Modified Methods in Starch-Based Biodegradable Films

With plastics resistance to degradation in nature and lack of effective recycling practice, it has resulted in a serious threat to the environment. Concerns about the environmental pollution caused by plastics have led to serious demands for biodegradable plastic materials made from renewable source. Starch is a biopolymer that has been being an attractive alternative for packaging material. A general overview on the microstructures of starch is given in this essay. The modified methods in biodegradable starch-based films are reviewed, which include physical, chemical and enzymic modification. Physical modification involves ultrasonic, mechanical treatment and addition of additives, such as plasticizer and coupling agent. Chemical modification consists of etherification, esterification, cross-linking, grafting and oxidation. Enzymic modification includes debranching reaction of starch debranching enzyme which contains pulullanase and isoamylase. The biodegradation of starch-based films and the prospects of their future are also detailed.

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Changes in structure of starch and enzyme activities affected by sugary mutations in developing rice endosperm. Possible role of starch debranching enzyme (R-enzyme) in amylopectin biosynthesis

Physiologia Plantarum ◽

10.1034/j.1399-3054.1996.970311.x ◽

1996 ◽

Vol 97 (3) ◽

pp. 491-498 ◽

Cited By ~ 9

Author(s):

Yasunori Nakamura ◽

Takayuki Umemoto ◽

Yasuhiro Takahata ◽

Kozo Komae ◽

Etsuo Amano ◽

...

Keyword(s):

Enzyme Activities ◽

Debranching Enzyme ◽

Rice Endosperm ◽

Starch Debranching Enzyme

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Synthesis of biodegradable films obtained from rice husk and sugarcane bagasse to be used as food packaging material

Environmental Engineering Research ◽

10.4491/eer.2019.191 ◽

2019 ◽

Vol 25 (4) ◽

pp. 506-514 ◽

Cited By ~ 3

Author(s):

Himanshu Gupta ◽

Harish Kumar ◽

Mohit Kumar ◽

Avneesh Kumar Gehlaut ◽

Ankur Gaur ◽

...

Keyword(s):

Tensile Strength ◽

Sugarcane Bagasse ◽

Rice Husk ◽

Food Packaging ◽

Packaging Material ◽

Biodegradable Films ◽

Biodegradable Film ◽

Biocomposite Film ◽

Biopolymer Film ◽

Lignocellulose Biomass

The current study stresses on the reuse of waste lignocellulose biomass (rice husk and sugarcane bagasse) for the synthesis of carboxymethyl cellulose (CMC) and further conversion of this CMC into a biodegradable film. Addition of commercial starch was done to form biodegradable film due to its capacity to form a continuous matrix. Plasticizers such as Glycerol and citric acid were used to provide flexibility and strength to the film. Biopolymer film obtained from sugarcane bagasse CMC showed maximum tensile strength and elongation in comparison to the film synthesized from commercial CMC and CMC obtained from rice husk. It has been observed that an increase in sodium glycolate/NaCl content in CMC imposed an adverse effect on tensile strength. Opacity, moisture content, and solubility of the film increased with a rise in the degree of substitution of CMC. Therefore, CMC obtained from sugarcane bagasse was better candidate in preparing biopolymer/biocomposite film.

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Industrial Production of Poly-β-hydroxybutyrate from CO2: Can Cyanobacteria Meet this Challenge?

Processes ◽

10.3390/pr8030323 ◽

2020 ◽

Vol 8 (3) ◽

pp. 323 ◽

Cited By ~ 4

Author(s):

Roberta Carpine ◽

Giuseppe Olivieri ◽

Klaas J. Hellingwerf ◽

Antonino Pollio ◽

Antonio Marzocchella

Keyword(s):

Low Cost ◽

Operation Mode ◽

Commercial Production ◽

Continuous Operation ◽

Attractive Alternative ◽

Bacterial Fermentation ◽

Plastic Materials ◽

Phb Production ◽

Global Concern ◽

Environmentally Friendly Process

The increasing impact of plastic materials on the environment is a growing global concern. In regards to this circumstance, it is a major challenge to find new sources for the production of bioplastics. Poly-β-hydroxybutyrate (PHB) is characterized by interesting features that draw attention for research and commercial ventures. Indeed, PHB is eco-friendly, biodegradable, and biocompatible. Bacterial fermentation processes are a known route to produce PHB. However, the production of PHB through the chemoheterotrophic bacterial system is very expensive due to the high costs of the carbon source for the growth of the organism. On the contrary, the production of PHB through the photoautotrophic cyanobacterium system is considered an attractive alternative for a low-cost PHB production because of the inexpensive feedstock (CO2 and light). This paper regards the evaluation of four independent strategies to improve the PHB production by cyanobacteria: (i) the design of the medium; (ii) the genetic engineering to improve the PHB accumulation; (iii) the development of robust models as a tool to identify the bottleneck(s) of the PHB production to maximize the production; and (iv) the continuous operation mode in a photobioreactor for PHB production. The synergic effect of these strategies could address the design of the optimal PHB production process by cyanobacteria. A further limitation for the commercial production of PHB via the biotechnological route are the high costs related to the recovery of PHB granules. Therefore, a further challenge is to select a low-cost and environmentally friendly process to recover PHB from cyanobacteria.

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Structural modification of fiber and starch in turmeric residue by chemical and mechanical treatment for production of biodegradable films

International Journal of Biological Macromolecules ◽

10.1016/j.ijbiomac.2018.12.206 ◽

2019 ◽

Vol 126 ◽

pp. 507-516 ◽

Cited By ~ 5

Author(s):

Bianca C. Maniglia ◽

Delia R. Tapia-Blácido

Keyword(s):

Mechanical Treatment ◽

Structural Modification ◽

Biodegradable Films

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Structural basis of carbohydrate binding in domain C of a type I pullulanase from Paenibacillus barengoltzii

Acta Crystallographica Section D Structural Biology ◽

10.1107/s205979832000409x ◽

2020 ◽

Vol 76 (5) ◽

pp. 447-457

Author(s):

Ping Huang ◽

Shiwang Wu ◽

Shaoqing Yang ◽

Qiaojuan Yan ◽

Zhengqiang Jiang

Keyword(s):

Binding Site ◽

Binding Sites ◽

Structural Basis ◽

Carbohydrate Binding ◽

Type I ◽

Debranching Enzyme ◽

Crystal Forms ◽

Aromatic Residues ◽

Starch Debranching Enzyme ◽

Paenibacillus Barengoltzii

Pullulanase (EC 3.2.1.41) is a well known starch-debranching enzyme that catalyzes the cleavage of α-1,6-glycosidic linkages in α-glucans such as starch and pullulan. Crystal structures of a type I pullulanase from Paenibacillus barengoltzii (PbPulA) and of PbPulA in complex with maltopentaose (G5), maltohexaose (G6)/α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) were determined in order to better understand substrate binding to this enzyme. PbPulA belongs to glycoside hydrolase (GH) family 13 subfamily 14 and is composed of three domains (CBM48, A and C). Three carbohydrate-binding sites identified in PbPulA were located in CBM48, near the active site and in domain C, respectively. The binding site in CBM48 was specific for β-CD, while that in domain C has not been reported for other pullulanases. The domain C binding site had higher affinity for α-CD than for G6; a small motif (FGGEH) seemed to be one of the major determinants for carbohydrate binding in this domain. Structure-based mutations of several surface-exposed aromatic residues in CBM48 and domain C had a debilitating effect on the activity of the enzyme. These results suggest that both CBM48 and domain C play a role in binding substrates. The crystal forms described contribute to the understanding of pullulanase domain–carbohydrate interactions.

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