Xenobiotic compounds including pesticides, nitrophenols, pyridine, polycyclic aromatic compounds and polychlorinated biphenyls are widely spread in environment due to anthropogenic activities. Most of them are highly toxic to living beings due to their mutagenic and carcinogenic properties. Therefore, the removal of these compounds from environment is an essential step for environmental sustainability. Microbial remediation has emerged as an effective technology for degradation of these xenobiotic compounds as microorganisms have unique ability to utilize these compounds as their sole source of carbon and energy. The primary goal of this book is to provide detailed information of microbial degradation of many xenobiotic compounds in various microorganisms.

This book brings together contributions from global experts who have helped to facilitate the exciting and rapid advances that are taking place in microbial metabolomics. The main application of this field is in clinical and veterinary microbiology, but there is a great potential to apply metabolomics to help to better understand complex biological systems that are dominated by multiple-species microbial populations exposed to changing growth and nutritional conditions. In particular, environmental (e.g., water, soil), food (e.g., microbial spoilage, food pathogens), and agricultural and industrial applications are seen as developing areas for microbial metabolomics. As such, the book includes contributions with clinical, environmental, and industrial perspectives.

Stable isotope probing is a cultivation-independent technique that allows researchers to identify microorganisms that metabolize substrates that are labeled with stable isotopes. However, to understand the genetics and physiology of microbial processes, experiments using pure culture are often necessary. Polaromonas naphthalenivorans CJ2 was identified as a key member of the naphthalene-degrading community in coal tar-contaminated sediment, and was successfully isolated in pure culture. Using respirometry, metabolite detection by gas chromatography/mass spectrometry, and cell-free enzyme assays, strain CJ2 was shown to metabolize naphthalene via gentisate. Growth assays revealed that strain CJ2 is inhibited by naphthalene concentrations of 78 muM (10 ppm) and higher. Despite being able to use naphthalene as a carbon and energy source, strain CJ2 must balance naphthalene utilization against two types of toxicity. Naphthalene directly inhibited growth, and the accumulation of putative naphthalene metabolites resulted in the loss of cell viability. Stable isotope probing of benzoic acid metabolizing bacteria in agricultural soil revealed the role of Burkholderia species, and cultivation efforts led to isolation of a representative of the benzoic acid-degrading population, Burkholderia sp. strain EBA09. Growth of the population represented by EBA09 in the field was demonstrated using MPN-PCR. The potential for dynamic secondary ion mass spectrometry (SIMS) ion microscopy to complement SIP studies by measuring 13C assimilation into individual bacterial cells grown on 13C-labeled organic compounds was explored. A clear relationship between mass 27 and 26 signals in cells grown in media containing varying proportions of 12C- to 13C-glucose was observed; a standard curve was generated to predict 13C-enrichment in unknown samples. Differences in 13C signals measured by SIMS were shown to be due to 13C assimilation into cell biomass. The application of SIMS ion microscopy to soil samples from a field experiment receiving 12C- or 13C-phenol revealed that 13C-labeled cells were detected in soil that was dosed a single time with 13C-phenol, and in soil that received 12 doses of 13C-phenol, 27% of the cells in the total community were more than 90% 13C-labeled.

The ideal starting point for investigating, developing, and implementing stable isotope technologies. • Guides researchers through basic, tested, and proven protocols including DNA, RNA, protein, and phospholipid fatty acid (PLFA) SIP, from concept and history through detailed methodology, troubleshooting, and interpretation to optimal and future uses. • Explores important and emerging applications of SIP in environmental microbiology, ranging from bioremediation and gene mining to carbon tracking and gut microflora function. • Examines explorations of further elegant isotope labeling technologies such as Raman-FISH, NanoSIMS, and isotope arrays. • Serves as a valuable resource for environmental microbiology students and researchers and genomics, biotechnology, and medical microbiology professionals.

Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.