Biotechnology Letters 23: 893–898, 2001. © 2001 Kluwer Academic Publishers. Printed in the Netherlands. 893 Environmental concentrations of polyhydroxyalkanoates and their potential as bioindicators of pollution L.J.R. Foster 1,∗ , A. Saufi 1 & P.J. Holden 2 1 Department of Biotechnology, The University of New South Wales, UNSW-Sydney NSW 2052, Australia 2 Australian Nuclear Science & Technology Organisation (ANSTO), Lucas Heights, NSW 2258, Australia ∗ Author for correspondence (Fax: +61 2-9313-6710; E-mail: J.Foster@unsw.edu.au) Received 19 February 2001; Revisions requested 2 March 2001; Revisions received 26 March 2001; Accepted 27 March 2001 Key words: bioindicator, environment, pollution, polyhydroxyalkanoates Abstract A quick and inexpensive protocol based on gas chromatography was used to identify and measure environmental concentrations of microbial polyhydroxyalkanoates, PHAs. Samples taken from apparently unpolluted sites char- acterised by agricultural land or native vegetation possessed concentrations ranging from 0.12 to 0.40 mg PHA per g sample. In contrast, environments impacted by anthropogenic activity displayed concentrations 14 to 40 times higher. The results support the suggestion that PHAs could be used as pollution bioindicators in preliminary assessments of environmental health. Introduction Environmental monitoring of polluted environments is reliant upon expensive and somewhat time-consuming chemical analysis of organic and inorganic contami- nants. The monitoring of these hazardous chemicals is usually only applied to localised sites where a pollu- tion spill is known to have occurred. The application of bacterial markers as bioindicators of pollution could provide advanced warning of pollution prior to its im- pact at higher trophic levels and devastation of the ecosystem. Polyhydroxyalkanoates (PHAs) are a diverse fam- ily of intracellular biopolymers synthesised by a wide range of microorganisms under conditions of nutri- ent stress. The accumulated biopolymer serves as a carbon and energy source and, in certain genera, as an ion sink. Similarly, PHAs play an important role in encystment and sporulation (Dawes & Senior 1973). PHAs have potential as biodegradable replace- ments for conventional bulk commodity plastics and therefore promote sustainable development (Braunegg et al. 1998). Despite the relative wealth of research reporting their environmental biodegradation, there is, however, comparatively little data on their en- vironmental occurrence (Deinema 1972, Wallen & Rohwedder 1974, Odham et al. 1986, Mas-Castella & Guerrero 1995). The biota in environmental samples can be induced to produce significant concentrations of PHAs (Nickels et al. 1979). In contrast, ‘natural’ concentrations of PHAs are significantly lower occur- rence (Deinema 1972, Wallen & Rohwedder 1974, Odham et al. 1986, Mas-Castella & Guerrero 1995, Nickels et al. 1979). In their research measuring envi- ronmental PHA concentrations in sediment, Findley & White (1983) speculated that PHAs might be used to elucidate the nutrient history of the sampling environ- ment. In this paper we report on the concentrations of PHAs from a variety of environments including those impacted by anthropogenic activity, and discuss the possibility of using PHAs as preliminary indicators of environmental health. Materials and methods Environmental sampling Approximately 35–45 g of solid sample material were taken from a variety of environments as shown in Table 1, and frozen during storage.