1.
Growth, Yield and Biochemical Impact of Anti-transpirants on Sunflower Plant Grown under Water Deficit.
Abdallah, MMS, Bakry, BA, El-Bassiouny, HMS, El-Monem, AAA
Pakistan journal of biological sciences : PJBS. 2020;(4):454-466
Abstract
BACKGROUND AND OBJECTIVE Climate change affecting on weather in many different ways especially drought and temperature rise. This will drastically down plant production, if not start looking for another source to increase water productivity to cope up with water stress conditions. In this study efforts were conducted to interpret the use of anti-transpirants to conserving irrigation water, aiding plant survival under dry conditions and protecting plant against drought stress. MATERIALS AND METHODS Two field experiments were carried out during 2017 and 2018 successive growing summer seasons at the experimental farm of National Research Centre, Nubaria, El-Beheira Governorate, Egypt. Anti-transparent ,i.e., chitosan (100 and 150 mg L-1), calcium carbonate (5 and 10 g L-1), salicylic acid (200 and 300 mg L-1) were foliar sprayed on sunflower plants grown under two water levels (normal 100% and deficit 50%). RESULTS The results showed that water stress decreased growth criteria, photosynthetic pigments, osmoprotectants, yield components, oil and carbohydrate (%) as compared to 100% of irrigation requirements. Meanwhile, water deficit induced significant increases in (proline). Foliar treatments of sunflower plant with chitosan, calcium carbonate, salicylic acid increased growth criteria, yield components, photosynthetic pigments, total soluble sugars, proline and free amino acid as compared to control plant. Data also illustrated that, all used treatment improved seed yield, oil and carbohydrate% of sunflower plants. CONCLUSION Generally, it could be concluded that 10 g L-1 CaCO3 and 300 mg L-1 SA at 50% level of water irrigation could be recommended for sunflower plant grown under similar field conditions in order to get optimum yield and to save irrigation water.
2.
Comparative Study of Electrochemical Sensors Based on Enzyme Immobilized into Polyelectrolyte Microcapsules and into Chitosan Gel.
Plekhanova, YV, Tikhonenko, SA, Dubrovsky, AV, Kim, AL, Musin, EV, Wang, GJ, Kuznetsova, IE, Kolesov, VV, Reshetilov, AN
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry. 2019;(9):1037-1043
Abstract
The characteristics of an electrochemical biosensor based on a Prussian-blue screen-printed electrode containing glucose oxidase incorporated into polyelectrolyte microcapsules (PMC) are considered. PMC with the embedded enzyme were formed using sodium polystyrene sulfonate and poly(allylamine hydrochloride). The characteristics were compared with those of the enzyme immobilized in chitosan gel. We assessed the dependences of biosensor signals on the composition of the buffer solution, on the glucose concentration; the operational and long-term stabilities. The enzyme immobilized in PMC proved to be more sensitive to buffer molarity at a maximum within 35 - 40 mM. The apparent Michaelis constants were 1.5 and 4.1 mM at the immobilization in, respectively, chitosan and PMC. The developed biosensors were used to assay commercial juices. The biosensors' data on the glucose contents were shown to have a high correlation with the standard spectrophotometric assay (0.92 - 0.95%), which implies a possible application of the fabricated biosensors in foodstuff analysis.
3.
Chitosan-containing gum chewing accelerates antibacterial effect with an increase in salivary secretion.
Hayashi, Y, Ohara, N, Ganno, T, Ishizaki, H, Yanagiguchi, K
Journal of dentistry. 2007;(11):871-4
Abstract
OBJECTIVES This study was designed to confirm the mechanical efficacy of chewing chitosan-containing gum to suppress the growth of oral bacteria compared to a mouth rinse, and to demonstrate the increased salivary secretion due to chewing chitosan-containing gum. METHOD Twelve healthy subjects were recruited from among the staff and students of Nagasaki University School of Dentistry. For the slab of gum study, the subjects chewed chitosan-containing gum for 5 min and then rested for 5 min. For the testing of the chitosan mouth rinse solution, the subjects gargled 10 mL of solution for 30s followed by resting for 9 min 30s. These protocols were continuously repeated five times for 50 min on the same day. For the salivary secretion experiment, the gum chewing was repeated three times per day for 2 days. RESULTS The amount of oral bacteria in the subjects who chewed chitosan-containing gum significantly decreased during all three sampling times except at 60 min for total bacteria in comparison to those in the rinse group. Chitosan-containing gum chewing also significantly increased the secretion of saliva. CONCLUSIONS Chitosan-containing gum chewing has a greater antibacterial effect and it also increases salivary secretion. The present findings strongly indicate that the application of natural materials such as chitosan is useful for both oral health and the quality of life.