Lactobacillus Plantarum Isolates Research Articles

THE SYNERGISTIC EFFECTS OF LIPOPEPTIDES AND BACTERIOCINS PRODUCED BY Lactobacillus sp. OF HUMAN SAMPLES AGAINST CLINICAL PATHOGENS OF WOUND INFECTION

This study was performed for production, purification, characterization and evaluation the antibacterial activity of biosurfactant BS which were produced from local isolate Lactobacillus plantarum Z9 with bacteriocin and studying the synergistic effect .A total 100 different samples 85(%) isolates of Lactobacillus sp. were isolated from different sources and identified by biochemical tests then subjected to the primary and secondary screening processes to select the active isolate for bacteriocin and biosurfactant production. Among the vagina isolates screened, the results found that Lactobacillus sp. Z9 isolated from the clinical samples of Iraqi healthy women had the highest productivity of the bacteriocin and biosurfactant. Partial purification of biosurfactant that produced from L. plantarum Z9 was conducted using solvent system (chloroform: methanol, 2:1). A 1:1 ratio of n-butanol was used to extract of partially purified bacteriocin, where the bacteriocin activity up to 320 AU/ml against both Staphylococcus aureus and Pseudomonas aeruginosa respectively compared to 20 AU/ml before purification.. Antibacterial activity of Bacteriocin displayed a significant activity with inhibition zones diameter ranged from (11 to 26 mm) and (10 to 25 mm) against P. aeruginosa and S. aureus at concentration ranged from 50 to 200 mg/ml. Maximum antibacterial activity of bacteriocin against P. aeruginosa and S. aureus showed at concentration 200 mg/ml of bacteriocin. Partial purified lipopeptide of L. plantarum Z9 was examined against pathogenic bacteria using well diffusion method. The lipopeptide had inhibition zones diameter ranged from (14 to 28 mm) and (13 to 29 mm) against P. aeruginosa and S. aureus respectively at concentration ranged from 25 to 200 mg/ml. The combination of lipopeptide with bacteriocin increased the range of inhibition zones and made the pathogens sensitive.

Effects of adding isolated Lactobacillus plantarum, Leuconostoc mesenteroides, and their mixtures on the quality indices of pickled Chinese cabbage

Pickled Chinese cabbage traditional fermented vegetables is popular in China, especially the northeast, owing to their special flavors. Spontaneous fermented Chinese cabbage usually has rich and mellow flavor because of abundant microorganism in the fermentation broth. In our study, LAB were screened from spontaneous Chinese cabbage and identified including morphology, physiology and biochemistry, and molecular levels. 11 of these were used as a single inocula to ferment Chinese cabbage, and acid contents, soluble sugar contents, Vc contents, cellulose contents and nitrite contents of these pickled Chinese cabbage were measured. Overall, three superior strains mixture(X1, M2, and D2) were inoculated to improve the fermentation characteristics of pickled Chinese cabbage. Furthermore, pickled Chinese cabbage with the mixture had the highest acid and Vc contents, the lowest nitrite content, and medium fiber content. The sensory quality mixed inocula was also the best compared with products prepared with single strain and spontaneous fermentation.
 Keywords: Lactobacillus plantarum; Leuconostoc mesenteroides; pickled Chinese cabbage, mixed LAB

Gamma-Aminobutyric Acid (GABA) Producing Lactobacillus plantarum TSUB-17 and Probiotic Properties for Using as Probiotics Additive in Swine Feed

Due to the use of probiotics in animal husbandry has recently increased, the selection of high-quality probiotic strains is crucial. Since the uses of probiotics for animal feed supplements have to be applied at high doses of bacteria to be effective, the cultures’ safety is essential. This study successfully isolated the novel Lactobacillus sp. from swine fecal samples and identified it as L. plantarum TSUB-17. The L. plantarum TSUB-17 exhibited excellent probiotic properties, including 100 % resistance to 3 % acids and 1 % bile salts, and effectively inhibits pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella Typhimurium (isolated ESBL strain). L. plantarum TSUB-17 was also found to adhere to the intestinal wall and form a biofilm. Furthermore, the bacteria have revealed some unique properties of GABA production and detected the glutamate decarboxylase B (gadB) gene similar to L. brevis both in nucleotide sequence and secondary structure of the glutamate decarboxylase enzyme that was deduced from the nucleotide. The isolated bacteria also have antioxidant activity, and most importantly, the isolated strain was safe; it is non-hemolysis and susceptible to the tested antimicrobials. Therefore, L. plantarum TSUB-17 is suitable for further development as a probiotic additive in animal feed. HIGHLIGHTS This study successfully isolated Lactobacillus plantarum TSUB-17 with a high potential to develop as a probiotic for animals. The isolated bacterium has excellent properties: It tolerates high levels of acids and bile salts. It is effective against many pathogenic bacteria, produces gamma-aminobutyric acid (GABA) and shows high levels of antioxidant activity. Moreover, L. plantarum TSUB-17 is very safe due to its non-hemolytic strain and susceptibility to numerous antimicrobial drugs. GRAPHICAL ABSTRACT

Effect of probiotics on hematological parameters of male and female Wistar rats

In the present study, the effect of probiotics on the hematology of Wistar rats was examined. Locally isolated Lactobacillus plantarum MZ707748 (Pro 1), L. plantarum MZ710117 (Pro 2), Weisella confusa MZ727611 (Pro 3), and L. plantarum MZ735961 (Pro 4) were used. One strain of probiotic, L. acidophilus-14 (Pro 5), was purchased commercially. Different groups were designed as G1, G2, G3, G4, and 5, G5/PC consisting only pro 5 and NC & 0 day were untreated. Different groups have different probiotics like G1 containing Pro 1 and Pro 2, G2 comprising Pro 3 and Pro 4, G3 containing Pro 2, Pro 3 and Pro 5, G4 having Pro 1–5, and G5 containing Pro 5. A complete count of blood, serum chemistry, fecal analysis, and histopathological examination of the thymus and liver were done. Statistical differences were seen in the complete blood count parameters (p < 0.05). No difference was observed in AST, ALT, bilirubin, albumin, IL-6, and IgA (p > 0.05) except for TP, creatinine, and globulin (p < 0.05). Fecal strains of probiotic groups were antibiotic-resistant. In males, Lactobacillus helveticus OQ152020, Enterococcus lactis OQ1519891, E. faecium OQ152017, L. gasseri OQ152017, and E. lactis OQ152019 were isolated from positive control, G1, G2, G3, and G4 respectively. In females, Enterococcus sp. OP800231, Limosilactobacillus fermentum OQ151985, E. lactis OP800267, L. plantarum OP800244, and E. faecium OQ151988 were isolated from positive control, G1, G2, G3 and G4, respectively. It was concluded that all probiotic strains were safe to use and had beneficial effects on the hematology of Wistar rats.

Preparation and Evaluation of a Dosage Form for Individualized Administration of Lyophilized Probiotics

Probiotics have been used in human and veterinary medicine to increase resistance to pathogens and provide protection against external impacts for many years. Pathogens are often transmitted to humans through animal product consumption. Therefore, it is assumed that probiotics protecting animals may also protect the humans who consume them. Many tested strains of probiotic bacteria can be used for individualized therapy. The recently isolated Lactobacillus plantarum R2 Biocenol™ has proven to be preferential in aquaculture, and potential benefits in humans are expected. A simple oral dosage form should be developed to test this hypothesis by a suitable preparation method, i.e., lyophilization, allowing the bacteria to survive longer. Lyophilizates were formed from silicates (Neusilin® NS2N; US2), cellulose derivates (Avicel® PH-101), and saccharides (inulin; saccharose; modified starch® 1500). They were evaluated for their physicochemical properties (pH leachate, moisture content, water absorption, wetting time, DSC tests, densities, and flow properties); their bacterial viability was determined in conditions including relevant studies over 6 months at 4 °C and scanned under an electron microscope. Lyophilizate composed of Neusilin® NS2N and saccharose appeared to be the most advantageous in terms of viability without any significant decrease. Its physicochemical properties are also suitable for capsule encapsulation, subsequent clinical evaluation, and individualized therapy.

Improved viability of probiotics encapsulated in soybean protein isolate matrix microcapsules by coacervation and cross-linking modification

The objective of this research was to encapsulate probiotic bacteria based on soy protein isolate (SPI) matrix using either coacervation, cross-linking modification or their combination, and investigate the influences on the survival of probiotic bacteria during spray drying, in vitro gastrointestinal digestion, heating, UV irradiation and storage. A probiotic isolate Lactobacillus plantarum 550 was spray dried in SPI solution combined with either pectin (PEC), transglutaminase (TGase) or their combination. High survival rate and low moisture content were obtained for all the samples. Microcapsules fabricated using either SPI-PEC coacervation or TGase induced cross-linking obtained well cell survival during gastric digestion, heat/UV treatment and storage, however, combination of these two modification methods generated microcapsules with lower cross-linking degree and loose package structure corresponding with significant negative effects to the cell viability during gastric digestion and storage. Among the formulations tested, SPI-PEC microparticles provided the best protection to the probiotic cells, as pectin own well thermal stability and digestion resistibility, could fill the cracks and voids existed in SPI matrix and form hydrogen bond to stabilize cell membrane during processing. In conclusion, the current study demonstrated that SPI based probiotic microcapsules with high structural density and cross-linking degree may provide better protection to adverse external environment.

Utilization of RSM for optimization of physical variables to improve bacteriocin production from Lactobacillus plantarum strain MS

The utilization of natural antimicrobial substances has been increased in the pharmaceutical sector due to their stability and inhibition activity against pathogenic microorganisms. In the current study, the bacteriocin synthesis by locally isolated Lactobacillus plantarum MS from yogurt, has been optimized by using response surface methodology. Statistical optimization of physical variables by using Box-Behnken design, 3200 AU/mL bacteriocin activity was detected at 30 C temperature, 18h incubation time, and pH 6 against Staphylococcus aureus. The resulting bacteriocin was found to be stable a broad range of pH (2-12) and temperature (37-100 C) but the activity of bacteriocin was slightly disturbed at 121 C. Besides, bacteriocin showed stability after treatment with various enzymes (catalase, amylase, and lipase), salt (NaCl), and surfactants (triton X-100, EDTA, and SDS) but found sensitive by treating with proteolytic enzymes (proteinase K and trypsin) in comparison with untreated bacteriocin. Because of such biochemical characteristics, these antibacterial peptides could be possibly incorporated in the field of pharmacy to fulfil consumers' demand for natural remedies. Keywords: Lactic acid bacteria, bacteriocin, antibacterial activity, response surface methodology, Box-Behnken design.

Oral feed-based administration of Lactobacillus plantarum enhances growth, haematological and immunological responses in Cyprinus carpio

The effect of probiotic bacteria (Lactobacillus plantarum isolate FLB1) on the immunological responses of Cyprinus carpio (Common carp) was tested in a feeding trial. Fingerlings were divided into five treatment groups and fed with graded probiotic diets [@ 0 (T1), 106 colony-forming unit (CFU)/g (T2), 107 CFU/g (T3), 108 CFU/g (T4), and 109 CFU/g (T5) of test meal] in triplicate. Fish fed probiotic supplemented diets had significantly (P < 0.05) improved growth performance, haematological parameters, blood Haemoglobin (Hb), Total Erythrocyte Count (TEC), Total Leucocyte Count (TLC), Packed Cell Volume (PCV)/ Hematocrit (Ht), Mean Corpuscular Haemoglobin (MCH), and Mean Corpuscular Haemoglobin Concentration (MCHC), with the greatest improvement in the treatment T5. Significant (P < 0.05) increase in total serum protein and globulin, as well as lower Albumin (Alb)/ Globulin (Glb) ratio values were also reported. These values indicated the overall improvements in non-specific immune markers. In all the probiotic fed fish groups, significantly (P < 0.05) reduced values of blood glucose levels, total cholesterol, Triglycerides (TG), and High-Density Lipoprotein (HDL) were observed. Increased numbers of lactic acid bacteria (LAB) were detected in the gastrointestinal tract of probiotic-fed groups indicating the viability and survival of L. plantarum in the fish gut. The results showed that supplementing the diet with L. plantarum @ 109CFU/g feed during the growth period of the fish in a semi-intensive culture system could improve growth and health status of C. carpio.

Selection of Lactic Acid Bacteria Isolated from Cocoa and Cassava Fermentation as Potential Probiotic for Pathogenic Microorganisms Control in Poultry Farming

Aims: The overuse of antibiotics in animal farming sector is leading to an increase drug resistant bacteria rate. This situation makes it difficult to treat pathologies in both humans and animals. The aim of this study was to assess some probiotic profiles of lactic acid bacteria strains isolated from cocoa fermentation and traditional cassava ferment for possible use as potentially probiotic strains for the monitoring of pathogenic microorganisms in poultry farming.&#x0D; Methodology: Thus, a total of 267 lactic acid bacteria strains were tested for analysis of the antibacterial activity against the growth capacity of Salmonella and E. coli isolates. Probiotic properties of Lactic acid bacteria were consisted of acidification capacity, resistance to acid shock and to salt bile containing in culture medium and capacity to produce proteolytic and lipolytic enzymes.&#x0D; Results: Among them, 25 strains have induced the high bacterial growth inhibition against these pathogenic bacteria with inhibition zone diameters ranged from 9 to 27 mm. Among these strains, 20 isolates showed high resistance to acid shock at pH ≥ 4 and six strains were able to grow at pH 3.5 with survival rate range from 30 % to 89 %. Moreover, six of these strains, including four isolates of Lactobacillus plantarum (T1GB8, T11AB17, LAB26, LAB 127), one strain of Leuconostoc mesenteroides (T0AB9) and one isolate of Enterococcus facium (LAB18), have shown capacity to growth with 1 % of bile salts in the medium. Even better, these strains exhibited capacity to produce proteolytic and lipolytic enzymes with halo around the well diameters reached 29 mm for some strains.&#x0D; Conclusion: This study shows the possibility of use probiotics lactic acids bacteria as antibiotics alternative in poultry sector to reduce some avian pathologies affecting the poultry sector in Côte d'Ivoire.

Poteng Local Food Potential with isolate Lactobacillus Plantarum in Preventing Depression

Depression is a global problem whose symptoms are easier to observe than cure. With a fairly high prevalence in Indonesia, which is up to 6.1% in 2018, this problem practically does not only affect the sufferer but also has an impact on the people around him which in turn will further reduce the quality of life of the sufferer. Lombok Island has a local food called poteng which is the result of fermented sticky rice. Poteng is able to act as a probiotic because it contains Lactobacillus plantarum. Probiotics can play a role in helping people with depression with the Gut Brain Axis mechanism by reducing Interleukin-6, increasing gamma-Aminobutyric Acid, and influencing Vitamin D and its receptors. In a depressed state, Interleukin-6 was observed to increase whereas GABA was observed to decrease. The Gut Brain Axis mechanism affects depression through neuroanatomical pathways, regulation of microbial metabolites (Short-Chain Fatty Acid), Tryptophan metabolism, and Immune Regulation.

Fermented Cranberry Fortified Buckwheat Product—Phenolic Composition, Antioxidant and Microbiological Properties

This study determined the effect of fermentation by Fresco DVS 1010 starter culture with added probiotic strain Lactobacillus rhamnosus GG and potentially probiotic isolate Lactobacillus plantarum HM1, at fermentation times (0, 8 h) and cold storage period (24 h, 4th day, 7th day, 14th day), on microbial parameters, pH changes, total phenolic content, phenolic compounds profile, and antioxidant activity of buckwheat water- and milk-based mashes, flavored with cranberries and unflavored. The tested starter Fresco culture effectively fermented the buckwheat products and the viable cell counts of potentially probiotic bacteria were sufficient to demonstrate the health-promoting properties of final products. Lactic acid bacteria had a positive impact on total phenolic compound content, total flavonoid content, and antioxidant activity of buckwheat mashes, whereby final values (14 days) were higher by about 16.9–130.8%, 13.4–37.7%, and 14.5–145.9%, respectively, in comparison to initial values (0 h). Seven phenolic acids (gallic, protocatechuic, vanillic, syringic, caffeic, p-coumaric, and ferulic) and two flavonoids (rutin and quercetin) in buckwheat mashes were measured during the experimental period. The content of quercetin, gallic, and protocatechuic acids increased and, conversely, p-coumaric acid decreased, in all products. Prepared buckwheat fermented products have the potential to meet the criteria for potentially functional foods.

Assessment of the Antimicrobial Activity of Lactic Acid Bacteria from Sorghum Slurry on Clinical Strains of Diarrhoeagenic Escherichia coli

Background: Sorghum is a nutrient-rich grain ground into flour to make different types of delicacies, and it has been reported to possess probiotic potentials.&#x0D; Objective: To assess the antimicrobial activity of Lactobacillus plantarum obtained from sorghum slurry on strains of enteropathogenic Escherichia coli from cases of diarrhoea.&#x0D; Methods: A total of 36 samples of wet-milled sorghum slurry and liquor pH were obtained and cultured on MRSA and were, after that, biochemically characterized for Lactobacillus plantarum, which was tested by agar well diffusion against 15 strains of Escherichia coli isolated from cases of diarrhoea.&#x0D; Results: Microbiological analysis of the 36 samples of sorghum explored produced 15 isolates of Lactobacillus plantarum. A progressive increase in acidity in relation to an increase in the period of fermentation was observed. Ninety-five per cent of the Escherichia coli strains showed resistance against some standard antibiotics. At the same time, the isolates of Lactobacillus plantarum obtained inhibited isolates of diarrhoeagenic Escherichia coli tested, showing potential usefulness of the sorghum slurry as a probiotic.&#x0D; Conclusion: The inhibitory activity of Lactobacillus plantarum isolated from sorghum slurry showed antimicrobial potentials that could be used for therapeutic purposes in treating diarrhoea caused by Escherichia coli, pending further investigation.

Molecular Characteristics of Iraqi Lactobacillus plantarum Isolates and Evaluate its Natural Bacteriocin(plantaricins) Antimicrbial Activity against Pathogenic Bacteria

In this study, local strains of Lactobacillus plantarum bacteria were isolated from traditional Iraqi rawmilk and milk products. The present study was aimed to study the molecular aspects of Iraqi Lactobacillusplantarum isolates and to evaluate its natural plantaricins antimicrobial activity against pathogenic bacteria. For complete detection for Lactobacillus spp. the partial sequencing of 16S rDNA gene result was analyzedand compared with those in GenBank to find out the different in the sequence using the BLAST program(http:// www. ncbi. nlm.nih). The result was 17 samples diagnosed as Lactobacillus plantarum. Moreover14 isolates of local Lactobacillus plantarum bacteria were show 100% similarity with those previouslyrecorded in GenBank, while 3 isolates were found to display more than 99% similarity with L. plantarumstrains were previously listed in GenBank. Moreover the study also reveals that all L.plantarum strains wasshowed antibacterial activity against three studied indicators bacteria and the plnEF gene (530bp) wasdetected in all 17 isolates of L.plantarum.

ОЦЕНКА БИОСОВМЕСТИМОСТИ БАКТЕРИАЛЬНЫХ ИЗОЛЯТОВ – КОМПОНЕНТОВ БИОКОНСЕРВАНТОВ

The aim of this work was to study the relationship between the isolates of Bacillus subtilis EFS, Lactobacillus plantarum, Propionibacterium freudenreichii, Lactococcus lactis, and Strepto-coccus lactis, which have the potential for the development of a bacterial preparation that improves the safety of plant-based feed during harvesting and storage. The possibility of using the tested iso-lates as part of the association was identified by the drip method, which is high quality and most suitable for primary testing. The method involved direct joint cultivation of microorganisms on the surface of a dense nutrient medium and visual assessment of signs of suppression or enhancement of the growth of one culture by another. As a result of the study, the following types of interactions between microorganisms were identified: neutrality, contact progression, antagonism, and contact regression. For inclusion in the association, isolates that showed neutrality and contact progression to each other were selected. The corresponding types of relationships were characteristic of B. sub-tilis EFS, L. plantarum, P. freudenreichii, and L. lactis isolates. Based on this, six recipes were formed that are promising for further research in order to develop a biological preparation that helps to improve the safety of plant-based feed during harvesting and storage.

In Vitro Evaluation of Probiotic Properties of Lactobacillus plantarum UBLP40 Isolated from Traditional Indigenous Fermented Food.

In this study, traditional indigenous fermented food isolate Lactobacillus plantarum UBLP40 was screened for in vitro probiotic properties, antibiotic susceptibility, hemolytic activity, production of lactic acid, hydrogen peroxide, bile salt hydrolase and phytase, and antioxidative activity. Results showed that Lact. plantarum UBLP40 can survive simulated gastrointestinal conditions, adhere to mucin, possess a hydrophobic cell surface, ability to auto-aggregation, and possessed antimicrobial activity against Micrococcus luteus MTCC 106, methicillin-resistant Staphylococcus aureus subsp. aureus ATCC® BAA-1720, Pseudomonas aeruginosa MTCC 1688, and Escherichia coli MTCC 1687. Lact. plantarum UBLP40 produced 48.59 U/mg phytase and 1.78 ± 0.01 gm % lactic acid and showed the ability to produce hydrogen peroxide and bile salt hydrolase. Moreover, the usual antibiotic susceptible profile and non-hemolytic activity indicated the safety of the strain. The intracellular extract of UBLP40 showed 13.8 ± 1.4% (equivalent to ~8µM butylated hydroxytoluene) α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity, reducing activity equivalent to 1µg L-cysteine, Fe2+ chelation equivalent to 5µM ethylenediaminetetraacetic acid, and exhibited 17.73 ± 4.40µM glutathione per gram of protein. In conclusion, this study demonstrates that Lact. plantarum UBLP40 is a potential probiotic candidate.

DETERMINATION OF THE OPTIMUM CONDITIONS FOR BIOSURFACTANT PRODUCTION BY LOCAL ISOLATE OF LACTOBACILLUS PLANTARUM AND EVALUATE ITS ANTIMICROBIAL ACTIVITY

Eighty five local isolates of Lactobacillus sp. which were isolated from different sources and identified by biochemical test then subjected to the primary and secondary screening processes to select the active Lactobacillus sp. isolate for biosurfactant production. Among the isolates screened, twenty six isolates with maximum for tests in primary screening were selected for secondary screening. It has been found that Lactobacillus sp. ADK2 had the highest productivity of the biosurfactant. The selected isolate with highest level of biosurfactant activity was identified as Lactobacillus plantarum ADK2 according to PCR technique. The optimum conditions of biosurfactant production by isolate Lactobacillus plantarum ADK2 using submerged fermentation were obtained in the synthetic mineral salt medium (MSM) and natural BCDFTM medium the best production medium separately, 1.5% (lactose and egg) as the best carbon source, 2% meat extract and 3.5% Pease as nitrogen source, temperature 30 °C for two media and pH 5 with pH 3 in MSM and BCDFTM respectively, after 96 hr and 72 hr in MSM and BCDFTM respectively of incubation period.

Enhancement of the antibacterial potential of plantaricin by incorporation into silver nanoparticles

BackgroundBacteriocins are proteinaceous compounds produced from lactic acid bacteria. Bacteriocins are well-known for their antibacterial potential and safety for application in food. However, the commercial availability of bacteriocin is facing several limitations; among them is the low yield and short stability period. That calls for a new strategy for overcoming these hurdles. Among these approaches is incorporating bacteriocin in nanoparticles. So, the aim of this study was to enhance the plantaricin produced from isolated Lactobacillus plantarum strain using nanotechnology. ResultsIn this study, the plnEF genes encoding plantaricin EF have been identified and sequenced (accession number of MN172264.1). The extracted bacteriocin (EX-PL) was obtained by the ammonium sulfate method. Then, it was used for biosynthesizing plantaricin-incorporated silver nanoparticles (PL-SNPs). The synthesized nanoparticles were confirmed by SEM-EDAX analysis. The antibacterial activity of both combined (PL-SNPs) and extracted plantaricin (EX-PL) were tested against some strains of foodborne pathogenic bacteria. The results revealed that the antibacterial activities were increased by 99.2% on the combination of bacteriocin with the silver nanoparticle. The MIC of EX-PL (7.6 mg/mL) has been lowered after incorporating into silver nanoparticles and reached 0.004 mg/mL for PL-SNPs. Despite that extracted plantaricin showed no inhibitory activity towards Listeria monocytogenes, plantaricin-incorporated silver nanoparticles displayed inhibitory activity against this strain. Furthermore, the stability period at 4 °C was increased from 5 days to 60 days for EX-PL and PL-SNPs, respectively. ConclusionsPlantaricin-incorporated silver nanoparticles possess higher antibacterial activity and more stability than the free one, which makes it more fitting for combating foodborne pathogens and open more fields for applications in both food and pharmaceutical industries. Graphical abstract▪

Probiotic Properties and Safety Profiling of &lt;i&gt;Lactobacillus plantarum&lt;/i&gt; Isolated from Spontaneously Fermented Milk in Kenya

The aim of this study was to assess the probiotic potential and safety profile of a Lactobacillus plantarum strain isolated from Kenyan spontaneously fermented milk, Amabere amaruranu. The Lactobacillus plantarum isolate was tested for temperature sensitivity (at 15°C, 30°C, 37°C, and 45°C), pH tolerance (at 2.0, 2.5, 3.0, 3.5, and 6.5 as control), and 0.4% phenol tolerance to observe its survival in the gastrointestinal tract of humans. For safety evaluation of the isolate, antagonistic activity was tested against pathogenic strains of Staphylococcus aureus, Escherichia coli, Salmonella enterica serovar Typhi, and Candida albicans, while antibiotic susceptibility pattern was examined using nalidixic acid, ampicillin, azithromycin, ciprofloxacin, tetracycline, gentamicin, and chloramphenicol antibiotic discs and haemolytic activity was done using lamb blood agar. Lactobacillus plantarum isolate had an optimal growth at 37°C, it also demonstrated low pH tolerance (2.0–3.5). It was able to maintain its viability (~100%) after exposure to 0.4% phenol. The selected isolate showed inhibition (antagonistic activity) against the pathogens with S. typhi having the largest (ZDI = 31.0 ± 1.73 mm) zone of diameter inhibition (ZDI) and Candida albicans having the least (ZDI = 18.0 ± 0.76 mm). Lactobacillus plantarum isolate was sensitive to Azithromycin, tetracycline and chloramphenicol and was intermediately sensitive to gentamycin, while it was resistant to nalidixic acid, ampicillin, and ciprofloxacin. The isolate also exhibited γ-haemolytic activity hence safe for use as a starter culture. The selected isolate can be used as a starter culture and a probiotic since it had excellent probiotic properties.

UTILIZATION OF ISOLATED THERAPEUTIC BACTERIA IN TOPICAL OINTMENT FOR INFECTION TREATMENT

This study includes the using therapeutic bacteria isolate in topical ointment for bacterial vaginosis treatment and to compare it with metronidazole ointment that use in a clinical trial under medical supervision. Four active Lactobacillus probiotics bacteria were cultured in %12 skim milk , three of these bacteria were commercial types and one Iraqi local isolate , the total bacterial count of probiotics bacteria were around ≥ 1012 cfu/ml . %10 of individually culture free cells filtrate were added to Muller Hinton broth with secretions of patients infected with bacterial vaginosis "BV", %50 of natural organic components and %50 of local isolate Lactobacillus plantarum cultured in skim milk were mixed to prepare the natural ointment. Eighty-nine BV volunteers were divided into two group, first was 43 volunteers used probiotic ointment, the second group was 46 volunteers used metronidazole ointment "as control group", both groups were under medical observation for two weeks. The results shown that Iraqi local isolate Lb . plantarum gave best inhibition in vitro, according to Amsel criteria the rate of healing with Lb . plantarum ointment group was %97.87, it was higher than metronidazole ointment %91.30 and the healed cases numbers were increased at the day 7 and 14,it has been noticed that the results were positive based on vaginal secretions, and whiff test, clue cell and the pH was above 4.5 shown significant progress. According to Nugent criteria Lb . plantarum ointment gave higher healing percentage which was %95.35.

Screening of Lactobacillus plantarum with broad-spectrum antifungal activity and its application in preservation of golden-red apples

Fungal food spoilage is a common problem that leads to both great economic losses and serious health problems. This study screened the antifungal activity of 137 Lactobacillus plantarum isolates against six common food spoilage indicator fungi using an overlay method and indicator strains of the species Aspergillus flavus, Fusarium moniliforme, Penicillium expansum, Penicillium chrysogenum, Cladosporium cladosporioides, and Aspergillus niger. Among Lactobacillus plantarum isolates, strain IMAU80174 was selected as the most effective based on the results of mycelium growth inhibition by its cell-free supernatant (CFS) and tolerance to simulated gastrointestinal juices and bile. The CFS of Lactobacillus plantarum IMAU80174 showed heat and protease resistance, and it was active only in a low pH environment. The application of the CFS to golden-red apples could slow down spoilage caused by inoculation of Penicillium expansum.