Types Of Lactic Acid Bacteria Research Articles

Understanding Ligilactobacillus salivarius from Probiotic Properties to Omics Technology: A Review.

Ligilactobacillus salivarius (basonym: Lactobacillus salivarius, L. salivarius) is a type of lactic acid bacteria (LAB) commonly found in the oropharyngeal-gastrointestinal tract (OGT). It has gained significant attention due to its probiotic and functional properties as well as its various health-promoting roles. L. salivarius strains exhibit strong resistance and adhesion in the OGT along with outstanding antioxidant and antimicrobial properties. Additionally, numerous L. salivarius strains have the ability to produce bacteriocins with antagonistic activity. These probiotic characteristics of L. salivarius indicate its remarkable potential in promoting favorable effects on human health. It has also been observed that L. salivarius has a positive effect on the composition of intestinal microbiota, thereby improving the metabolic profiling of intestinal microbiota, promoting a healthy and balanced internal environment. In recent years, multi-omics technologies such as genomics, transcriptomics, proteomics and metabolomics have been employed to gain a deeper understanding of the roles and mechanisms of L. salivarius associated with its functional properties. This review aims to provide an overview of the probiotic characteristics of L. salivarius, containing its specific interactions with the host microflora, as well as insights from omics studies.

FERMENTASI PORANG (AMORPHOPHALLUS MUELLERI B.I ) DENGAN LACTOBACILLUS SP TERHADAP KANDUNGAN KALSIUM OKSALAT, GLUKOMANAN DAN PROTEIN

Porang (Amorphophallus muelleri B.I) is nutritional plant with high glucomannan (~ 55% on a dry basis). Porang has 5% to 80% oxalate of its weight, which harmful for health. This research examines method of reducing calcium oxalate and increase glucomannan using principle of fermentation in porang fermented flour products. This research was carried out using factorial RAK with bacterial type factors (L.palatarum and L rhamnosus) and fermentation time (three and five days) and repeated twice. The results were analyzed using SPSS 22 one way ANOVA test and followed by randomized block design test with factorial pattern at p< 0.05 using Duncan follow-up test to determine the differences between the treatments. Analysis of glucomannan and protein levels in porang fermented flour with Lactobacillus plantarum and Lactobacillus rhamnosus bacteria during three and five days of fermentation was influenced by the length of fermentation time, while the decrease in calcium oxalate levels in porang fermented flour influenced by the type of lactic acid bacteria used. The best fermented porang flour is porang flour fermented with Lactobacillus plantarum for five days with an increase in glucomannan levels of 145.19% and decrease in calcium oxalate and protein content levels of 61.29% and 14.66 respectively.

Some enzymatic properties of lactic acid bacteria isolated from dairy products

This article presents data on the study of physiological and biochemical properties, antagonistic and enzymatic activity of lactic acid bacteria isolated from dairy products. 9 types of lactic acid bacteria were studied: Lactobacillus bulgaricus GM – 08, Lactobacillus bulgaricus KZh – 01, actobacillus bulgaricus GS – 03, Lactococcus cremoris – 6, Lactococcus cremoris – 17, Lactococcus cremoris – 26, Lactococcus lactis – 1, Lactococcus lactis – 15, Lactococcus lactis – 23. These strains were found to have resistance to 2% and 4%-vertical NaCl concentrations, bile and phenol. In addition, the antagonistic activity of Gram-positive and Gram-negative microorganisms in relation to test cultures of Staphylococcus aureus, Salmonella dublin,Escherichia coli, Bacillus subtilis, Sarcina flava was studied. All studied lactic acid bacteria showed activity in Test cultures with different inhibition zones. The Lactococcus lactis – 23 strains showed high activity for all cultures, with an inhibition zone of 17-25 mm. Further, 5 strains were selected from these strains and their aroma-forming properties, the formation of diacetyl and ammonia from arginine, hemolytic and lecithinase activity were studied. Compositions were compiled from these strains to make yeast. The compatibility of strains of lactic acid bacteria was checked with each strain individually and with the duration of milk clotting according to organoleptic indicators compared to the duration of milk clotting. Thus, the most active clot formation was obtained by the Lactococcus lactis – 23 strain of the selected combinations.

Anti-breast cancer activity of biosynthesized selenium nanoparticles using Bacillus coagulans supernatant

BackgroundIn the present study, Selenium Nanoparticles (SeNPs) were prepared using Bacillus coagulans, which is a type of Lactic Acid Bacteria (LAB), and then they were applied to treat breast cancer cells. MethodsThe chemicophysical properties of the bioengineered SeNPs were investigated by Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), zeta potential, dynamic light scattering, Fourier Transform Infrared Spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). The cytotoxic potential of SeNPs was evaluated by MTT assay against MCF-7 breast cancer cell line. The expression levels of apoptotic genes including BAX, BCL2, VEGF, ERBB2, CASP3, CASP9, CCNE1, CCND1, MMP2 and MMP9 were determined by real-time PCR. The rate of apoptosis and necrosis of the cancer cells as well as the results of the cell cycle were evaluated by flow cytometry method. ResultsThe synthesized SeNPs had an average particle size of about 24–40 nm and a zeta potential of –16.1 mV, indicating the high stability of SeNPs. EDX results showed presence of SeNPs because amount of selenium in SeNPs was 86.6 % by weight. The cytotoxicity results showed a concentration-dependent effect against MCF-7 cells. The half-maximal inhibitory concentration (IC50) values of B. coagulans supernatant and SeNPs against breast cancer cells were 389.7 µg/mL and 17.56 µg/mL, respectively. In addition, SeNPs synthesized by the green process exhibited enhanced apoptotic potential in MCF-7 cancer cells compared with bacterial supernatants. Cancer cells treated with IC50 concentration of SeNPs induced 32 % apoptosis compared to untreated cells (3 % apoptosis). The gene expression levels of BAX, CASP3, and CASP9 were upregulated, while the expression levels of BCL2, CCNE1, CCND1, MMP2, MMP9, VEGF, and ERBB2 were downregulated after SeNPs treatment of cells. The potential of SeNPs to induce cell apoptosis was demonstrated by the increase in the expression level of BAX gene and the decrease in the expression level of BCL2 after treatment of cancer cells with SeNPs. ConclusionThe obtained results indicated that SeNPs had strong potential to induce significant cell apoptosis and are cytotoxic against the MCF-7 cancer cell line.

ANALYTICAL REVIEW OF BIOTECHNOLOGICAL PROBLEM OF UKRAINIAN HARD CHEESES

An analytical review of the biotechnological process of production of various hard and semi-hard cheeses in the EU and Ukraine, as well as domestic recipes of fermented cheeses for production at craft cheese factories and at home, was conducted. An analysis of the conditions of the key stages of production, including fermentation, coagulation and ripening, was carried out. The composition and type of lactic acid bacteria in sourdough for fermented cheeses, as well as enzymes for fermentolysis and coagulation of milk casein, were studied. As a result of a complex study, a total of 73 types of hard and semi-hard cheeses were analyzed: 35 recipes of the New England Cheesemaking Supply Company by Jim Wallace; 30 production processes of hard and semi-hard cheeses from the EU; 8 technical conditions of hard cheeses of Ukrainian producers. It is shown that the prospects for optimizing the development of new types of hard and semi-hard cheeses in Ukraine are mainly related to the regulation of the time and temperature of fermentation, cooking and ripening of cheeses, as well as the expansion of the biodiversity of the primary and secondary microbiome of starter cultures to improve the taste and aroma of the ready-to-use product. Purpose: to analyze the fermentation process and recipes for the production of hard cheeses in Ukraine with the main world samples, to compare the composition and type of lactic acid bacteria in industrial and craft starters, as well as the types of enzymes for fermentolysis and casein coagulation of milk, in order to optimize production to improve the taste and aroma of ready-to-use product. Materials and methods. Methodical analysis and abstract-logical method for summarizing the evaluation criteria of the biotechnological process of various hard and semi-hard domestic cheeses with world samples according to recommendations, requirements and standards with the development of patents, technical conditions of their production in the EU and Ukraine; DSTU 6003 (Solid cheeses); New England Cheesemaking Supply Company cheese recipes by Jim Wallace. The obtained data were processed by methods of statistical analysis, systematization, comparison and generalization of information. Results. In this study, the documentation was examined and the data of standards, regulations, requirements and recommendations regarding the biotechnology of hard and semi-hard cheeses were analyzed, an analysis of the market of hard cheeses and the peculiarities of the fermentation process of their production was carried out with the determination of critical points and key stages of production using industrial deposited fermentation producers and protein enzymes coagulation and biodiversity of lactic acid bacteria in sourdoughs for fermented cheeses at world productions, with an assessment of the prospects for developing new and improving the biotechnology of Ukrainian benign and safe hard cheeses for healthy nutrition.

Isolation and some basic characteristics of lactic acid bacteria from beetroot (Beta vulgaris L.) —A preliminary study

The carbohydrate content of fruit and vegetable juices has made them a suitable environment for the growth of lactic acid bacteria. Various studies have shown that beetroot can be a good substrate for the production of probiotic drinks for consumers. Therefore, this study was performed to isolate and identify lactic acid bacteria from beetroot juice. Beetroot juice was prepared from two kilograms of washed beetroot with a cold press. Sterile samples of beetroot juice were first enriched in MRS broth and then cultured on MRS agar. Gram and catalase tests were used for the initial detection of lactic acid bacteria. Then, to identify the species of lactic acid bacteria, biochemical confirmation tests such as the melting of gelatin, and the growth of bacteria has been studied in the ideal condition that is 15-45° C, sugars fermentation, gas production from glucose, and growth in at different concentrations of salt were performed. The final verification of species was done using polymerase chain reaction-amplified 16S rRNA-specific DNA. All isolates formed creamy white round colonies on MRS agar medium, were gram-positive, were able to grow in anaerobic conditions, and were also rod-shaped and catalase-negative. Based on biochemical tests, four types of lactic acid bacteria (Lactobacillus plantarum, Lactobacillus helveticus, Lactobacillus salivarius, and Lactobacillus acidophilus) were identified. The findings of this study indicated the presence and diversity of lactic acid bacteria in beet juice, which can be a potential platform for the production of probiotic beetroot juice as a non-dairy product.

Transcriptome analysis reveals the tetracycline resistance mechanism of Lacticaseibacillus rhamnosus FXJWS19L2 and Lacticaseibacillus paracasei FQHXN23L6

Lacticaseibacillus rhamnosus and Lacticaseibacillus paracasei are widely used and regularly consumed probiotics. However, before they are used in food, safety evaluation of antibiotic resistance should be performed to assess the risk of transferring resistance genes. Our study found that L. rhamnosus FXJWS19L2 and L. paracasei FQHXN23L6 exhibited a high tetracycline resistance phenotype but did not contain any known tetracycline resistance genes in their genomes. To investigate the molecular mechanisms underlying tetracycline resistance in these two strains, we performed a transcriptomic analysis combined with gene overexpression techniques to explore potential resistance genes and validate their functions. The transcriptome analysis identified 963 and 372 differentially expressed genes (DEGs) in L. rhamnosus FXJWS19L2 and L. paracasei FQHXN23L6, respectively, after tetracycline induction. The DEGs in these two strains were mainly involved in ribosomal protein synthesis, ABC transporters, and the metabolism of many substances. Moreover, the overexpression of the most significantly up-regulated gene (yjcA), which encodes an ABC transporter, improved the resistance of bacteria to tetracycline. This study reveals the resistance mechanism of these two strains to tetracycline and provides a theoretical reference for the safe application of this type of lactic acid bacteria in food.

Application and Research Progress of Recombinant Lactic Acid Bacteria by Genetic Engineering

Lactic acid bacteria, as a kind of food-grade microorganism, is widely used in food industry, medical care and other fields. The special function of lactic acid bacteria has been increasingly valued and needed, and the traditional strain screening method is complex, long cycle and low cost, which hinders the development and progress of lactic acid industry. At this time, the rapid development of modern genetic engineering has brought new opportunities for the medical application of LAB. By developing new functional strains of LAB, genes with specific functions can be introduced into the genome of LAB, so that LAB can meet the requirements of designers and users. First of all, this article summarizes the characteristics of lactic acid bacteria and discusses the dominant types of lactic acid bacteria in transgenic bacteria. Then, six medical applications of LAB in vaccine delivery vector, virus prevention and control, allergy treatment, cervical cancer, inflammation, lactose intolerance after genetic engineering were reviewed. Finally, the genetically motified LAB is used in the diagnosis and treatment of diseases, such as immune tolerance, vector development, immune mechanism and other issues were reviewed, and the future application of LAB in the field of genetic engineering and cancer treatment was discussed.

Evaluation of Probiotic Properties of Lactic Acid Bacteria Isolated from Dairy Products

Seventy samples were collected from different sources, including dairy samples, soil samples, and samples of therapeutic bacteria supplements available in pharmacies to isolate and diagnose the types of lactic acid bacteria, study some of their traits that are used as bio-enhancers, and identify the most efficient isolates, De Man, Rogosa, and Sharp Agar (MRS) medium were used to isolate the bacteria of lactic acid. After the phenotypic tests for colonies and microscopic and biochemical tests were made, 38 isolates were obtained that belong to lactic acid bacteria, the results showed that most of the isolates belonged to the genus Bifidobacterium, as their number was 14 isolates with a rate of 36.8%, while the number of isolates belonging to the genus Lactobacillus was 12 with a rate of 31.57%. In addition for isolates belonging to the genus Leuconostoc, the number of isolates was 8 with a rate of 21.1%. Also, it was possible to obtain 4 isolates with a rate of 10.5% belonging to the genus Streptococcus. The biological properties of bacterial isolates that are isolated in terms of their ability to grow at different temperatures were studied, the results showed that all isolates being studied have the ability to grow at a temperature of 37° C, 42.8% of the isolates have the ability to grow at a temperature of 10° C, and 50% of the isolates have the ability to grow at a degree of 45° C, also, it appears from the results that all bacterial isolates being studied have the ability to grow in saline concentrations of 6.5%, except for two isolates; S. uberis and S. lactis, also, all bacterial isolates have the ability to grow in a saline concentration of 4.5 % except for B. bifidum, B. infants, B. breve, B. longum. The results also showed that the bacterial isolate L. lactis had the highest pH resistance, as it significantly outperformed the rest of the isolates and gave a growth rate of 123 × 103 CFU / ml, it is followed by isolate S.uberis, and then isolate B.berve, which gave an average growth rate of (113.75, 111.5) × 103 CFU/ml, in terms of its resistance to bile salts, all isolates could resist 0.2, 0.3 g/ml concentrations, L. lactis gave the highest growth rate reached 159 CFU/ml.

Effects of the type of lactic acid bacteria, hot-pressing temperature, and moisture content of fermented bamboo residue on the properties of self-bonding common particleboards

Self-bonding bamboo particleboards were prepared via hot pressing of bamboo residue fermented by lactic acid bacteria. An orthogonal experiment was designed to investigate the effects of three factors (type of lactic acid bacteria used for fermentation, moisture content (MC) of the fermented residue, and hot-pressing temperature) on the resulting self-bonding particleboards. The bending strength and internal bonding strength of the prepared self-bonding particleboards were tested. Fracture characterization was performed on the cross-section of the prepared self-bonding particleboards after bending breakage. The hot-pressing temperature, moisture content (MC), and type of lactic acid bacteria of the fermented residue had a significant effect on the mechanical strength of self-bonding particleboards, and with increased hot-pressing temperature, the strength of self-bonding particleboards increased. Analysis of the cross-sectional morphology and porosity confirmed the significant effect of hot-pressing temperature on the density distribution of self-bonding particleboards. The self-bonding particleboard produced at the hot-pressing temperature of 180 °C, MC of 30%, and that used Lactobacillus plantarum as a fermentation strain showed the best overall performance and reached Chinese standard requirements for common particleboards.

Analysis of D-amino acid in Japanese post-fermented tea, Ishizuchi-kurocha.

The D-amino acid content of Ishizuchi-kurocha, a post-fermented tea produced in Ehime, Japan, was measured. Ishizuchi-kurocha mainly contains D-glutamic acid and D-alanine, but it also contains a small amount of D-aspartic acid. Two types of lactic acid bacteria, Lactiplantibacillus plantarum and Levilactobacillus brevis, are the main species involved in lactic acid fermentation during the tea fermentation process. Therefore, the D-amino acid-producing abilities of strains of these two species isolated from Ishizuchi-kurocha were examined. Specifically, the production of D-aspartic acid, D-alanine, and D-glutamic acid by L. brevis and L. plantarum strains was observed. The amount of D-aspartic acid produced by L. plantarum was low. D-glutamine was detected in culture supernatant but not in bacterial cells. D-arginine was detected in bacterial cells of the L. plantarum strains but not in the culture supernatant. Both the L. brevis and L. plantarum strains possessed at least three kinds of putative racemase genes: alanine racemase, glutamate racemase, and aspartate racemase. However, their expression and enzyme activity remain unknown. L. plantarum and L. brevis could play an important role in the production of D-amino acids in Ishizuchi-kurocha. In fact, Ishizuchi-kurocha is expected to possess the effective physiological activities of D-amino acids.

김치에서 분리한 유산균의 생리적 특성 및 지방축적억제 효과

In this study, probiotic properties such as acid resistance, bile tolerance, intestinal adhesion and fat accumulation inhibition of lactic acid bacteria isolated from kimchi were investigated in order to develop probiotics effective anti-adipogenic effects. Among the 120 types of lactic acid bacteria isolated from kimchi, 42 types of lactic acid bacteria being to acid resistance, 35 types of lactic acid bacteria being to bile resistance, and 24 types of lactic acid bacteria being to both acid resistance and bile resistance were selected. These 24 types were tested for the intestinal adhesion ability which is an essential factor of probiotics’ function and L. rhamnosus GG was used as a positive control in this test. 10 types of lactic acid bacteria having the intestinal adhesion ability were selected. The selected 10 types of lactic acid bacteria were treated in 3T3-L1 cells and intracellular fat was stained with Oil Red O reagent to measure fat accumulation. As a result, in the group treated with lactic acid bacteria OS-15, 48, 102 and 120, fat accumulation was significantly decreased compared with the non-treated group. And the strain OS-48 showed the greatest inhibitory effect on fat accumulation. The lactic acid bacterium OS-48 was identified as Lactiplantibacillus plantarum by analysis based on 16S rRNA sequencing and was named Lactiplantibacillus plantarum OS-48. Therefore, based on the results of this study, L. plantarum OS-48 is expected to be very useful as probiotics with anti-obesity effect in the food industry such as fermented food and functional food.

Effects of lactic acid bacteria fermented feed and three types of lactic acid bacteria (L. plantarum, L. acidophilus, B. animalis) on intestinal microbiota and T cell polarization (Th1, Th2, Th17, Treg) in the intestinal lymph nodes and spleens of rats.

In this study, we investigated the effects of Rubus coreanus-derived lactic acid bacteria (LAB) fermented feed (RC-LAB fermented feed) and three types of LAB (Lactobacillus plantarum, Lactobacillus acidophilus, Bifidobacterium animalis) on the expression of transcription factors and cytokines in Th1, Th2, Th17, and Treg cells in the intestinal lymph nodes and spleens of rats. In addition, the effect on intestinal microbiota composition and body weight was investigated. Five-week-old male rats were assigned to five treatments and eight replicates. The expression of transcription factors and cytokines of Th1, Th2, Th17, and Treg cells in the intestinal lymph nodes and spleens was analyzed using real-time reverse transcriptase polymerase chain reaction assays. Intestinal tract microbiota compositions were analyzed by next-generation sequencing and quantitative polymerase chain reaction assays. RC-LAB fermented feed and three types of LAB increased the expression of transcription factors and cytokines in Th1, Treg cells and Galectin-9, but decreased in Th2 and Th17 cells. In addition, the intestinal microbiota composition changed, the body weight and Firmicutes to Bacteroidetes (F/B) ratio decreased, and the relative abundance of LAB increased. LAB fermented feed and three types of LAB showed an immune modulation effect by inducing T cell polarization and increased LAB in the intestinal microbiota.

Microbial Communities and Metabolites of Whole Crop Corn Silage Inoculated with Lentilactobacillus plantarum and Lentilactobacillus buchneri

To investigate the effects of different types of lactic acid bacteria (LAB) on aerobic stability, microbial community and metabolites of whole crop corn silage ensiled with Lentilactobacillus plantarum (LP) and Lentilactobacillus buchneri (LB) or not (CK), the fermentation parameters, aerobic stability, microbial community and metabolite differential components of whole crop corn silage were analyzed after ensiling for 8 months. The results showed that the pH of the whole treatment was lower than 4.2, which indicates good fermentation quality. Compared with the LP group, the LB group significantly improved the aerobic stability of whole crop corn silage (p < 0.05). The addition of LB and LP both increased the number of LAB and the relative abundance of Lentilactobacillus. Metabolite analysis results showed that 28 metabolites were significantly different between the LP and CK groups (p < 0.01), 15 metabolites were significantly different between the LB and CK groups (p < 0.01), and 17 metabolites were significantly different between the LP and LB groups (p < 0.01). The antioxidant metabolites 9-oxo-10(E), 12(E)-octadecadienoic acid and 9(Z),11(E),13(E)-octadecatrienoic acid ethyl ester in the LB group were significantly higher than those in the lp group (p < 0.01). Therefore, compared with LP, obligate heterofermentative LB is more beneficial to maintain the stability of whole crop corn silage after cellar opening.

Productivity and slaughter rates of rabbits fed by probiotic supplement probi-ol

The productivity, slaughter parameters and weight of internal organs of fattening young rabbits of the White Giant breed additionally fed by probiotic supplement Probiol containing three types of lactic acid bacteria (Streptococcus faecium, Lactobacillus plantarum, Lactobacillus salius) have been researched. It was found out that additional feeding by probiotic supplement Probiol in the amount of 0.025 % to weight of feed has a positive effect on productivity, survival and slaughter indicators of young rabbits. The second experimental group rabbits have increased live weight by 14.4%, survival by 13%; feed consumption per 1 kg of growth decreased by 12 %. Slaughter rates in experimental group exceeded their counterparts in the control group, which confirms the feasibility of introducing a probiotic supplement to rabbits for fattening.

Use of Probiotic Bacteria and Bacteriocins as an Alternative to Antibiotics in Aquaculture.

In addition to their use in human medicine, antimicrobials are also used in food animals and aquaculture, and their use can be categorized as therapeutic against bacterial infections. The use of antimicrobials in aquaculture may involve a broad environmental application that affects a wide variety of bacteria, promoting the spread of bacterial resistance genes. Probiotics and bacteriocins, antimicrobial peptides produced by some types of lactic acid bacteria (LAB), have been successfully tested in aquatic animals as alternatives to control bacterial infections. Supplementation might have beneficial impacts on the intestinal microbiota, immune response, development, and/or weight gain, without the issues associated with antibiotic use. Thus, probiotics and bacteriocins represent feasible alternatives to antibiotics. Here, we provide an update with respect to the relevance of aquaculture in the animal protein production sector, as well as the present and future challenges generated by outbreaks and antimicrobial resistance, while highlighting the potential role of probiotics and bacteriocins to address these challenges. In addition, we conducted data analysis using a simple linear regression model to determine whether a linear relationship exists between probiotic dose added to feed and three variables of interest selected, including specific growth rate, feed conversion ratio, and lysozyme activity.

Effects of dietary Lactobacillus reuteri and Pediococcus acidilactici on the cultured water qualities, the growth and non-specific immune responses of Penaeus vannamei

This study discussed the effects of two types of lactic acid bacteria, Lactobacillus reuteri (L. reuteri) and Pediococcus acidilactici (P. acidilactici), on the growth and nonspecific immunity of Penaeus vannamei (P. vannamei) and developed probiotic applications for shrimp cultivation.This study incorporated two types of lactic acid bacteria in shrimp feed through spraying. The shrimps were grouped according to the type and concentration of effective bacteria incorporated into their feed. This research was separated into 3 individual feeding treatment as control, L. reuteri (Lr groups) and P. acidilactici (Pa groups). The shrimp was feeding with 103, 105, and 107 cfu/feed (g) L. reuteri namely as Lr3, Lr5, and Lr7. The shrimp was feeding with 103, 105, and 107 cfu/feed (g) P. acidilactici were named Pa3, Pa5, and Pa7, respectively. Through 8 weeks of feeding, the results revealed that the use of shrimp feed incorporated with lactic acid bacteria did not cause negative effects on water quality. The testing items include ammonia-nitrogen concentration, nitrite-nitrogen concentration, and total vibrio count in the water. In addition, the lactic acid bacteria concentration in the water were in the range of 1.33 ± 0.58 × 101 to 9.77 ± 1.34 × 102 cfu/mL. Observations of the growth performance of the white shrimps after 8 weeks of feeding revealed that both bacteria were beneficial to shrimp growth. In particular, group Lr7 had the highest percentage weight gain (107.99 ± 3.92%), special growth rate (1.93 ± 0.07%), feed conversion ratio (3.34 ± 0.05), and survival rate (97.22 ± 4.81%).Furthermore, observations of the nonspecific immunity reactions of the white shrimps after 4 weeks of feeding indicated that on day 4, the total number of haemocyte in shrimps in groups Lr5, Lr7, Pa3, and Pa5 significantly increased. On days 1 and 4, the phenoloxidase activity and superoxide axion production rates of the Lr group and Ls group increased. This phenomenon was the most significant in group Lr7, and the effect continued until day 28. After day 7, the phagocytic rate of groups Lr5 and Lr7 significantly increased. In addition, Lr and Pa groups exhibited significant increases in the phagocytic index after days 4 and 14, respectively. This phenomenon was also the most significant in group Lr7.

Enterocins: Classification, Synthesis, Antibacterial Mechanisms and Food Applications

Enterococci, a type of lactic acid bacteria, are widely distributed in various environments and are part of the normal flora in the intestinal tract of humans and animals. Although enterococci have gradually evolved pathogenic strains causing nosocomial infections in recent years, the non-pathogenic strains have still been widely used as probiotics and feed additives. Enterococcus can produce enterocin, which are bacteriocins considered as ribosomal peptides that kill or inhibit the growth of other microorganisms. This paper reviews the classification, synthesis, antibacterial mechanisms and applications of enterocins, and discusses the prospects for future research.

Effects of mixed inoculation of Leuconostoc citreum and Lactobacillus plantarum on suansun (Sour bamboo shoot) fermentation

To study the effects of mixed starter consisted of different fermentative type of lactic acid bacteria (LAB) on the fermentation of suansun, two lactic acid bacteria (Leuconostoc citreum NM-12 and Lactobacillus plantarum L01) isolated from Chinese traditional fermented vegetable were used in the preparation of suansun. The fermentation was carried out at ambient temperature (around 25 °C）for 96 h by inoculating different mixing ratios of LAB (inoculated fermentation) or using natural microbes (natural fermentation). The changes of pH, titratable acid (TA), microbe communities, free sugars, organic acids, nitrite and volatile compounds during fermentation were evaluated. Suansun treated with high Leuconostoc citreum ratio inoculation exhibited a quickly change in pH and TA, resulting from the rapid increase in the number of viable cells, at the early stage of fermentation and produced more mannitol (0.12–0.46 mg/mL) and acetic acid (0.93–3.56 mg/mL). However, Suansun treated with high Lactobacillus plantarum ratio inoculation had lower pH and higher TA at the later stage of fermentation and produced more lactic acid (5.32–7.68 mg/mL). No mannitol was detected in suansun when only Lactobacillus plantarum was inoculated in fermentation. No p-cresol was produced in the inoculated fermentation with mixed starter culture, in addition to the production of ethyl acetate and 2.3-butanedione, which had a positive effect on the flavor of suansun. In summary, this study demonstrated the application value of mixed starter consisted of different fermentative type of LAB. LAB types and mixing ratios greatly affected the types and concentration of metabolites in suansun fermentation.

Effect of cultured white soft cheese on the histopathological changes in the kidneys and liver of albino rats

Three different types of lactic acid bacteria (Lactobacillus helveticus, Lactobacillus rhamnosus and Streptococcus thermophilus S3855) were used to manufacture white soft cheese. The resultant white soft cheeses were pickled for 28 days at refrigerator temperatures and were fed to the experimental rats. The chemical and microbiological analyses of white soft cheese were conducted at different storage periods (fresh, 7 days, 14 days, 21 days, and 28 days). The pH values and protein content of white soft cheese gradually decreased during the storage peroid. Conversely, the moisture content, titratable acidity, and fat/DM % of white soft cheese were found to increase with of the increase in pickling periods of up to 28 days. Microbiologically, the total viable count of bacteria in the control samples was lower than that in the other treatments. Furthermore, the treatments containing the L. helveticus and L. rhamnosus strains had the highest lactoacilli counts whereas the treatment containing the S. thermophilus strain had the highest streptococci counts. Twenty-five male Albino rats were used for experiemntal technique. Rats were fed with 70% basal diet with addition of 30% white soft cheese. Several pathological findings were present in all experimental groups apart from the control rats, and the kidney samples exhibited renal vascular congestion especially in the cortical area. The changes of the glomeruli comprise atrophy, distortion, hypocellularity of the glomerular tuft, and focal lymphoid cell reactions. The renal tubular epithelium showed a series of degenerative changes ranging up to necrosis. The liver samples showed variable hepatic injury in the form of thickening in the Glisson capsule, as well as dissociation and disorganization of hepatic cords. Hepatocellular vacuolar degeneration, presence of focal areas of nodular hyperplasia, the hyperplastic cells mixed with lymphocytic infiltration, congestion in the portal vein, periportal fibrosis and edema with the presence of newly formed nonfunctional bile ductulus. Based on the histopathology scores, the severity of renal and hepatic changes was significantly increased (P ≤ 0.05) in all of the experimental groups compared with the control group. Generally, the chemical composition, microbiological analysis and vital organs were significantly affected by using cultured white soft cheese.