Supercritical Fluid CO₂ Technique for Destruction of Pathogenic Fungal Spores in Solid Clinical Wastes

Abstract

The present study deals with the inactivation of fungal spores in clinical waste using the advanced supercritical carbon-dioxide (SC-CO 2 ) treatment technique. The process of inactivation was investigated under different conditions of pressure, temperature, and processing time. The efficiency of SC-CO 2 was determined in terms of log reduction and inactivation rate of fungal spores. Almost 100% inactivation of initial fungal spores was obtained. Predicted and experimental log reduction of fungal spores was found to be 5.93 and 6.00, respectively, under optimal conditions (35 MPa, 75°C in 90 min). SC-CO 2 treated Aspergillus niger and Penicillium simplicissimum spores were examined using scanning electron microscopy which showed spore damage in the form of rupture, tear, and shape distortion. These damages confirmed complete spore inactivation when no renewed fungal growth occurred after the treated samples were cultured onto fresh media. The inactivation of fungal spores using SC-CO 2 and autoclave inhibits the production of lipase, cellulase, amylase, and protease enzymes. Thus, without addition of any chemicals, the SC-CO 2 sterilization method can be potentially used for the inactivation of microorganisms in clinical waste as well as in food and pharmaceutical products.

Carvacrol: A Promising Environmentally Friendly Agent to Fight Seeds Damping-Off Diseases Induced by Fungal Species

“…Moreover, earlier works reported closer MIC value For M. nivale treated with essential oils contained carvacrol [38][39][40][41]. The difference in MICs can be due to the use of different methods, in particular, the concentration of spore inoculum, effects of incubation temperature, time of reading on broth dilution, the use of detergents or solvents for carvacrol dispersion, which affect the antifungal activity [26,42]. Methods by which MIC is evaluated (liquid or agar medium), as well as the difference in culturing techniques, cannot be excluded [20,43].…”

“…The number of spores in the mother suspension was counted using a hemocytometer calculator with light microscopy before being diluted to be about 10 6 spores/mL. Next, the number of cells per average square was counted (area: 0.0025 mm 2 ; depth: 0.2 mm) using microscopy before being diluted to 10 6 spores/mL [26].…”

Biowastes of slaughterhouses and wet markets: an overview of waste management for disease prevention

“…Segregation processes are key for reducing the health risk of slaughterhouse and wet market wastes and minimizing the survivability of infectious agents, where the solids in wastewater contribute effectively to the colonization of microbes. After segregation, the solid wastes from slaughterhouses and wet markets are collected and stored in a refuse room not exceeding 24 h to minimize the growth of fungi and bacteria (Noman et al 2016 ). The solid wastes separated during different processes are skin trimmings, meat trimmings, dung, and rumens.…”

Qualitative Characterization of Healthcare Wastes

“…The application of segregation process would lead to minimize the economic cost for the clinical waste management which needs a special transportation and treatment due to their hazardous contents. The storage process for the clinical wastes before the treatment process or the transportation to the incineration is a temporary process; according to Saini et al (2004), the storage period should be less than 24 h. However, in the small clinics, these wastes are collected and stored for few months (Noman et al 2016b). The long period of the storage represents a contamination point for the hospital or clinics with several pathogens.…”