Lower Microbial Load Research Articles

Microbial Level and Microbiota Change of Laver in Dried Laver Processing Line During Production Seasons

To understand better the high microbial load in dried laver (Porphyra yezoensis or nori), this study analyzed the aerobic plate count (APC), coliform count, temperature change, and microbiota of processing water, laver materials, and food contact surface (FCS) samples from three processing plants during the dried laver processing season from December 2023 to April 2024. The seawater used for the first washing had a low microbial load (APCs < 1–2.85 log CFU/g; coliform < 1 log CFU/g) and was dominated by Proteobacteria, Firmicutes, and Bacteroidota. The microbial load of fresh laver (4.21–4.76 log CFU/g) remained unchanged after seawater washing, but significantly increased after continuous shredding, sponge dehydration, first drying, and with the seasonal temperature rise. The microbiota of laver before drying was vulnerable between processing steps and seasons, but consistently shifted back to fresh laver microflora and was dominated by Flavobacteriaceae after drying. The FCSs (except for the curtain), which had a high microbial load (APCs 5.25–8.26 log CFU/g; coliform 1.52–4.84 log CFU/g) with similar microbiota to seawater, caused the secondary contamination of laver during processing. This study revealed the microbial proliferation of laver and seawater microflora in the continuous processing line with high nutrients and with the seasonal processing water temperature rise caused by the local weather, highlighting the need for routine cleaning and sanitizing, better washing of fresh laver, and low temperature control for future dried laver production.

BIOFILM DAIRY FOODS REVIEW: Microbial Community Tracking from Dairy Farm to Factory: Insights on Biofilm Management for Enhanced Food Safety and Quality.

This review aimed to assess the scope of the literature on tracking the microbial community of biofilms, focusing on the dairy farm and processing environments. The majority of studies focused on either production, storage, transport or processing of milk, while 5 combined the investigation of both production and processing facilities. Factors influencing short-term changes in dairy microbiota such as the occurrence of mastitis and season were distinguished from factors revealed through long-term studies, such as feed and weather, rather than the milking equipment. Knowledge gaps were identified in relation to the study design, methods, data analysis and interpretation. The application of DNA sequencing technologies is particularly challenging with respect to samples with low microbial load (milk, swabs). There are few studies on the microbial composition of in situ biofilms, which might require new technologies for detection before sampling. Fundamental studies on the structure of biofilms are needed to identify the on-farm practices impacting the cycle of biofilm development in milking systems.

Airway Mycobiota-Microbiota During Pulmonary Exacerbation of Cystic Fibrosis Patients: A Culture and Targeted Sequencing Study.

The airways of patients with cystic fibrosis (pwCF) harbour complex fungal and bacterial microbiota involved in pulmonary exacerbations (PEx) and requiring antimicrobial treatment. Descriptive studies analysing bacterial and fungal microbiota concomitantly are scarce, especially using both culture and high-throughput-sequencing (HTS). We analysed bacterial-fungal microbiota and inter-kingdom correlations in two French CF centres according to clinical parameters and antimicrobial choices. Forty-eight pwCF with PEx from Creteil (n = 24) and Lille (n = 24) CF centres were included over 2 years. Sputa were collected for culture and targeted-HTS (ITS2 and V3-V4 targets). Sequencing and culture data, along with clinical, radiological and treatment data, were analysed. Two-level stratified analysis was performed to study potential confounding factors (age, CF mutation, FEV1 and antibiotics) on the centre factor. Inter-kingdom correlations were analysed. Significant differences in the bacterial microbiota profile were found between centres (p-value = 0.03). For mycobiota, the taxonomic distribution and diversity were comparable. HTS provided concordant but more detailed information than culture and increased detection of main CF fungi (> 25% more positive samples for Aspergillus or Scedosporium). FEV1 and systemic antibiotic before PEx influenced bacterial microbiota, but no clinical association was found with the mycobiota. No inter-kingdom correlation between Pseudomonas and fungi was found. Describing concomitant bacterial and fungal communities of pwCF at the beginning of PEx using culture and HTS shows greater diversity in HTS and better detection in case of low microbial load. Interesting inter-kingdom correlations were observed, requiring further research on larger cohorts to understand the potential microbial interactions.

Standardisation and quality evaluation of millet-based Chikki using Quinoa and Bajra

Millet Chikki is a nutritionally enriched snack crafted from millet grains, an ancient gluten-free staple. This innovative take on traditional Chikki blends the goodness of millets with essential nutrients, catering to modern health-conscious consumers. Since, millets are known to be rich in proteins, fibre, vitamins, and minerals, it provides a sustainable source of energy. This study focuses on the standardization and quality evaluation of millet-based Chikki incorporating quinoa and bajra, with jaggery syrup as a sweetener. Three different formulations of Chikki were prepared: Sample-A (60% roasted quinoa, 30% jaggery syrup, 10% other ingredients), Sample-B (60% roasted bajra, 30% jaggery syrup, 10% other ingredients), and Sample-C (30% roasted quinoa, 30% roasted bajra, 30% jaggery syrup, 10% other ingredients). Sensory evaluation revealed that Sample-A had superior sensory attributes, including aroma, appearance, texture, taste, and overall acceptability, compared to Sample-B and Sample-C. Nutritional analysis showed that Sample-A had the highest energy content (699 kcal/100g) and a balanced nutrient profile. Antioxidant assays demonstrated significant free radical scavenging and reducing capabilities in Sample-A, while microbiological analysis confirmed its safety with low microbial load and absence of harmful pathogens. These findings highlight that the inclusion of roasted quinoa enhances both the sensory appeal and nutritional value of millet-based Chikki, making Sample-A the optimal formulation.

Enhancement of the quality and preservation of frozen burgers by active coating containing Rosa canina L. extract nanoemulsions

This study aimed to assess the impact of an edible coating holding within chia seed gum (CSG) and Rosa canina L. extract (RCE) nanoemulsions (10%, 20%, and 40% w/w) on the oxidation, microbial load, and sensory characteristics of burgers in a 90-day frozen storage period. Based on the findings, the active CSG coatings showed remarkable antioxidant and antimicrobial activities. By increasing the level of RCE nanoemulsions, the functional activity of coatings significantly increased (P < 0.05). Upon the termination of the storage period, the lowest microbial load (i.e., a decrease of 0.5–2 log CFU/g in the number of different bacteria compared to the control) and oxidation stability were observed in burgers coated with a CSG solution containing 40% RCE nanoemulsions. This burger also showed the highest sensory acceptance on the last day. In conclusion, it is proposed to use the active coating produced in this study to maintain meat products' quality and safety and increase their shelf-life.

Meconium microbiota in naturally delivered canine puppies

BackgroundMicrobial colonization during early life has a pivotal impact on the host health, shaping immune and metabolic functions, but little is known about timing and features of this process in dogs. The objectives of this study were to characterize the first step of intestinal microbiota development in naturally delivered canine puppies and to investigate its relationship with the maternal bacterial flora, using traditional culture and molecular analyses. Sixty puppies of two breeds, Appenzeller Cattle Dog (n = 3 dams) and Lagotto Romagnolo (n = 6), housed in the same breeding kennel, were included in the study. Swabs were collected in duplicate (for culture and for molecular analysis) from the dams’ vagina and rectum at the end of parturition, from puppies’ rectum, before maternal care, and from the environment (floor of the nursery and parturition box).Results93.3% meconium samples showed bacterial growth, limited to a few colonies in 57.0% of cases. High growth was detected for Enterococcus faecalis, which was the most frequently isolated bacterium. The genus Enterococcus was one of the most represented in the dams’ rectum and vagina (88.9% and 55.6%, respectively). The genera Staphylococcus, Enterococcus, Escherichia and Proteus were also often isolated in meconium but were usually present in maternal samples as well, together with ubiquitous bacteria (Acinetobacter, Psychrobacter). In the environmental samples, just a few bacterial species were found, all with low microbial load. Additionally, bacteria of the phyla Proteobacteria, Firmicutes, and Actinobacteria were identified in meconium through molecular analysis, confirming the culture results and the early colonization of the newborn gut. Maternal, meconium and environmental samples had similar alpha diversity, while beta-diversity showed differences among families (i.e. a dam and her litter), and association indexes revealed a significant correlation between family members and between sample origin, suggesting a strong contribution of the maternal flora to the initial seeding of the canine neonatal gut and a strong individual dam imprint.ConclusionThis study showed that the meconium of vaginally delivered puppies has its own microbiota immediately after birth, and that it is shaped by the dam, which gives a specific imprint to her litter.

Exploring bioactive compounds and antioxidant potentials in cake, biscuits, and papad innovations with wheatgrass powder (Triticum aestivum L.)

Wheatgrass has been attracting a lot of attention recently because of its potent nutritional profile and health benefits. This study's objective was to estimate the amount of phenolic and antioxidant activity in baked items prepared with wheatgrass. To prepare cakes and biscuits, wheatgrass powder (WGP) was substituted for wheat flour at 0, 5, 7, and 9 %. For papad, green gram flour was replaced by added WGP at 0, 3, 6, and 9 %. Total phenol, DPPH activity, and β-carotene levels were significantly greater in Cake C3 (9 %). Again, compared to other samples, papad P3 (9 %) had higher levels of flavonoids. The nutritional qualities of baked items were impacted by all levels of wheat flour substitution with wheatgrass powder; however, a 3–6 % substitution level is advised to improve the sensory qualities of these products. The papad and biscuits were microbiologically safe to store for up to 30 days and 60 days, respectively, due to their low microbial load. But after just six days of preparation, the cake was ruined. However, Wheatgrass can be used in baked products, pasta, and snacks, as well as juices and smoothies, to boost their nutritious content. Wheatgrass extracts can also be utilized as a natural food flavoring or coloring, giving it a distinctive green color.

Effects of Speleotherapy on Aerobiota: A Case Study from the Sežana Hospital Cave, Slovenia

Speleotherapy is one of the non-pharmacological methods for the treatment and rehabilitation of patients with chronic respiratory diseases, especially those with chronic obstructive pulmonary disease (COPD) and asthma. On the one hand, one of the alleged main advantages of speleotherapeutic caves is the low microbial load in the air and the absence of other aeroallergens, but on the other hand, due to the lack of comprehensive air monitoring, there is little information on the pristine and human-influenced aerobiota in such environments. The aim of this study was to assess the anthropogenic effects of speleotherapy on the air microbiota and to investigate its potential impact on human health in Sežana Hospital Cave (Slovenia). From May 2020 to January 2023, air samples were collected in the cave before and after speleotherapeutic activities using two different volumetric air sampling methods—impaction and impingement—to isolate airborne microbiota. Along with sampling, environmental data were measured (CO2, humidity, wind, and temperature) to explore the anthropogenic effects on the aerobiota. While the presence of patients increased microbial concentrations by at least 83.3%, other parameters exhibited a lower impact or were attributed to seasonal changes. The structure and dynamics of the airborne microbiota are similar to those in show caves, indicating anthropization of the cave. Locally, concentrations of culturable microorganisms above 1000 CFU/m3 were detected, which could have negative or unpredictable effects on the autochthonous microbiota and possibly on human health. A mixture of bacteria and fungi typically associated with human microbiota was found in the air and identified by MALDI-TOF MS with a 90.9% identification success rate. Micrococcus luteus, Kocuria rosea, Staphylococcus hominis, and Staphylococcus capitis were identified as reliable indicators of cave anthropization.

Comparison of the Effect of Drying Treatments on the Physicochemical Parameters, Oxidative Stability, and Microbiological Status of Yellow Mealworm (Tenebrio molitor L.) Flours as an Alternative Protein Source

The increasing production of edible insects on an industrial scale makes it crucial to implement appropriate technologies after harvesting to process safe and high quality insect products. The aim of this work was to compare the impact of different drying treatments used in the production of flour from Tenebrio molitor larvae. The larvae were subjected to freeze-drying (FD), conventional drying (CD), microwave drying (MWD), microwave drying without freezing prior blanching (MWDL), and microwave drying with addition of 0.1% butylated hydroxytoluene (BHT) during the blanching of the larvae (MWDA). The studied parameters included water activity (aw), instrumental colour, chemical composition, lipid oxidative processes, antioxidant activity, as well as microbiological status. The freeze-drying and conventional drying of the larvae reduced the aw of the derived flours (p &lt; 0.0001); however, their nutritional profile revealed lower protein (p &lt; 0.0001) and considerably higher fat content (p &lt; 0.0001) compared to the flours after microwave treatments. The conventional drying and microwave treatment with BHT induced significantly darker colour (p &lt; 0.0001) in comparison to the other methods. Despite the advantages of the microwave drying as a fast and energy efficient method, it displayed some negative effects associated with low lipid stability such as higher acid value (AV) and secondary products of lipid oxidation (TBARS) (p &lt; 0.0001). This was also observed in the MWDA flour, indicating a certain pro-oxidative effect of the BHT. Regardless of the drying method, all the flours had a low microbial load.

Effects of active film based on chitosan/polyvinyl alcohol on the quality of refrigerated sea bass (Lateolabrax Japonicus) fillets

There has been a growing interest in employing active films for fish preservation due to the environmental concern of plastic packaging and the high perishability of fish. This work aimed to develop active films (CPB0.8) based on chitosan/polyvinyl alcohol integrated with ginger essential oil (GEO) -loaded bacterial cellulose, and to evaluate the preservation effect of the films on refrigerated sea bass fillets. Different active films were obtained by the solution blending method. It was evaluated by measuring microbiological indicators, physicochemical indexes, and water loss of sea bass fillets. The sample wrapped by CPB0.8 film had a lower microbial load after 12 days of storage. The results showed that the sample wrapped by CPB0.8 film had a lower microbial load after 12 days of storage compared to the active film sample without GEO and the control sample. Besides, the reduction of hardness and springiness of fillets packaged with CPB0.8 film was markedly inhibited. Additionally, the fillets wrapped by CPB0.8 film indicated a lower K-value (56.54%) under the rejection limit (60%) on the 10th day, which confirmed that CPB0.8 films extended the shelf-life of fillets to 10 days. Also, the active packaging could preserve fish quality by controlling water migration and lipid oxidation. Overall, these findings indicate that CPB0.8 films can be useful for the preservation of fish and effectively reduce petroleum-based plastics.

A metatranscriptomics strategy for efficient characterization of the microbiome in human tissues with low microbial biomass

ABSTRACT The high background of host RNA poses a major challenge to metatranscriptome analysis of human samples. Hence, metatranscriptomics has been mainly applied to microbe-rich samples, while its application in human tissues with low ratio of microbial to host cells has yet to be explored. Since there is no computational workflow specifically designed for the taxonomic and functional analysis of this type of samples, we propose an effective metatranscriptomics strategy to accurately characterize the microbiome in human tissues with a low ratio of microbial to host content. We experimentally generated synthetic samples with well-characterized bacterial and host cell compositions, and mimicking human samples with high and low microbial loads. These synthetic samples were used for optimizing and establishing the workflow in a controlled setting. Our results show that the integration of the taxonomic analysis of optimized Kraken 2/Bracken with the functional analysis of HUMAnN 3 in samples with low microbial content, enables the accurate identification of a large number of microbial species with a low false-positive rate, while improving the detection of microbial functions. The effectiveness of our metatranscriptomics workflow was demonstrated in synthetic samples, simulated datasets, and most importantly, human gastric tissue specimens, thus providing a proof of concept for its applicability on mucosal tissues of the gastrointestinal tract. The use of an accurate and reliable metatranscriptomics approach for human tissues with low microbial content will expand our understanding of the functional activity of the mucosal microbiome, uncovering critical interactions between the microbiome and the host in health and disease.

Preventing Microbial Growth in Game Meat by Applying Polyphenolic Extracts from Olive Mill Vegetation Water.

We studied the efficacy of different formulations of polyphenol extracts (mainly containing hydroxytyrosol and tyrosol) from olive mill vegetation water on the microflora on the surfaces of game meat cuts with high or low initial bacterial loads. Meat with a high microbial load (>5 Log cfu/g; mean value = 6.83 ± 0.45 standard deviation) was immersed for 10 or 60 sec into 25% and 10% solutions of microencapsulated freeze-dried and non-encapsulated polyphenolic extracts. Aerobic colony, Enterobacteriaceae, Pseudomonas spp., and lactic acid bacteria counts were determined on treated samples compared to controls after 7 days of storage (in vacuum-packed conditions at +3 °C). Significant differences were registered only for aerobic colony count for a 10% liquid extract treatment (0.64 log reduction). In contrast, the dipping or immersion of game meat with low initial microbial loads (<5 Log cfu/g; mean value = 3.58 ± 0.72 standard deviation) in 10% solutions of the polyphenol extracts effectuated significant reductions in all bacteria counts (p < 0.002) at 7 and 14 days of storage for different extracts, independently from the application methods. The use of the extracts to inhibit bacterial growth in game meat should only be considered if a good hygienic baseline is guaranteed.

A molecular toolbox for fast and convenient diagnosis of emerging and reemerging bacterial pathogens causing fever of intermediate duration

PurposeFever of intermediate duration (FID) is defined as a fever in the community without a specific origin or focus, with a duration between 7 and 28 days. FID is often caused by pathogens associated with animal contact or their arthropods parasites, such as ticks, fleas, or lice. The purpose of this work is to design a collection of molecular tools to promptly and accurately detect common bacterial pathogens causing FID, including bacteria belonging to genera Rickettsia, Bartonella, Anaplasma, and Ehrlichia, as well as Coxiella burnetii.MethodsReference DNA sequences from a collection of Rickettsia, Bartonella, Anaplasma, and Ehrlichia species were used to design genus-specific primers and FRET probes targeted to conserved genomic regions. For C. burnetii, primers previously described were used, in combination with a newly designed specific probe. Real-time PCR assays were optimized using reference bacterial genomic DNA in a background of human genomic DNA.ResultsThe four real-time PCR assays can detect as few as ten copies of target DNA from those five genera of FDI-causing bacteria in a background of 300 ng of human genomic DNA, mimicking the low microbial load generally found in patient’s blood.ConclusionThese assays constitute a fast and convenient “toolbox” that can be easily implemented in diagnostic laboratories to provide timely and accurate detection of bacterial pathogens that are typical etiological causes of febrile syndromes such as FID in humans.

P080 High faecal pH and low total microbial load associate with normalisation of faecal calprotectin in children with Crohn’s disease treated with exclusive enteral nutrition; results from iPENS, a multicentre, prospective study

Abstract Background Exclusive enteral nutrition (EEN) is a main therapy for active Crohn’s disease (CD) in children, but normalisation of faecal calprotectin (FCAL) varies among patients, even in those who enter clinical remission. To better understand disease characteristics related to EEN efficacy and its mechanism of action, we compared clinical and microbial parameters between patients whose FCAL normalised against those who did not at EEN completion. Methods Children with CD, clinically responding to EEN, were recruited from 11 UK hospitals (January 2020- May 2023, NCT04225689) and provided a single faecal sample before EEN completion. Patients were divided in two groups according to levels of FCAL at EEN completion (FCAL&amp;lt;250 and FCAL&amp;gt;250 mg/kg). Levels of faecal short chain fatty acids (SCFA), faecal sample characteristics (pH, water content (%), bristol stool score) and total microbial load (qPCR) were compared between the two groups. Anthropometric and clinical parameters (blood inflammatory markers, use of immunosuppressants, disease duration, disease location) were also compared. Machine learning using feature elimination with data imputation for missing data was performed to identify associations between clinical, anthropometry, microbial parameters and FCAL normalisation. Results At EEN completion, 84 children (female, 35%) were recruited [age, median (IQR): 13.2 (11.8, 14.9 years)] with a median (Q1, Q3) FCAL of 643 (146, 2033) mg/kg. Out of 84 patients, 35 (42%) had an FCAL&amp;lt;250 mg/kg. Total microbial load and SCFA were measured in a subset of patients (n=44). Patients with FCAL&amp;lt;250mg/kg had a higher faecal pH and lower microbial load compared to those with FCAL&amp;gt;250mg/kg [faecal pH; FCAL&amp;lt;250 mg/kg: 8.3 (8.1, 8.6) vs FCAL&amp;gt;250 mg/kg; 7.95 (7.6, 8.3), p=0.001; microbial load (log10 16S rRNA gene copies/g): FCAL&amp;lt;250mg/kg: 10.7 (10.4, 10.9) vs FCAL&amp;gt;250mg/kg: 11.0 (10.5, 11.2), p=0.02]. Median BMI z-score was also non-significantly (p=0.052) higher in patients with FCAL&amp;lt;250mg/kg. The use of immunosuppressants at EEN completion, disease duration, disease location and other faecal parameters were not different between the two groups. A multicomponent random forest model (clinical, blood inflammatory markers, anthropometry, faecal parameters) predicted normalisation of FCAL with 71% accuracy (sensitivity: 69%, specificity: 71%, p=&amp;lt;0.001, Figure 1). Higher faecal pH, BMI z-scores and lower total microbial load were the most influential parameters relating to FCAL&amp;lt;250mg/kg. Conclusion We showed that the efficacy of EEN in reducing gut inflammation might be, at least in part, mediated via reducing gut bacterial biomass and modulating luminal pH and the downstream effects this may have on inflammatory members of the microbial community.

Isochoric freezing to extend the shelf life of pomegranate juice.

Pomegranate juice was treated by isochoric freezing (-15°C/130MPa) for 24h and then stored under three different conditions for up to 4weeks: 4°C/0.1MPa, 24°C/0.1MPa, and -10°C/100MPa. The juice microbiological stability and quality were compared to those using heat treatment at 95°C for 15s followed by cold storage at 4°C. Heat-treated and isochoric frozen (IF) pomegranate juice stored under isochoric conditions showed no spoilage microorganisms after 4weeks of storage. Also, IF juice stored at 4 or 24°C for 4weeks had lower microbial loads than those in fresh pomegranate juice. IF juice stored under isochoric conditions showed greater color stability, antioxidant capacity, and nutrient retention (anthocyanins, ascorbic acid, and total phenolic compounds) than heat-treated juices stored at 4°C. IF juice stored at 4°C also showed greater anthocyanin and ascorbic acid contents compared with heat-treated juice. PRACTICAL APPLICATION: Isochoric freezing storage at -10°C can be used to preserve the quality properties of fresh pomegranate juice. Isochoric freezing at -15°C for 24h can also be used as a pretreatment to extend the shelf life of refrigerated pomegranate juice since the applied pressures reached total inactivation levels of spoilage microorganisms.

Entomophagy — An evaluation of quality and acceptability of Raphia palm weevil larvae (&lt;i&gt;Rhynchophorus phoenicis&lt;/i&gt;) as influenced by thermal processing methods

In this study, the quality and acceptability factor of Raphia palm weevil larvae (Rhynchophorus phoenicis) as influenced by different thermal processing methods were investigated. Raphia palm weevil larvae (n=1000) were randomly distributed into four groups of 250 larvae per group according to a treatment, namely: T1 = boiling (100 °C), T2 = roasting (120 °C) T3 = frying (160 °C) and T4 = oven-drying (180 °C). All treatments lasted 20 minutes. Analyses were carried out to determine the physical, chemical, vitamin and mineral composition, and microbial load. In addition, sensory characteristics were evaluated. Weevil larvae processed by the boiling method had the highest cooking yield (97.59%), water holding capacity (21.78%) and the lowest cooking loss (2.41%). The protein and fat content was higher in weevil larvae processed by frying (37.63% and 17.70%, respectively), while moisture was lowest (18.68%) in oven-dried larvae. The calcium, magnesium and phosphorus content was higher in oven-dried larvae, while there were no significant differences in iron, manganese, zinc and vitamins in the processed larvae irrespective of the methods. Boiled larvae had a higher microbial load, while fried and oven-dried larvae had the lowest microbial load. Fried larvae elicited highest sensory characteristics except tenderness, which was higher in boiled larvae, but fried larvae had higher overall acceptability than those processed by other methods. Therefore, it has been shown that the frying method is an appropriate method of processing Raphia palm weevil larvae for enhanced quality and acceptability.

ОСОБЕННОСТИ МИКРОБНОЙ КОЛОНИЗАЦИИ КОНСТРУКЦИОННЫХ МАТЕРИАЛОВ, ИСПОЛЬЗУЕМЫХ В КОСМИЧЕСКОЙ ТЕХНИКЕ, ПРИ ИХ МНОГОЛЕТНЕМ ЭКСПОНИРОВАНИИ В СРЕДЕ ОБИТАНИЯ МЕЖДУНАРОДНОЙ КОСМИЧЕСКОЙ СТАНЦИИ

The paper presents the results of studying quantitative dynamics, changes in composition and species diversity (Shannon diversity index, SDI) of the cultivable microbial community on samples of structural materials in the course of long-term exposure inside the International space station (space experiment Biorisk). It was found that the total number and species diversity of microorganisms changed in waves but the general trend was downward. In all, over the period of the experiment we detected, after cultivation in nutrient media, 20 bacterial species and 5 species of microscopic fungi grown on the samples of structural materials. Among bacteria, dominating species belonged to genus Bacillus, and species of the normal cutaneous and mucous microbiota belonged to genus Staphylococcus and Micrococcus. Genus Aspergillus and Penicillium dominated among fungi. Species diversity of the cultivable microbial community was maximal for textured glass and minimal for polyvinylchloride. SDI was 2.99 and 1.72 respectively. Also, these materials were populated by the largest (11) and least (5) numbers of cultivable microorganisms. The low microbial load on all types of materials after different periods of exposure suggests eco-safety of the ISS environment and effectiveness of the respective control measures.

Sensory, physicochemical, microbiological properties and commercialization preference of formulated spicy salted fish Ginamos

The purpose of this study was to reintroduce the spicy salted fish Ginamos made from anchovies (Stolephorus spp.) as a commercial product. Two formulations were prepared: F1 (one part of salt and five parts of fish) and F2 (one part of salt and four parts of fish). Panelists evaluated the sensory properties and general acceptability of the two formulations packaged as last product, after 45 days of storage. The product formulation was further analyzed for its moisture content and microbial load. The results indicated that both formulations positively impacted sensory attributes such as color, odor, texture, flavor, and overall acceptability. Additionally, all panelist agreed that both formulated spicy salted fish Ginamos products were suitable for commercialization. Moreover, the moisture content of F1 was not significantly different (P&amp;gt;0.05) than the moisture content in F2. However, there was a significant difference between F1 and F2 in terms of microbial load, indicating that F1 had a microbial load of 3.279 log cfu/g, as opposed to F2, which had a microbial load of 2.827 log cfu/g. Hence, it was determined that the F2 formulation of spicy salted fish Ginamos product had a lower microbial load and was safer for human consumption.

Alternative amplicon-PCR protocol for maximizing bacterial and fungal sequencing in low-biomass samples

Determining bacterial and fungal communities from low-biomass samples remains a challenge for high-throughput sequencing. Due to the low microbial load and host contamination, some sites, including the female upper reproductive tract and the lower respiratory tract, were even considered sterile until recent years. Despite efforts to improve sampling and DNA isolation protocols, some samples provide insufficient microbial DNA input for library preparation and sequencing. Herein, we propose an alternative amplicon-PCR protocol to be used in bacterial and fungal sequencing in low-biomass samples, targeting 16S-rDNA and the internal transcribed spacer region (ITS), respectively. Similar to a nested-PCR, we performed two sequential PCR reactions to maximise the target amplicon. We compared metagenomic results from the original Illumina protocol (Protocol 1 – P1) and the alternative one (Protocol 2 – P2), using a mock community and clinical samples with different microbial loads. Our findings showed no significant differences in data generated by P1 and P2, indicating that the second amplification round does not bias the microbiota diversity rates. Thus, the alternative protocol can be applied for low-biomass samples when the original protocol results in spurious output, preventing library preparation and sequencing.

Optimization and modeling of vacuum impregnation of pineapple rings and comparison with osmotic dehydration.

The vacuum impregnation (VI) process parameters (vacuum pressure=20-60kPa; VI temperature=35-55°C; concentration of the sucrose solution=40-60°Brix; and vacuum process time=8-24min) for pineapple rings were optimized based on the moisture content (MC), water loss (WL), solids gain (SG), yellowness index (YI), and total soluble solids (TSS) content of pineapple rings using response surface methodology (RSM). A relationship was developed between the process and response variables using RSM and artificial neural network (ANN) techniques. The effectiveness of VI was evaluated by comparing it with the osmotic dehydration (OD) technique. The optimum condition was found to be 31.782kPa vacuum pressure, 50.441°C solution temperature, and 60°Brix sucrose concentration for 20.068min to attain maximum TSS, YI, SG, and WL, and minimum MC of pineapple rings. The R2 values of RSM models for all variables varied between 0.70 and 0.91, whereas mean square error values varied between 0.76 and 71.58 and for ANN models varied between 0.87-0.93 and 0.53-193.78, respectively. Scanning electron micrographs (SEM) revealed that parenchymal cell rupture was less in VI than in OD. The VI pineapple rings exhibited more pores and high SG, as compared to OD, due to the pressure impregnation. Spectroscopic analysis affirmed that the stretching vibrations of intermolecular and intramolecular interactions were significant in VI as against OD. The VI reduced the drying time by 35% compared to OD, with the highest overall acceptability score and lower microbial load during storage. PRACTICAL APPLICATION: Pineapple is a perishable fruit, which necessitates processing for extended shelf life. This study highlights the potential of the vacuum impregnation process as a promising alternative to conventional preservation methods such as osmotic dehydration for pineapples.