Exogenous application of nano-silicon, potassium sulfate, or proline enhances physiological parameters, antioxidant enzyme activities, and agronomic traits of diverse rice genotypes under water deficit conditions.

Water deficit is a critical obstacle that devastatingly impacts rice production, particularly in arid regions under current climatic fluctuations. Accordingly, it is decisive to reinforce the drought tolerance of rice by employing sustainable approaches to enhance global food security. The present study aimed at exploring the effect of exogenous application using different biostimulants on physiological, morphological, and yield attributes of diverse rice genotypes under water deficit and well-watered conditions in 2-year field trial. Three diverse rice genotypes (IRAT-112, Giza-178, and IR-64) were evaluated under well-watered (14400 m3/ha in total for the entire season) and water deficit (9170 m3/ha) conditions and were exogenously sprayed by nano-silicon, potassium sulfate, or proline. The results showed that drought stress substantially decreased all studied photosynthetic pigments, growth traits, and yield attributes compared to well-watered conditions. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased compared with those under well-watered conditions. However, the foliar application of nano-silicon, potassium sulfate, and proline substantially mitigated the deleterious effects of drought stress and markedly enhanced photosynthetic pigments, antioxidant enzyme activities, growth parameters, and yield contributing traits compared to untreated stressed control. Among the assessed treatments, foliar spray with nano-silicon or proline was more effective in promoting drought tolerance. The exogenous application of proline improved chlorophyll a, chlorophyll b, and carotenoids by 21.4, 19.6 and 21.0% followed by nano-silicon treatment, which enhanced chlorophyll a, chlorophyll b, and carotenoids by 21.1, 17.6 and 9.5% compared to untreated control. Besides, the application of proline demonstrated a superior improvement in the content of proline by 52.5% compared with the untreated control. Moreover, nano-silicon exhibited the maximum enhancement of catalase and peroxidase activity compared to the other treatments. The positive impacts of applied exogenously nano-silicon or proline significantly increased panicle length, number of panicles/plant, number of grains/panicle, fertility percentage, 1000-grain weight, panicle weight, and grain yield, compared to untreated plants under water deficit conditions. In addition, the physiological and agronomic performance of evaluated rice genotypes significantly contrasted under drought conditions. The genotype Giza-178 displayed the best performance under water deficit conditions compared with the other genotypes. Consequently, the integration of applied exogenously nano-silicon or proline with tolerant rice genotype as Giza-178 is an efficient approach to ameliorating drought tolerance and achieving agricultural sustainability under water-scarce conditions in arid environments.

Prevalence, types and disclosure of complementary and alternative medicine (CAM) use among chronic kidney disease (CKD) patients in Saudi Arabia.

INTRODUCTION: Despite the paucity of scientific evidence, CAM is widely used for the prevention and treatment of illness among patients with chronic kidney disease, including end-stage renal disease and kidney transplant recipients. It is evident that the irrational use of CAM among CKD patients and its non-disclosure to healthcare providers could lead to adverse drug events. Hence, the current study was conducted to evaluate the prevalence, types, and non-disclosure of CAM use among CKD patients and kidney transplant recipients in Saudi Arabia. METHODS: A cross-sectional study was conducted on 170 CKD patients (121 with stages 3 and 4, two with stage 5 and on hemodialysis, and 47 kidney transplant recipients). Face-to-face questionnaire-based interviews were conducted employing a convenience sampling technique. The study outcomes were the prevalence of CAM, types of CAM use, monthly expenditure on CAM, the source of information about CAM, and CAM disclosure to healthcare providers. A p-value of < 0.05 was considered significant. RESULTS: The study found that out of 170, 60 (35.3%) CKD patients use CAM. The most used CAM was Acacia gum (49, 81.6%) followed by spiritual therapies (34, 56.6%). Female CKD patients had higher use of CAM compared to the male gender (p = 0.015). The monthly expenditures that most users (47, 78.3%) spent on CAM were less than 50 Saudi Riyals (SR). The study results also showed that 55% of CKD patients did not report their CAM use to their physicians. Furthermore, 46.6% of CAM users discontinue their use of CAM after observing no benefit. CONCLUSION: This study reported relatively high use of CAM among CKD patients in Saudi Arabia. The study found that most CKD patients use Acacia gum and spiritual therapies and do not disclose the use of CAM to healthcare professionals, which could lead to adverse drug events. Therefore, the study recommends that healthcare providers should inquire and provide evidence-based counselling about the use of CAM to CKD patients to prevent any adverse drug event or unwanted effect on the renal function of the patients.

Biodiesel Production by Single and Mixed Immobilized Lipases Using Waste Cooking Oil.

Biodiesel is one of the important biofuels as an alternative to petroleum-based diesel fuels. In the current study, enzymatic transesterification reaction was carried out for the production of biodiesel from waste cooking oil (WCO) and experimental conditions were optimized, in order to reach maximum biodiesel yield. Bacillus stearothermophilus and Staphylococcus aureus lipase enzymes were individually immobilized on CaCO3 to be used as environmentally friendly catalysts for biodiesel production. The immobilized lipases exhibited better stability than free ones and were almost fully active after 60 days of storage at 4 °C. A significant biodiesel yield of 97.66 ± 0.57% was achieved without any pre-treatment and at 1:6 oil/methanol molar ratio, 1% of the enzyme mixture (a 1:1 ratio mixture of both lipase), 1% water content, after 24 h at 55 °C reaction temperature. The biocatalysts retained 93% of their initial activities after six cycles. The fuel and chemical properties such as the cloud point, viscosity at 40 °C and density at 15 °C of the produced biodiesel complied with international specifications (EN 14214) and, therefore, were comparable to those of other diesels/biodiesels. Interestingly, the resulting biodiesel revealed a linolenic methyl ester content of 0.55 ± 0.02% and an ester content of 97.7 ± 0.21% which is in good agreement with EN14214 requirements. Overall, using mixed CaCO3-immobilized lipases to obtain an environmentally friendly biodiesel from WCO is a promising and effective alternative for biodiesel production catalysis.

Exploitation of biological wastes for the production of value-added hydrolases by Streptomyces sp. MSWC1 isolated from municipal solid waste compost.

Actinomycetes with the ability to degrade natural polysaccharides were isolated during a screening programme from soil, farmyard manure and municipal solid waste compost. One of the most potent isolates was identified as Streptomyces sp. MSWC1 using morphological and biochemical properties along with 16S rDNA partial sequence analysis. The highest enzyme production by Streptomyces was observed for the xylanase and chitinase activity on different carbon sources with an optimum of 12,100 IU ml(-1) and 110 IU ml(-1) at 3 days' culture on 1% of xylan and chitin, respectively. To meet the demand of industry, low-cost medium is required for the production of hydrolases by Streptomyces sp. Strain MSWC1 grown on manure, compost, and a natural carbon source was used to evaluate the re-utilisation of biological wastes for the production of value-added products. Despite the presence of a high amount of toxic heavy metals in the compost, Streptomyces produced interesting enzymes that have been biochemically characterized.

Structural investigation and homology modeling studies of native and truncated forms of alpha-amylases from Sclerotinia sclerotiorum.

The filamentous ascomycete Sclerotinia sclerotiorum is well known for its ability to produce a large variety of hydrolytic enzymes for the degradation of plant polysaccharide material. Two alpha-amylases designated as ScAmy54 and ScAmy43 were biochemically characterized and predicted to play an important role in starch degradation. Those enzymes produce specific oligosaccharides, essentially maltotriose, that have a considerable commercial interest. The primary structures of the two enzymes were analyzed by N-terminal sequencing, MALDI-TOF mass spectrometry, and cDNA cloning, and implied that the two proteins have the same N-terminal catalytic domain and ScAmy43 was produced from ScAmy54 by truncation of 96 amino acids at the carboxyl-terminal region. The result of genomic analysis suggested that the two enzymes originated from the same alpha-amylase gene and that truncation of ScAmy54 to ScAmy43 occurred probably during the S. sclerotiorum cultivation. The structural gene of ScAmy54 consisted of 9 exons and 8 introns, containing a single 1,500-bp open reading frame encoding 499 amino acids including a signal peptide of 21 amino acids. ScAmy54 exhibited high amino acid identity to other liquefying fungal alpha-amylases, essentially in the four conserved regions and in the putative catalytic triad. A 3D structure model of ScAmy54 and ScAmy43 was built using the 3D structure of 2guy from A. niger as template. ScAmy54 with three domains A, B, and C, including the well-known (beta/alpha)8-barrel motif in domain A, has a typical structure of the alpha-amylase family. ScAmy43 composed only of domains A and B constitutes a smallest fungal alpha-amylase with only a catalytic domain.