• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1163-1169
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• 2015

Poly-gamma-glutamic acid (γ-PGA) is a natural polymer that is synthesized by Bacillus species and has been reported to have antitumor activity. The aim of this study was to investigate the effect of γ-PGA on the treatment of vaginal intraepithelial neoplasia (VAIN). A retrospective observational study on γ-PGA therapy for biopsy-proven VAIN was conducted. The efficacy was assessed by evaluating the results of Pap cytology and the viral load of high-risk HPV at three time points: at enrollment, and at the first and second post-treatment visits. Of 17 patients treated with γ-PGA, only 12 patients who had a high-risk HPV infection were included in the analysis. Histology was VAIN1 in seven patients, VAIN2 in two patients, and VAIN3 in three patients. γ-PGA was administered for newly diagnosed VAIN in five (41.7%) patients and persistent VAIN in seven (58.3%) patients for the mean time of 4.5 months. At the first and second post-treatment visits, cytological regression was observed in five (41.7%) and six (50%) patients, respectively. Regarding the HPV load, the overall response rate was 66.7%, and the mean level was 670.6 ± 292.5 RLU at the first follow-up, which was lower than the initial viral load of 1,494.8 ± 434.5 RLU (p = 0.084). At the second follow-up, the overall response rate was 58.3%, and the mean viral load level was 924.2 ± 493.7 RLU. γ-PGA may be helpful for the cytological regression and reduction of viral load in patients with high-risk HPV-positive VAIN, suggesting that γ-PGA is a promising treatment option for primary or persistent VAIN.

• Polymer(Korea)
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• v.31 no.2
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• pp.168-176
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• 2007

The sub-micron particles of poly ($\gamma-glutamic$ acid) (PGA) containing lysozyme have been prepared using supercritical antisolvent (SAS) precipitation process at various experimental conditions such as pressure, temperature, inner diameter of nozzle, and concentration. As overall results of the application of SAS process to this system, the smaller size powder has been produced as (i) increasing pressure, (ii) decreasing temperature, (iii) decreasing the inner diameter of nozzle, and (iv) decreasing the concentration of PGA and lysozyme. It is found by means of FT-IR analysis that during SAS process, the composition has changed from the original composition of PGA : lysozyme=50 : 50 into PGA : lysozyme=33 : 67 at final product powder. It means that PGA has higher solubility for the mixed solvent of carbon dioxide and dimethyl sulfoxide (DMSO). Due to such difference of solubility, this particle forms the core-shell structure of which the core consists mainly of lysozyme. It is also found that the residual DMSO amount of $7.8\times10^{-3}wt%$ exists inside the powder.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.855-858
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• 2005

The bioavailability of Ca is currently one of the most important topics in nutrition research and is correlated with gastrointestinal solubility. Thus, to increase the solubility of calcium, this study was undertaken to examine the effect of $\gamma$-PGA on intestinal Ca solubility. The calcium solubility increased when the amount of $\gamma$-PGA was increased, due to the inhibition of the formation of an insoluble Ca complex with phosphate. Therefore, when $\gamma$-PGA-500 (avg. MW 5,000 kDa) was added at 0.5 mg/ml, $75\%$ of the total Ca was soluble. The amount of soluble Ca uptake in the small intestine was investigated using Balb/c mice as an animal model system. The soluble Ca uptake in the mice orally administered with $\gamma$-PGA-500 (avg. MW 5,000 kDa) was significantly higher than that in the $\gamma$-PGA-l00 (avg. MW 1,000 kDa)-administered mice (P<0.05). Accordingly, these results strongly support the notion that the molecular size of $\gamma$-PGA is correlated with Ca solubility. The effects of other factors, such as casein phosphopeptide and vitamin D, on intestinal Ca absorption have also previously been investigated. Therefore, it is hoped that the present observations will help clarify the role of $\gamma$-PGA in Ca solubility and its industrial application as an additive.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.449-454
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• 2008

Some pretreatment methods have been proposed to enhance the biodegradability and to shorten the hydrolysis reaction time. By means of efficient pretreatment the suspended solids (SS) can be made of better accessible for the anaerobic bacteria. There are several ways how this can be accomplished, which include biological, mechanical, thermal, and chemical methods. For the sludge solubilization using the cavitation phenomenon, we have tried to develop a pretreatment process consisted of a reactor and pumps. The objectives of this study were to develop a advanced wastewater treatment consisted of IABR and the cavitation with PGA. The most effective removal for organic matter and nutrients were occured when both cavitation pretreatment and ${\gamma}$-PGA were applied at the IABR process. Only small portion of ${\gamma}$-PGA at a rate of 1.38mg/L, was enough to improve sedimentation ability, SS removal efficiencies, and sludge volume reduction. After the sludge solubilization by the cavitation, SCOD increased to 193% and SS decreased to 36%. The removal ratio of BOD was 94.5%, T-N removal ratio was 85.5% and T-P removal ratio was 84.9%. The combination process of the IABR with the cavitation and PGA addition seems to be very effective alternative wastewater treatment process.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.436-436
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• 2005

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.175-179
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• 2006

A bacterium that produced a large amount of poly-$\gamma$-glutamate (PGA) was isolated from the compost and designated as Bacillus subtilis CH-10. The optimum temperature and pH for PGA production were at $37^{\circ}C$ and 7.5, respectively. The maximum amount of PGA production (18.84 mg/ml) was obtained when it was grown in a medium containing 3% L-glutamate and 5% sucrose at $37^{\circ}C$ with shaking. The result that the L-glutamate significantly induced PGA production indicates that it produces a PGA by the glutamate dependent manner. Some properties of the PGA obtained at different times of cultivation were investigated by SDS-PAGE and ninhydrin analysis. The PGA production was elongated along with cultivation time and maximum amount was achieved at 96 h. Average molecular weight of PGA was estimated to be 1100 kDa by FDNB method.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.160-169
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• 2009

Poly-$\gamma$-glutamic acid ($\gamma$-PGA) was mixed natural flora of Bacillus subtilis, contaminated from cooked soybeans. Also, it was performed to find out the antiallergic activity by using NC/Nga mice, in vitro. The $\gamma$-PGA (PGA-HM : PGA-high molecular weight), Molecular weight 300 kDa, was decomposed and made PGA-LM (PGA-low molecular weight) which has molecular weight below 30 kDa by sonication. Therefore, it was same result between PGA-HM and PGA-LM, and reported PGA-LM as basic result. We found that PGA-LM contains antiallergic efficacy that inhibit B cells and Th2 cells activation from isolated CD4+T cells in NC/Nga atopic dermatitis model mice, and not show a cytotoxicity in the hFCs. To investigate the effects of these PGA-LM in vitro, isolation of splenic B cell and CD4+ T cells in atopic dermatitis mice were used. To elucidate the role of PGA-LM in anti-CD40+ interleukin-4 (IL-4)-mediated B-cell activation, showed that the capacity of B cells to expression IL-$1\beta$, IL-6, and TNF-$\alpha$ mRNA down-regulated, and IL-10 mRNA up-regulation by PGA-LM treatment, but it had no effect on TGF-$\beta$ expression. In addition to CD4+IFN-$\gamma$+ and CD4+CD25+foxp3+, the functions of PGA-LM in the development of the CD4+CD25+foxp3+ and CD4+IFN-$\gamma$+cells, the phenotype and functions of PGA-LM induced CD4+CD25+foxp3+, and CD4+IFN-$\gamma$+cells in CD4+T cells. These results suggested that PGA-LM could change cytokine production and generate CD4+CD25+foxp3+ Tregs in NC/Nga mice, and may be effective for immunotherapy in patients with AD.

• Nutrition Research and Practice
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• v.18 no.5
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• pp.663-673
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• 2024

BACKGROUND/OBJECTIVES: Poly-γ-glutamic acid (γ-PGA), a natural polymer found in fermented soybean products, has been reported to play a prebiotic role in the gut. This intervention study investigated the effects of γ-PGA-containing supplement consumption on urinary microbiota in healthy adults because of limited data on such investigation. SUBJECTS/METHODS: A 4-week parallel trial including 39 male and female Korean adults, who were free of chronic diseases and infection, was designed as a randomized, double-blinded, placebo-controlled study. A total of 30 participants completed the study wherein the intervention group (n = 17) received a mixture supplement containing 600 mg/day of γ-PGA and 100 mg/day of vitamin B6, while the control group (n = 13) received a placebo. Paired datasets (baseline and endpoint data) of microbiota profiles, which were constructed via urinary assays of microbe-derived extracellular vesicles, were analyzed and compared between the two groups. RESULTS: Only the intervention group yielded significant results for the Bray-Curtis and Jaccard dissimilarity indices between baseline and endpoint data (P < 0.05). In the phylum-level analysis of microbial composition, the Firmicutes to Bacteroidetes ratio (FB ratio) tended to decrease from baseline in the intervention group; however, it increased in the control group. Differences between the baseline and endpoint FB ratios were significant between the two groups (P < 0.05). CONCLUSION: This study's findings suggest that γ-PGA-vitamin B6 supplementation potentially alters the microbial community composition of a host. Further investigation into the biological consequences of commensal microbiota alteration by γ-PGA-containing supplement consumption is warranted.

• Nutrition Research and Practice
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• v.15 no.3
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• pp.309-318
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• 2021

BACKGROUD/OBJECTIVES: Data regarding the effects of poly-γ-glutamic acid (γ-PGA) on sleep status are limited. This study aimed to test whether γ-PGA and vitamin B₆ (VitB6) supplements improve sleep duration and quality. SUBJECTS/METHODS: A factorial randomized, double-blinded, placebo-controlled crossover study included 47 adults (25 men and 22 women) who were free of chronic disease. Stratified randomized allocation considered age and gender for three interventions, group A (supplementation with γ-PGA 600 mg; n = 16), group B (supplementation with VitB6 100 mg; n = 14), and group C (dual supplementation of both γ-PGA 600 mg and VitB6 100 mg; n = 17). Participants underwent a 1-mon intervention period, followed by a 1-mon washout period, and then a second 1-mon intervention period. Differences (mean ± SD) in nighttime sleep status before and after supplementation were compared between the placebo and intervention groups using nonparametric tests. RESULTS: Significant changes in sleep duration (0.27 ± 0.98 h, P < 0.05) and the Pittsburgh Sleep Quality Index global score (-0.52 ± 1.58, P < 0.05) indicating improved sleep status were observed in the intervention compared with the placebo of group C while no significant changes were observed in groups A and B. No statistical significance was detected between the intervention and the placebo; however, there was a greater increase in the group C intervention (4.59 ± 38.5 ng/mL) in serum serotonin concentrations than the groups A and B interventions. No side effects were observed. CONCLUSIONS: On the basis of these findings, the dual supplementation of γ-PGA and VitB6 may be effective as functional food components to improve nighttime sleep status.

• Journal of Veterinary Clinics
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• v.29 no.4
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• pp.283-296
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• 2012

Allergic contact dermatitis (ACD) is an inflammatory skin disease and regarded as a prototype of T-cell mediated delayed-type hypersensitivity reactions. Poly-${\gamma}$-glutamic acid (PGA) is a biodegradable polymer that is produced by Bacillus subtilis. This study was performed to assess the effects of PGA in a canine model of ACD. ACD was induced on the back of dogs induced by sensitization and repeated application by 2,4-dinitro-1-chlorobenzene (DNCB). Topical treatment of PGA was applied once a day for 12 days and skin biophysical parameters including transepidermal water loss (TEWL), skin hydration, skin pH, skin thickness and erythema index, were measured every two days during experimental periods. Histopathology and immunohistochemistry were performed to evaluate the antiinflammatory effect. In skin biophysical parameters, TEWL, skin hydration, skin thickness and erythema index were significantly increased, with a maximum increase appeared on day 2 (p < 0.05). On the other hand, skin pH was significantly decreased, with a maximum decrease appeared on day 2 (p < 0.01). After the completion of PGA treatment, skin biophysical parameters were significantly reached those of baseline in a time-dependent manner (p < 0.05). In histopathology, marked increases of epidermal thicknesses were induced after DNCB challenge with numerous inflammatory cell infiltrations and edematous changes, decreases of connective tissue occupied regions in dermis. In addition, marked increases of cytokine - tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interferon-${\gamma}$ (IFN-${\gamma}$)-immunoreactivities in the dermis and of apoptotic markers - caspase-3 and PARP-immunoreactivities in the epidermis were observed in DNCB-PBS control as compared with intact control, respectively (p < 0.01). It means, the ACD and related apoptotic changes were induced by DNCB in the present study. However, these ACD induced by DNCB and related apoptosis in epidermis were significantly inhibited by treatment of PGA treated skin, the decreases of infiltrated inflammatory cells and related decreases of pro-inflammatory cytokine immunoreactivities were also observed (p < 0.01). Based on these findings, PGA may have anti-inflammatory and alleviatory effects in the allergic contact dermatitis.