Genus Lactococcus Research Articles

Causal Relationships Between Gut Microbiota, Metabolites, and Diabetic Nephropathy: Insights from a Two-Sample Mendelian Randomization Analysis.

Previous studies have established a correlation between gut microbiota, metabolites, and diabetic nephropathy (DN). However, the inherent limitations of observational studies, including reverse causality and confounding factors, made this relationship uncertain. In this study, we compiled summary statistics from a genome-wide association study (GWAS) conducted on gut microbiota, metabolites, and DN. We employed a two-sample Mendelian randomization (MR) approach, utilizing inverse variance weighted (IVW), MR-Egger, weighted median, and weighted mode methods. We detected the protective nature of genetically predicted representatives from the family Bacteroidaceae (OR: 0.716, 95% CI: 0.516-0.995, p = 0.046), family Victivallaceae (OR: 0.871, 95% CI: 0.772-0.982, p = 0.026), genus Bacteroides (OR: 0.716, 95% CI: 0.516-0.995, p = 0.046), genus Coprococcus 2 (OR: 0.745, 95% CI: 0.576-0.963, p = 0.025), and genus Lactococcus (OR: 0.851, 95% CI: 0.730-0.992, p = 0.039) against the development of DN. Conversely, we identified a positive correlation between the incidence of DN and entities, such as Phylum Bacteroidetes (OR: 1.427, 95% CI: 1.085-1.875, p = 0.011), class Bacteroidia (OR: 1.304, 95% CI: 1.036-1.641,p = 0.024), order Bacteroidales (OR: 1.304, 95% CI: 1.035-1.641, p = 0.028), genus Catenibacterium (OR: 1.312, 95% CI: 1.079-1.594, p = 0.006), genus Lachnoclostridium (OR: 1.434, 95% CI: 1.129-1.821, p = 0.003), and genus Parasutterella (OR: 1.270, 95% CI: 1.070-1.510, p = 0.006). In our analysis, none of the gut metabolites demonstrated a causal relationship with DN. Our results substantiated the potential causal association between specific gut microbiota and DN. Therefore, our study offers novel insight into the mechanisms underlying DN. This finding provides a theoretical foundation for the future development of targeted strategies for the prevention and treatment of DN.

Prebiotic properties of extruded maize starch-caffeic acid complexes: A study from the small intestine to colon in vitro

Recent studies show that starch-polyphenols complexes exert positive effects on gut health, but the probiotic effects of maize starch-caffeic complexes remain underexplored. Therefore, this study aimed to investigate the probiotic effect of maize starch-caffeic complexes from the small intestine to the colon. First, maize starch was extruded with caffeic acid and subjected to in vitro digestion, and the undigested parts were fermented in vitro, and the structural characteristics, short chain fatty acids (SCFAs) and microbiota communities were investigated. Results showed that caffeic acid reduced the long/short-range order of maize starch after extrusion, significantly increasing resistant starch to 30.35±2.36%. In vitro fermentation indicated that microbiota utilized the amorphous area of the residues first, promoting SCFAs production and the growth of Bifidobacterium and Lactococcus genus. Overall, the probiotic properties of extruded maize starch-caffeic acid complexes suggest they could serve as a functional food for health benefits.

Ameliorated Viability of Lactic Acid Bacteria in Fruit Juice Isolated from Indigenous Dahi with Prebiotics (Asparagus falcatus and Zingiber officinale)

Dahi is a fermented milk product containing probiotic lactic acid bacteria. This study aimed to isolate, identify, and characterize lactic acid-producing bacteria from native Dahi and evaluate their viability in orange juice using natural prebiotics. Dahi samples were obtained from local shops in Chattogram and Bogura, Bangladesh. Lactic acid-producing bacteria were isolated using MRS (de Mann Rogosa and Sharpe) medium. The isolated bacteria were identified through colony morphology, biochemical tests, and probiotic characteristics. Molecular identification was performed using polymerase chain reaction (PCR) targeting conserved 16S rDNA regions. Isolates of the genus Lactobacillus and Lactococcus lactis sp. Lactis were confirmed and used to develop probiotic orange juice. Prebiotics (Asparagus falcatus and Zingiber officinale) were added to the juice to support probiotic growth. The inoculated cell’s viability and the juice’s physicochemical parameters were evaluated during fermentation (48 hours) and storage (28 days). All fruit juice samples showed a mean number of viable cells of at least 1×105 CFU/mL during the 48-hour fermentation and 28-day storage in the refrigerator. Using natural prebiotics positively affected the survival of lactic acid bacteria, as demonstrated by bacterial colony growth on Petri dishes. Developing probiotic fruit juice enriched with prebiotics could be an effective alternative for individuals allergic or intolerant to milk-based products. Incorporating lactic acid bacteria from native Dahi into orange juice, combined with natural prebiotics, resulted in viable probiotic cells throughout fermentation and storage.

Bioproduction of exopolysaccharides by lactic acid bacteria using agave by-products

Bioproduction of exopolysaccharides by lactic acid bacteria using agave by-products

Dissecting causal relationships between gut microbiota, blood metabolites, and glioblastoma multiforme: a two-sample Mendelian randomization study.

Given the increasing interest in the role of gut microbiota in glioblastoma multiforme (GBM), our objective was to examine the potential causal relationship between gut microbiota and GBM, as well as the mediating effects of specific metabolites. A bidirectional two-sample Mendelian randomization (MR) analysis was conducted to investigate the associations between 196 microbial taxa and GBM. A two-step MR technique was used to identify significant mediators in this relationship. Subsequently, a mediation analysis was performed to explore and quantify the mediating effects of specific metabolites on the causal relationship between gut microbiota and GBM. Five taxa showed significant associations with GBM. Among them, family Victivallaceae [odds ratio (OR): 1.95; 95% confidence interval (CI): 1.21, 3.13; p = 0.005] and genus Lactococcus (OR: 1.81; 95% CI: 1.04, 3.15; p = 0.036) were positively correlated with the risk of GBM, while phylum Cyanobacteria had a protective effect against GBM (OR: 0.45; 95% CI: 0.22, 0.89; p = 0.021). The mediation analysis revealed that the connections among family Victivallaceae, genus Lactococcus, phylum Cyanobacteria and GBM were mediated by Methyl-4-hydroxybenzoate sulfate, phosphoethanolamine and dehydroepiandrosterone sulfate. Each of these accounted for 7.27, 7.98, and 8.65%, respectively. Our study provides evidence supporting a potential causal association between certain gut microbiota taxa and GBM. The study highlights the central role of gut microbiota in GBM pathogenesis and their interactions with vital serum metabolites. This paves the way for potential novel therapeutic interventions in GBM management.

Causal relationship between gut microbiota and functional outcomes after ischemic stroke: A comprehensive Mendelian randomization study

To investigate the association of the genetic predisposition of specific gut microbiotas with the clinical outcome of ischemic stroke. We leveraged publicly available genome-wide association study (GWAS) data to perform Mendelian randomization (MR) analysis. The gut microbiota-related GWAS data from 18,340 individuals from the international consortium MiBioGen was used. The summary data for functional outcomes after ischemic stroke was obtained from the Genetics of Ischemic Stroke Functional Outcome (GISCOME) network meta-analysis. The primary outcomes were judged by the modified Rankin Scale (mRS). The principal analyses were conducted using the inverse-variance weighted (IVW) MR method. The Cochran's Q test, weighted median, MR-Egger regression, leave-one-SNP-out analysis, MR-Pleiotropy Residual Sum, and Outlier methods were adopted as sensitivity analyses. Furthermore, we performed bi-directional MR analysis and the MR Steiger directionality test to examine the direction of the causal relations. The results demonstrated that the genetic predisposition of genus Lactococcus, genus Ruminococcaceae NK4A214 group, family Peptostreptococcaceae, and genus Odoribacter was positively associated with favorable functional outcome after ischemic stroke. Genus Collinsella, genus Ruminococcaceae UCG005, genus Akkermansia, genus Eubacterium oxidoreducens group, and family Verrucomicrobiaceae were identified to be associated with worse functional outcomes after ischemic stroke. Our results showed no evidence of heterogeneity, directional pleiotropic effects, or collider bias, and the sensitivity of our analysis was acceptable. The genetic predisposition of different gut microbiotas was associated with the clinical outcome of ischemic stroke. Microbiota adjustment was a promising method to improve the clinical outcome of ischemic stroke.

Investigating lactic acid bacteria genus Lactococcus lactis properties: Antioxidant activity, antibiotic resistance, and antibacterial activity against multidrug-resistant bacteria Staphylococcus aureus

Lactic acid bacteria (LAB) are utilized as a starter culture in the manufacturing of fermented dairy items, as a preservative for various food products, and as a probiotic. In our country, some research has been carried out, even if LAB plays a principal role in food preservation and improves the texture and taste of fermented foods, that is why we tried to evaluate their probiotic effect. The objective of this research was to determine the antibacterial activity of Lactococcus lactis (L. lactis) against Staphylococcus aureus (S. aureus) ATCC 29213, investigate their antioxidant activity, and characterize their sensitivity against 18 antibiotics. A total of 23 LAB (L. lactis subsp. cremoris, L. lactis subsp. Lactis diacetylactis, L. lactis subsp. lactis) were isolated from cow's raw milk. The antibacterial activity was performed using two techniques, competition for nutrients and a technique utilizing components nature, using the disk diffusion method. The sensitivity of the studied LAB to different antibiotics was tested on Man rogosa sharp (MRS) agar using commercial antibiotic disks. All strains of LAB were examined for their antioxidant activity. The antioxidant activity of L. lactis was tested by 2,2-diphenyl-1 picrylhydrazyl (DPPH). The results showed that the MRS medium was more adapted than Muller Hinton Agar (MHA) to investigate the antibacterial activity of L. lactis against S. aureus ATCC 29213. Also, L. lactis exhibited a notable degree of antibacterial activity against S. aureus ATCC 29213. L. Lactis subsp. Lactis displayed higher antibacterial activities, followed by L. lactis ssp. lactis biovar. diacetylactis, and lastly, L. lactis ssp. cremoris against S. aureus ATCC 29213. Lc 26 among all strains of L. lactis showed a high potential antibacterial activity reaching 40±3mm against S. aureus ATCC 29213. All strains of L. lactis showed a slightly moderate antioxidant activity (10.56±1.28%-26.29±0.05%). The results of the antibiotic resistance test indicate that all strains of L. lactis were resistant to cefotaxime, sulfamethoxazole-trimethoprim, and streptomycin and were sensitive to Ampicillin, Amoxicillin, Penicillin G, Teicoplanin, Vancomycin, Gentamicin 500, Tetracycline, and Chloramphenicol. These test results indicate that this strain falls within the criteria of not posing any harmful effects on human health. The important antibacterial properties recorded for all L. Lactis strains were derived from the production of antibacterial active metabolites, such as protein, diacetyl, hydrogen peroxide, and lactic acid, together with the fight for nutrients. This study suggests that the strains of L. lactis could be added as an antibacterial agent against S. aureus ATCC 29213 and can provide an important nutritional property for their antioxidant potential.

Short communication: Comparing the microbiota diversity from the core, middle part and rind of six Spanish commercial goat cheeses

Short communication: Comparing the microbiota diversity from the core, middle part and rind of six Spanish commercial goat cheeses

Effects of kefir consumption on gut microbiota and health outcomes in women with polycystic ovary syndrome.

Polycystic Ovary Syndrome (PCOS), which is common among women of reproductive age, is characterized by low-grade chronic inflammation and is associated with several health problems and dysbiosis. Kefir has been shown to have many beneficial health effects; however, its effect on PCOS is unknown. This study aimed to examine the effect of kefir on the intestinal microbiota and health outcomes in PCOS. In this intervention study, 17 women with PCOS consumed 250 mL/day of kefir (containing Lactobacillus kefiranofaciens subsp. kefiranofaciens, Lactobacillus kefiranofaciens subsp. kefirgranum, Lactobacillus kefiri, Lactobacillus acidophilus, Lactobacillus parakefiri, Lactobacillus bulgaricus, Lactobacillus reuteri, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus helveticus, Lactococcus lactis, Leuconostoc mesentereoides, Bifidobacterium bifidum, Streptococcus thermophilus, Kluyveromyces marxianus, Kluyveromyces lactis, Acetobacter pasteurianus, and Saccharomyces cerevisiae) for 8 weeks. Food consumption and physical activity records, anthropometrical measurements, quality of life, and fecal and blood samples were taken at the study's beginning and end. Quality of life in mental health (58.8 ± 15.08; 64.0 ± 15.23, respectively) and physical function (95.00 and 100.00, respectively) categories showed a significant increase after kefir intervention (p < .05). Additionally, Interleukin-6 (IL-6), one of the inflammatory cytokines, significantly decreased (174.00 and 109.10 ng/L, respectively) (p < .05). The intestinal barrier permeability was evaluated with zonulin, and no significant change was observed. Gut microbiota analysis showed that while the relative abundance of the class Bacilli and genus Lactococcus significantly increased, the genus Holdemania decreased with kefir consumption (p < .05). In conclusion, kefir appears to be beneficial for improving the microbiota and some health outcomes, like reducing inflammation and improving quality of life in PCOS. Therefore, kefir may be useful in the treatment of PCOS.

Microbial Diversity and Community Structure of Chinese Fresh Beef during Cold Storage and Their Correlations with Off-Flavors.

To investigate the diversity and dynamics of microorganisms in Chinese fresh beef (CFB) without acid discharge treatment during cold storage, high-throughput sequencing was employed to analyze the CFB refrigerated for 0, 3, 7, and 10 days. The results showed that the community richness of the fungi and bacteria decreased significantly. However, the diversity decreased in the early stage and increased in the later stage. At the phylum level, Ascomycota (74.1-94.1%) and Firmicutes (77.3-96.8%) were the absolutely dominant fungal and bacterial phyla. The relative abundance of both fungal and bacterial phyla displayed a trend of increasing and then decreasing. At the genus level, Candida (29.3-52.5%) and Lactococcus (19.8-59.3%) were, respectively, the dominant fungal and bacterial genera. The relative abundance of Candida showed a trend of increasing and then decreasing, while Lactococcus possessed the opposite trend. KEGG metabolic pathways analysis suggested that carbohydrate metabolism, membrane transport, and amino acid metabolism were the major metabolic pathways of bacteria. Bugbase prediction indicated the major microbial phenotype of bacteria in CFB during cold storage was Gram-positive (17.2-31.6%). Correlation analysis suggested that Lactococcus, Citrobacter, Proteus, and Rhodotorula might be the main microorganisms promoting the production of off-flavor substances in CFB. This study provides a theoretical basis for the preservation of Chinese fresh beef.

Intestinal microbiota and gene expression alterations in leopard coral grouper (Plectropomus leopardus) under enteritis

Enteritis poses a significant threat to fish farming, characterized by symptoms of intestinal and hepatic inflammation, physiological dysfunction, and dysbiosis. Focused on the leopard coral grouper (Plectropomus leopardus) with an enteritis outbreak on a South China Sea farm, our prior scrutiny did not find any abnormalities in feeding or conventional water quality factors, nor were any specific pathogen infections related to enteritis identified. This study further elucidates their intestinal flora alterations, host responses, and their interactions to uncover the underlying pathogenetic mechanisms and facilitate effective prevention and management strategies. Enteritis-affected fish exhibited substantial differences in intestinal flora compared to control fish (P = 0.001). Notably, norank_f_Alcaligenaceae, which has a negative impact on fish health, predominated in enteritis-affected fish (91.76%), while the probiotic genus Lactococcus dominated in controls (93.90%). Additionally, certain genera with pathogenesis potentials like Achromobacter, Sphingomonas, and Streptococcus were more abundant in diseased fish, whereas Enterococcus and Clostridium_sensu_stricto with probiotic potentials were enriched in control fish. At the transcriptomic level, strong inflammatory responses, accompanied by impaired metabolic functions, tissue damage, and iron death signaling activation were observed in the intestines and liver during enteritis. Furthermore, correlation analysis highlighted that potential pathogen groups were positively associated with inflammation and tissue damage genes while presenting negatively correlated with metabolic function-related genes. In conclusion, dysbiosis in the intestinal microbiome, particularly an aberrantly high abundance of Alcaligenaceae with pathogenic potential may be the main trigger for this enteritis outbreak. Alcaligenaceae alongside Achromobacter, Sphingomonas, and Streptococcus emerged as biomarkers for enteritis, whereas some species of Lactococcus, Clostridium_sensu_stricto, and Enterococcus showed promise as probiotics to alleviate enteritis symptoms. These findings enhance our understanding of enteritis pathogenesis, highlight intestinal microbiota shifts in leopard coral grouper, and propose biomarkers for monitoring, probiotic selection, and enteritis management.

Early life consumption of a "processed" diet high in advanced glycation end products impairs memory function and alters the gut microbiome in rats

Recent evidence indicates that “ultra-processed” foods constitute ~65% of total energy intake among children in the U.S. The impacts of excessive processed food consumption during development are poorly understood, in part because there are neither clear definitions of, nor a robust classification system accounting for, the complexity of food processing variables and how they interrelate in final food products. Heat treatment, a common form of food processing, can induce the chemical Maillard reaction and lead to foods rich in advanced glycation end products (AGEs). The neurocognitive implications of high levels of AGE consumption, particularly during early life, are unknown. Here, we used a rat model to evaluate the effects of adolescent consumption of a heat-treated diet high in AGEs on cognition and the gut microbiome in adulthood. In a series of studies, rats received either an otherwise healthy AGE-rich diet (AGE rats; AIN-93G diet heated at 160ºC for 60min) or a non-AGE-rich diet (CTL rats; AIN-93G diet without heat treatment) during adolescence (postnatal days 26-60). Metabolic, behavioral, and gut microbiome assessments were performed in adulthood. Results revealed that AGE rats exhibited hippocampal (HPC)-dependent memory deficits relative to CTL rats in the absence of altered body weight, body composition, glucose tolerance, and behavioral measures of anxiety. Administering a drug to break down AGEs (alagebrium; 1mg/kg/day) concomitantly with the heat-treated diet prevented memory impairments, supporting a causal role of AGEs in early life diet-induced HPC dysfunction. Microbiome sequencing analyses revealed that AGE rats had substantially reduced abundance of the bacterial genus Lactococcus relative to controls, and Lactococcus abundance was strongly correlated with memory performance. Administration of Lactococcus lactis by oral gavage (109 colony forming units/day) from PN 26-40 during exposure to the heat-treated diet rescued the AGE diet-induced memory impairments. Collective findings from this work identify a connection between a specific food processing variable (i.e., increased dietary AGEs through heat treatment), the gut microbiome, and impaired neurocognition. This work was supported by the National Institute of Diabetes and Digestive and Kidney Diseases under grant DK123423 (awarded to SEK and AAF); the National Institute on Aging through a Postdoctoral Ruth L. Kirschstein National Research Service Award under grant F32AG077932 (awarded to AMRH); and a National Science Foundation Graduate Research Fellowship (awarded to LT). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Isolation and Identification of Lactic Acid Bacteria from Red Dragon Fruit (Hylocereus polyrhicus) as Exopolysaccharide Producers

Cherry tomatoes are a type of Red Dragon Fruit that has various benefits, including lowering cholesterol levels, preventing colon cancer, and strengthening the working power of muscles. Isolation of LAB isolated from Dragon Fruit as a production material for EPS. This study aims to isolate and identify LAB as a producer of EPS from red dragon fruit (Hylocereus polyrhiruz), which can produce exopolysaccharides. This research uses a descriptive research method. Data from experimental research in the laboratory obtained 10 LAB isolates, namely isolates NG1, NG2, NG3, NG4, NG5, NG6, NG7, NG8, NG9 and NG10. Based on the identification results, isolate NG1 has similarities with the genus Lactococcus (spherical, gram-positive, nonmotile, non-spore). While isolates NG2, NG3, NG4, NG5, NG6, NG7, NG8, NG9 and NG10 have similarities with the genus Lactobacillus (rod form, nonmotile, gram-positive). Based on the morphological characteristics, which are gram-positive, catalase-negative and non-spore. The ten isolates of lactic acid bacteria are capable of producing EPS. these are the results of EPS acquisition, namely: NG1(152.1 mg/L), NG2(127.9 mg/L), NG3(134.6 mg/L), NG4(130.9 mg/L), NG5(137 mg/L), NG6(139.2 mg/L), NG7(204.9 mg/L), NG8(156.2 mg/L), NG9(136.4 mg/L), and NG10 (157, 3 mg/L). The highest amount of EPS was isolated NG7 at 204.9 mg/L. Meanwhile, the lowest EPS was isolated NG4 at 130.9 mg/L.

Evaluation of Probiotic Bacteria Isolated from Indigenous Honeybee Species of Pakistan

The honey bee gut is inhabited by many useful bacteria such as Lactic Acid Bacteria (LAB). These LAB possess active probiotic properties that are beneficial to other animals and even humans. The LAB is declared as generally recognized as safe (GRAS). The LAB is non-pathogenic and produces different metabolites having antimicrobial potential. In the current study LAB species isolated from four honey bee species (Apis melifera, Apis dorsata, Apis cerana, and Apis florae) prevalent in Pakistan were identified and investigated for their probiotic potential. The strains were identified using morphological, biochemical, and molecular techniques as genus Lactobacillus and Lactococcus. Current results confirmed that the honey bee gut has a rich source of lactic acid bacteria. Isolated strains were further evaluated for their ability to resist physiological stresses encountered in the human gastrointestinal tract. Safety testing of the isolates such as hemolytic assay revealed that these isolates have γ-hemolytic activity and were adjudged to be safe. Hence the present study concluded that honey bee gut is thesource of potential probiotic bacteria and can be used in pharmaceuticals, fermented foods, and nutraceuticals and may be used as a natural food preservative

Bacterial proteome adaptation during fermentation in dairy environments

The enzymatic repertoire of starter cultures belonging to the Lactococcus genus determines various important characteristics of fermented dairy products but might change in response to the substantial environmental changes in the manufacturing process. Assessing bacterial proteome adaptation in dairy and other food environments is challenging due to the high matrix-protein concentration and is even further complicated in particularly cheese by the high fat concentrations, the semi-solid state of that matrix, and the non-growing state of the bacteria. Here, we present bacterial harvesting and processing procedures that enable reproducible, high-resolution proteome determination in lactococcal cultures harvested from laboratory media, milk, and miniature Gouda cheese. Comparative proteome analysis of Lactococcus cremoris NCDO712 grown in laboratory medium and milk revealed proteome adaptations that predominantly reflect the differential (micro-)nutrient availability in these two environments. Additionally, the drastic environmental changes during cheese manufacturing only elicited subtle changes in the L. cremoris NCDO712 proteome, including modified expression levels of enzymes involved in flavour formation. The technical advances we describe offer novel opportunities to evaluate bacterial proteomes in relation to their performance in complex, protein- and/or fat-rich food matrices and highlight the potential of steering starter culture performance by preculture condition adjustments.

Effects of the diet enrichment with β-glucan, sodium salt of butyric acid and vitamins on growth parameters and the profile of the gut microbiome of juvenile African catfish (Clarias gariepinus)

Effects of the diet enrichment with β-glucan, sodium salt of butyric acid and vitamins on growth parameters and the profile of the gut microbiome of juvenile African catfish (Clarias gariepinus)

Probiotics and their Beneficial Health Effects.

Probiotics are living microorganisms that are present in cultured milk and fermented food. Fermented foods are a rich source for the isolation of probiotics. They are known as good bacteria. They have various beneficial effects on human health including antihypertensive effects, antihypercholesterolemic effects, prevention of bowel disease, and improving the immune system. Microorganisms including bacteria, yeast, and mold are used as probiotics but the major microorganisms that are used as probiotics are bacteria from the genus Lactobacillus, Lactococcus, Streptococcus, and Bifidobacterium. Probiotics are beneficial in the prevention of harmful effects. Recently, the use of probiotics for the treatment of various oral and skin diseases has also gained significant attention. Clinical studies indicate that the usage of probiotics can alter gut microbiota composition and provoke immune modulation in a host. Due to their various health benefits, probiotics are attaining more interest as a substitute for antibiotics or anti-inflammatory drugs leading to the growth of the probiotic market.

Biochemical Characterization of Three Heterologous Lactic Acid Bacteria Laccases from Pediococcus, Lactobacillus, and Lactococcus Genus and Their Potential to Degrade Biogenic Amines Using ABTS and Epicatechin as Mediators

In this study, we cloned and characterized three bacterial laccases from strains of the species Pediococcus parvulus, Lacticaseibacillus paracasei, and Lactococcus lactis isolated from wine and cheese and evaluated their biogenic amine degradation abilities in the presence/absence of artificial 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) or natural (epicatechin) mediator compounds. Although some recombinant bacterial laccases have been characterized and found to be biological tools for degrading biogenic amines with or without the use of mediators, no prior research has investigated the role of natural mediators, like phenolic substrates found in wine and certain vegetable foods, in the degradation of biogenic amines. The three recombinant bacterial laccases exhibited sigmoidal kinetics and had similar molecular mass but varied in k0.5, kcat, and specific activity toward ABTS. They are acidophilic and have an optimal temperature of 28 °C. However, they exhibit low thermal stability at temperatures higher than 37 °C. The three laccases were capable of degrading dopamine without the use of mediators, while the other amines were not degraded. The presence of ABTS enhanced the degradation of dopamine and tyramine, but the addition of epicatechin did not improve their degradation. This study presents a comparison of the laccases’ biogenic amine-degrading efficiency using different mediators. This is the first time such a comparison has been made.

Bacterial diversity in honey bee environment: Embu County, Kenya

Bacterial diversity in honey bee environment: Embu County, Kenya

Associations of genetic variants contributing to gut microbiota composition in diabetic nephropathy.

The gut microbiota is strongly associated with multiple kidney diseases, and since microbial composition is heritable, we hypothesized that genetic variations controlling gut microbiota composition were associated with diabetic nephropathy susceptibility or clinical subphenotypes. The genetic variations associated with gut microbiota were retrieved from the genome-wide association study database and analysed in our diabetic nephropathy susceptibility gene screening cohort. Candidate microorganisms with possible genetic associations were identified using the annotation of microbial quantitative trait loci. Finally, the candidate microorganisms were verified by 16S rDNA gene sequencing. There were 13 genetic variation loci associated with susceptibility to diabetic nephropathy. The TCF7L2 risk genotype was associated with a long duration of diabetes and high diastolic blood pressure, the ZCWPW2 risk genotype was associated with increased glycosylated hemoglobin, and the ZNRF3 risk genotype was associated with an increased urinary microalbumin-to-creatinine ratio. Both the ZNRF3 and SPECC1L risk genotypes were associated with the abundance of Lactococcus. 16S rDNA sequencing confirmed that there was indeed a significant difference in the Lactococcus genus between DN and DM patients. In this study, we preliminarily confirmed that the gut microbiota of diabetic nephropathy patients is influenced by host genetics and provide a new basis for future accurate diagnosis and treatment.