Section Four
BIOLOGICAL SYSTEMS-A. GENERAL
31    DEGRADATION OF ACETONITRILE BY
PSEUDOMONAS AERUGINOSA
Mohamed Nawaz, Research Associate
Juddie D. Richardson, Student
Kirit D. Chapatwala, Chairman
Division of Natural and Applied Sciences
Selma University
Selma, Alabama 37601
James H. Wolfram, Task Leader
Biotechnology, INEL EG & G,
Idaho, Inc.
Idaho Falls, Idaho 83415
INTRODUCTION
Nitrile compounds and their derivatives are used in increasing amounts in a number of industrial
operations as chemical solvents, extractants and recrystallizing agents. Consequently, there is also a
concomitant increase in the dissemination of these chemicals into the environment via the industrial
waste water streams. Increasing accumulation of such compounds in the ecosystem may cause deleterious effects, as most of them are highly toxic and tend to destabilize the ecological balance, by
inhibiting beneficial microbial growth. Currently, a number of these compounds are listed as priority
pollutants by the Environmental Protection Agency.1 Biodegradation, the microbial transformation
of organic compounds, has been recognized as an effective process for the removal of toxic chemicals
from the environment.
Microbial ecosystems exposed to cyanide in the soil especially in sewage plants treating industrial
waste water have been studied.2 However, only a few reports have appeared, on pure cultures utilizing
cyanide as sole carbon substrate. A majority of these microorganisms were strictly autotrophic
actinomycetes3 and just a few microbial strains such as Arthobacter4^ Brevibacterium6-^ and Rhodo-
coccus sp9 were shown to hydrolyse nitrile compounds into amides. Little is known about microorganisms utilizing acetonitrile, a methyl cyanide of increasing industrial use and having potential of
becoming a major pollutant, as a substrate. Our present study was undertaken to isolate and characterize various bacteria that were able to use acetonitrile, as the sole carbon source and to define the
optimal conditions for growth of such organisms. This report describes one such isolate.
MATERIALS AND METHODS
Chemicals
AH nitrile compounds were purchased from Aldrich Chemical Company, Milwaukee, WI. Acetonitrile (14C) (sp.act. 3.0 mCi/mM, purity 99.0%) was purchased from Pathfinder Laboratories, Inc.,
St.Louis, MO. Aquasol-2 was purchased from NEN Research Products, MA.
Cultures and Media
Acetonitrile-utilizing bacteria were isolated from contaminated industrial soil and water, by use of a
phosphate buffer medium (PBM), consisting of the following (g/1): K2HP04, 4.3; KH2P04, 3.4;
(NH4)2S04, 2.0; MgCl2-H20, 0.3; amended with 0.5 ml of the trace element solution containing
43rd Purdue Industrial Waste Conference Proceedings, © 1989 Lewis Publishers, Inc., Chelsea, Michigan 48118.
Printed in U.S.A.
251