Biodegradability Of Bioplastics Research Articles

Advances in microbial exoenzymes bioengineering for improvement of bioplastics degradation

Plastic pollution has become a major global concern, posing numerous challenges for the environment and wildlife. Most conventional ways of plastics degradation are inefficient and cause great damage to ecosystems. The development of biodegradable plastics offers a promising solution for waste management. These plastics are designed to break down under various conditions, opening up new possibilities to mitigate the negative impact of traditional plastics. Microbes, including bacteria and fungi, play a crucial role in the degradation of bioplastics by producing and secreting extracellular enzymes, such as cutinase, lipases, and proteases. However, these microbial enzymes are sensitive to extreme environmental conditions, such as temperature and acidity, affecting their functions and stability. To address these challenges, scientists have employed protein engineering and immobilization techniques to enhance enzyme stability and predict protein structures. Strategies such as improving enzyme and substrate interaction, increasing enzyme thermostability, reinforcing the bonding between the active site of the enzyme and substrate, and refining enzyme activity are being utilized to boost enzyme immobilization and functionality. Recently, bioengineering through gene cloning and expression in potential microorganisms, has revolutionized the biodegradation of bioplastics. This review aimed to discuss the most recent protein engineering strategies for modifying bioplastic-degrading enzymes in terms of stability and functionality, including enzyme thermostability enhancement, reinforcing the substrate binding to the enzyme active site, refining with other enzymes, and improvement of enzyme surface and substrate action. Additionally, discovered bioplastic-degrading exoenzymes by metagenomics techniques were emphasized.

Keratin-based bioplastics extracted from chicken feathers: Effect of chitosan concentration on the structural, chemical bonding, and mechanical properties of bioplastics

Keratin was synthesized by alkaline hydrolysis from chicken feathers and then continue by casting method for producing bioplastics with additional various amounts of chitosan as a filler, polyvinyl alcohol (PVA) and glycerol as a plasticizer. The main purpose is analysis the effect of chitosan on the structural properties using quantitative analysis of X-ray diffraction (XRD) spectra, chemical bonding by Fourier transforms infrared (FTIR) spectra, and mechanical properties by texture analyser to the keratin-based bioplastics. Biodegradation of bioplastics was analysed from the loss of weight by burying in the soil. It's found that, the additional of chitosan (0 %, 2 %, 5 %, and 8 %) increased the crystallinity of bioplastics by 11.83 %, 11.12 %, 18.99 %, and 17.03 %, respectively, but decreasing tensile strength and elasticity of bioplastics. Degradation of bioplastic keratin-based shows that the addition of chitosan can reduce the degradation time which is directly proportional to the loss of CO bonds. The highest degradation rate is 89.29 % in 49 days for keratin-based bioplastics with 8 % chitosan, indicated that high potential for future production.

Characteristics of bioplastics prepared from cassava starch reinforced with banana bunch cellulose at various concentrations

Human activities have led to the pollution of the environment through the accumulation of plastic waste. Since plastics are resistant to decomposition resulting negative impact on the environment, there is a pressing need for the development of bioplastics. Starch is a such of natural material that can be used made of bioplastics. However, bioplastics from starch were needed to improve starch-based bioplastics due to their brittle properties. To address this issue, researchers focused on enhancing starch-based bioplastics by incorporating cellulose, particularly derived from kepok banana bunch fibers and cassava starch variety UJ3. The production process involved adding varying concentrations of 2.5, 5, 7.5, and 10 % (wt) of kepok banana bunch cellulose. The findings indicated that increasing cellulose concentration improved the characteristics of the bioplastic materials significantly. The results showed that the addition of cellulose concentration improved the mechanical properties, water vapor absorption, and biodegradability of bioplastics. With an optimal cellulose concentration level at 7.5%, remarkable enhancements in tensile strength (from 2.92 to 6.72 MPa), reduced elongation percentage (from 20.89 to 4.06%), increased Young’s Modulus values (from 13.98 to 172.52 MPa), decreased water vapor absorption rate (from 15,93 to 11,48%), and enhanced bio-degradability rating (from 29,81 to 50,69%) were observed.

Ecotoxicological Impact of Bioplastics Biodegradation: A Comprehensive Review

The emergence of bioplastics presents a promising solution to the environmental impact of the plastics industry. Bioplastics are engineered to degrade in aquatic or soil environments. However, not all bioplastics are completely biodegradable, and some, like petrochemical-based plastics, may contribute to plastic pollution. The biodegradability of bioplastics is significantly different in different environmental conditions such as soil, marine, and composting environments. At the same time, bioplastics produced from natural resources contain a mixture of known and unknown materials and show 32% cytotoxicity, 42% oxidative stress, 67% baseline toxicity, and 23% antiandrogenicity in bioassays. The extensive biodegradation of bioplastics in soil can also change the soil nutrients, leading to eutrophication or stunted plant growth. However, many concerns have arisen, according to which bioplastics may not be an alternative option for global plastic pollution in the long run, and limited studies focus on this scenario. This review aims to provide a comprehensive overview of the biodegradation of bioplastics in different environmental conditions and by microorganisms and their ecotoxicological impacts on soil and marine health. In conclusion, while bioplastics have the potential to be a sustainable alternative to conventional plastics, it is essential to address concerns regarding their complete biodegradability and toxicity. Therefore, sustainable methods must be used for their production and biodegradation to ensure a positive impact on the environment.

A Review on Biodegradation of Bioplastics in Different Environmental Conditions

A Review on Biodegradation of Bioplastics in Different Environmental Conditions

Correlation of Two Biodegradability Indices of PLA-Based Polymers under Thermophilic Aerobic Laboratory Conditions

The biodegradation of bioplastics is a topic of interest worldwide. This work aims to measure the biodegradability of five polylactic acid (PLA)-based bioplastics under aerobic, thermophilic laboratory conditions and correlate their weight loss with their CO2 generation over a 3-month period, as both are considered indexes of biodegradation. The experimental design was based on the simulation of composting conditions by placing the bioplastic samples mixed with compost in sealed glass vessels that were regularly opened. The results showed significant variability in biodegradation, as dry weight losses ranged from 15.1–99.7%, while CO2 generation ranged from 9.2–14.9 g C–CO2/kg dry mixture (bioplastic + inoculum) depending on the sample. Moreover, no significant correlation between the weight losses and the gross CO2 production was calculated (p = 0.656), indicating the importance of carefully selecting the methods to assess biodegradation potential. This lack of correlation also reveals that different pathways are likely involved during the biodegradation of bioplastics and that the weight loss alone cannot indicate the conversion of solid C to CO2. This work proposes the need to develop an optimal degradation index for bioplastics that would provide a better understanding of their biodegradability in composting reactors. This index should combine dry weight loss and CO2 generation to assess the biodegradation of bioplastics with high confidence.

Bioplastics: Environment-friendly materials and their production technologies

Objective: To analyze the recent contributions of bioplastics in addressing environmental problems caused by plastic pollution. Design/Methodology/Approach: A literature review was carried out on the definitions of plastics and bioplastics, the sources of raw materials, processing technologies and methods to assess biodegradation. Current practices for final disposal and/or reuse were also examined. Special emphasis was placed on polylactic acid (PLA), one of the most widely used biodegradable materials today. Results: Over the years, there have been significant developments in the definitions of plastics and bioplastics, as well as in the sources of raw materials and processing technologies used to create final plastic products. By using bioplastics instead of conventional plastics, it is possible to reduce the dependence on petroleum and mitigate the pollution associated with plastic production and disposal. Furthermore, the enhanced biodegradability of bioplastics ensures that they break down more readily in natural environments, reducing the accumulation of plastic waste and its detrimental impact on ecosystems. The production of bioplastics using plant fibers, biological materials, and polymeric waste materials presents an opportunity for integration into the productive activities of the agro-industrial sector. This integration brings several benefits and synergies between agriculture and industry. Study limitations/Implications: We provide a report based on the literature. Findings/Conclusions: there is a notable current trend in the utilization of bioplastics as a viable substitute for conventional plastics. In order to assess the biodegradability and compostability of these materials, specific testing and certification standards have been established by reputable organizations. These standards serve as a reliable framework for evaluating the environmental impact and degradation characteristics of bioplastics. By adhering to these guidelines, manufacturers can ensure that their bioplastic products meet the necessary criteria for sustainable use.

Anaerobic Biodegradability of Commercial Bioplastic Products: Systematic Bibliographic Analysis and Critical Assessment of the Latest Advances.

Bioplastics have entered everyday life as a potential sustainable substitute for commodity plastics. However, still further progress should be made to clarify their degradation behavior under controlled and uncontrolled conditions. The wide array of biopolymers and commercial blends available make predicting the biodegradation degree and kinetics quite a complex issue that requires specific knowledge of the multiple factors affecting the degradation process. This paper summarizes the main scientific literature on anaerobic digestion of biodegradable plastics through a general bibliographic analysis and a more detailed discussion of specific results from relevant experimental studies. The critical analysis of literature data initially included 275 scientific references, which were then screened for duplication/pertinence/relevance. The screened references were analyzed to derive some general features of the research profile, trends, and evolution in the field of anaerobic biodegradation of bioplastics. The second stage of the analysis involved extracting detailed results about bioplastic degradability under anaerobic conditions by screening analytical and performance data on biodegradation performance for different types of bioplastic products and different anaerobic biodegradation conditions, with a particular emphasis on the most recent data. A critical overview of existing biopolymers is presented, along with their properties and degradation mechanisms and the operating parameters influencing/enhancing the degradation process under anaerobic conditions.

Bioplastic from Cassava peel and eggshell waste

The accumulation of plastic waste and excessive use of plastic is a common environmental issue in Indonesia. Plastics are synthetic polymers that are stable, water-resistant, light, flexible, and firm but very difficult to break down by microorganisms. Decomposition of plastic waste by burning can cause other environmental issues and, during the combustion process can produce dioxin compounds that are harmful to health. An available and affordable alternative to reduce the use of plastic is by using bioplastics. Bioplastics are plastics made from natural materials that microorganisms can break down, so they are more environmentally friendly than commercial plastics. Generally, the main ingredients for making bioplastics are starch or chitosan. The source of starch used in this project comes from cassava peel waste. In this project, researchers also utilize waste from chicken eggshells. The function of adding eggshell waste is to give biodegradable plastic complex characteristics. The ratio between cassava peel and eggshell used was 1:0, 1:1, 1:3, and 1:5. With a 1:1 ratio is the most optimal. The addition of eggshells with the correct ratio (1:1) increased the ability of biodegradation of bioplastics. The results of the Tensile Strength Test of Bioplastic Samples with a ratio of 1:0, 1:1, 1:3, and 1:5 are 9.2 x10-3kgf/cm2, 4.4 x10-3 kgf/cm2, 2 x10-3 kgf/cm2, and 2 x10-3 kgf/cm2.©2022 JNSMR UIN Walisongo. All rights reserved.

KARAKTERISTIK DAYA SERAP AIR DAN BIODEGRADABILITAS PADA BIOPLASTIK BERBASIS PATI SINGKONG DENGAN PENAMBAHAN POLYVINYL ALCOHOL

The increasing of conventional plastics has become a major concern because it is the largest supplier of waste problems. In addition, conventional plastics also produce petroleum which is a non-renewable material. Bioplastics are substitutes for conventional plastics with renewable materials and easily decomposed by microorganisms into water and carbon dioxide. Starch-based bioplastics have weaknesses such as low mechanical characteristics compared to conventional plastics, but these problems can be overcome by addingfillers such as ZnO, plasticizers, and additives such as PVOH to improve the characteristics of bioplastics. This type of bioplastic is made by mixing cassava starch with 15% w/w, glycerol, ZnO filler, and PVOH BP-05 with a concentration of 7% w/w into water with continuous heating and stirring. The results showed that bioplastics with ZnO filler had good water absorption but had lower biodegradability. The addition of PVOH increases the biodegradability of bioplastics with ZnO filler. Bioplastic with the addition of ZnO filler and PVOH BP-05 with a concentration of 7% w/w resulted in good water absorption with a water absorption value of 73.47%, while biodegradability produced the best value with a value of 73.03%. Decomposition of bioplastics in general will decompose for six months compared to conventional plastics which can decompose for hundreds of years. Therefore, bioplastics can be a major highlight in replacing conventional plastics.

A Comprehensive Study on Starch Nanoparticle Potential as a Reinforcing Material in Bioplastic.

Starch can be found in the stems, roots, fruits, and seeds of plants such as sweet potato, cassava, corn, potato, and many more. In addition to its original form, starch can be modified by reducing its size. Starch nanoparticles have a small size and large active surface area, making them suitable for use as fillers or as a reinforcing material in bioplastics. The aim of reinforcing material is to improve the characteristics of bioplastics. This literature study aims to provide in-depth information on the potential use of starch nanoparticles as a reinforcing material in bioplastic packaging. This study also reviews starch size reduction methods including acid hydrolysis, nanoprecipitation, milling, and others; characteristics of the nano-starch particle; and methods to produce bioplastic and its characteristics. The use of starch nanoparticles as a reinforcing material can increase tensile strength, reduce water vapor and oxygen permeability, and increase the biodegradability of bioplastics. However, the use of starch nanoparticles as a reinforcing material for bioplastic packaging still encounters obstacles in its commercialization efforts, due to high production costs and ineffectiveness.

Utilization of Japanese Seeds and Soybean Seeds as Raw Materials for Making Flour

The accumulation of plastic waste and excessive use of plastic is a common environmental issue in Indonesia. Plastics are synthetic polymers that are stable, water-resistant, light, flexible, and strong, but are very difficult to be broken down by microorganisms. Decomposition of plastic waste by burning can cause other environmental issues and during the combustion process can produce dioxin compounds that are harmful to health. An available and affordable alternative to reduce the use of plastic is by using bioplastics. Bioplastics are plastics made from natural materials that can be broken down by microorganisms, so they are more environmentally friendly than commercial plastics. Generally, the main ingredients of making bioplastics are starch or chitosan. The source of starch used in this project comes from cassava peel waste. In this project, researchers also utilize waste from chicken egg-shells. The function of adding eggshell waste is to give biodegradable plastic hard characteristics. The ratio between cassava peel and egg shell used was 1:0, 1:1, 1:3, and 1:5. With a 1:1 ratio is the most optimal. the addition of egg shells with the right ratio (1:1) made the ability of biodegradation of bioplastics to increase. The results of the Tensile Strength Test of Bioplastic Samples with a ratio of 1:0, 1:1, 1:3 and 1:5 are 9.2 x10-3 kgf/cm2, 4.4 x10-3 kgf/cm2, 2 x10-3 kgf/cm2 and 2 x10 -3 kgf/cm2.

Simultaneous monitoring of each component on degradation of blended bioplastic using gas chromatography-mass spectrometry

The increasing interest in bioplastics, with regard to future environmental issues, has rendered research on bioplastic biodegradation highly important. However, only a few tools directly monitor the degradation of bioplastics without measuring the levels of gaseous products, such as carbon dioxide. Classical nonquantitative methods, such as clear zone tests on solid plates, and less-sensitive weight-loss experiments in liquid media measured using a precision scale, are still employed to screen the microbial players associated with bioplastic degradation and monitor the biodegradation rates. However, the simultaneous monitoring of the degradation of each component of blended bioplastics has not been previously reported. In the present study, to provide information regarding the degradation rates and compositional changes of different bioplastics in a blend in a time-dependent manner, we simultaneously monitored and quantified the degradation of four bioplastics, polyhydroxybutyrate (PHB), polybutylene succinate (PBS), polycaprolactone (PCL), and poly(butylene adipate-co-terephthalate) (PBAT), by Bacillus sp. JY36 using gas chromatography-mass spectrometry (GC-MS) analysis after fatty acid methyl ester (FAME) derivatization. Our results demonstrate the feasibility of using the GC-MS-based method described here to obtain comprehensive data regarding blended bioplastics and their degradation. Moreover, our findings indicate that this method may support classical analytic tools for assessing bioplastic biodegradation.

The effect of ZnO (zinc oxide) and glycerol concentrations on the mechanical properties of bioplastics made from Canna tuber (Canna edulis) starch

The problem of plastic waste in Indonesia is increasingly worrying due to its long degradation duration. Bioplastics made from starch are easily degradable in nature and have a lower contribution to environmental pollution. This study aimed to determine the effect of ZnO and glycerol additions on the thickness, tensile strength, elongation, Young’s Modulus, water absorption, and biodegradation of bioplastics. The results indicate that adding ZnO and glycerol has significant effects on thickness, tensile strength, elongation, Young’s Modulus, water absorption, and biodegradation. A high concentration of ZnO and glycerol was parallel to an increase in the thickness of bioplastic. A high ZnO concentration and low glycerol concentration increases the tensile strength and Young’s Modulus, but decreases the water absorption. Glycerol at high concentration and ZnO at low concentration increases the elongation. The addition of ZnO in a small amount positively affects the biodegradation of bioplastics.

Valorization of poly-\u03b2-hydroxybutyrate (PHB)-based bioplastic waste in anaerobic digesters of food waste for bioenergy generation: reactor performance, microbial community analysis, and bioplastic biodegradation

This study aims to investigate the significance and biodegradation pathways of PHB-based bioplastic in anaerobic digesters treating food waste, where the reactor performance of changed methane generation, bioplastic biodegradation efficiency, and bioinformatic analysis of functional microbes were emphasized. The results showed that PHB-based plastic film could be partially biodegraded in the food waste digester, and a bioaugmentation use of Alcaligenes Faecalis (AF) and Bacillus Megaterium (BM) was beneficial to largely accelerate the degradation process through a beneficial shift of both the functional bacterial and archaeal species. Microbial community analysis indicated that the major bacterial species belonged to genera Candidatus_Cloacimonas, Rikenellaceae, and Defluviitoga, while the dominant methanogenic archaeal species belonged to genera Methanomassiliicoccus, Methanosarcina, and Methanosaeta. Bioplastic biodegradation analysis suggested that the optimal fractions of AF and BM for PHB-based plastic degradation were 50%AF and 75%BM, respectively, which deserves further optimization and scale-up validation. The finding of this study would contribute to the combined management of PHB-based bioplastic with food waste for clean energy recovery and a greener environment.

Biodegradation Kinetic Study of Cassava & Tannia Starch-Based Bioplastics as Green Material in Various Media

The rate of biodegradation of cassava – tannia starch bioplastic in various media was evaluated. Bioplastic degradation profile for a period of 4 weeks was seen following the Hills Equation where the speed of bioplastic biodegradation in sand media had higher yields than farm soil and compost media with the value up to 98.84 %. This is also proven by measuring the rate of degradation reaction using a first order reaction rate, where the value of the constant rate of reaction from bioplastics in sand is a little bit higher compared to farm soil and compost media (0.77647, 0.67133, and 0.15779 week-1, respectively). According to SEM pictures, there were numerous bacteria (either aerobic or anaerobic) and fungal species on the bioplastic surface, which have a role in the biodegradability of the polymer in bioplastics. The FTIR spectra of bioplastic biodegradation showed a decrease in the peak at 3400 - 3200 cm-1, and loss of the peak was present in the control at 2900 cm-1 which showed a breakdown of the polymer chain in the bioplastic especially in the O-H and C-H bonds, respectively. It can be concluded that farm soil and sand are the most optimal media in the bioplastic biodegradation process, while compost has potential but its maturity must be considered.

Manifesting sustainable food packaging from biodegradable materials: A review

AbstractThe application of petroleum‐based plastic worldwide causes the accumulation of plastic waste in landfills, which negatively impacts the environment such as reducing the quality of soil and may cause soil and water pollution. Most of the conventional plastics used have a long lifespan to completely degrade. According to the rapid development of the food industry, plastic packaging plays a key role in food quality and safety, thus making it a major role in controlling the food security system. The alternative use of plastic sources from biopolymers is one of the methods to support environmental sustainability actions. This review provides an overview of studies on principles and challenges of sustainable packaging including different types of biopolymer compounds properties and biodegradability of bioplastics in soil by microorganisms. The biopolymers composition in biodegradable plastic is important in designing better mechanical, physical, and barrier properties during degradation by microorganisms and application in food industries.

Towards monitoring biodegradation of starch-based bioplastic in anaerobic condition: Finding a proper kinetic model

Bioplastic biodegradation showed varying behavior during the process of biodegradation. The First-order and Gompertz models are the most prevalent models for monitoring biodegradation in an anaerobic digestion (AD) process, which do not suit adequately bioplastics fermentation modeling. This research aimed at studying the kinetics of methane production during AD of starch-based bioplastic by using a large library of non-linear regressions (NLRs) and an artificial neural network (ANN). Although 26 NLR models (25 were outlined in the AD literature + 1 modified by authors) have been analyzed, 9 of them were proper predictors for the whole AD process for methane production. In the end M9, which has been proposed by authors, was selected owing to the simplicity of regression as well as good statistical criteria. Moreover, MLP-ANN could outperform the NLR model and has been selected as the superior model that can define the kinetics of bioplastic AD.

Bioplastic composed of starch and micro-cellulose from waste mango: mechanical properties and biodegradation

Waste mango was used to obtain starch and micro-cellulose for the production of bioplastic. Three different formulations were made: positive control or cotyledon starch/glycerol; SC1 or cotyledon starch/glycerol and cellulose at 0.1% and SC5 or cotyledon starch/glycerol and cellulose at 0.5% w/w. The bioplastics were mechanically analyzed (tensile strength, elongation and Young´s modulus) and, aerobic biodegradation analysis was realized with a standard test method based on the amount of material carbon converted to CO2. The mechanical tests indicated that with the addition of cellulose, the bioplastics improved their mechanical properties. The biodegradation at 30 days showed 93 and 94% for SC1 and SC5. Therefore, the biodegradation of bioplastics depends on both, the addition of cellulose and the environment where they are placed (e.g., soil characteristics: pH level, C:N ratio, moisture). These bioplastics offer new opportunities for fast degrading biomaterials in agricultural applications (padding and protection bags).

Biodegradation of bioplastics under aerobic and anaerobic aqueous conditions: Kinetics, carbon fate and particle size effect

The biodegradation of PHB, PHBV, PBS, PBAT, PCL, PLA, and a PLA-PCL blend was compared under aerobic and anaerobic aqueous conditions assessing biodegradation kinetics, extent, carbon fate and particle size influence (in the range of 100–1000 µm). Under standard test conditions, PHB and PBHV were biodegraded anaerobically (83.9 ± 1.3% and 81.2 ± 1.7%, respectively) in 77 days or aerobically (83.0 ± 1.6% and 87.4 ± 7.5%) in 117 days, while PCL was only biodegraded (77.6 ± 2.4%) aerobically in 177 days. Apparent biomass growth accounted for 10 to 30.5% of the total initial carbon depending on the bioplastic and condition. Maximum aerobic and anaerobic biodegradation rates were improved up to 331 and 405%, respectively, at the lowest particle size tested (100–250 µm). This study highlights the usefulness of analysing biodegradation kinetics and carbon fate to improve both the development and testing of biodegradable materials, and waste treatments in the context of a circular bioeconomy.