Isolation Of Protease Producing Bacteria Research Articles

Isolation of Protease-Producing Bacteria from Shrimp Paste and the Characteristics of Fermenting Catfish Paste

ABSTRACT In this study, six protease-producing halophilic bacterias were isolated from traditional shrimp paste. These strains were used as mixed starter culture to ferment minced catfish muscle. The pH and total volatile base nitrogen in the group with mixed starter cultures (ZB) was lower than that of the group without starter (ZA). The total acidity and the content of amino acid nitrogen and free amino acid in ZB was higher. Additionally, the ZB exhibited a strong umami and fermented flavor. The results show that protease-producing bacteria could improve the flavor and nutritive value of fermented Chinese long-snout catfish by-products.

Isolation and Characterization of Protease Producing Bacteria from Soil, in Arba Minch University, Abaya Campus

Microbes are ubiquitous and live in familiar settings such as soil, water, food and animal intestines as well as in more extreme setting such as rocks, glaciers, hot springs and deep-sea vents. They are essential component of the biodiversity as they account for 50% of the living biomass of this planet. The aim of this work was isolation and screening of protease producing bacteria from soil collected from the study area. Isolation of protease producing bacteria was performed by the serial dilution and spread plate technique using skim milk agar medium. Accordingly, 131 isolates were positive on skim milk agar and of which 13 (10%) of them are protease producer. Four best isolates were selected on the basis of their clear zone size, one from each site for further study. IS-4 has larger clear zone size with 10.5mm followed by IS-2 (6mm). All potential isolates have circular in shape of colony and flat in height of colony except IS-1 which is irregular and raised respectively. Most of potential isolates have opaque in their colonial optical density. All isolates were found to be Gram positive and spore producers. Morphological and biochemical results have revealed that three of four active enzyme producing bacteria are identified as Bacillus spp. Members of the genus Bacillus produce a large variety of extracellular enzymes (proteases) particularly significant for industrial application.

Isolation of Protease Producing Bacteria from Soil for Polyester and Silver Recovery from Waste X-ray Film

Proteases are multipurpose group of enzymes which mainly produced from microorganism and used in various industries such as detergent, silver recovery, food, pharmaceutical, leather and textile industries. This work aimed to isolate protease producing bacteria from local environment for use as silver recovery and reuse of polyester from waste X-ray film. Isolation of protease producer was undertaken using skim milk agar medium. A total of 36 protease positive bacteria were isolated from the study area (Arba Minch fish processing site). Five isolates were screened which had relatively higher clear zone and further examined gelatin removal efficiency of their crude enzymes. One isolate designated as <i>Bacillus sp.</i> THZ14 was selected on the basis of gelatin removal efficiency. The crude enzyme from this strain removed gelatin on waste X-ray film at pH 9, 40°C in 40 min. These properties suggest that protease from <i>Bacillus sp.</i> THZ14 could find potential application in silver recovery process and reuse of polyester sheet which have an economic implication.