Development and Control of Bacterial Biofilms on Dairy Processing Membranes

Abstract

Membrane fouling is a major operational problem that leads to reduced membrane performance and premature replacement of membranes. Bacterial biofilms developed on reverse osmosis membranes can cause severe flux declines during whey processing. Various types of biological, physical, and chemical factors regulate the formation of biofilms. Extracellular polymeric substances produced by constitutive microflora provide an effective barrier for the embedded cells. Cultural and microscopic techniques also revealed the presence of biofilms with attached bacterial cells on membrane surfaces. Presence of biofilms, despite regular cleaning processes, reflects ineffectiveness of cleaning agents. Cleaning efficiency depends upon factors such as pH of the cleaning agent, temperature, pressure, cleaning agent dose, optimum cleaning time, and cross-flow velocity during cleaning. Among different cleaning agents, surfactants help to prevent bacterial attachment to surfaces by reducing the surface tension of water and interfacial tension between the layers. Enzymes mixed with surfactants and chelating agents can be used to penetrate the biofilm matrix formed by microbes. Recent studies have shown the role of quorum-sensing-based cell-to-cell signaling, which provides communication within bacterial cells to form a mature biofilm, and also the role of applying quorum inhibitors to prevent biofilm formation. Major cleaning applications are also summarized in Table 1.

Evaluation of a non-submerged cultivation assay combined to ESEM imaging for analysis of biofilms formed by dairy-associated sporeforming bacteria

“…At the morphological level, ESEM imaging showed that, non-submerged biofilms often displayed homogeneous matrix, previously reported to be less stable compared to their heterogeneous counterparts (Anand et al, 2014), enhancing the risk of cell dissemination into processing environments. These findings are interesting cues for the dairy industry.…”

A sequencing approach targeting the 16S rRNA gene unravels the biofilm composition of spiral-wound membranes used in the dairy industry

“…However, even with daily care, long-term fouling of the membranes remains a major issue affecting the performance of membrane systems and leads to expensive membrane replacements (Jirjis and Luque 2010;Anand et al 2014). For most dairy fluids, short-and long-term fouling results from the accumulation of proteins (Bégoin et al 2006) and minerals (Anand et al 2014) on membrane surfaces.…”

“…For most dairy fluids, short-and long-term fouling results from the accumulation of proteins (Bégoin et al 2006) and minerals (Anand et al 2014) on membrane surfaces. However, concerns around bacterial adhesion warrant further investigation in the dairy industry because of the great resilience of biofilms exposed to cleaning procedures (Tang et al 2009;Hassan et al 2010;Anand et al 2012;Anand and Singh 2013;Anand et al 2014) and the high bacterial counts observed in filtered products (Anand et al 2012). Biofouling, through biofilm development, has been reported in desalination plants (Matin et al 2011;Khan et al 2013;Levi et al 2016) and membrane bioreactors (Ivnitsky et al 2007;Malaeb et al 2013;Vanysacker et al 2014b).…”

“…The pioneer bacteria grow and modify surface properties, producing extra polymeric substances (EPS) that affect membrane performance and permit recruitment of other bacteria as the biofilm matures (LappinScott and Costerton 1989;Ivnitsky et al 2007;Vanysacker et al 2014a). In the dairy industry, biofouling may also result in serious quality issues for the filtered fluid and subsequent dairy products because of the presence of spore-forming or pathogenic bacteria on membranes (Burgess et al 2010;Anand et al 2014) and their concurrent microbial enzyme production (Raats et al 2011;Teh et al 2014). However, only a few studies described the microbial composition of biofilm detected on dairy processing membranes, and they have been limited to microscopy (Hassan et al 2010) or culture-based observations (Tang et al 2009;Tang et al 2010;Anand et al 2012;Anand and Singh 2013).…”

The current knowledge on the application of anti-biofilm enzymes in the food industry

“…Therefore, a relevant strategy for removing biofilms from industrial systems is to employ enzymes. Indeed, these have been used for the treatment of biofilms formed in food areas (Anand, Singh, Avadhanula, & Marka, 2014;Lequette, Boels, Clarisse, & Faille, 2010).…”