Pathogenicity Scoring System for Selection of Bacterial Consortium Formulated as Bioremediation Agent of Hospital Wastewater in Central Java

Abstract

The search of cost-effective bioremediation agent of hospital wastewater is critical since current methods to treat biomedical waste worldwide are still costly and not environmentally friendly. Use of hydrolytic bacteria as bioremediation agent has been known, yet it is important to ensure that they fit safety requirement. This study aimed to establish and implement a simple plate-based pathogenicity selection scoring method to determine the pathogenicity levels of 26 indigenous hydrolytic bacteria isolated from the untreated wastewater of two hospitals in Semarang, Central Java, Indonesia. Bacterial cultivations were carried out in parallel on MacConkey Agar Plate (MAP), Blood Agar Plate (BAP) and Chocolate Agar Plate (CAP) followed by molecular identification. Next, a scoring system was set based on the ability of isolates to produce violet colour on the MA and hemolysis characteristics of the bacteria on both the BAP and CAP media. Based on the scoring system, 6 out of 26 bacterial isolates mostly belong to the members of Bacillus velezensis, B. amyloliquefaciens and B. licheniformis were identified having low pathogenicity, which make them a suitable bioremediation agent of the studied hospital wastewater. As conclusion, the set plate-based pathogenicity scoring system could be a simple, yet useful and reliable tool for selecting non-pathogenic indigenous hydrolytic bacterial strains potential as a bioremediation agent.