The effect of ion environment changes on retention protein behavior during whey ultrafiltration process.

The factors affecting membrane fouling are very complex. In this study, the membrane fouling process was revealed from the perspective of ion environment changes, which affected the whey protein structure during ultrafiltration. It was found that the concentrations of Ca2+ and Na+ were overall increased and the concentrations of K+, Mg2+ and Zn2+ were decreased at an ultrafiltration time of 11 min, which made more hydrophilic groups buried inside and increased the content of α-helix, leading to more protein aggregation. The relatively higher K+ ratio in retention could lead to an antiparallel ß-sheet configuration, aspartic acid, glutamic acid and tryptophan increased, which resulted in more protein aggregation and deposition on the membrane surface at 17 min. When the ion concentration and ratio restored the balance and were close to the initial state in retention, the protein surface tension decreased, and the hydrophilic ability increased at 21-24 min.

Significantly enhanced substrate tolerance of Pseudomonas putida nitrilase via atmospheric and room temperature plasma and cell immobilization.

The objective of the study was to enhance the substrate tolerance of Pseudomonas putida nitrilase via atmospheric and room temperature plasma (ARTP) and cell immobilization. The mutant library was constructed by ARTP and rapidly screened by an OPA-TCA microscale reaction. A mutant strain of mut-D3 was obtained and its optimum substrate concentration was improved to 150mM from 100mM. It could accumulate 189g/L nicotinic acid (NA) from 3-cyanopyridine (3-CP), which was increased by 42% compared with that of wild type (WT). Additionally, composite immobilization of mut-D3 was performed and SA-PVA immobilized cells could catalyze 250mM 3-CP each batch with finally accumulating 346g/L NA, while free cells accumulated 175g/L NA. These results indicated that the free or immobilized catalysts of mut-D3 could serve as a good choice for NA production. This is the first report on mutation breeding of nitrilase-producing microorganisms by ARTP.

Role of moxibustion in inflammatory responses during treatment of rat ulcerative colitis.

AIM: To investigate the efficacy of moxibustion in ulcerative colitis (UC) rats from morphological, immunological and molecular biological perspectives. METHODS: Thirty-two Sprague-Dawley rats were randomly assigned to a blank control group (normal rats, n = 6) and a model replication (MR) group (UC rats, n = 26). A UC model was established by 2,4,6-trinitrobenzenesulfonic acid/dextran sulfate sodium enema. Rats in the MR group were further randomly assigned to a 9-min moxibustion (9M) group (9 moxa-cone, n = 6), 6-min moxibustion (6M) group (6 moxa-cone, n = 6), 3-min moxibustion (3M) group (3 moxa-cone, n = 6), and a waiting list control (WLC) group (no moxibustion treatment, n = 6). Rats in the moxibustion treatment group were treated in 14 sessions over 28 d. Disease activity, local tissue morphology, serum level of interleukin (IL)-8 and IL-10, and expression of Toll-like receptor (TLR)9 as well as nuclear factor (NF)-κB p65 in colonic tissue were determined by disease activity index (DAI), hematoxylin and eosin staining, electron microscopy, enzyme-linked immunosorbent assay and Western blotting, respectively. RESULTS: DAI was lowest in the 9M group and highest in the WLC group. The differences in DAI between the moxibustion treatment (3M, 6M, 9M) and no treatment groups were significant for all one-to-one comparisons (0.60 ± 0.54 vs 1.20 ± 0.44, 0.60 ± 0.54 vs 1.80 ± 0.45, 0.60 ± 0.54 vs 3.0 ± 0.45, respectively, P < 0.05). Light and electron microscopy showed that the neatness of the glandular arrangement in colonic mucosal epithelia gradually increased in the WLC, 3M, 6M to 9M groups. IL-8 level successively decreased while IL-10 level increased from the WLC to 3M, 6M and 9M groups. The differences among these groups were significant for all comparisons (105.46 ± 8.75 vs 76.61 ± 3.58, 105.46 ± 8.75 vs 69.78 ± 1.87, 105.46 ± 8.75 vs 67.41 ± 1.84, respectively, P < 0.01 for IL-8; and 30.83 ± 1.29 vs 75.64 ± 1.90, 30.83 ± 1.29 vs 80.90 ± 3.16, 30.83 ± 1.29 vs 83.46 ± 2.37, respectively, P < 0.01 for IL-10), except comparison of 6M vs 9M. Expression of TLR9 and NF-κB p65 decreased in order: highest in the WLC group and lowest in the 9M group. In addition, the differences among the WLC, 3M, 6M and 9M groups were significant for all comparisons (0.492 ± 0.026 vs 0.380 ± 0.022, 0.492 ± 0.026 vs 0.355 ± 0.005, 0.492 ± 0.026 vs 0.327 ± 0.015, respectively, P < 0.05 for TLR9; and 0.436 ± 0.041 vs 0.326 ± 0.022, 0.436 ± 0.041 vs 0.293 ± 0.006, 0.436 ± 0.041 vs 0.265 ± 0.017, respectively, P < 0.05 for NF-κB p65). CONCLUSION: Moxibustion repairs damaged colonic mucosa, suppresses serum IL-8, activates serum IL-10 level, and decreases expression of TLR-9 and NF-κB p65 in UC rats.