Feather wastes-byproduct of commercial poultry processing plant is produced in large amounts. Keratinolytic enzymes produced by feather degrading bacteria can easily degrade these waste products releasing pure keratin as a residue. The aim of present study was to isolate, and characterize feather degrading bacteria as well as assess the keratinolytic potential of purified enzyme. Three feather degrading bacteria (dps3, wps1 and dcs1) were isolated from feathers of domestic chickens. Preliminary characterization of isolated bacteria revealed these isolates belonging to genus Bacillus. 16S rRNA gene sequencing identified the isolates as B. subtilis dps3 (MW255302), B. cereus wps1 (MW255303) and B. licheniformis dcs1 (MW255304). Cell free supernatant of B. licheniformis dcs1 degraded feathers completely in 14 days indicating its keratinolytic ability. Purification of keratinase enzyme from B. licheniformis dcs1 was performed using column chromatography. SDS-PAGE indicated its molecular weight as 32 KDa. Kerotinolytice activity was maximum at optimum pH of 7 and 45°C temperature. Enzyme showed the potential to degrade keratin material such as hairs and nails of humans. Findings of current study suggested that purified enzyme possess potential to upgrade nutritional quality of poultry waste containing keratin and might play as important biotechnological tool for keratin hydrolysis.
Humoral practice is a fundamental natural biological phenomenon in earthworm defensive system which protects them from infectious bacteria and irritating agents by different mechanisms. The defensive system of earthworms is highly complicated because they lack antibodies in their blood circulatory system but their body extracts and coelomic fluid comprise of different bioactive agents (i.e. peptides and proteins) that defend these worms. There are various groups of bioactive agents such as proteases (name depends on proteins/peptide function or formal earthworm species name), metabolites (total 59 metabolites found in Eisenia fetida), metal binding proteins (2 proteins such as Ca2+ binding calmodulin and metallothionein), active proteins (include lysozyme, lysenin and eiseniapore etc.), antimicrobial peptides (antibacterial vermi-peptides family (AVPF), antimicrobial peptide I (PP-I), coelomic cytolytic factor (CCF, CCF-I and CCF like protein), fetidin, lysenin, lumbricin (lumbricin I, lumbricin PG, and lumbricusin), organic acids (fatty acids, succinic acids, and lauric acid) and other organic compounds (such as purine and vitamin D). The presence of above mentioned molecules confer therapeutic potential that affect energy intake and involve in decreasing oxidative stress, metabolic disturbances and pro-inflammatory conditions. The future perspectives of earthworm bioactive compounds are concerned with the development of provisional standards, purification and classification for utilizations in pharma industry.
1 November 2020 in Environmental Toxicology and Pharmacology
The present study was designed to determine chemical composition of essential oils extracted from different species of the Myrtaceae family and to evaluate their insecticidal activities against Tribolium castaneum (Coleoptera: Tenebrionidae). The essential oils of 10 species were extracted by hydrodistillation and analyzed by a gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The main component of Eucalyptus crebra, E. microtheca, E. rudis and Melaleuca quinquenervia essential oils was 1,8-cineole (31.6-49.7%). E. melanophloia and E. tereticornis contained p-cymene (41.8-58.1%) as a major component, while Eucalyptus kitsoniana and E. pruinosa essential oils were dominated by α-pinene (25.8-31.4%). Eugenol methyl ether was identified as a major component in M. bracteata essential oil (82.3%). α-Pinene (31.4%) was the main component in the C. viminalis essential oil. Essential oils of all selected plant species showed good insecticidal activities against T. castaneum when compared with pyrethroid as a positive control. Eucalyptus rudis proved most potent against T. castaneum, followed by M. bracteata, M. quinquenervia, and C. viminalis. The results of this study indicate that essential oil of Myrtaceae leaves have potential to be used in the control of T. castaneum.
Diversity in avian assemblages of urban (UR), peri-urban (PE) and rural (RU) areas was studied to explore variations in the avian community dynamics in rural – urban gradient. For this purpose, sampling was done from September 2013 to August 2015. A total of 35 sites, each covering an area of 300 m2 were sampled by using point count method. At each site, randomly three points (minimally 5 m apart from each other) were selected to study the birds. According to data, species richness (F2, 32=47.18, P<0.001) varied significantly along a rural-urban gradient. A significant difference in avian density per sampling site (F2, 32=105.41, P<0.001) was also observed along urbanization gradient. In PE and RU areas, avian assemblages were more diverse than UR areas. Among avian guilds, omnivores were the most abundant in UR while insectivores in PE areas. Frugivores and carnivores were abundant in RU areas. Granivores were recorded in all habitats with similar diversity. A close association was recorded in bird density of RU and PE areas than UR areas. Bird species richness and diversity showed negative correlation with built area and positive correlation with vegetation cover in an area.