Isolation, identification and characteristics of Clostridium butyricum CB-a together with its high-density fermentation

SummaryMicroencapsulation of bacteria in hydrocolloid beads is known as a potential way to enhance and protect their survivability in the digestive tract. We encapsulated a mix of two lactic bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) in sodium alginate (AG) and chitosan (CH) matrices. The morphological parameters of beads containing bacteria were comparatively measured. The FTIR fingerprint can discriminate the presence of bacteria into the beads, identifying specific absorption peaks for bacteria located at 1750, 2852 and 2926 cm−1. To check the survivability of bacteria, beads were incubated in simulated gastric juice (pH 1.5) and intestinal juice (pH 7.2) for different periods of time, up to 120 min. The 2% AG beads, better than CH beads, provided best protection of bacterial survivability. Encapsulated mix of S. thermophilus and L. delbrueckii subsp. bulgaricus can behave as a probiotic bacteria, viable, surviving in the simulated gastric and intestinal juice.

Cocoa flavanols and procyanidins possess wide-ranging biological activities. The present study investigated the stability of the cocoa monomers, (-)-epicatechin and (+)-catechin, and the dimers, epicatechin-(4beta-8)-epicatechin (Dimer B2) and epicatechin-(4beta- 6)-epicatechin (Dimer B5), in simulated gastric and intestinal juice and at different pH values. The dimers were less stable than the monomers at both acidic and alkaline pH. Incubation of Dimer B2 and Dimer B5 in simulated gastric juice (pH 1.8) or acidic pH resulted in degradation to epicatechin and isomerization to Dimer B5 and Dimer B2, respectively. When incubated in simulated intestinal juice or at alkaline pH, all four compounds degraded almost completely within several hours. These results suggest that the amount, and type, of flavanols and procyanidins in the gastrointestinal tract following the consumption of cocoa can be influenced by the stability of these compounds in both acidic and alkaline environments.

Breast milk is an important food for the neonates during their early months of development, primarily educating their immune system and protecting them for pathogens. The aim of this research was to investigate the probiotic properties (resistance to acid and bile salt) of free and microencapsulated Lb. rhamnosus LC705 strain isolated from mothers’ breast milk. Lb. rhamnosus LC705 was encapsulated into alginate (AL)-whey protein isolate (WPI) microspheres and morphology and particle size of the microcapsules were determined. The Viability of free and encapsulated forms in simulated gastric and intestinal juice was studied. Entrapment efficiency (emulsion method) was ~ 88%. The images of the scanning electron microscope (SEM) illustrated spherical shaped microcapsules with approximate diameters of less than 100 μm. The survival of free and microencapsulated Lb. rhamnosus LC705 was reduced to 6 and 4 log cycle in simulated gastric juice (pH 2.5, 2 h). Microencapsulated Lb. rhamnosus LC705 (D-values 27.10 min) survived better than the free cells (D-values 13.38 min) against bile salts (0.5%, 2 h). The survival of microencapsulated cells was significantly (p < 0.05) better than the free cells. Therefore microencapsulation of Lb. rhamnosus LC705 in AL–WPI containing matrix has the potential to increase the strain viability against simulated gastrointestinal conditions.

The metabolic activity and behavior of Lactobacillus casei were investigated during lactic fermentation and after microencapsulation. L.casei metabolic activity in vitro was investigated by HPLC and Infrared spectrometry (FTIR). Following the fermentation during 78 h, we identified lactic acid (retention time at 4.59 min) and its synthesis to begin after 3h and increasing gradually, up to a productivity of 6.89 mg mL-1 after 78 h. We noticed a high activity in the first 6 hours, and the media was totally consumed before 12 hours. By FT-IR fingerprint during fermentation we identified changes of the spectra pattern, specific increasing peaks of lactic acid (1127 cm-1) during fermentation (from 3 to 78 h) and other specific absorption peaks at 1420 cm-1, 2845 and 2929 cm-1. &#x0D; The comparative behavior of L.casei microencapsulated in different matrices, in simulated gastric and intestinal juice were also studied. L.casei was microencapsulated in sodium alginate (AG), chitosan (CH), alginate: guar gum (AG:GU) and alginate: xanthan gum (AG:XA). The microencapsulation effects on the changes in survival rate of bacteria, during exposure in simulated gastric and intestinal juice were studied. The survivability of the strains, were expressed as the destructive value (decimal reduction time). The alginate beads 2% prevented acid-induced reduction of the cell density in simulated gastric juice, resulting in significant (P

Optimization of nutritional conditions for nattokinase production by Bacillus natto NLSSE using statistical experimental methods

In-vitro bioaccessibility of five pyrethroids after human ingestion and the corresponding gastrointestinal digestion parameters: A contribution for human exposure assessments

Staphyloxanthin is a virulence factor of Staphylococcus aureus which gives the bacteria a gold color. In this study, we observed the production of the carotenoid when the organism is grown on nutrient agar (NA), but not on tryptic soy agar (TSA) as colonies appeared white. The addition of different carbon sources such as glucose, sucrose or maltose at minimal doses of 0.1%, 0.1% and 0.3% can inhibit carotenoid production, respectively. In contrast, enhanced carotenoid production in S. aureus was observed with supplementation of nitrogen sources, using soy peptone, yeast extract and peptone in decreasing order. Golden S. aureus showed higher H2O2 tolerance and shorter lag phase when grown in nutrient broth compared to bleached colonies. Glucose concentration required for bleached colonies is positively pro-portional to the concentration of soy peptone added in NA. The addition of 1% soy peptone in nutrient agar (NASP) was developed as base medium to screen inhibitory activity of staphyloxanthin from methanol or water extracts of 141 Chinese herbs. Results showed inhibitory activities in methanol extracts of Paeonia lactiflora, Biota orientalis, Ermichebula chebulia, Galla chinensis, Asarum sieboldii, Rheum tanguticum, Lindera strychnifolia, Acacia catechu and water extracts of Biota orientalis, Ermichebula chebulia, Galla chinensis. Soybean protein isolate treatment may affect the minimal inhibitory concentration of some herb extracts.

Lactic acid bacteria (LAB) are commonly associated with agricultural produces like cereals, fruits, and vegetables. Probiotic lactobacilli are the potential microbes to reduce unavoidable pesticide absorption besides their ability to degrade pesticides in humans and wildlife. The present study aimed to evaluate the strains Lactobacillus plantarum Pb3, Lactobacillus acidophilus Pc1 and Lactobacillus lactis Pt4 for their antioxidant ability and tolerance to simulated gastric and intestinal juice to understand their effects against oxidative damage induced by the pesticides chlorpyriphos, imidacloprid and chlorantraniliprole. Among the three strains, L. plantarum Pb3 exhibited the highest antioxidant ability and tolerance to simulated gastric and intestinal juices, followed by L. acidophilus Pc1 and L. lactis Pt4. Intact cells possessed higher activity than cell-free extracts and cellfree supernatant. The lipid peroxidation inhibition ability of intact cells of L. plantarum Pb3 in the presence of chlorpyriphos, imidacloprid and chlorantraniliprole was 58.12%, 50.75% and 48.88% respectively, and it was 46.19% in the absence of pesticides. Hydroxyl radical scavenging abilities of intact cells of L. plantarum Pb3 in the presence of chlorpyriphos, imidacloprid, and chlorantraniliprole were 52.09%, 49.88%, and 49.15% respectively, as against 45.56% in the absence of pesticides. Under simulated gastric and intestinal juices, a 70 to 75% survival rate was recorded in L. plantarum Pb3. The antioxidant ability of LAB and the tolerance of simulated gastric and intestinal juices indicated the potential protective effects of L. plantarum Pb3 against the adverse effect of pesticides on human health.

The utilisation of E. faecalis HZNU S1 as a probiotic is hindered by its sensitivity to gastrointestinal and storage environments. Therefore, the aim of the present work was to encapsulate E. faecalis HZNU S1 using alginate (ALG) and rice milk (RM) as encapsulating materials through the extrusion method. The resulting microbeads were characterised in terms of their size, encapsulation efficiency, and probiotic resistance under simulated gastrointestinal conditions, and also with regard to various storage conditions. The microbeads had a mean particle size of 1.60 ± 0.20 mm, and an encapsulation efficiency of 97.40%. The viability of free-state probiotics exposed to simulated gastric juice (SGJ) was found to be poor. After the treatment with SGJ under pH 2.0 and 2.5 for 1.0 h, the viability of encapsulated cells was found to be greater than 6.0 log CFU/g. Furthermore, encapsulation led to an enhancement in the viable rate of cells when incubated in bile salt solution. After exposure to bile salt solution (0.30%), the viable count entrapped cells significantly decreased from 10.01 to 6.92 log CFU/g after 1 h of exposure. The full release of entrapped cells was observed when exposed to simulated intestinal juice (SIJ) within 120 min. Furthermore, encapsulation also was able to improve the storage stability of probiotics. After 12 days of storage, viable counts of encapsulated cells were 9.1 and 6.3 log CFU/g at 4 and 25°C, respectively. Therefore, the present work suggested that encapsulating E. faecalis HZNU S1 within ALG/RM microbeads could enhance its survival during both gastric-intestinal tract and storage conditions.

Simulated gastrointestinal tract metabolism and pharmacological activities of water extract of Scutellaria baicalensis roots

The survival of Lactobacillus delbrueckii UFV H2b20 was assessed in fermented milk, both during the storage period and after exposure to simulated gastric and intestinal juices, as well the detection of the gene fbpA involved in adherence to human gastrointestinal tract. L. delbrueckii UFV H2b20 remained stable and viable for 28 days under refrigerated storage conditions. After one day of storage, that strain exhibited a one-log population reduction following exposure in tandem to simulated gastric and intestinal juices. After 14 days of storage, a two-log reduction was observed following 90 min of exposure to the simulated gastric conditions. However, the strain did not survive following exposure to the simulated intestinal juice. The observed tolerance to storage conditions and resistance to the simulated gastric and intestinal conditions confirm the potential use of L. delbrueckii UFV H2b20 as a probiotic, which is further reinforced by the detection of fbpA in this strain.

A novel and oral colon targeted isoliquiritigenin delivery system: Development, optimization, characterization and in vitro evaluation

The influence of coating materials on some properties of alginate beads and survivability of microencapsulated probiotic bacteria

Probiotic bacteria are a living microbial supplement providing beneficial effects by balancing the gut microorganisms. The benefits of probiotic bacteria depend on the ability of these organisms to survive in the product, such as yoghurt, and also survive and multiply within the host. The improvement of survivability of probotic bacteria in yoghurt by microencapsulation in alginate beads was the key focus of this research. This was combined with an investigation of the use of UHT processing in yoghurt manufacture in place of the traditional batch heating proves. This research consisted of three experimental parts: 1. The influence of coating materials on the beads containing microencapsulated probiotics, 2. Texture profile of yoghurt made from UHT- and conventionally treated milks, and 3. Survival of microencapsulated probiotics in stirred yoghurt from UHT milk. The influence of coating materials on the properties of alginate beads and the survival of probiotic bacteria in an in vitro digestive system was studied. Three probiotics, Lactobacillus acidophilus 547, Bifidobacterium bifidum ATCC 1994, and Lactobacillus casei 01 were entrapped in alginate beads by the extrusion method. The beads were coated with three types of coating material, chitosan, sodium alginate, and poly-L-lysine in combination with alginate. Addition of coating materials increased the size of the calcium alginate bead by approximately 17%. Texture analysis and transmission electron microscopy detected no differences in the bead strength and thickness of beads with the different coating materials. The survivability of three probiotics in uncoated beads, coated beads, and as free cells (unencapsulated) was conducted in three test solutions: 0.6% bile salt solution, and simulated gastric juice (pH 1.55) followed by incubation in simulated intestinal juice with and without 0.6% bile salt. Chitosan-coated alginate beads provided the best protection for L. acidophilus and L. casei in all treatments. However, B. bifidum did not survive the acidic conditions of gastric juice even when encapsulated in coated beads. Texture profile of yoghurt made from UHT- and conventionally treated milks during fermentation were investigated by using a destructive method (Rapid Visco Analysis, RVA) and a non-destructive method (High Resonance Ultrasonic Spectroscopy). The yoghurt premixes, containing 2% sucrose and fortified with low-heat skim milk powder to 16, 18, and 20% total solids, were UHT processed at 143°C for 6 seconds using steam infusion and heated at 85°C for 30 minutes using the conventional method. Three percent of yoghurt cultures, Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in the ratio 1:1, were used in this experiment. For the RVA analysis, samples were collected every 15 minutes and stirred for 30 seconds prior to viscosity measurement. For measurements by ultrasonic spectroscopy, the instrument was operated at 45 °C for 4 hours and the ultrasound scarming was performed at frequencies of 7-8 MHz. The times for detection of the onset of gelation obtained by the ultrasound method were shorter than those obtained by RVA. The none-invasive ultrasonic spectrometric analysis might be a superior technique for investigating the fermentation and subsequent gelation of yoghurt due to the sensitivity and uninterrupted test of the same sample. The type of heat treatment and the level of total solids had no effect on growth of the yoghurt cultures during fermentation; however, the acidity was the highest in the yoghurts with the highest total solids contents. The UHT process delayed the gelation time of yoghurt, detected by both RVA and ultrasonic spectroscopy. The viscosity of yoghurt made from UHT-treated milk at 20% total solids during fermentation was close to that of yoghurt made from conventionally treated milk with 16% total solids, but the finished UHT yoghurt (after ≥1day) still had lower viscosity and gel strength than that of yoghurts made fi-om conventionally treated milk. On the other hand, yoghurts made from UHT-treated milk (20% total solids) had less syneresis than those made from conventionally treated milk when stored at 4 °C for 4 weeks. Survival of the microencapsulated probiotics, L. acidophilus, B. bifidum and L. casei, in stirred yoghurt from UHT milk at low temperature storage was studied. The probiotic cells both in the form of free cells and microencapsulated cells (in alginate beads coated with chitosan) were added into 20% total solids stirred yoghurt from UHT-treated milk and 16% total solids yoghurt from conventionally treated milk after fermentation. The products were kept at 4°C for 4 weeks. The survivability of encapsulated probiotic bacteria was higher than free cells approximately by 1 log. The number of probiotic bacteria was maintained above the therapeutic minimum (106 cfu/g) throughout the storage except for B. bifidum. The viability of probiotic bacteria in yoghurts from both UHT- and conventionally treated milk was similar.

Bacillus subtilis natto is the key microorganism for the industrial production of menaquinone-7. The fermentation of this bacterium in static culture is associated with biofilm formation. The objective of this study was to determine the effect of biofilm formation on menaquinone-7 production to develop a suitable bio-reactor for the production of menaquinone-7. In the static culture, menaquinone-7 biosynthesis showed a linear correlation with biofilm formation (R (2)=0.67) and cell density (R (2)=0.7). The amount of biofilm, cell density and menaquinone-7 formation were a function of nutrient and processing conditions. Glycerol, soy peptone, and yeast extract mixture and 40°C were found to be the optimum nutrients and temperature for accelerating both biofilm and menaquinone-7 biosynthesis in static culture. However, glucose, mixture of soy peptone and yeast extract and 45°C were found to be the optima for cell density. As compared to the static culture, the biofilm formation was significantly inhibited when a shaken fermentation was used. However, shaking caused only a small decrease on menaquinone-7 production. These results demonstrate that the biofilm formation is not essential for menaquinone-7 biosynthesis. This study underlines the feasibility of using large scale stirred fermentation process for menaquinone-7 production.