Unraveling Microbial Biofilms of Importance for Food Microbiology

Abstract

The presence of biofilms is a relevant risk factors in the food industry due to the potential contamination of food products with pathogenic and spoilage microorganisms. The majority of bacteria are able to adhere and to form biofilms, where they can persist and survive for days to weeks or even longer, depending on the microorganism and the environmental conditions. The biological cycle of biofilms includes several developmental phases such as: initial attachment, maturation, maintenance, and dispersal. Bacteria in biofilms are generally well protected against environmental stress, consequently, extremely difficult to eradicate and detect in food industry. In the present manuscript, some techniques and compounds used to control and to prevent the biofilm formation are presented and discussed. Moreover, a number of novel techniques have been recently employed to detect and evaluate bacteria attached to surfaces, including real-time polymerase chain reaction (PCR), DNA microarray and confocal laser scanning microscopy. Better knowledge on the architecture, physiology and molecular signaling in biofilms can contribute for preventing and controlling food-related spoilage and pathogenic bacteria. The present study highlights basic and applied concepts important for understanding the role of biofilms in bacterial survival, persistence and dissemination in food processing environments.

A halotolerant thermostable lipase from the marine bacteriumOceanobacillussp. PUMB02 with an ability to disrupt bacterial biofilms

“…26 It is not surprising then perhaps that maximum lipase production in Oceanobacillus PUMB02 was observed up to 7% NaCl and that upon purification and subsequent biochemical characterization that the lipase displayed a high level of stability over a wide range of both pH (3)(4)(5)(6)(7)(8)(9)(10)(11) and temperature (10-70 °C). This phenomenon of marine derived halotolerant lipases having a high level of stability over a range of pH and temperatures is common; with the Lpc53E1 lipase which was isolated from the metagenome of the marine sponge Haliclona simulans similarly displaying good activity across broad pH (3)(4)(5)(6)(7)(8)(9)(10)(11)(12) and temperature (4-60 °C) ranges. 16 While another metagenome derived lipase LipC12, isolated from a metagenomic library constructed from fat-contaminated soil collected from a wastewater treatment plant has also been reported to be stable up to 3.7 M NaCl and from pH 6 to 11 and to be active within the pH 4.5 to 10 range.…”

“…37 The biofilm phenotype typically confers an increased resistance to not only environmental stresses such as UV light but also resistance to various chemical cleaning agents including disinfectants, which are typically used in the food processing area, which makes elimination of these biofilms extremely challenging. 10 Enzymes have the potential to be employed in the removal of biofilms formed by food related microorganisms, with proteinase containing disinfectants being reported to be effective against biofilms of Lactobacillus bulgaricus, Lactobacillus lactis, and Streptococcus thermophilus. 38 Both the Oceanobacillus PUMB02 lipase and the recombinant Lpc53E1 lipase were effective in disrupting preformed biofilms of E. coli, B. cereus, Pseudomonas sp., Vibrio sp., Serratia sp., and Listeria sp; with the PUMB02 lipase being active against all biofilms tested, while the Lpc53E1 lipase was particularly active against E. coli biofilms (Fig.…”

“…9 In addition, biofilm formation by food pathogens is common in the food industry, where attachment to food products or to surfaces that are in contact with products leads not only to economic losses but also to an increased risk of occurrence of bacterial food borne diseases within the consumer food chain. 10 Most of the current procedures for the removal of biofilm rely on stringent chemical cleaning regimes of the colonized surfaces, with a wide range of biocides, sanitizers, and disinfectants being used in controlling biofilms. However these chemical agents have little or no effect on established biofilms.…”

Prevalence and risk of heterotrophic microorganisms in a carbonated soft drink factory

“…Biofilms have been described as accumulated mass of microorganisms and their extracellular matrix on a solid surface (O'Toole et al, 2000).The process of adhesion to surfaces includes a reversible phase and an irreversible molecular phase (Donlan and Costerton, 2002). Acccording to Winkelströter et al (2014) the biological cycle of biofilms depends on the organism and includes developmental phases such as initial attachment, maturation, maintenance, and dispersal. It is generally known that biofilms are difficult to remove from a food processing facility and may remain in the environment for a long period due to resistance to sanitizing agents (Chmielewski and Frank, 2003).…”

Effect of small chain N acyl homoserine lactone quorum sensing signals on biofilms of food-borne pathogens

“…were known to form biofilm in the food processing plants (Giaouris et al 2012). Biofilm formation by the pathogens protects the bacteria from environmental stress, increases their tolerance to biocides which makes it difficult to remove them from food processing environments (Winkelstroter et al 2014). Pathogenic Escherichia coli represents a significant risk to human health as these have specific biofilm formation factors which help in colonizing the gastrointestinal tract in hosts and also on abiotic surfaces (Yeom et al 2012).…”