Degradation of Bioplastics in Soil and Their Degradation Effects on Environmental Microorganisms

Degradation of three kinds of bioplastics and their effects on microbial biomass and microbial diversity in soil environment were analyzed. The degradation rate of bioplastic in soil was closely related to the main components in the bioplastics. Poly (butylene succinate)-starch (PBS-starch) and poly (butylene succinate) (PBS) were degraded by 1% to 7% after 28 days in a soil with an initial bacterial biomass of 1.4 × 109 cells/g-soil, however poly lactic acid (PLA) was not degraded in the soil after 28 days. When the powdered-bioplastics were examined for the degradation in the soil, PBS-starch also showed the highest degradability (24.4% degradation after 28 days), and the similar results were obtained in the case of long-term degradation experiment (2 years). To investigate the effect of bacterial biomass in soil on biodegradability of bioplastics, PBS-starch was buried in three kinds of soils differing in bacterial biomass (7.5 × 106, 7.5 × 107, and 7.5 × 108 cells/g-soil). The rate of bioplastic degradation was enhanced accompanied with an increase of the bacterial biomass in soil. 16S rDNA PCR-DGGE analysis indicated that the bacterial diversity in the soil was not affected by the degradation of bioplastics. Moreover, the degradation of bioplastic did not affect the nitrogen circulation activity in the soil.

3D Printing of Polylactic Acid Bioplastic–Carbon Fibres and Twisted Kevlar Composites Through Coextrusion Using Fused Deposition Modeling

Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechanical properties which reduced its usability as a functional prototype in a real-world application.In the present study,two PLA composites are created through coextruded with 3K carbon fibres and twisted Kevlar string(as core fibre)to form a fibre reinforced parts(FRP).The mechanical strength of printed parts was examined using ASTM D638 standard with a strain rate of 1 mm/min.It has been demonstrated that the FRPs coextruded with 3K carbon fibres had achieved significant improvement in Young’s modulus(+180.6%,9.205 GPa),ultimate tensile strength(+175.3%,103 MPa)and maximum tensile strain(+21.6%,1.833%).Although the Young’s modulus of Kevlar FRP was found to be similar to as compared to unreinforced PLA(~3.29 GPa),it has gained significant increment in terms of maximum tensile strain(+179.7%,104.64 MPa),and maximum tensile strain(+257%,5.384%).Thus,this study revealed two unique composite materials,in which the 3K carbon FRP can offer stiff and high strength structure while Kevlar FRP offers similar strength but at a higher elasticity.

Influence of Weather and Purity of Plasticizer on Degradation of Cassava Starch Bioplastics in Natural Environmental Conditions

The threat posed by plastics to the environment has prompted the development of bioplastics. Starch plasticized by glycerol is a key renewable resource in the production of high-quality bioplastics. Previous studies have availed information on the mechanical quality of starch-based bioplastics however there is limited information about their degradation pattern in the natural environment which this research presents. Bioplastics were buried in holes in loam sandy soil and weekly photographic data and weight were collected to reveal the effect of degradation. Weather parameters of rainfall, temperature, relative humidity, sunshine intensity and sunshine hours were recorded to establish influence of weather on degradation. A control set up in the laboratory was used to compare the results. Over time the tests revealed that as the hydrophilic enzymes break down the bioplastic, its weight initially increases (up to 87%) due to absorption of moisture and after saturation, the bioplastic is disintegrated which initiates decomposition and the bioplastic weight is steadily reduced. Degradation was further enhanced by invasion of soil organisms like worms, termites among other soil microbes. Rainfall (r = 0.857) increased the moisture in the soil which initially increased the weight of the bioplastic up to a point when the hydrophilic enzymes set into breakdown the bioplastic then the weight started to drop. This was the same case for relative humidity (r = ﹣0.04) however;the sunlight intensity (r = 515) and hours of illumination indirectly affect the process by influencing microbial activity. An increase in the sunshine intensity increased the activity of soil organisms up to a point beyond which increased exposure caused the organisms to burrow deeper in the soil. Increase in microbial activity increased the rate of degradation of the buried bioplastics which took five to ten weeks to fully decompose (98.3%). The reduced time of degradation means that starch-based bioplastics have a high potential as sustainable substitute for petroleum-based plastics.

Carbon Metabolism and Bioplastic Production by Halophilic Archaea

1 Introduction Haloarchaea represents a distinct group of Archaea that typically inhabits hypersaline environments,such as salt lakes and sea salterns.They are easy to culture and many haloarchaea are genetically tractable,hence they are excellent model systems for research of archaeal genetics,

A Methodological Outlook on Bioplastics from Renewable Resources

Bio plastics products have a rapid growing demand and market across the globe. Polymers synthesized from renewable resources have gained immense popularity, in numerous applications ranging from films, bottles, food packaging, drug delivery, bags to agriculture mulch films. Various naturally occurring resources available for starch and PLA extraction and the associated polymer processing techniques are discussed. Alongside some basic concepts on blown film extrusion, the modifications needed for such specialized polymer processing techniques are also explored, giving a comprehensive outlook on bioplastics. Special process analysis, for its application as films are discussed. In the current scenario, as the world aspires for environmental and polymer sustainability, Bioplastic products are of high value. The review article would be beneficial to those embarked on designing bio-plastics products from renewable resources.

Effects of Light Radiation Absoption on the Resistance of Sweet Potato Starch-Based Bioplastics

The strength of starch-based bioplastics is a challenge, we tried to overcome this limitation by using electromagnetic radiation in the visible range. Synthetically obtained retrograde bioplastics were subjected to radiation from an Edison-type incandescent lamp. A cross-linked network is obtained within the bioplastic matrix considerably attenuating the usual hygroscopicity of starch and increasing the ability to resist rupture. After this positive behavior, the bioplastics were colored in order to optimize the action of light radiation. The results show a stronger and more compact bioplastic. The green-colored bioplastics show the best performance in the optimization of the resistance.

Architectural Vantage Point to Bioplastics in the Circular Economy

In a circular economy,bio-based plastics or bioplastics as emerging innovative materials are increasingly being used in many industries,from packaging to building materials and agricultural products to electronic and biomedical devices.Further,there is increasing research on the evaluation of bioplastics in architecture,both as a material or as a design element in interior design.Therefore,this article is a step toward understanding the importance of bioplastic materials in circular economies and in architecture regarding the negative carbon footprint and long-term environmental effects of fossil-based plastics.

Impact of Photonic Action on the Hygroscopy of Sweet Potato Starch-Based Bioplastics from Congo

The work carried out here opens another perspective in the valorization of sweet potatoes produced in Congo Brazzaville other than those proposed by BOULA and all. We have shown in this work that the hydrophilic property of starch which limits the production of starch-based bioplastics can be inhibited by using the effects of photonic incandescence. Indeed, light significantly impacts the bioplastic matrix causing a decrease of the sites likely to bind water molecules. However, it would be desirable to apply rheology for a better follow-up of this cross-linking phenomenon. The synthesized retrograde bioplastic having undergone a photonic stress shows better physical properties to be used as packaging and thus to answer the environmental protection.

Computer Aided Design and Performance Analysis of Inverse Fluidized Bed Biofilm Reactors with Special Reference to Bioplastic Synthesis

Poly Laevo Lactic Acid (PLLA), in spite of being an excellent bioplastic, has exorbitantly high market price due to the high cost of raw material (lactose, glucose, sucrose). Hence, its manufacture is being attempted starting from waste effluents such as cheese whey and molasses. Earlier studies on the same in fluidized bed and semifluidized bed biofilm reactors yielded encouraging results. The present study therefore involves design and analysis of inverse fluidized bed biofilm reactors for lactic acid synthesis. The performance features of the bioreactor have been studied both mathematically as well as experimentally. The inverse fluidized bed biofilm reactor has been found to provide more than 75% conversion of sucrose/lactose even at high capacities (high feed flow rates) exceeding 56,000 L/hr, within a reasonably low reactor volume. The fractional substrate conversion increases, though sluggishly, with increase in feed flow rate due to bed expansion and also with increase in cell mass concentration in biofilm due to enhancement in intrinsic rate of bioconversion. The inverse fluidized bed biofilm reactor of proposed design could be safely recommended for the commercial synthesis of polymer grade lactic acid from waste effluents such as cheese whey and molasses. The low operating cost of the bioreactor (due to downflow mode of operation) enhances the economy of the process. This would also help in significantly lowering the market price of the green plastic (PLLA) and shall promote its large scale manufacture and utilisation.

Biodegradability of bioplastics in different aquatic environments:A systematic review

Bioplastics were first introduced as environmentally friendly materials,with properties similar to those of conventional plastics.A bioplastic is defined as biodegradable if it can be decomposed into carbon dioxide under aerobic degradation,or methane and CO_(2)under anaerobic conditions,inorganic compounds,and new cellular biomass,by the action of naturally occurring microorganisms.This definition however does not provide any information on the environmental conditions,timescale and extent at which decomposition processes should occur.With regard to the aquatic environment,recognized standards have been established to assess the ability of plastics to undergo biodegradation;however,these standards fail to provide clear targets to be met to allow labelling of a bioplastic as biodegradable.Moreover,these standards grant the user an extensive leeway in the choice of process parameters.For these reasons,the comparison of results deriving from different studies is challenging.The authors analysed and discussed the degree of biodegradability of a series of biodegradable bioplastics in aquatic environments(both fresh and salt water)using the results obtained in the laboratory and from on-site testing in the context of different research studies.Biochemical Oxygen Demand(BOD),CO_(2)evolution,surface erosion and weight loss were the main parameters used by researchers to describe the percentage of biodegradation.The results showed a large variability both in weight loss and BOD,even when evaluating the same type of bioplastics.This confirms the need for a reference range of values to be established with regard to parameters applied in defining the biodegradability of bioplastics.

Bioplastic classifications and innovations in antibacterial,antifungal,and antioxidant applications

Conventional plastics exacerbate climate change by generating substantial amounts of greenhouse gases and solid wastes throughout their lifecycle.To address the environmental and economic challenges associated with petroleum-based plastics,bioplastics have emerged as a viable alternative.Bioplastics are a type of plastic that are either biobased,biodegradable,or both.Due to their biodegradability and renewability,bioplastics are established as earth-friendly materials that can replace nonrenewable plastics.However,early bioplastic development has been hindered by higher production costs and inferior mechanical and barrier properties compared to conventional plastics.Nevertheless,studies have shown that the addition of additives and fillers can enhance bioplastic properties.Recent advancements in bioplastics have incorporated special additives like antibacterial,antifungal,and antioxidant agents,offering added values and unique properties for specific applications in various sectors.For instance,integrating antibacterial additives into bioplastics enables the creation of active food packaging,extending the shelf-life of food by inhibiting spoilage-causing bacteria and microorganisms.Moreover,bioplastics with antioxidant additives can be applied in wound dressings,accelerating wound healing by preventing oxidative damage to cells and tissues.These innovative bioplastic developments offer promising opportunities for developing sustainable and practical solutions in various fields.Within this review are two main focuses:an outline of the bioplastic classifications to understand how they fit in as the coveted conventional plastics substitute and an overview of the recent bioplastic innovations in the antibacterial,antifungal,and antioxidant applications.We cover the use of different polymers and additives,presenting the findings and potential applications within the last decade.Although current research primarily focuses on food packaging and biomedicine,the exploration of bioplastics with specialized properties is still in its early stages,offering a wide range of undiscovered opportunities.

Bioplastic production in terms of life cycle assessment:A state-of-theart review

The current transition to sustainability and the circular economy can be viewed as a socio-technical response to environmental impacts and the need to enhance the overall performance of the linear production and consumption paradigm.The concept of biowaste refineries as a feasible alternative to petroleum refineries has gained popularity.Biowaste has become an important raw material source for developing bioproducts and biofuels.Therefore,effective environmental biowaste management systems for the production of bioproducts and biofuels are crucial and can be employed as pillars of a circular economy.Bioplastics,typically plastics manufactured from bio-based polymers,stand to contribute to more sustainable commercial plastic life cycles as part of a circular economy in which virgin polymers are made from renewable or recycled raw materials.Various frameworks and strategies are utilized to model and illustrate additional patterns in fossil fuel and bioplastic feedstock prices for various governments'long-term policies.This review paper highlights the harmful impacts of fossil-based plastic on the environment and human health,as well as the mass need for eco-friendly alternatives such as biodegradable bioplastics.Utilizing new types of bioplastics derived from renewable resources(e.g.,biowastes,agricultural wastes,or microalgae)and choosing the appropriate end-of-life option(e.g.,anaerobic digestion)may be the right direction to ensure the sustainability of bioplastic production.Clear regulation and financial incentives are still required to scale from niche polymers to large-scale bioplastic market applications with a truly sustainable impact.

Development and characterization of food packaging bioplastic film from cocoa pod husk cellulose incorporated with sugarcane bagasse fibre

Agricultural wastes,including cocoa pod husk(waste from the chocolate industry)and sugarcane bagasse(waste from the sugar industry),are increasing day by day.The development of food packaging biofilms from these two wastes could be beneficial to the environment and human.Therefore,this study was conducted to develop biodegradable plastic films by using cocoa pod husk and sugarcane bagasse.Cellulose and fibre were extracted from cocoa pod husk and sugar-cane bagasse,respectively.The developed bioplastic films were divided into several concentration ratios of cellulose and fibre which are 100꞉0(100%cellulose),75꞉25(cellulose꞉fibre),50꞉50(cel-lulose꞉fibre),25꞉75(cellulose꞉fibre),and 0꞉100(100%fibre).The physicochemical properties for all bioplastic concentration ratios were determined in terms of sensory evaluation,drying time,moisture content,water absorption and water vapor permeability.From the observation and anal-ysis of the physicochemical properties of bioplastic,we found that the most suitable bioplastic film for food packaging goes to the combination of 75%cellulose and 25%fibre bioplastic,as it demonstrated the lowest water absorption percentage and water vapor permeability.

牦牛内脏器官原位整体塑化标本三维建模与可视化的研究

目的:研究基于结构光三维扫描技术制作牦牛内脏器官原位整体塑化标本的可视化三维模型方法。方法:利用生物塑化技术制作牦牛的内脏器官原位整体塑化标本,再利用结构光三维扫描技术构建出塑化后的牦牛内脏器官原位整体的彩色数字三维模型,然后构建基于互联网的webvr系统,实现虚拟数字标本的可视化展示等流程,完成牦牛内脏器官原位整体塑化标本的三维建模与可视化展示。结果:基于生物塑化技术和结构光三维扫描技术构建出来的可视化三维牦牛内脏器官原位整体塑化标本模型,能真实再现牦牛的全身各部位的肌肉层次结构和内脏的形态及位置毗邻关系,精度高、清晰度好,可以任意角度旋转和缩放,能更好地辅助教学、科研和科普等工作,为后续建立其他大型动物标本的三维数字化模型积累经验。

ZnCl2／凹凸棒石催化合成生物增塑剂C22-三酸酯研究

以地沟油制废弃油脂脂肪酸甲酯(WOFAME)与马来酸二丁酯(DBM)为原料,在自制ZnCl_2/凹凸棒石催化剂作用下合成结构不同的生物增塑剂C22-三酸酯。采用IR、MS、1H-NMR和HPLC等手段对合成产物进行定性、定量分析,根据产物的组成结构对可能的合成路径进行探讨;试验优化了产物合成工艺条件,研究了产物的耐热及增塑性能。结果表明,在ZnCl_2/凹凸棒石作用下WOFAME中亚油酸甲酯与DBM可分别经Diels-Alder环加成及双烯加成反应合成"环己烯式"与"悬挂式"的C22-三酸酯;合成产物的适宜工艺条件为:反应温度240℃,反应时间4 h,n(DBM)∶n(亚油酸甲酯)=1.1∶1,催化剂用量为WOFAME用量的10%;此条件下,亚油酸甲酯转化率及产物选择性分别可达97%、94%以上。与碘催化反应相比,三分子加成副产物显著减少。此外,合成的C22-三酸酯的耐热性能及增塑性能均优于碘催化合成的产物,且明显优于邻苯类增塑剂DOP。

Starch Based Bio-Plastics: The Future of Sustainable Packaging

Petroleum derived plastics dominate the food packaging industry even today. These materials have brought a lot of convenience and attraction to agro, food and packaging industry. These materials also have brought along with them problems relating to the safe-disposal and renewability of these materials. Due to the growing concern over environmental problems of these materials, interest has shifted towards the development and promoting the use of “bio-plastics”. Bio-plastic is a term used for sustainable packaging materials derived from renewable resources i.e. produced from agro/food sources, materials such as starch, cellulose, etc. and which are considered safe to be used in food applications. To enhance the mechanical properties, and water barrier properties, it can be blended easily with other polymer as well as nano fillers. The current paper is a review of the progress of research in starch based sustainable packaging materials.

Sustainable Materials Based on Cellulose from Food Sector Agro-Wastes

Biopolymers exhibit unique properties and can be produced from plants’ and crops’ wastes. Cellulose has beenused for the production of sustainable materials, nevertheless due to the difficulty inherent to its extraction,several methods have been studied in order to optimize the process. Therefore, this paper reports the extractionof natural polymers from food sector agro-food wastes, including cellulose, following a green chemistry aproach.The cellulose extracted from pumpkin peel was acetylated and dispersed in a polylactic acid (PLA) matrix. Thedeveloped materials were characterized in terms of their structure, morphology and thermal stability. Theresults demonstrated the efficient chemical modification of cellulose and confirmed its good dispersion withinthe PLA matrix.

Blend of Polyhydroxyalkanoates Synthesized By Lipase Positive Bacteria From Plant Oils

A total of 5 biochemically characterized lipase positive bacterial strains were screened for Polyhydroxyalkanoates(PHA)production by Nile blue staining and confirmation was done by Sudan Black B.PHA production ability for all strains was optimized followed by time profiling calculation and comparison via using glucose and two plant oils i.e.,canola and mustard oil.Quantitative analysis showed that glucose can serve as a carbon source for maximum biomass(2.5 g/L CDW for strain 5)and PHA production(70.3%for strain 2).PHA produced by strain 2 was further analyzed for its chemical composition and type via Fourier Transform Infrared(FT-IR)spectroscopy.It revealed homopolymer(PHB)and copolymer(PHB-co-PHV)production of PHA(peaks at 1743 cm-1 and 2861 cm-1,respectively)with both canola and mustard oil unlike glucose which produced only homopolymer one i.e.,PHB(peaks at 1110 cm-1,1411 cm-1 and 1650 cm-1).Crystallinity of FT-IR analyzed PHA was calculated using mathematical formulas which showed decrease from glucose to canola to mustard oil.This study revealed that plant oils can serve as better carbon source to produce better quality(ductile and copolymer)PHA.Moreover,16S rRNA gene sequencing analysis showed that strain 1,strain 2,strain 3,strain 4 and strain 5 are Stenotrophomonas sp.N3,Exiguobacterium sp.N4,Exiguobacterium sp.Ch3,Cellulosimicrobium sp.A8 and Klebsiella sp.LFSM2,respectively.

A Literature Review on Sustainability of Bio-Based and Biodegradable Plastics:Challenges and Opportunities

This study examines the literature on bio-based and biodegradable plastics published between 2000 and 2021 and provides insights and research suggestions for the future.The study gathers data from the Scopus and ISI Web of Science databases,then picks 1042 publications objectively and analyses their metadata.Furthermore,144 papers from the Web of Science are analysed to present insights and classifications of the literature based on content analyses,including assessment/evaluation of the sustainability of bio-based and biodegradable Plastics,sustainability of biodegradable Plastics,and factors driving the uptake of biodegradable plastics.The study finds that most research on bio-based and biodegradable plastic film evaluations considered only one dimension of sustainability,few considered two dimensions,and very few considered three dimensions.Though,in recent years,academic and industrial interest has grown dramatically in biodegradable plastics towards sustainability.The triple bottom line method in this report(economic benefit,social responsibility,and environmental protection)was employed to assess the biodegradable plastics towards sustainability.Top journals,Influential authors,top contributing institutions,top contributing nations,and contributions by fields are all identified in this study.This research gives a detailed but straightforward theoretical design of bio-based and biodegradable polymers.The study’s results and future research initiatives provide a new path for further investigation and contribution to the field.

Reexamining intra and extracellular metabolites produced by Pseudomonas aeruginosa

Objective:To isolate,screen and analyze bacteria from different areas of Pakistan for the production of antimicrobial compounds,zinc solubilization and bioplastic production.Methods:Isolation and purification was proceeding with streak plate method.Antagonistic assay was completed with well diffusion and thin-layer chromatography.In vivo analysis of bioplastic was analyzed with Nile blue fluorescence under UV and Sudan staining.Results:A total of 18 bacterial strains purified from soil samples while 148 strains form stock cultures were used.Out of 166 only 94 showed antimicrobial activity against each of Grampositive and Gram-negative;cocci and rods.In case of heavy metal(ZnO and Zn_(3)(PO_(4))_(2)·4H_(2)O)solubilization,54 strains solubilized ZnO and 23 strains solubilized Zn_(3)(PO_(4))_(2)·4H_(2)O,while 127 strains grown on polyhydroxyalkanoate detection meedia supplemented with Nile blue medium showed bioplastic production by producing fluorescence under UV light.Four bacterial strains(coded as 100,101,104 and 111)were selected for further characterization.Induction time assay showed that strains 101,104,and 111 showed inhibitory activity after 4 h of incubation while strain 100 showed after 8 h.All four strains were tolerable to the maximum concentration of ZnO.Amplified products of both 16S rRNA and PhaC gene fragments of strain 111 were sequenced and submitted to GenBank as accession numbers EU781525 and EU781526.Conclusions:Bacterial strain Pseudomonas aeruginosa-111 has potential to utilize as biofertilize and bioplastic producer.