ISOLATION AND SELECTION OF PROTEIN DEGRADING BACTERIAL STRAINS FROM WASTEWATER COLLECTION TANKS OF SEAFOOD PROCESSING FACTORIES AT TRA NOC INDUSTRIAL ZONE - CAN THO CITY

Abstract

This study was aimed at investigating and selecting protein degrading bacterial strain (VK-Pro) from wastewater and waste sludge sources of catfish processing factories in Tra Noc industrial Zone of Can Tho city. The pure VK-Pro isolates were investigated the qualitative and quantitative ass essment of protease activity under in vitro conditions, the ability of the VK-Pro with high degradation index to degrade by products of catfish and of pork meat and identified the potential beneficial bacterial isolates. The results showed that 40 VK-Pro strains that produced halo zones on the protein medium were isolated. Among them, 20 bacterial isolates gained significantly higher the degradation index (%). Based on the quanlitative test, 4 VK-Pro strains were selected for their highest tyrosine-degrading capacity up to 96 hours of incubation, with proteae activity ranging from 905.2 ± 25.3 to 4,312.8 ± 41.6 U/mL. With a bacterial density of 10⁸ CFU/gkk,  the SR3 strain gained the highest degradation efficiency for both catfish (82.0 ± 0.3%) and pork (66.2 ± 0.54%) by products and the HVD7 strain was the second effective strain in degrading fish (75.0 ± 0.52%) and pork (65.2 ± 0.36%) by products compared to those of other treatments. These strains were identified as a species specy of Pseudomonas sp. SR3 (99.04% of the similarity) and Priestia sp. HVD (100 % of the similarity) based on the 16S rRNA sequence. The study successfully selected two bacterial strains with the potential application for treating biological organic wastes containing high protein-based by-products from catfish and pork.