State Water Resources Research Institute Program
Project ID: 2011DE208B
Title: Predation of Bacteria by the White Rot Fungi, Pleurotus ostreatus
Project Type: Research
Start Date: 3/01/2011
End Date: 2/28/2012
Congressional District: At large
Focus Categories: Wastewater, Water Quality, Treatment
Principal Investigators: Chirnside, Anastasia; Harris, John Paul
Federal Funds: $ 1500
Non-Federal Matching Funds: $ 3000
Abstract: In 2010 the Environmental Protection Agency (EPA) proposed a revision to the Total Coliform Rule (TCR), a national primary drinking water regulation, that would "require public water systems that are vulnerable to microbial contamination to identify and fix problems, and establish criteria for systems to qualify for and stay on reduced monitoring, thereby providing incentives for improved water system operation." And while the white rot fungi have already been praised for their ability to degrade aromatic hydrocarbons such as pyrene, anthracene, phenanthrene (Aggelis et al., 2003) via their ligninolytic extracellular enzymes, some of the white rot fungi in the genus Pleurotus have also been shown to be predatory on bacteria.
Under low nutrient conditions very fine directional hyphae of Pleurotus ostreatus have been seen to actively search out and enter nearby micro-colonies of bacteria. These hyphae ramify within the colony and form haustoria-like branches of specialized cells that secrete lytic and other enzymes capable of destroying and digesting the bacteria (Barron, 2003). Predations of specific species of bacteria have not been described and the potential for Pleurotus ostreatus to degrade some of the more problematic bacteria such as fecal coliform has yet to be explored.The primary objectives of this research are to determine the effectiveness of Pleurotus in degrading harmful bacteria and assess its potential as a practical biofilter. The steps towards these objectives are: (1) Confirming strains of Pleurotus are predatory upon bacteria other than the N-fixing types; (2) Constructing a simple reactor/biofilter using the fungi in an attempt to quantify the predation; (3) Measuring the nutrient levels of the effluent; (4) Determining bacterial content of the reactor biomass over time and after digestion.
Progress/Completion Report, 2011, PDF