Mussel Processing Research Articles

Metabolic responses of the marine mussel Mytilus galloprovincialis after exposure to microplastics of different shapes and sizes

Microplastics (MP) are ubiquitous pollutants with diverse shapes, sizes, and characteristics that pose critical risks to marine organisms and the environment. In this study, we used the Mediterranean mussel Mytilus galloprovincialis as a marine benthic organism model to investigate the metabolic consequences of exposure to different polyethylene terephthalate MP sizes and shapes: round (27–32 μm), small fibers (200–400 μm), large fibers (3000 μm), small fragments (20 μm), medium fragments (45–75 μm), and large fragments (>150 μm). After exposure to high concentrations (100 mg L−1) of MP for 14 days, round and small fiber-type MP were highly accumulated in mussels. Metabolomic analysis revealed that exposure to round and small fiber-type MP induced significant changes in 150 metabolites. Partial least squares-discriminate analysis (PLS-DA) showed that the round and small fiber MP treatment groups displayed similar cluster patterns that differed from those of the control group. In addition, only 22 annotated metabolites related to histidine, valine, leucine, and isoleucine degradation/biosynthesis and vitamin B6 and aminoacyl-tRNA biosynthesis were significantly affected by round or small fiber-type MP. Among the histidine metabolites, round and small fiber-type MP upregulated the levels of L-histidine, L-glutamate, carnosine, imidazole-4-acetaldehyde, 4-imidazolone-5-propanoate, and methylimidazole acetaldehyde and downregulated methylimidazole acetic acid and N-formimino-L-glutamate. These results suggest novel insights into the potential pathways through which MP of specific sizes and shapes affect metabolic processes in mussels.

Perfluoroalkyl substances (PFAS) occurrence, concentrations and spatial distribution along the French Mediterranean coast and lagoons, based on active biomonitoring

Tracking PFAS in ecosystems is challenging. In this context, monitoring programs are crucial to fill data gaps, especially in marine environments, which are the ultimate outlets for these forever chemicals. The 2021 chemical contamination monitoring campaign along the French Mediterranean coast established a baseline for PFAS concentrations in mussels, with 90 % of measurements below quantification limits. When detected, long-chain PFCA's were predominant. Spatial distribution patterns suggested continuous PFAS inputs and complex dynamics, shaped by the influence of large watersheds and rivers (Rhône, Aude, Huveaune). Lapeyrade shallow lagoon stood out as the most contaminated site. Similar PFAS profiles in connected sites implied shared sources but raised questions about accumulation processes in mussels. While certain sites had evident sources (e.g., military airbase for Palo lagoon), others remained uncertain (e.g., Toulon bay). Coastal stations (Banyuls, Cap Agde, Brégançon, Pampelonne) showed PFAS contamination without clear onshore sources, possibly due to insufficient transportation process understanding.

Comparative antioxidant and metabolomic analysis for the identification of differential response of mussel (Mytilus coruscus) to four succinate dehydrogenase inhibitor fungicides.

Succinate dehydrogenase inhibitor fungicides (SDHIs) are frequently detected in the marine environment. However, studies on the toxicity of SDHIs to marine organisms, Mytilus coruscus (M. coruscus), are poorly reported. Therefore, the antioxidant activities and metabolomic response of four SDHIs, namely, boscalid (BC), thifluzamide (TF), fluopyram (FO), and bixafen (BIX), to (M. coruscus), were comprehensively investigated. The antioxidant activity of BC and TF was significantly increased (p<0.05), whereas those of FO and BIX were significantly decreased. Furthermore, metabolite discriminations among M. coruscus to four SDHIs were illustrated by an untargeted metabolomics approach. A total of 52, 50, 93, and 129 differential metabolites were obtained for BC, TF, FO, and BIX. KEGG of the different metabolites show that the four SDHIs had differential effects on the metabolic pathways of M. coruscus. The current study demonstrated four SDHIs triggered glucose metabolism, lipid metabolism, tricarboxylic acid cycle, and oxidative phosphorylation processes and caused the disruption of nutrient and energy conversion processes in mussels. Finally, five biomarkers were screened by analyzing common differential metabolites that emerged from the four SDHI exposures, which could be used for risk assessment of marine ecosystem exposure to SDHIs. Our results demonstrated the use of metabolomics to understand the potential mechanisms of toxicity of four SDHIs to mussels and to identify potential targets for future targeted risk assessment.

Molecular confirmation of pearl formation in arctic mussels (Mytilus edulis) caused by Gymnophallus bursicola (Odhner 1900) metacercariae.

In recent field studies, suspected gymnophallid metacercariae were histologically located in the mantle of mussels from the Norwegian Sea. Mussels from the sites in which that infection was detected also presented abnormally high pearl numbers. It has been previously described that gymnophallid metacercariae could cause pearl formation processes in mussels, as a host reaction to encapsulate these metacercariae. Given the pathological host reaction these parasites elicit, a study was performed to identify gymnophallid metacercariae found in mussels collected from Tromsø at morphological and molecular level and to assess, by the use of molecular tools, the relationship between the parasite and the biological material inside the pearls. As a result, Gymnophallus bursicola metacercariae infecting Norwegian Mytilus edulis were identified according to morphological characters, along with the first 18S rDNA and COI sequences for this trematode species. In addition, parasite DNA from the core of the pearls was extracted and amplified for the first time, confirming the parasitological origin of these pearls. This procedure could allow identifying different parasitic organisms responsible for the generation of pearls in bivalves.

Nisin Production from Waste: A Review

Nisin is a bacteriocin produced by microbial fermentation of the well-known starter culture for dairy products, Lactococcus lactis. A major challenge in food safety and security is the prevention of the emergence of unwanted microbes. Artificial preservatives added to prolong the shelf life of foods may have negative effects on consumer health. An alternative approach is to use bio-preservatives. However, the cost of production of nisin is relatively higher than other chemical-based alternatives, because of which it has low marketability. Traditional production techniques are expensive and harmful to the environment. This review investigates sustainable alternatives employing waste products as fermentation substrates, including whey, corn stover, cane molasses, soya-bean cake, bean pulp and mussel processing waste. These eco-friendly strategies minimize negative environmental effects while providing resource and cost-efficient solutions. This review demonstrates the possibility for India to become self-sufficient in nisin production and reduce reliance on imports by emphasizing waste-to-value techniques. Keywords: Nisin, Bio-preservatives, Waste-to-value, Sustainable, Eco-friendly

Liquid Side Streams from Mussel and Herring Processing as Sources of Potential Income.

The seafood industry generates significant amounts of process waters which can generate value upon recovery of their nutrients. Process waters from the herring marination chain and cooking of mussels were here characterized in terms of crude composition, volatile compounds, and nutritional and potentially toxic elements. Protein and total fatty acid contents of herring refrigerated sea water (RSW) reached 3 and 0.14 g/L, respectively, while herring presalting brine (13%) reached 16.3 g/L protein and 0.77 g/L total fatty acid. Among three herring marination brines vinegar brine (VMB), spice brine (SPB), and salt brine (SMB), SPB reached the highest protein (39 g/L) and fatty acids (3.0 g/L), whereas SMB and VMB at the most had 14 and 21 g protein/L, respectively, and 0.6 and 9.9 g fatty acids/L, respectively. Essential amino acid (EAA) in marination brines accounted for up to 59% of total amino acid (TAA). From mussel processing, cooking juice had more protein (14-23 g/L) than the rest of the process waters, and in all water types, EAA reached up to 42% of TAA. For all process waters, the most abundant nutritional elements were Na, K, P, Ca, and Se. The content of all potentially toxic elements was mostly below LOD, except for As which ranged from 0.07 to 1.07 mg/kg among all tested waters. Our findings shed light on liquid seafood side streams as untapped resources of nutrients which can be valorized into food/feed products.

Physicochemical Characterization of Calcium Oxide from Freshwater Mussel (Pilsbryoconcha sp.) Shell

Freshwater mussel (Pilsbryoconcha sp.) shells have a proportion of 51.93%, which is included in the solid waste resulting from the processing of mussels. In fact, mussel shells are rich in minerals, especially high calcium, with a calcium content of 39.55%. So innovation is needed so that the utilization of mussel shells is maximized. One way is through the valorization of mussel shells into products with high added value. This study aimed to determine the physicochemical characteristics of the CaO (calcium oxide) extract of freshwater mussel shells. Valorization of mussel shells into calcium oxide (CaO) flour by calcination method at 1000°C temperature. The test parameters were yield, functional groups using the FTIR instrument, macro (calcium, potassium, magnesium, phosphorus) and micro minerals (Manganese, zinc, iron, and sodium) using the AAS instrument. The results showed that the physicochemical characteristics of calcium oxide (CaO) flour from the shell of the freshwater mussel (Pilsbryoconcha sp.) included: the proportion of shell 51.90%, the proportion of meat and viscera 48.10%; CaO yield of 56.47%; identified the Ca-O group at a wavelength of 1 661, 1 409, 1 116, and 875 cm-1; and dominated by calcium content of 76.27% to potential as a calcium precursor in the synthesis of hydroxyapatite.

Waste biorefinery towards a sustainable biotechnological production of pediocin: Synergy between process simulation and environmental assessment

The development of biotechnological processes through which high added value products can be obtained, using non-valuable industrial streams, has become a primary objective in the scope of sustainability and circular economy strategies. It is in this context where this research report is framed, in which a biorefinery approach has been developed using mussel processing wastes (MPW) as a resource, thus avoiding the environmental impacts involved in their management. Through an enzymatic pre-treatment and a batch fermentation process, this waste stream is valorized, and three high added value products are obtained: pediocin, lactic acid and crude protein. To develop comparative scenarios, a detailed analysis of the environmental impacts associated with the production of pediocin at two purity levels (2.5 % and 95% w/w), using the MPW and a commercial fermentation medium (MRS) has been performed by applying the life cycle assessment (LCA) methodology. The results obtained show the great potentiality of MPW as C-source, both from an environmental, economic and technological point of view since, when compared with MRS, the carbon footprint is reduced from 24.02 to 15.87 and from 23.85 to 15.66 kg CO 2 eq/kg of products for a purity of 2.5% and 95% w/w of pediocin, respectively. Besides, analogous impact reduction values are observed for the rest of the impact categories evaluated. However, certain hot spots have been identified, which future improvement studies should focus: energy and calorific requirements, mainly, as a contribution higher than 50% is observed for most of the impact categories. • Valorization of mussel processing waste (MPW). • Large scale simulation using SuperPro Designer tool. • Life Cycle Assessment and environmental analysis. • High and low purity pediocin, lactic acid and crude protein co-production. • MPW as a promising C-source for biotechnological fermentation processes.

A comparative study of the effect of different cooking methods on the quality and shucking of mussels

Fresh mussels (Mytilus galloprovincialis) were heat-treated for various time intervals, using moist-heat and dry-heat processes such as boiling, steaming, baking, and microwaving. The effect of heat treatment methods on cooking loss and shucking (shell opening) of mussels was investigated. All heat treatment methods succeeded 100% shell opening. Results indicated that cooking loss and shell opening of the heat-treated mussels significantly increased with increasing process time. The cooking loss was for the majority of the heat-treated mussels higher than 20% while greater cooking loss values were recorded for the steam-treated mussels. Microwave heating scored better results in shell opening of the mussels compared to the other methods. Multiple response optimization of process parameters revealed that the microwave treatment was found to be the optimal for improving the quality (cooking loss) and the efficiency of shell opening of mussels. The color of the heat-treated mussel meat was more or less orange. Practical applications Nowadays, the food industry faces the challenge to explore new methodologies in order to improve the quality characteristics of their products and, thereby, gain the consumers acceptability. During mussel heat processing, cooking loss is a very important factor strongly related to the heat treatment methods and affects the quality and yield of the final product. Although heating may lead to significant cooking losses, it is required in order to facilitate the shucking of mussels. To address this matter, in this study, the effect of different heat treatment methods on cooking loss and shell opening of mussels are investigated. The results suggest that the microwave heat treatment method can potentially be implemented in industrial mussel processing, guarantying better quality end products than the other methods do.

Sustainable alternatives for by-products derived from industrial mussel processing: A critical review

The industrial mussel processing generates significant quantities of waste. Nearly 30% of one metric tonne of processed mussel is finally destined for human consumption. Regardless of the mussel commodities, an important quantity of waste is concentrated at several sub-processes, such as input reception, washing and declumping shells, and mussel meat extraction stages, or by means of the rejection of mussels only due to a size characteristic criterion established by the target market. Despite the main segregated waste comprising shells, byssus threads, residual meat and wastewater, a heterogeneous composition must be taken into account, since much of the solid waste is commonly gathered and compacted for landfill transportation purposes. This paper reviews the sustainable management strategies for mussel by-products, addressing their limitations for an industrial implementation to obtain value-added products. It is concluded that, although there is a well-known diversity of waste sustainable management alternatives, several proposed products (e.g., collagen, bio-adhesives, biopolymer, and adsorbent for pollutants) still remain in a potential framework, circumscribed into laboratory results, subject to an optimization process, to a validation by industrial pre-scale trials, or even limited by the associated production costs. Future researches should focus on reducing the uncertainties linked with their technical–economic feasibility for an industrial scale development.

Recovery of Polyhydroxyalkanoates from Cooked Mussel Processing Wastewater at High Salinity and Acidic Conditions

Polyhydroxyalkanoates (PHA) are biodegradable polymers that can be intracellularly produced by microorganisms valorizing organic-rich wastes. In the present study, a PHA production system was fed with mussel cooker wastewater after acidogenic fermentation. Besides low pH (4.0 ± 0.3) and high salt (21.7 ± 2.9 g NaCl/L) concentrations, this wastewater also contained nitrogen concentrations (0.8 ± 0.1 g N/L), which were previously reported to be a challenge to the PHA accumulating bacteria enrichment. Bacteria with a PHA storage capacity were selected in an enrichment sequencing batch reactor (SBR) after 60 days of operation. The enriched mixed microbial culture (MMC) was mainly formed by microorganisms from phylum Bacteroidetes, and genera Azoarcus, Comamonas and Thauera from phylum Proteobacteria. The MMC was able to accumulate up to 25 wt% of PHA that was mainly limited by the wastewater nitrogen content, which promoted biomass growth instead of PHA accumulation. Indeed, when the presence of nutrient was limited, PHA stored in the accumulation reactor increased to up to 40.9 wt%. This work demonstrated the feasibility of the enrichment of a MMC with a PHA storage ability valorizing the fish-canning industrial wastewater at low pH, which is generally difficult to treat in wastewater treatment plants.

Review on extraction of polyhydroxyalkanoates and astaxanthin from food and beverage processing wastewater

The recovery of value-added products from food and beverage processing wastewater, polyhydroxyalkanoates, and astaxanthin, via various chemical and microbiological extraction techniques has been summarized in this contribution. While wastewaters from several food industries like olive oil, brewery, starchy, and agro-cultural have been utilized to produce polyhydroxyalkanoates as an alternative to the petrochemical sources, seafood wastewaters such as mussel processing, shrimp cooking, and chitin production have been used to recover astaxanthin. In these studies, the wastewater's carbon content has been found as an essential parameter for the recovery of polyhydroxyalkanoates and astaxanthin. The type of additional nitrogen source, microorganism properties, ambient conditions, and polymer extraction methods were mostly examined parameters for the polyhydroxyalkanoate recovery. Olive oil mill wastewater has been presented as one of the most promising industries for the recovery of polyhydroxyalkanoate with the highest polymer yield of 4.93 g L−1. Shrimp cooking wastewaters provide one of the highest astaxanthin yields as 10–13 μg mL−1. In addition to summarizing polyhydroxyalkanoates and astaxanthin yields from various wastewaters, technological obstacles and solutions regarding efficient extraction and large scale production have been discussed in this review.

Volatile fatty acid production from saline cooked mussel processing wastewater at low pH

The production of VFA using as substrate the wastewater produced in a cooked mussel processing factory, containing large COD (13.7 ± 3.2 g COD/L), salt concentrations (21.8 ± 2.8 g NaCl/L) and characterized by low pH (4.6 ± 0.6) was evaluated. This wastewater was fed to a 5-L completely stirred tank reactor operated in continuous mode. The conversion efficiency of its COD content into volatile fatty acids (VFA) was evaluated. The maximum acidification of 43% (total VFA on soluble COD basis) was obtained when an organic loading rate of 2.5 ± 0.4 g COD/(L·d) was applied to the reactor and corresponded to a VFA volumetric productivity of 0.72 ± 0.07 g CODVFA/(L·d). Under steady-state conditions, the obtained mixture of VFA was composed by 80:18:2 as acetic:propionic:butyric acids (percentage of VFA on soluble COD basis). Carbohydrates were degraded up to 96% while protein fermentation did not take place, probably due to the low pH value, limiting the maximum acidification of the wastewater. Batch experiments showed that the increase of the pH from 4.2 to 4.9 by the addition of NaHCO3 resulted in the improvement of the acidification and changed the VFA mixture composition. Thus, this study demonstrates the opportunity of using complex substrates, as cooked mussel processing wastewater, to produce rich-VFA streams under unfavourable operational conditions, such as high salinity and low pH.

Optimization of an enriched mixed culture to increase PHA accumulation using industrial saline complex wastewater as a substrate

Polyhydroxyalkanoates (PHA) appear as good candidates to substitute conventional petroleum-based plastics since they have similar properties but with the advantage of being biodegradable. Wastewater streams with high organic content are feasible substrates for PHA production resulting in an opportunity for waste recovery. One of the main challenges is the optimization of the selection of microorganisms with high PHA storage capacity. This microbial selection is performed in sequencing batch reactors (SBR) operated under an aerobic feast/famine (F/F) regime. In the present study, a settling stage was added at the end of the feast phase of the enrichment cycle of a SBR fed with pre-acidified cooked mussel processing wastewater (containing up to 12 g NaCl/L). Settling and subsequent supernatant discharge favoured the wash-out of non-accumulating microorganisms as well as the removal of substances that enhanced their undesired development (proteins and carbohydrates). Microbial analysis performed by fluorescence in situ hybridization (FISH) technique showed shifts in the microbial community; the presence of genus Paracoccus increased whereas genera Comamonas decreased. Moreover, the process efficiency was improved with the increase of the PHA production yield (YPHA) and the maximum PHA storage capacity (max. PHA) from 0.48 to 0.72 CmmolPHA/CmmolVFA and from 40 to 60 wt%, respectively. The polymer composition also changed, its HB:HV ratio varied from 83:17 to 70:30. Results obtained in the present study showed that settling after the feast phase promoted the removal of carbon sources that did not contribute to PHA production and the washout of non-storing bacteria, which favoured the culture enrichment.

The Multixenobiotic resistance system as a possible protective response triggered by microplastic ingestion in Mediterranean mussels (Mytilus galloprovincialis): Larvae and adult stages

The emerging paradigm on plastic pollution in marine environments is that microsize particles (MPs) have far more subtle effects than bigger fragments, given their size range overlapping with that of particles ingested by filter-feeders. The impacts include gut blockage, altered feeding and energy allocation, with knock-on effects on widespread physiological processes. This study investigated whether ingestion of polystyrene MPs (PS-MPs) triggers protective processes in marine mussels. The Multixenobiotic resistance (MXR) system is a cytoprotective mechanism acting as an active barrier against harmful xenobiotics and a route of metabolite detoxification. Both larvae and adults were employed in laboratory experiments with different concentrations of 3-μm PS-MPs (larvae), and 3-μm and 45-μm PS-MPs (adults) matching size range of planktonic food through the mussel lifecycle. Embryos grown in the presence of 3-μm PS-MPs showed significant reduction of MXR activity and down-regulation of ABCB and ABCC transcripts encoding the two main MXR-related transporters P-glycoprotein and the Multidrug resistance-related protein, respectively. In adults, effects of PS-MPs were assessed in haemocytes and gills, which showed different modulation of MXR activity and ABCB/ABCC expression according to MP size (haemocyte and gills) or particle concentration (haemocyte). These data showed that modulation of MXR activity is part of a generalized response triggered by particle ingestion.

The Joint Effect of pH Gradient and Glucose Feeding on the Growth Kinetics of Lactococcus lactis CECT 539 in Glucose-Limited Fed-Batch Cultures.

Two glucose-limited realkalized fed-batch cultures of Lactococcus lactis CECT 539 were carried out in a diluted whey medium (DW) using two different feeding media. The cultures were fed a mixture of a 400 g/l concentrated lactose and a concentrated mussel processing waste (CMPW, 101.72 g glucose/l) medium (fermentation I) or a CMPW medium supplemented with glucose and KH2PO4 up to concentrations of 400 g glucose/l and 3.21 g total phosphorus/l, respectively (fermentation II). For an accurate description and a better understanding of the kinetics of both cultures, the growth and product formation by L. lactis CECT 539 were both modelled, for the first time, as a function of the amounts of glucose (G) added and the pH gradient (VpH) generated in every realkalization and feeding cycle, by using an empirical polynomial model. With this modeling procedure, the kinetics of biomass, viable cell counts, nisin, lactic acid, acetic acid and butane-2,3-diol production in both cultures were successfully described (R2 values > 0.970) and interpreted for the first time. In addition, the optimum VpH and G values for each product were accurately calculated in the two realkalized fed-batch cultures. This approach appears to be useful for designing feeding strategies to enhance the productions of biomass, bacteriocin, and metabolites by the nisin-producing strain in wastes from the food industry.

САНІТАРНА ОЦІНКА ВІДХОДІВ ВІД ПЕРЕРОБКИ МОРСЬКИХ ГІДРОБІОНТІВ, ЩО ВИКОРИСТОВУЮТЬ ДЛЯ ВИГОТОВЛЕННЯ КОРМІВ

САНІТАРНА ОЦІНКА ВІДХОДІВ ВІД ПЕРЕРОБКИ МОРСЬКИХ ГІДРОБІОНТІВ, ЩО ВИКОРИСТОВУЮТЬ ДЛЯ ВИГОТОВЛЕННЯ КОРМІВ

Production of a highly concentrated probiotic culture of Lactococcus lactis CECT 539 containing high amounts of nisin.

In this study, probiotic biomass and nisin productions by Lactococcus lactis CECT 539 were followed in two realkalized fed-batch cultures in diluted whey (DW) supplemented with KH2PO4 up to a total phosphorus concentration of 0.459g/L. Increased biomass (5.12g/L, 2.18 × 1010 CFU/mL) and nisin (235.23 BU/mL) concentrations were obtained in the culture fed concentrated whey and concentrated mussel processing waste (CMPW) medium supplemented with glucose up to a concentration of 400g/L (CMPW + G medium) compared with similar fed-batch fermentations in DW medium. In the second fed-batch fermentation, the feeding medium CMPW + G was supplemented with KH2PO4 up to a TP concentration of 3.21g/L. With this approach, increased production of biomass (5.49g/L, 2.33 × 1010 CFU/mL) and nisin (257.59 BU/mL) was obtained. Considering the substantial availability of these wastes at very low prices from local dairy and mussel processing plants in Galicia, their use as culture media could offer an attractive alternative for a low-cost production of probiotic biomass and nisin at a high scale.

Prospects for Biocontrol of Vibrio parahaemolyticus Contamination in Blue Mussels (Mytilus edulus)-A Year-Long Study.

Vibrio parahaemolyticus is an environmental organism normally found in subtropical estuarine environments which can cause seafood-related human infections. Clinical disease is associated with diagnostic presence of tdh and/or trh virulence genes and identification of these genes in our preliminary isolates from retail shellfish prompted a year-long surveillance of isolates from a temperate estuary in the north of England. The microbial and environmental analysis of 117 samples of mussels, seawater or sediment showed the presence of V. parahaemolyticus from mussels (100%) at all time-points throughout the year including the colder months although they were only recovered from 94.9% of seawater and 92.3% of sediment samples. Throughout the surveillance, 96 isolates were subjected to specific PCR for virulence genes and none tested positive for either. The common understanding that consuming poorly cooked mussels only represents a risk of infection during summer vacations therefore is challenged. Further investigations with V. parahaemolyticus using RAPD-PCR cluster analysis showed a genetically diverse population. There was no distinct clustering for “environmental” or “clinical” reference strains although a wide variability and heterogeneity agreed with other reports. Continued surveillance of isolates to allay public health risks are justified since geographical distribution and composition of V. parahaemolyticus varies with Future Ocean warming and the potential of environmental strains to acquire virulence genes from pathogenic isolates. The prospects for intervention by phage-mediated biocontrol to reduce or eradicate V. parahaemolyticus in mussels was also investigated. Bacteriophages isolated from enriched samples collected from the river Humber were assessed for their ability to inhibit the growth of V. parahaemolyticus strains in-vitro and in-vivo (with live mussels). V. parahaemolyticus were significantly reduced in-vitro, by an average of 1 log−2 log units and in-vivo, significant reduction of the organisms in mussels occurred in three replicate experimental tank set ups with a “phage cocktail” containing 12 different phages. Our perspective biocontrol study suggests that a cocktail of specific phages targeted against strains of V. parahaemolyticus provides good evidence in an experimental setting of the valuable potential of phage as a decontamination agent in natural or industrial mussel processing (343w).

Combination of food wastes for an efficient production of nisin in realkalized fed-batch cultures

Nisin production by Lactococcus lactis CECT 539 was studied in four realkalized fed-batch cultures in diluted whey with feeding with lactose- and glucose-containing substrates. The first and third cultures were fed with mixtures of whey (W) and a 400g/L concentrated glucose (CG), or with a concentrated mussel processing waste (CMPW) and CG, respectively.The second and fourth cultures were respectively performed under the same conditions as in the first and third fermentations. However, these cultures were supplemented with mixtures of W plus a 2% (w/v) yeast extract (WYE2) and CG (second culture), or with CMPW plus a 2% (w/v) yeast extract (CMPWYE2) (fourth culture) after sample extractions at 132 and 168h, respectively. From these times, each culture was fed with mixtures of WYE2 and CG, or CMPWYE2 and CG, respectively.The final concentrations of nisin obtained in the third (223.98BU/mL) and fourth (350.61BU/mL) cultures, fed with glucose-containing substrates (CG and CMPW), were considerably higher than those obtained in the first (108.00BU/mL) and second (158.53BU/mL) cultures fed with the mixture of lactose- and glucose-containing substrates (W and CG).