Biochemical and Molecular Characterization of a New Local Keratinase Producing Pseudomomanas sp., MS21

Abstract

This study aimed to isolate and identify a new local bacterial strain, able to completely degrade keratin-rich wastes into soluble and useful materials which can be used in many proposes. Bacterial keratinases are of particular interest because of their action on insoluble keratin substrates and generally on a broad range of protein substrates. These enzymes have been studied for de-hairing processes in the leather industry and hydrolysis of feather and keratin. Samples from poultry industry wastes, soil, water, fodder and feather were collected from different places in Jeddah, Saudi Arabia. Each sample was plated on feather meal agar plates containing 5 g LG feather as the sole carbon and nitrogen source and 1 the obtained colonies were selected, purified and their growth were detected on skimmed milk agar and feather meal broth media. The well grown isolates on feather meal agar which producing the largest clearing zone on skimmed milk plate were selected for keratinase assays. Out of 23 bacterial isolates, 7 isolates were selected. The best keratinase producing bacterium kera MS21 was selected and identified based on morphological, physiological and some biochemical characteristics. It was recorded as a species belonging to the genus Pseudomonas and identified as Pseudomonas sp. The results of identification were confirmed by 16S rDNA studies. Precipitation and purification of the keratinase enzyme in addition to factors affecting enzyme activity were studied. The enzyme molecular weight was determined to be of 30 KDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. The optimum temperature and pH were determined to be 37°C and pH 8.0, respectively. The effect of some proteases inhibitors and activators were also studied.

Purification and properties of a novel fungal alkaline keratinase from Cunninghamella echinulata

“…The optimum temperature for keratinase activity was determined at different incubation temperatures between 0 and 100°C [13]. + were tested.…”

“…Finally, the feathers were washed several times with tap water to eliminate the solvent residual, dried for 3 days at 50°C and ground using an electrical blender. The ground keratin was used for further studies [13].…”

Isolation and Molecular Identification of Keratinase-Producing Bacteria from the Sludge of Qeshm Island

“…In this study, we aimed at isolation and molecular identification of bacterial strains from sludge samples collected from Peyposht and Qeshm, which have high quantities of keratin-rich waste. In a study by Tork et al, 7 of 23 bacterial isolates with bright halos on skim milk agar were identified as keratinase producer (15). A study by Sangali and Brandli reported the keratinolytic activity of Vibrio sp.…”

Characterization of Keratin Degrading Alkaliphiles

“…The genomic DNA was used as a template for PCR amplification of the 16S rRNA gene using forward primer 5'-AGTTTGATCATGGTCAG-3' and reverse primer 5' GGTTACCTTGTTACGACT 3' (Tork, Aly, & Nawar, 2010). The PCR product of each of the tested isolates was purified and sequenced.…”