Production, Characterization, and Antioxidant Activities of an Exopolysaccharide Extracted from Spent Media Wastewater after Leuconostoc mesenteroides WiKim32 Fermentation.

Bacterial exopolysaccharides (EPSs) are important alternatives to plant polysaccharides in fermented products and exhibit antioxidant activity, which is particularly desirable for functional foods. This study evaluated the use of spent media wastewater (SMW) derived from kimchi fermentation for the production of an EPS and analyzed the characterization and antioxidant activity of the resulting EPS. The EPS concentration and conversion yields of sequential purification were 7.7-9.0 g/L and 38.6-45.1%, respectively. Fourier transform infrared spectra and NMR spectra indicated that the EPS was a linear glucan with α-(1 → 6) linkages. The EPS also exhibited thermal tolerance to high temperatures. In vitro antioxidant activity analyses indicated the scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, thiobarbituric acid reactance (TBAR), and ferric ion reducing antioxidant power (FRAP) values of 71.6-79.1, 28.2-33.0%, and 0.04-0.05 mM FeCl3, respectively. These results reveal that the EPS extracted from SMW has potential as a thermally tolerant, nontoxic, and natural antioxidant for industrial applications.

Coffee residue as a valorization bio-agent for shelf-life extension of lactic acid bacteria under cryopreservation.

The present work describes the feasibility of coffee residue extracts as cryoprotective agents in the storage stability of freeze-dried lactic acid bacteria. Coffee residue extracts were extracted from coffee residue, produced after coffee extraction for coffee powder and instant coffee preparation, using an autoclave. Leuconostoc mesenteroides WiKim32 was selected to evaluate the ability of coffee residue extracts to protect bacteria during freeze-dried storage. The storage stability of freeze-dried Leu. mesenteroides WiKim32 with coffee residue extracts was comparable to those with commercial cryoprotective agents. Coffee residue extracts contributed to storage stability immediately after freeze-drying (61.2%) and subsequent storage (48.7%). Our data indicate that the protective effect of the coffee residue extracts is associated with ions, carbohydrates, and phenolic compounds. Coffee residue extracts are feasible materials, which can reduce the storage and distribution costs compared to commercial agents currently available.

Biorefining Process of Carbohydrate Feedstock (Agricultural Onion Waste) to Acetic Acid.

The biorefining of agricultural waste into green chemicals has clear potential for improving global environmental sustainability. In this study, we evaluated the potential of acetic acid production from carbohydrate feedstock (onion waste, OW) as a more environmentally friendly source than feedstock produced from natural gas. In particular, OW is an ideal feedstock for the biorefining process as it contains a sufficient amount of carbohydrates (69.7%). Five days of the simultaneous saccharification and two-step fermentation (SSTF) process produced acetic acid from OW more efficiently than the simultaneous saccharification and cofermentation (SSCF) process. SSTF produced 19.3 g/L acetic acid and recorded the highest conversion yield (90.5%) from OW (6% substrate loading, w/v). These results suggested that acetic acid can be efficiently and sustainably produced from OW by the SSTF process.

Guided bone regeneration using cyanoacrylate-combined calcium phosphate in a dehiscence defect: a histologic study in dogs.

PURPOSE: This study evaluated the effects of cyanoacrylate-combined calcium phosphate (CCP) as a candidate for a barrier membrane substitute in guided bone regeneration and the space maintenance capability of CCP placed in a dehiscence defect model. MATERIALS AND METHODS: Six standardized dehiscence defects (5 × 3 mm, height × width) around dental implants were created on unilateral edentulous ridges in 5 dogs, where each defect was treated with sham surgery, biphasic calcium phosphate (BCP), CCP, barrier membrane (MEM), BCP + MEM, and CCP + MEM. The animals were sacrificed after an 8-week healing interval for histologic and histometric analyses. RESULTS: The BCP and CCP sites showed increased bone formation compared with the control sites, although incomplete defect resolution occurred; bone regeneration heights (area) averaged 3.52 ± 0.69 mm (4.94 ± 2.59 mm(2)), 3.51 ± 0.16 mm (4.10 ± 1.99 mm(2)), and 1.53 ± 0.42 mm (1.01 ± 0.74 mm(2)) for the BCP, CCP, and control sites, respectively. All the MEM sites showed more bone formation compared with the sites that received the same biomaterials without a MEM, and the BCP + MEM and CCP + MEM sites showed extensive bone formation within the defect and on top of the implant; the bone regeneration heights (area) averaged 3.96 ± 2.86 mm (12.46 ± 11.61 mm(2)), 5.45 ± 0.25 mm (11.63 ± 1.97 mm(2)), and 2.62 ± 0.27 mm (3.43 ± 0.98 mm(2)) for the BCP + MEM, CCP + MEM, and MEM sites, respectively. CONCLUSIONS: CCP can be a good scaffold for supporting an MEM as opposed to acting as a substitute for the MEM in guided bone regeneration.

Distribution and biosynthesis of 20-hydroxyecdysone in plants of Achyranthes japonica Nakai.

There is increasing interest in phytoecdysteroids (PEs) because of their potential role in plant defense against insects. To understand the mechanism regulating their levels in plants, the fluctuation, distribution, and biosynthesis of PE 20-hydroxyecdysone (20E) examined in Achyranthes japonica. The total amount of 20E per individual plant initially remained at a constant level, and increased markedly after the first leaf pair (LP) stage, while the concentration of 20E in a given plant decreased rapidly during vegetative growth. In addition, the incorporation of [2-(14)C]-mevalonic acid into 20E did not differ significantly depending on plant organs and developmental stages, suggesting that biosynthesis of 20E is not restricted to particular organs or growth stages.

Chondrocyte viability in press-fit cryopreserved osteochondral allografts.

The viability of chondrocytes in press-fit glycerol-preserved osteochondral allografts was compared to that in fresh autografts, after transplantation into load-bearing and non-load-bearing sites in mature sheep stifle joints. We used macroscopic grading, tonometer pen indentation testing, histology, sulfate uptake and viability as determined by confocal-microscopy to assess cartilage condition. Despite there being no statistical differences between macroscopic appearance and tonometer testing of all grafts, confocal microscopy and histology demonstrated a positive effect of load-bearing placement on cryopreserved osteochondral allografts. Allografts transplanted into load-bearing sites demonstrated superior confocal microscopy-measured chondrocyte viability (77%+/-17%SD) than those transplanted into non-load-bearing sites (25%+/-2%). Load-bearing effect was not seen in autografts (78%+/-15%), and was comparable in adjacent cartilage (83%+/-9%). Similarly, load-bearing allografts demonstrated histological scoring closer to that of autografts and adjacent cartilage, all of which fared significantly better than non-load-bearing allografts. Load-bearing allografts had a greater amount of fibrocartilage than autografts or adjacent cartilage but less fibrocartilage than non-load-bearing allografts. Both autografts and allografts had non-significant increases in metabolism compared to adjacent cartilage as measured by sulfate-uptake. Load-bearing placement improved chondrocyte viability of glycerol cryopreserved osteochondral allograft following a press-fit implantation.