Comparison of the Stability of Poly-��-Glutamate Hydrogels Prepared by UV and ��-Ray Irradiation

Park, Sang-Joon; Uyama, Hiroshi; Kwak, Misun; Sung, M.H.

doi:10.4014/jmb.1812.12018

Cited by 10 publications

(2 citation statements)

References 23 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be assumed that both blood components (blood meal and lyophilized Hb) contain the intracellular components of RBCs necessary for the growth of fastidious bacteria, which are released when RBCs are lysed during the dehydration process performed by the manufacturer and during autoclaving before addition to the medium [24]. In this context, we hypothesized that gamma irradiation, a commonly used sterilization method for pharmaceutical and food products [25][26][27], would degrade Hb protein, stimulating the release of hemin [28,29] without the formation of precipitates, which negatively affect CA medium production. However, the poor growth obtained suggests the medium prepared with irradiated BP (CA-PR) provided a much lower hemin concentration than the one containing autoclaved BP (CA-PT).…”

Section: Discussionmentioning

confidence: 99%

Use of Blood Powder (Ground and Irradiated) for the Manufacture of Chocolate Agar

Casino¹,

López²,

Peiró³

et al. 2023

IJMS

View full text Add to dashboard Cite

Chocolate agar (CA) is an enriched medium for the isolation and identification of fastidious bacteria. Defibrinated blood is used to manufacture CA, but this expensive product is not always affordable for companies in developing countries. Blood powder (BP) is potentially a cheaper alternative, although its pre-treatment using autoclaving can impair the quality of the media. Therefore, optimization of BP as a substitute for defibrinated blood for CA manufacture deserves further research. CA was manufactured with irradiated BP (dehydrated bovine blood powder) and its physical and microbiological characteristics were compared with those of conventional CA and CA prepared with autoclaved BP. Each medium was seeded with 20–200 CFU of target bacteria using the spiral pouring method. Finally, another medium was prepared using BP pre-treated by grinding and gamma irradiation and its performance assessed. Compared to conventional CA, the medium containing ground and irradiated BP provided a similar CFU count for both fastidious (Neisseria, Haemophilus, Campylobacter, and Streptococcus) and non-fastidious (Moraxella, Staphylococcus, Enterococcus, Klebsiella, and Pseudomonas) species, unlike the medium prepared with BP subjected only to irradiation, which provided a lower growth of fastidious species. Morphology and characteristics of all bacterial colonies were very similar in conventional CA and the new medium, the number of Pseudomonas CFU being higher in the latter. The medium prepared with ground plus irradiated vs. irradiated BP more closely resembled conventional CA, having a browner background. The new CA medium prepared with ground and gamma irradiation-sterilized BP has comparable productivity properties to conventional CA. Therefore, it could be a more practical and economical methodology to facilitate large-scale CA manufacture.

show abstract

Section: Discussionmentioning

confidence: 99%

Use of Blood Powder (Ground and Irradiated) for the Manufacture of Chocolate Agar

Casino¹,

López²,

Peiró³

et al. 2023

IJMS

View full text Add to dashboard Cite

show abstract

“…When γ-PGA was present with lysozyme, γ-PGA might take away lysozyme from the lens surface resulting in a reduction of friction coefficient (Figure 5a). Lysozyme was positively charged while both γ-PGA and Etafilcon-A were negatively charged [17,18], thus γ-PGA could take away lysozyme by forming an ionic bond. However, why lysozyme would bind to γ-PGA instead of Etafilcon-A requires further investigation.…”

Section: Discussionmentioning

confidence: 99%

The Bio-Tribological Effect of Poly-Gamma-Glutamic Acid in the Lysozyme-Ionic Contact Lens System

Yeh

Lai

et al. 2020

Polymers

View full text Add to dashboard Cite

Feeling comfortable is an important issue for contact lens wearers as contact lenses are worn for an extensive period of time. It has been shown that the in vitro friction coefficient of contact lenses is correlated to the degree of in vivo comfort, thus many studies focus on establishing friction testing methods for investigating the friction coefficient of contact lenses or contact lens care solution. We have previously demonstrated the lubricating property of poly-gamma-glutamic acid (γ-PGA)-containing care solution, and it could reduce the high friction coefficient caused by lysozyme. However, the mechanism of how γ-PGA-containing care solution reduces the lysozyme-induced friction coefficient of contact lenses is unclear. We investigated the bio-tribological effect of γ-PGA on ionic contact lenses in the presence of lysozyme by testing load and velocity variations. The ability to remove lysozyme deposition by γ-PGA and viscosity analysis of γ-PGA-containing care solutions were also investigated to understand the potential mechanism. Our results showed that the friction coefficient of γ-PGA-containing care solution with lysozyme was the lowest in both load and velocity variations, and γ-PGA functions distinctly in the lysozyme-ionic contact lens system. We proposed a model of how γ-PGA could reduce the friction coefficient in these two conditions.

show abstract

Construction of a mutant Bacillus subtilis strain for high purity poly-γ-glutamic acid production

Liu

Ban

2022

Biotechnol Lett

View full text Add to dashboard Cite

To construct a Bacillus subtilis strain for improved purity of poly-γ-glutamic acid. ResultsThe construction of strain GH16 was achieved by knocking out ve extracellular protein genes and an operon from Bacillus subtilis G423. Then we analyzed the protein content in the γ-PGA produced by the resultant strain GH16/pHPG which decreased by 6.08%. Subsequently the a-che operon, PBSX and the yrpD, ywoF and yclQ genes were knocked out successively and the mutant strain GH17, GH18, and GH19 was obtained. Ultimately, the protein content was reduced by 43.9%. In addition, the polysaccharide content in the γ-PGA was decreased from 2.21-1.93% due to the epsA-O operon was knocked. Conclusionγ-PGA has potential applications as a drug carrier, sustained-releasing agent and medical composite in medicine. To our knowledge, this is the rst report of engineered Bacillus subtilis strains which can produce γ-PGA with a purity higher than 97%. Our results con rmed that this upstream strategy signi cantly enhanced speci c protein purity by the removal of extracellular protein genes in Bacillus subtilis, and it is promising in other protein puri cation.

show abstract

Comparison of the Stability of Poly-��-Glutamate Hydrogels Prepared by UV and ��-Ray Irradiation

Cited by 10 publications

References 23 publications

Use of Blood Powder (Ground and Irradiated) for the Manufacture of Chocolate Agar

Use of Blood Powder (Ground and Irradiated) for the Manufacture of Chocolate Agar

The Bio-Tribological Effect of Poly-Gamma-Glutamic Acid in the Lysozyme-Ionic Contact Lens System

Construction of a mutant Bacillus subtilis strain for high purity poly-γ-glutamic acid production

Contact Info

Product

Resources

About