used a linear mixed-effects model (LMM) to analyze the main factors affecting the decomposition of polystyrene and extracted key information from the statistical model in Table 3. The following is a detailed explanation of each statistical statistic in the table.

[0082] 1. R 2 Value (coefficient of determination)

[0083] The R² value is an important indicator for measuring the extent to which a model explains the variation in data. It represents the proportion of variation in the target variable (polystyrene quality in this study) that the model can explain.

[0084] -Marginal R 2 (R 2 m = 0.6364

[0085] This value indicates that fixed effects in the model (such as different feed types and experimental times) can explain 63.47% of the polystyrene quality variation. This means that these variables in the model are better able to explain the decomposition rate.

[0086] -Condition R2 (R2c = 0.6364)

[0087] This value indicates that the fixed and random effects in the model explain 63.47% of the overall variation. Since the explanatory power of the fixed and random effects is consistent (R²m = R²c), it can be inferred that random effects (such as individual differences) have a relatively small impact on the results of this study, which are primarily driven by the fixed effects.

[0088] 2. Effect size (Eta) 2 )

[0089] Effect size is used to quantify the contribution of each factor to the target variable (polystyrene decomposition rate), and helps to understand the relative importance of each factor.

[0090] - Feed type (Eta2 = 0.12)

[0091] This indicates that different feed types (essential amino acids, non-essential amino acids, and control) affect the polystyrene decomposition rate by approximately 12%. This effect size suggests that feed type has a significant impact on the decomposition process, but the impact is relatively small compared to time.

[0092] -Time (Eta) 2 =0.54)

[0093] Time had the greatest effect on polystyrene decomposition, explaining 57% of the variation. Confidence intervals [0.52, 1.00] indicate that the effect of time on the decomposition rate is highly significant and statistically consistent.

[0094] - Interaction between feed type and time (Eta2 = 0.01)

[0095] The interaction between feed type and time explained only 1% of the variation, indicating that the interaction has a very small effect on polystyrene decomposition.

[0096] The confidence interval is [0.00, 1.00], indicating that although there may be an interaction, its actual effect is extremely small.

[0097] Summarize

[0098] The R2m and R2c values ​​are consistent (both 0.6364), indicating that our model effectively explains the changes in polystyrene decomposition, and that the fixation effect plays a major role in the model.

[0099] - Time has the greatest impact on the decomposition rate, explaining 54% of the variance, indicating its dominant role in the decomposition process.

[0100] - Feed type also had a significant impact (12%), but its impact was much smaller than that of time.

[0101] - The interaction between type and time has a very small effect, explaining only 1% of the variance, and shows a weak impact in practical applications.

[0102] This embodiment demonstrates that free amino acids alone can increase the rate of polystyrene biodegradation by mealworms.

Claims

1. A method for decomposing polystyrene waste, characterized in that, include: a) Treating mealworms with free amino acids; as well as b) Using treated mealworms to decompose the polystyrene waste.

2. A method for decomposing polystyrene waste, characterized in that, include: a) Contact the free amino acids with the polystyrene waste; b) Using mealworms to decompose polystyrene waste that has come into contact with the free amino acids.

3. The method according to claim 1 or 2, characterized in that, in, The free amino acids are selected from essential amino acids, non-essential amino acids and their salts.

4. The method according to claim 3, characterized in that, in, The essential amino acids are selected from phenylalanine, tryptophan, valine and their salts.

5. The method according to claim 3, characterized in that, in, The non-essential amino acids are selected from cysteine, glutamine, glutamic acid and their salts.

6. The method according to claim 1, characterized in that, in, The free amino acids are added to the mealworm feed in the form of solid powder or solution.

7. The method according to claim 2, characterized in that, in, The free amino acids are sprayed onto the polystyrene waste in the form of an aqueous solution with a concentration of 0.5 mol / L to 10 mol / L.

8. The method according to claim 7, characterized in that, in, The free amino acids are sprayed onto the polystyrene waste in the form of an aqueous solution with a concentration of 1 mol / L to 5 mol / L.

Images