iProbiotics: a machine learning platform for rapid identification of probiotic properties from whole-genome primary sequences.

Lactic acid bacteria consortia are commonly present in food, and some of these bacteria possess probiotic properties. However, discovery and experimental validation of probiotics require extensive time and effort. Therefore, it is of great interest to develop effective screening methods for identifying probiotics. Advances in sequencing technology have generated massive genomic data, enabling us to create a machine learning-based platform for such purpose in this work. This study first selected a comprehensive probiotics genome dataset from the probiotic database (PROBIO) and literature surveys. Then, k-mer (from 2 to 8) compositional analysis was performed, revealing diverse oligonucleotide composition in strain genomes and apparently more probiotic (P-) features in probiotic genomes than non-probiotic genomes. To reduce noise and improve computational efficiency, 87 376 k-mers were refined by an incremental feature selection (IFS) method, and the model achieved the maximum accuracy level at 184 core features, with a high prediction accuracy (97.77%) and area under the curve (98.00%). Functional genomic analysis using annotations from gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Rapid Annotation using Subsystem Technology (RAST) databases, as well as analysis of genes associated with host gastrointestinal survival/settlement, carbohydrate utilization, drug resistance and virulence factors, revealed that the distribution of P-features was biased toward genes/pathways related to probiotic function. Our results suggest that the role of probiotics is not determined by a single gene, but by a combination of k-mer genomic components, providing new insights into the identification and underlying mechanisms of probiotics. This work created a novel and free online bioinformatic tool, iProbiotics, which would facilitate rapid screening for probiotics.

Buffalo yogurt fermented with commercial starter and Lactobacillus plantarum originating from breast milk lowered blood pressure in pregnant hypertensive rats.

Nutritional therapy, which may have advantages over medication, is being investigated as a novel treatment for pregnancy-induced hypertension. Several studies have shown that probiotic yogurt supplementation during pregnancy has beneficial effects on maternal and fetal health. In this study, fermented buffalo milk was produced with yogurt culture and Lactobacillus plantarum B, a probiotic isolated from healthy breast milk with high angiotensin-converting enzyme inhibitory activity. The fermentation conditions under which the angiotensin-converting enzyme (ACE) inhibitory activity reached 84.51% were optimized by the response surface method as follows: 2 × 106 cfu/mL of L. plantarum B, yogurt culture 2.5 × 105 cfu/mL, and 8 h at 37°C. The distribution of ACE inhibitory peptides from fermented buffalo milk and fermented cow milk were further analyzed by liquid chromatography-mass spectrometry. By searching according to the structural features of ACE inhibitory peptides, 29 and 11 peptides containing ACE inhibitory peptide features were found in fermented buffalo milk and fermented cow milk, respectively. To investigate the in vivo antihypertensive activity of fermented buffalo milk, 18 pregnant rats were divided into 3 groups (n = 6 in each group) and administered 10 mL of normal saline, yogurt (20 mg/kg), or labetalol hydrochloride (4 mg/kg) daily from the beginning of pregnancy to parturition. To induce hypertension, methyl nitrosoarginine (125 mg/kg) was injected subcutaneously every day from d 15 of pregnancy to the day of delivery. Blood pressure was not significantly changed in the yogurt and labetalol groups after induction of hypertension and was lower compared with the normal saline group, but there was no difference between the yogurt and labetalol groups. This implied that the buffalo yogurt had a preventive and antihypertensive effect in the pregnancy-induced hypertensive rat model. Further studies to determine the mechanism of action, as well as a randomized control trial, are warranted.

Analysis of the Influence of Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus Strains on Changes in the Hexachlorobenzene Content in Fermented Mare Milk during Refrigerated Storage.

(1) Background: Hexachlorobenzene (HCB) is a persistent organic pollutant that is possibly carcinogenic to humans. It is still found in the environment, humans and animals, and in foods, including milk and dairy products; (2) Methods: The influence of the probiotic cultures Lacticaseibacillus rhamnosus LCR and Lactiplantibacillus plantarum subsp. plantarum LP on the possibility of effecting the biodegradation of HCB in dairy products fermented from mare milk was investigated, taking into account the product storage time (maximum 21 days). HCB content was determined using the GC/MS method; (3) Results: A strong negative Pearson correlation (p < 0.05) was found between HCB concentration and the refrigeration storage time of the fermented beverages. The highest HCB reduction was observed in milk fermented with both Lacticaseibacillus rhamnosus LCR and Lactiplantibacillus plantarum subsp. plantarum LP (78.77%), while the lowest was noted when only Lactiplantibacillus plantarum subsp. plantarum LP was used (73.79%); (4) Conclusions: This pilot study confirmed that probiotics commonly used to give products health-promoting properties can also contribute to reducing the content of undesirable substances, and the bacterial cultures used might provide an alternative method for reducing HCB residues in fermented drinks.

Use of probiotic yeasts with biocontrol activity for fermentation of ewe's milk.

BACKGROUND: There are sufficient scienctific studies that support the benefit that fermented dairy products produce in those who consume them. Traditionally, cow's milk has been the most commonly used milk but there is a growing interest in the development of new dairy products, substituting cow's milk with milk from other sources, as well as in the use of microorganisms in fermentation to replace artificial preservatives or treatments that may affect the chemical and organoleptic characteristics of the product. For these reasons, the aim of the present work was to understand the behavior of five potential probiotic yeasts during the fermentation of ewe's milk and to consider their potential use as biocontrol agents. RESULTS: Saccharomyces cerevisiae 3 and Hanseniaspora osmophila 1056 provided the most promising kinetic parameters in the different salt, temperature and pH conditions tested in their technological characterization. The profiles of organic acids and volatile compounds after the fermentation period was noteworthy for contributing to the final aroma of the dairy product. Sensory analysis revealed the sour taste of all samples, and S. cerevisiae 3, Lachancea thermotolerans 1039, and H. osmophila 1056 stood out for an accentuated cheese flavor. In addition, all strains showed biocontrol activity; they reduced the mycelium of the mycotoxigenic molds. CONCLUSION: Saccharomyces cerevisiae 3 and H. osmophila 1056 could be inoculated along with bacterial starters to provide a functional fermented beverage with improved flavor. These strains also have an added value as they act as biocontrol agents. © 2022 Society of Chemical Industry.

Authenticity of probiotic foods and dietary supplements: A pivotal issue to address.

The market of probiotic foods and supplements is growing rapidly but frequently the commercialized products are not compliant with their labels in terms of claimed probiotic strain(s) and labeled number of viable probiotic cells, thus mining the authenticity of these probiotic products.In this review, we provide an up-to-date overview of: (i) the current regulatory aspects, (ii) the consistency of probiotic foods and supplements with their labels, (iii) the implications of mislabeling on the quality, safety and functionality of these products and (iv) the available and most promising methods to assess the authenticity of these products, taking into account the need to discriminate among the different physiological states probiotics might be in the carrier matrices. It arises that authenticity of probiotic foods and supplements is an urgent issue, of industrial and legislation relevance, that need to be addressed. A plethora of methods are available to reach this goal, each with its own advantages and disadvantages. Protocols that combine the use of propidium monoazide (PMA) with metagenomics or polyphasic approaches including the PMA real time PCR or flow cytometry (for the viability assessment) and the whole genome sequence analysis (for the identification and typing of the probiotic strain) are the most promising that should be standardized and used by producers and regulators.

Effects of the potential probiotic Bacillus subtilis D1-2 on growth, digestion, immunity and intestinal flora in juvenile sea cucumber, Apostichopus japonicus.

In the present study, a potential probiotic Bacillus subtilis D1-2 with antibacterial activity was isolated from the gut of Apostichopus japonicus. The purpose of this experiment was to assess the effect of B. subtilis D1-2 at different concentrations (C: 0 CFU/g, BL: 105 CFU/g, BM: 107 CFU/g and BH: 109 CFU/g) on the growth performance, digestive enzyme activity, immune ability and intestinal flora of A. japonicus. After the 56-day feeding trial, the final body weight and weight gain rate of juvenile sea cucumber A. japonicus fed B. subtilis D1-2 were significantly increased, especially in the BM group. Additionally, the lipase activity of the intestine was significantly increased in the BM and BH groups. Enhanced immunity was also found in sea cucumbers supplemented with B. subtilis D1-2. Alpha diversity indices showed that the B. subtilis D1-2-supplemented groups had higher intestinal microbial richness and diversity than the control group. The beta diversity analysis indicated that the bacterial communities in the B. subtilis D1-2-supplemented groups were quite similar but different from the bacterial communities in the control group. Dietary supplementation with B. subtilis D1-2 increased the relative abundance of some potential probiotic-related genera, including Lactobacillus, Clostridium, Lactococcus, Bifidobacterium and Streptococcus. In conclusion, dietary addition of B. subtilis D1-2 could effectively promote the growth of A. japonicus, improve its digestion and immunity capacity to a certain extent, and actively regulate the intestinal microflora of A. japonicus.

Functional bacterial cultures for dairy applications: Towards improving safety, quality, nutritional and health benefit aspects.

Traditionally, fermentation was used to preserve the shelf life of food. Currently, in addition to favouring food preservation, well standardized and controlled industrial processes are also aimed at improving the functional characteristics of the final product. In this regard, starter cultures have become an essential cornerstone of food production. The selection of robust microorganisms, well adapted to the food environment, has been followed by the development of microbial consortia that provide some functional characteristics, beyond their acidifying capacity, achieving safer, high-quality foods with improved nutritional and health-promoting properties. In addition to starters, adjunct cultures and probiotics, which normally do not have a relevant role in fermentation, are added to the food in order to provide some beneficial characteristics. This review focuses on highlighting the functional characteristics of food starters, as well as adjunct and probiotic cultures (mainly lactic acid bacteria and bifidobacteria), with a specific focus on the synthesis of metabolites for preservation and safety aspects (e.g. bacteriocins), organoleptic properties (e.g. exopolysaccharides), nutritional (e.g. vitamins) and health improvement (e.g. neuroactive molecules). Literature reporting the application of these functional cultures in the manufacture of foods, mainly those related to dairy production, such as cheeses and fermented milks, has also been updated.

Maternal probiotics supplementation improves immune and antioxidant function in suckling piglets via modifying gut microbiota.

AIM: Probiotics could improve the health, growth, and development of host or their foetuses/offspring via regulating gut microbiota. The present study was conducted to determine the effects of maternal probiotics supplementation on gut microbiota and metabolites of sows and their suckling piglets, as well as plasma biochemical parameters, oxidative/anti-oxidative indexes, and inflammatory cytokine levels of suckling piglets. METHODS AND RESULTS: A total of 32 pregnant Bama mini-pigs were selected and randomly divided into two groups. The sows were fed a basal diet (control group) or a basal diet supplemented with probiotics (probiotics group) from mating to day 21 of lactation. Samples from sows were collected on day 105 of pregnancy and day 21 of lactation and from piglets on day 21 of lactation. The results showed that probiotics supplementation increased the faecal abundances of Ruminococcus, Bacteroides, and Anaeroplasma and decreased Tenericutes on day 105 of pregnancy while increased the abundances of Actinobacteria and Anaerostipes and decreased Proteobacteria and Desulfovibrio on day 21 of lactation. In addition, probiotics supplementation decreased the faecal levels of tryptamine, putrescine, and cadaverine on day 105 of pregnancy and isovalerate and skatole on day 21 of lactation while increased butyrate level on day 21 of lactation. Further studies showed that maternal probiotics supplementation decreased the plasma levels of AMM, TC, LDL-C, Ala, Tau, MDA, H2 O2 , IL-1ß, IL-2, IL-6, and IFN-α of suckling piglets. Moreover, maternal probiotics supplementation increased the abundances of Deferribacteres, Fusobacteria, and Fusobacterium while decreased Anaerostipes in piglet's colon. Spearman's correlation analysis revealed a potential link between gut microbiota alterations and their metabolites. CONCLUSIONS: Dietary probiotics supplementation during pregnancy and lactation periods could improve sow status, alleviate oxidative stress and inflammation response, and improve nutrient metabolism of piglets by altering the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: The probiotics alter maternal and offspring's gut microbiota involving in offspring's physiological and metabolic changes, and present a new perspective that the effects of gut microbiota changes induced by probiotics supplementation will help in addressing the growth and development and health problem of their foetuses/offspring.

Impact of Probiotic Geotrichum candidum QAUGC01 on Health, Productivity, and Gut Microbial Diversity of Dairy Cattle.

Gut microbial diversity is a determinant of animal productivity and health. Probiotic supplementation in feed has been known to modulate the gut microbial diversity resulting in better feed utilization and resistance against diseases. The current study was designed to determine the probiotic potential of Geotrichum candidum QAUGC01 (VHDP00000000) in Sahiwal-Friesian crossbred dairy cows and its impact on gut microbial diversity, health, and productivity. To evaluate health and productivity, growth performance, determination of blood parameters, serum biochemistry, feed efficiency, milk yield & composition, and nutrients digestibility was determined and compared between control and experimental groups. Moreover, at the end of the experiment, the gut microbial diversity was evaluated through MiSeq (Illumina) sequencing of bacterial and fungal/yeast DNA in dung samples of both control and experimental cows. Inspite of a significant reduction in dry matter intake the increase in feed efficiency and milk yield was observed in experimental cows with normal hematological and serum biochemical profile. The increase in anaerobic bacterial count and decrease in the shredding of pathogenic flora was observed in experimental cows. Metagenomic analysis revealed Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes to be the four dominating phyla among bacteria and, Ascomycota followed by Basidiomycota and Neocallimastigomycota among the fungal population in both groups. The diversity of the core microbiome revealed high bacterial and Fungal Alpha diversity in the experimental group than in control via the Shannon index. This study provided insights into the safe use of G. candidum as a probiotic, to improve growth performance, health, productivity and gut microbial diversity of dairy cattle.

Synergistic effects of probiotic Bifidobacterium isolated from chicken's intestine in combination with polyvinylpyrrolidone on reduction of aflatoxin B1.

Food contamination with aflatoxin is one of the most critical concerns of health professionals. One of the best ways to reduce aflatoxin content in food is probiotics. Therefore, this study was performed to isolate Bifidobacterium from the chick's intestine; evaluate its probiotic activities and its application with Polyvinylpyrrolidone (PVP) to reduce aflatoxin B1 (AFB1 ) in the medium were investigated. Samples were isolated from the chick's intestine, and Bifidobacterium was isolated and identified by biochemical and molecular methods. Next, the potential probiotic characterization was assessed. Afterwards, the effect of selected isolate and PVP on reducing AFB1 in the medium was studied using ELISA and HPLC. Biochemical and molecular evaluations indicated isolation of Bifidobacterium bifidum strain from chick's intestine. One of the B. bifidum strains was selected for the next steps, which showed potential probiotic characterization and the ability to reduce the concentration of AFB1 in the medium (50% reduction). When used in combination with PVP showed synergistic effects in reducing the concentration of AFB1 from the medium (up to 90%). In the conclusion, it was found that selected B. bifidum strains and PVP could have synergistic effects in reducing AFB1 toxin in a medium up to 90%.

Lactobacillus reuteri-fortified camel milk infant formula: Effects of encapsulation, in vitro digestion, and storage conditions on probiotic cell viability and physicochemical characteristics of infant formula.

Lactobacillus reuteri fortified camel milk infant formula (CMIF) was produced. The effect of encapsulation in different matrices (sodium alginate and galacto-oligosaccharides) via spray drying, simulated infant gastrointestinal digestion (SIGID), and storage conditions (temperature and humidity) on the viability of L. reuteri in CMIF and the physicochemical properties of CMIF were evaluated. Compared with free cells, probiotic cell viability was significantly enhanced against SIGID conditions upon encapsulation. However, L. reuteri viability in CMIF decreased after 60 d of storage, predominantly at higher storage humidity and temperature levels. At the end of the storage period, significant changes in the color values were observed in all CMIF, with a reduction in their greenness, an increase in yellowness, and a wide variation in their whiteness. Moreover, pH values and caking behavior of all CMIF stored at higher temperature (40°C) and humidity [water activity (aw) = 0.52] levels were found to be significantly higher than the samples stored under other conditions. Over 30 d of storage at lower humidity conditions (aw = 0.11 and 0.33) and room temperature (25°C), no significant increase in CMIF lipid oxidation rates was noted. Fourier-transform infrared spectroscopy analysis showed that, compared with the other storage conditions, CMIF experienced fewer changes in functional groups when stored at aw = 0.11. Microscopic images showed typical morphological characteristics of milk powder, with round to spherical-shaped particles. Overall, camel milk fortified with encapsulated L. reuteri can be suggested as a promising alternative in infant formula industries, potentially able to maintain its physicochemical characteristics as well as viability of probiotic cells when stored at low humidity levels (aw = 0.11) and temperature (25°C), over 60 d of storage.

Fermentation process optimization, chemical analysis, and storage stability evaluation of a probiotic barley malt kvass.

Kvass is a popular low-alcohol beverage produced by the natural fermentation of dark rye bread or malt with complex microbial flora. However, few pieces of research focus on the microflora of traditional bread kvass, and the industrial kvass based on malt concentrate has some disadvantages, including the lack of viable probiotics and containing multiple artificial additives. Therefore, in the present study, based on the different homemade traditional bread kvass, the predominant species including Lacticaseibacillus paracasei, Acetobacter pasteurianus, and Saccharomyces cerevisiae were screened and identified. In addition, barley malt was used instead of bread for kvass production, and the co-fermentation conditions with three different strains were optimized as wort concentration of 7.4°Brix, cell ratio of 2/2/1 (S. cerevisiae/L. paracasei/A. pasteurianus), inoculum amount of 8%, fermentation temperature of 29.5 °C and fermentation time of 24.6 h. Moreover, the physicochemical (pH, total soluble solids, color, and alcohol content) and probiotic (microorganisms counting and antioxidant activity) properties of the barley malt kvass prepared at optimal conditions were symmetrically evaluated. Besides, compared with the commercial kvass products, the produced barley malt kvass exhibited better taste and more desirable antioxidant activity, and also maintained around 6-7 log CFU/mL of viable probiotic microorganisms during a week of storage. The present study not only enriched the biological resource of the traditional kvass, but also promoted the development of the kvass as a live-bacteria beverage.

Physicochemical characteristics, antioxidant properties and bacterial profiling of three Malaysian honey varieties: a study using multivariate analysis.

BACKGROUND: The physicochemical characteristics, antioxidant properties, and bacterial profiles of Heterotrigona itama, Apis dorsata, and Apis mellifera honey of Malaysian origin were studied and the results were assessed using Pearson correlation analysis and canonical correspondence analysis (CCA). RESULTS: The analysis showed that the Mellifera honey was characterized by high total sugar content (717.5 g kg-1 ); the Itama honey was characterized by high free acidity (347.5 meq kg-1 ); and the Dorsata honey was characterized by high radical scavenging activity (RSA; 69.3%RSA), total phenolic content (TPC; 1284.5 mg GAE kg-1 ) and hydroxymethylfurfural (HMF; 51.5 mg kg-1 ). Pearson correlation analysis showed that the TPC was positively correlated with HMF as well as RSA. The bacterial profile of Mellifera honey was significantly less diverse than Itama and Dorsata honey. Mellifera and Itama honey seemed to harbour a significant abundance of lactic acid bacteria, with relative abundance of 0.339 and 0.195, which suggests that it possesses probiotic potential. The Dorsata honey, however, contained pathogenic Clostridium genus, constituting 5% of its bacterial profile. CONCLUSION: The characteristic properties of the three investigated honey, Itama, Dorsata, and Mellifera were identified. The distinctive characteristics of the honey varieties informed the development of appropriate processing strategies for retaining the beneficial qualities of raw honey. It is hoped that the results of this study will shine light on Malaysian honey in a highly competitive global market. © 2022 Society of Chemical Industry.

Mining indigenous honeybee gut microbiota for Lactobacillus with probiotic potential.

The present study was done to explore the diversity of lactic acid bacteria (LAB) associated with the gastrointestinal tract (GIT) of honeybee species endemic to northeastern Pakistan. Healthy worker bees belonging to Apis mellifera, A. dorsata, A. cerana and A. florea were collected from hives and the surroundings of a major apiary in the region. The 16S rRNA amplicon sequencing revealed a microbial community in A. florea that was distinct from the others in having an abundance of Lactobacillus and Bifidobacteria. However, this was not reflected in the culturable bacteria obtained from these species. The isolates were characterized for safety parameters, and 20 LAB strains deemed safe were evaluated for resistance to human GIT stresses like acid and bile, adhesion and adhesiveness, and anti-pathogenicity. The five most robust strains, Enterococcus saigonensis NPL780a, Lactobacillus rapi NPL782a, Lactobacillus kunkeei NPL783a, and NPL784, and Lactobacillus paracasei NPL783b, were identified through normalized Pearson (n) principal components analysis (PCA). These strains were checked for inhibition of human pathogens, antibiotic resistance, osmotic tolerance, metabolic and enzymatic functions, and carbohydrate utilization, along with antioxidative and cholesterol-removing potential. The findings suggest at least three strains (NPL 783a, 784 and 782a) as candidates for further in vitro and in vivo investigations of their potential health benefits and application as novel probiotic adjuncts.

Acerola (Malpighia glabra L.) and guava (Psidium guayaba L.) industrial processing by-products stimulate probiotic Lactobacillus and Bifidobacterium growth and induce beneficial changes in colonic microbiota.

AIMS: This study evaluated whether by-products from industrial processing of acerola (Malpighia glabra L.; AB) and guava (Psidium guajava L.; GB) fruit may stimulate the growth and metabolism of probiotic Lactobacillus and Bifidobacterium and induce changes in human colonic microbiota. METHODS AND RESULTS: The ability of non-digested and digested AB or GB to stimulate the growth ad metabolism of Lactobacillus acidophilus LA-05, Lactobacillus casei L-26 and Bifidobacterium animalis subsp. lactis BB-12 was evaluated. Changes in populations of distinct bacterial groups of human colonic microbiota induced by digested AB and GB were evaluated using an in vitro colonic fermentation system. Non-digested and digested AB and GB favoured probiotic growth. No difference among counts of probiotics in media with glucose, fructooligosaccharides and non-digested and digested AB and GB was found during a 48-h cultivation. Cultivation of probiotics in media with non-digested and digested AB and GB resulted in decreased pH, increased organic acid production and sugar consumption over time. Digested AB and GB caused overall beneficial changes in abundance of Bifidobacterium spp., Lactobacillus-Enterococcus, Eubacterium rectall-Clostridium coccoides and Bacteroides-Provotella populations, besides to decrease the pH and increase the short-chain fatty acid production during a 24-h in vitro colonic fermentation. CONCLUSION: AB and GB could be novel prebiotic ingredients because they can stimulate the growth and metabolism of probiotics and induce overall beneficial changes in human colonic microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: AB and GB stimulated the growth and metabolism of probiotics, in addition to induce beneficial alterations in human colonic microbiota composition and increase short-chain fatty acid production. These results characterize AB and GB as potential prebiotic ingredients and fruit processing by-products as sources of added-value compounds.

Probiotic Greek yogurt: effect of the addition of prebiotic fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance.

In this research communication we evaluate the impact of the addition of prebiotic components (inulin, polydextrose, and modified starch, 40 g/l) as fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance of probiotic (Lacticaseibacillus casei 01, 108 CFU/ml) Greek yogurts during storage (7 °C, 28 d). All formulations had probiotic counts higher than 107 CFU/ml during storage and simulated gastrointestinal conditions (SGIC). The prebiotic components increased the probiotic survival to the enteric phase of the SGIC, with inulin producing the most pronounced effect. Inulin addition resulted in products with lower pH values and consistency and higher titratable acidity during storage, with negative impact on the sensory acceptance (flavor, texture, and overall impression) at the end of the storage period. Modified starch addition impacted negatively on the acceptance of the products (appearance, flavor, texture, and overall impression). Polydextrose addition resulted in products with lower consistency, but similar sensory acceptance to the full-fat yogurt. It can be concluded that it is possible to prepare potentially synbiotic Greek yogurts by desorption technique using L. casei as probiotic culture and inulin, polydextrose or modified starch as prebiotic components, with the utilization of polydextrose being advisable.

N, O-codoped hierarchical porous graphitic carbon for electrochemical immunosensing of Lactobacillus rhamnosus GG.

An ultrasensitive label-free electrochemical immunosensor was fabricated for quantitative detection of Lactobacillus rhamnosus GG (LGG). The N/O co-doped three-dimensional hierarchical porous graphitic (THPG) carbon was synthesized by a one-step synthesis of polyaniline hydrogel, and followed by simple carbonization and chemical activation procedures. Because of the unique structure design, the obtained THPG carbon networks possess an ultra-large specific surface area of 4859 m2 g-1 along with a class of highly graphitic carbons. The results offer an enormous surface area and excellent electrical conductivity for label-free electrochemical immunosensing of probiotic L. rhamnosus strain. Under optimal conditions, the immunosensor showed a good linear relationship between peak current and concentration of LGG (R2 = 0.9976), with a detection limit of 2 CFU mL-1. Furthermore, this label-free immunosensor also shows good specificity, long-term stability, and reliability, and could be applied to detect probiotic LGG in dairy products and drinks with satisfactory results. The present protocol was shown to be quite promising for practical screening and functional evaluation of probiotic products containing LGG. A ultrasensitive label-free electrochemical immunosensor based on THPG carbon was fabricated for detection of Lactobacillus rhamnosus GG.

Use of ultrafiltrated cow's whey for the production of whey cheese with Kefir or probiotics.

BACKGROUND: In Southern European countries, whey cheeses are normally produced with ovine or caprine whey. Cow's cheese whey can also be used, although the whey cheese yield is low (2-3%, w/v) which discourages its use. In the present study, bovine cheese whey was concentrated by ultrafiltration for the production of four types of whey cheeses (Requeijão): conventional, without any addition (WC); with 10% (w/w) addition of cream (WCC); with cream fermented with Kefir culture (WCCK); and with cream fermented with Bifidobacterium sp. culture (WCCBB12). RESULTS: Whey cheeses with cream presented lower protein content (330-360 g kg-1 , dry basis) and higher levels of total solids (220-250 g kg-1 ) and fat (300-330 g kg-1 , dry basis) than WC. C16:0 and C18:1 were the most abundant fatty acids present, with 31% and 38%, respectively. The small differences found concerning instrumental determination of colour and texture were not perceived by panelists. However, the presence of Kefir and probiotics decreased the elastic modulus (G') of the samples, as well as their viscosity. Fermentation with Kefir presented the highest counts of lactic acid bacteria (7 logUFC g-1 ). However, after 14 days of refrigerated storage, the counts of yeasts and moulds reached 6 logUFC g-1 in all products, indicating the need for appropriate packaging solutions. CONCLUSION: Ultrafiltration of bovine whey allows for the efficient production of bovine whey cheeses. The addition of cream fermented with Kefir or BB12 appears to be an efficient methodology to incorporate Kefir or probiotic bacteria in Requeijão, improving its nutritional and sensory characteristics, alongside the potential for the extension of its shelf-life. © 2020 Society of Chemical Industry.

Ultrasonic and enzymatic pretreatments of Monascus fermentation byproduct for a sustainable production of Bacillus subtilis.

BACKGROUND: Monascus fermentation byproduct (MFB) is a biowaste generated after food colorants are extracted. Using MFB to produce probiotics (Bacillus subtilis) is a sustainable way for the entire production to be used as food or animal feed additives. However, due to the rigidity of the Monascus mycelium cell wall, B. subtilis cannot sufficiently utilize the nutrients in MFB, leading to low biomass production efficiency. We studied the effects of ultrasonic treatment, papain, ß-glucanase, and chitosanase, and their combinations on improving the levels of soluble components from MFB. The effects of these treatments on mycelium cell walls were visualized using scanning electron microscopy, and their influence on B. subtilis production was analyzed. RESULTS: Ultrasonic treatment increased the soluble components by 210 g kg-1 , including 50 g kg-1 protein and 120 g kg-1 carbohydrates. An enzyme mixture increased the soluble components by 160 g kg-1 , including 30 g kg-1 protein and 90 g kg-1 carbohydrates. The combination of the two methods achieved the highest increase of soluble components (up to 400 g kg-1 ) leading to a maximum B. subtilis production of 1 × 1011 colony-forming unit mL-1 . This yield was about 20 times greater than that using untreated MFB and about eight times greater than treatments using only ultrasonic or enzymatic methods. CONCLUSION: The productivity of B. subtilis production using MFB as the sole medium can be greatly improved by ultrasound or enzymes, which cause the release of intercellular components or cell wall components. © 2020 Society of Chemical Industry.

Carob kibbles as an alternative raw material for production of kvass with probiotic potential.

BACKGROUND: Non-diary beverages with probiotic properties are of great interest nowadays. In this research, we evaluated the suitability of carob kibbles in the manufacture of kvass. Kvass is a low-alcohol drink popular in Central and Eastern Europe and indicated as a potential non-diary beverage with probiotic properties. Therefore, the viability of probiotic strains of Lactobacillus plantarum and Saccharomyces boulardii during 4 weeks' storage in manufactured beverages was tested. RESULTS: Carob kibbles introduced significant amounts of phenolic compounds into kvasses, especially gallic acid (up to 117.45 ± 10.56 mg L-1 ), and improved antiradical activity up to 78% after fermentation. Moreover, fermentation efficiently reduced furfural and hydroxymethylfurfural content in samples up to 12.9% and 29.9%, respectively. Kvasses with rye malt extract possessed coffee-like, chocolate-like, roasted and caramel-like odours and a more bitter taste. Whereas kvass with carob kibbles was characterized by fruit-like odour and sweeter taste. Fermentation contributed to a creation as well as degradation of volatiles. L. plantarum exhibited higher general mortality during storage, whereas, in the case of S. boulardii, the viability was significantly higher regardless of the sample composition. CONCLUSION: This is the first study reporting the use of carob kibbles for kvass production. The obtained results showed that carob kibbles can replace rye malt extract, at least partially, in the production of kvass, giving to the product added health benefits. Moreover, S. boulardii is a better choice for production of kvass with probiotic properties. © 2021 Society of Chemical Industry.