Survey methodology and objectives: A traditional review approach was taken to focus on the engineering of microbial -amylases to enhance industrially favoured characteristics. The action mechanisms of - and -amylases were compared to avoid any bias in the research background. This review aimed to discuss the advances in modifying microbial -amylases via protein engineering to achieve longer half-life in high temperature, improved resistance (acidic, alkaline and oxidative) and enhanced specificities (substrate and product). Captivating results were discussed in depth, including the extended half-life at 100C, pH 3.5 and 10, 1.8 M hydrogen peroxide as well as enhanced substrate (65.3%) and product (42.4%) specificities. These shed light to the future microbial -amylase engineering in achieving paramount biochemical traits ameliorations to apt in the industries.
Conclusions: Microbial -amylases can be tailored for specific industrial applications through protein engineering (rational design and directed evolution). While the critical mutation points are dependent on respective enzymes, formation of disulfide bridge between cysteine residues after mutations is crucial for elevated thermostability. Amino acids conversion to basic residues was reported for enhanced acidic resistance while hydrophobic interaction resulted from mutated hydrophobic residues in carbohydrate-binding module or surface-binding sites is pivotal for improved substrate specificity. Substitution of oxidation-prone methionine residues with non-polar residues increases the enzyme oxidative stability. Hence, this review provides conceptual advances for the future microbial -amylases designs to exhibit industrially significant characteristics. However, more attention is needed to enhance substrate specificity and oxidative stability since they are least reported.
RESULTS: The recovery yield for EBNhclean and EBNhcoP were 89.09 ± 0.01% and 47.64 ± 0.26%, respectively, indicating nearly 50% of glycopeptide can be recovered from the waste material. Meanwhile, N-acetylneuraminic acid, a major acid sugar in EBN glycoproteins, of EBNhcoP increased by 229% from 58.6 ± 3.9 to 192.9 ± 3.1 g kg-1 , indicating the enzymatic hydrolysis removed impurities and thus enhanced the N-acetylneuraminic acid content. Total soluble protein was more than 330 g kg-1 for all the samples. Colour parameter showed that hydrolysate samples have greater L* (lightness) values. Chroma result indicates the intensity of all the samples were low (
METHODOLOGY: All sera for AT1R-Ab were collected at the University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The sera were centrifuged and kept refrigerated at -80 °C before being transported to the South Australian Transplantation and Immunogenetics Laboratory (SATIS). Enzyme-linked immunosorbent assay kit (One Lambda) was used for the detection of AT1R-Ab, and it was performed according to the manufacturer's instructions. The level of >17.1 U/mL was considered to be AT1R-Ab positive; 10.0-17.1 U/mL at risk, and <10.0 U/mL negative.
RESULTS: A total of 115 samples were collected from 99 patients pre and post-kidney transplant recipients. From the pre-transplant sera (n = 68) 17.7% were positive, 35.3% were at risk and 47.0% were negative. The positive AT1R-Ab cohort were relatively younger, with a mean age of 34.7 ± 8.3 years old and statistically significant, with a p-value of 0.028. Among the sera that were tested positive, 19.0% were from the Chinese ethnicity, 6.7% from Malay and 16.7% from Indian. There was no difference in the rejection episodes, persistent or de novo HLA-DSA, and graft function between the group (AT1R-Ab negative vs AT1R-Ab at risk and positive) and the results were consistent in a model adjusted for all potential confounders.
CONCLUSION: The prevalence of positive (>17.1 U/mL) pre-transplant AT1R-Ab was 17.7% and 35.3% were at risk (10.0-17.1 U/mL) in our pre-transplant cohort.
RESULTS: The optimised values for alcoholic fermentation were pH 4.99, 28.29 °C, 131 h and a 0.42 culture ratio (42:58, P. pulmonarius mycelia:S. cerevisiae) with a predicted ethanol concentration of 22.25%. Through a verification test, soursop wine with 22.29 ± 0.52% ethanol was produced. The antioxidant activities (1,1-diphenyl-2-picrylhydrazyl and ferric reducing antioxidant power) showed a significant (P
Methodology: A total of 362 renal allograft protocol biopsies were performed in adult recipients of kidney transplantation between 2012 and 2017. After excluding those with poor quality or those performed with a baseline serum creatinine level >200 umol/L, we analyzed 334 (92.3%) biopsies. Histology reports were reviewed and categorized into histoimmunological and nonimmunological changes. The immunological changes were subcategorized into the following: (1) no acute rejection (NR), (2) borderline changes (BC), and (3) subclinical rejection (SCR). Nonimmunological changes were subcategorized into the following: (1) chronicity including interstitial fibrosis/tubular atrophy (IFTA), chronic T-cell-mediated rejection (TCMR), unspecified chronic lesions, and arterionephrosclerosis, (2) de novo glomerulopathy/recurrence of primary disease (RP), and (3) other clinically unsuspected lesions (acute pyelonephritis, calcineurin inhibitors toxicity, postinfective glomerulonephritis, and BK virus nephropathy). Risk factors associated with SCR were assessed.
Results: For the histoimmunological changes, 161 (48.2%) showed NR, 145 (43.4%) were BC, and 28 (8.4%) were SCR. These clinical events were more pronounced for the first 5 years; our data showed BC accounted for 59 (36.4%), 64 (54.2%), and 22 (40.7%) biopsies within <1 year, 1-5 years, and > 5 years, respectively (p = 0.011). Meanwhile, the incidence for SCR was 6 (3.7%) biopsies in <1 year, 18 (15.3%) in 1-5 years, and 4 (7.4%) in >5 years after transplantation (p=0.003). For the nonimmunological changes, chronicity, de novo glomerulopathy/RP, and other clinically unsuspected lesions were seen in 40 (12%), 10 (3%), and 12 (3.6%) biopsies, respectively. Living-related donor recipients were associated with decreased SCR (p=0.007).
Conclusions: Despite having a stable renal function, our transplant recipients had a significant number of subclinical rejection on renal allograft biopsies.
LAY SUMMARY: Candida virulence factors (VFs) including mainly enzymes and proteins play vital roles in breaching the human intestinal barrier and causing deadly invasive candidiasis. Limited VFs' structural studies hinder deeper comprehension of their mechanisms and thus the design of vaccines and antifungal drugs against fungal infections.