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Microbial biofilm formed on abiotic surfaces is an important area of research because of the wide range of possible affects and the disinfectant resistance of the cells. The colonization of solid surfaces by microorganisms is a very complicated process that depends mostly on extracellular molecule production. The biosynthesis of EPS reflected not only the attachment and aggregation process but also provided an optimal environment for the exchange of genetic material between the cells. The comparative and comprehensive analysis of all documented data concerning EPS production can enable the development and effective control strategies for biofilms. In this review some of the basic concepts concerning the biosynthesis of EPS and potential function of these compounds in biofilm development were discussed. In the paper the positive and negative aspects of EPS production in the environment also were described. [ABSTRACT FROM AUTHOR]

Aims: The effect of wheat kernel medium supplementation with octanoic acid on the formation of PR toxin and some volatiles by Penicillium roqueforti was investigated. Methods and Results: Octanoic acid was added to the medium once, prior to inoculation (4·55 mg g -1 ), or periodically (total 27·3 mg g -1 ) during the 10 day course of incubation. No octanoic acid was added to the reference sample. Levels of 2-heptanone, 2-heptanol and aristolochene, a volatile intermediate in PR toxin biosynthesis, were monitored using a solid phase microextraction (SPME) technique. The contents of PR toxin and ergosterol were determined after incubation. Aristolochene was observed in the reference sample, and 10·4 mg kg -1 of PR toxin was detected after 10 days. In cultures periodically supplemented with octanoic acid, no aristolochene or PR toxin were observed. However, in samples supplemented with octanoic acid only prior to incubation, the aristolochene level was 25% that in the reference sample, and PR toxin content was 3·4 mg kg -1 . Significance and Impact of the Study: These data suggest that a high level of octanoic acid in the medium prevents PR toxin formation by P. roqueforti . [ABSTRACT FROM AUTHOR]

Abstract: 1,3-Propanediol (1,3-PD) production by fermentation of glycerol was first described in 1881 but little attention was paid to this biosynthesis for over a century. An increasing interest in microbial 1,3-PD production is observed since late 1980s. The high growth rate of the biofuel market and the perspective of glycerol becoming abundant attract even more attention to this valuable chemical. Glycerol conversion to 1,3-PD is known to occur in Clostridia, Enterobacteriaceae and Lactobacillaceae. Some clostridial species are among the best 1,3-PD producers. This work is a review of the current state of research on Clostridium spp. strains that ferment glycerol to 1,3-PD. It focuses on the metabolic pathways and factors that influence the production of this diol. The effects of different environmental stresses on the process of 1,3-PD synthesis are also covered. Moreover, various genetic engineering methods utilized in order to improve the capabilities of bacteria used in this process are presented. [Copyright &y& Elsevier]