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May 2020 DOI 10.14302/issn.2641-4538.jphi-20-3338
Chibueze Izah SylvesterCorresponding author
Department of Microbiology, Faculty of Science, Bayelsa Medical University, Yenagoa, Bayelsa State, Nigeria
This study investigated the acute toxicity of Clariasgariepinusfingerlings. The fingerlings of Clariasgariepinuswere acclimatized for 1 week before the range-finding test was carried out at varying concentrations. Sublethal concentration (viz: 0.00ppm, 10.80 ppm, 18.00 ppm, 25.20 ppm, 32.40 ppm and 39.60 ppm of the 2,4-D Dimethylamine salt) were made in a rectangular aquarium. Each experimental concentration was carried out in triplicate with 10 fish each. The media were renewed at every 24 hours throughout the experimental duration viz: 96 hours. When the fish were introduced into the aquarium containing the toxicants, they exhibited some behavioural changes including opercular movement, air gulping and irregular swimming pattern. The mortality rate significantly increased as the concentration of the 2,4-D Dimethylamine salt increased for each of the exposure duration. The LC50 values at 24, 48, 72 and 96 were 86.15 ppm, 36.28 ppm, 18.72 ppm and 15.68 ppm, respectively. From the findings of this study, there is a need for exercise caution in the use of 2,4-D Dimethylamine salt based herbicides close to the aquatic ecosystem.
Jan 2019 DOI 10.14302/issn.2641-7669.ject-18-2550
C. N Angaye TariwariCorresponding author
Department of Biological Science, Faculty of Science, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria
The ecotoxicological effects of leachates from dumpsite have become a major problem. Leachates arising from waste dumpsites are transported by surface runoff or infiltration through the soil and become bioavailable in the ecosystem. The ecotoxicological assessment of leachates from 6 dumpsite in Yenagoa Metropolis were investigated against adult and fingerlings of Clarias gariepinus (African catfish). Ecotoxicological activities (LC50 values) were reported for the following stations; Akenpai (124.57 ppm), and Etegwe stations (95.38 ppm), as well as Opolo (157.95 ppm), and Kpansia Markets (123.82 ppm). In addition, leachates of the two stations from the central dumpsite (CDS), were the most active (CDS 1; 60.97 ppm, and CDS 2; 76.65 ppm). Notwithstanding, the order of toxicological activities of the leachates were reported as; CDS 1>CDS2>Etegwe>Akenpai>Kpansia market>Opolo Market. These results confirm the toxicity of leachates from the dumpsites. In addition, we recommend that government, regulators and all stakeholders should enact policies to treat, reduce, recycle and reduce waste stream in order to mitigate the adverse effects on the ecosystem.
May 2018 DOI 10.14302/issn.2690-4829.jen-18-2043
Rameshthangam PalanivelCorresponding author
Department of Biotechnology, Alagappa University, Karaikudi 630003, Tamilnadu, India
Disposal of chitin wastes from crustacean shell can cause environmental and health hazards. Chitin is a well known abundant natural polymer extracted after deproteinization and demineralization of the shell wastes of shrimp, crab, lobster, and krill. Extraction of chitin and its derivatives from waste material is one of the alternative ways to turn the waste into useful products. Chitinases are enzymes that degrade chitin. Chitinases contribute to the generation of carbon and nitrogen in the ecosystem. Chitin and chitinolytic enzymes are gaining importance for their biotechnological applications. The presence of surface charge and multiple functional groups make chitin as a beneficial natural polymer. Due to the reactive functional groups chitin can be used for the preparation of a spectrum of chitin derivatives such as chitosan, alkyl chitin, sulfated chitin, dibutyryl chitin and carboxymethyl chitin for specific applications in different areas. The present review is aimed to summarize the efficacy of the chitinases on the chitin and its derivatives and their diverse applications in biomedical and environmental field. Further this review also discusses the synthesis of various chitin derivatives in detail and brings out the importance of chitin and its derivatives in biomedical and environmental applications.
Nov 2017 DOI 10.14302/issn.2576-6694.jbbs-17-1783
Krishnaswamy VeenaGayathriCorresponding author
Department of Biotechnology, Stella Maris College, Chennai-86, Tamilnadu, India
Plastic materials have been used as packaging materials and also have other numerous applications because of their durability and stability. Plastic products are non degradable and they continue to exist in the environment thereby causing a serious threat to the ecosystem. Bioplastics which are biodegradable plastics are emerging out as a boon to overcome the problem of plastic accumulation. Polyhydroxybutyrate or PHB is a bioplastic that serves as an alternative to synthetic plastics. PHB is a lipid reserve material that gets accumulated within the cell wall of micro organisms under stress conditions. Halophilic microorganisms can be of much use in the production of PHB as it is cost – effective and recovery of PHB is much easier in halotolerant organisms. Hence this study focuses on the isolation of PHB producing halotolerant bacterial organisms from marine sources. Screening of PHB positive isolates was done by Sudan Black B and Nile blue A staining. Large scale production of PHB by the efficient bacterial strain was done by using wastewater as the substrate.