Bioplastics from waste biomass of marine and poultry industries.

Plastics are indispensable and typically derived from non-renewable sources. The extensive production and indiscriminate use of synthetic plastics pose a serious threat to the environment and lead to problems due to their non-biodegradability. Various forms of plastics that are used in daily life should be limited and replaced by biodegradable materials. To deal with the challenges of sustainability or environmental issues that occur due to the production and disposal of synthetic plastics, biodegradable and environment-friendly plastics are crucial. Utilizing renewable sources such as keratin derived from chicken feathers and chitosan from shrimp cell wastes as an alternative to obtain safe bio-based polymers has gained much attention because of rising environmental issues. Approximately, 2-5 billion tons of waste are produced by the poultry and marine industries each year, adversely impacting the environment. These polymers are more acceptable and ecofriendly compared with conventional plastics due to their biostability, biodegradability, and excellent mechanical properties. The replacement of synthetic plastic packaging with biodegradable polymers from animal by-products significantly reduces the volume of waste generated. This review highlights important aspects such as the classification of bioplastics, properties and use of waste biomass for bioplastics production, their structure, mechanical properties, and demand in industrial sectors such as agriculture, biomedicine, and food packaging.

Isolation and identification of low-density polyethylene degrading novel bacterial strains.

Plastics are usually made up of low-density polyethylene (LDPE) that serve as the environmental nuisance. The recalcitrant nature of plastics is a huge concern, whereas the increasing demand has made it difficult to handle the plastic waste that eventually leads to plastic pollution. In recent years, due to increasing demand and high pressure for its safe disposal, plastic biodegradation has gained a lot of attention. In the current study, four bacterial strains were isolated from the solid-waste dumpsites of Faisalabad, Pakistan, using enrichment culture technique. The isolated bacterial strains were capable of growing on media having polystyrene as the sole carbon source. Based on 16S rRNA gene sequencing and phylogenetic analysis of the isolated strains Serratia sp., Stenotrophomonas sp. and Pseudomonas sp. were identified as the potential strains for the biodegradation of LDPE. Serratia sp. resulted in 40% weight loss of the LDPE plastic pieces after 150 days of treatment. Stenotrophomonas sp. and Pseudomonas species resulted in 32 and 21% weight loss of the treated piece of plastics (LDPE), respectively. Polyethylene pieces were characterized by Fourier-transform infrared spectroscopy (FTIR) analysis before and after biodegradation. The FTIR spectra indicated that the isolated bacterial strains have a good potential to degrade LDPE. Future studies are required to investigate the bacterial genetic makeup, mechanisms of LDPE biodegradation and the factors that can enhance the biodegradable characteristics of these indigenously isolated bacterial strains.

Microbial L-asparaginase: purification, characterization and applications.

L-asparaginase (E.C.3.5.1.1) is an important enzyme that has been purified and characterized for over decades to study and evaluate its anti-carcinogenic activity against different lymphoproliferative disorders such as acute lymphoblastic leukemia (ALL) and Hodgkin's lymphoma. The ability of the enzyme to convert L-asparagine into aspartic acid and ammonia is the reason behind its anti-cancerous activity. Apart from its medicinal uses, it is widely used in food industry to tackle acrylamide, a probable human carcinogen and, production in carbohydrate-rich foods cooked at high temperatures. There are variety of organisms including microorganisms such as bacteria, fungi, algae, and plants that produce L-asparaginase. The enzyme obtained from different microbial and plant sources have different physiochemical properties and kinetic parameters. L-asparaginases have an optimum pH range between 6 and 10 and an optimum temperature between 37 and 85 °C. This article has reviewed the lowest molecular mass for L-asparaginase in Yersinia pseudotuberculosis Q66CJ2 which is 36.27 kDa, while the highest for Pseudomonas otitidis which has a molecular mass of 205 ± 3 kDa. This review is an attempt to summarize most of the available sources, their phylogenetic relationships, purification methods, data regarding different physiochemical and kinetic properties of L-asparaginase.