Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThe Effect of Ultraviolet Radiation on Photosynthetic pigments in Euglena gracilis
تأثير الأشعة فوق البنفسجية في أصبغة التركيب الضوئي عند طحلب الأوغلينا Euglena gracilis
1647
2 5
0.0
(
0
)
Added by
Tishreen University ورقة بحثية
Publication date
2018
fields
Life Science
and research's language is
العربية
Created by
Shamra Editor
Ask ChatGPT about the research
أجريت هذه الدراسة خلال عام 2017 في مخابر قسم علم الحياة النباتية، كلية العلوم، جامعة تشرين، اللاذقية، سوريا. تم تحري تأثير الأشعة فوق البنفسجية (بنوعيها UV-C و UV-B) لفترات زمنية مختلفة (0.5، 1، 3، 5، 15، 30، 45، 60 دقيقة) في صبغات التركيب الضوئي و إجراء القياسات على ثلاث مراحل (بعد 0، 6، 24 ساعة من نهاية فترة التعرض للأشعة) عند طحلب الأوغلينا Euglena gracilis. بينت النتائج التأثير السلبي لأشعة UV-C في الأصبغة اليخضورية (اليخضور a و اليخضور b) و الأصبغة الكاروتينويدية مقارنة بأشعة UV-B. ارتبطت هذه القيم بزيادة زمن التعرض للأشعة فوق البنفسجية، لتصل إلى أقل قيمة لها بعد 60 دقيقة من التعرض (انخفاض حوالي 97.83، 98.73، 99.18% لليخضور a و اليخضور b و الأصبغة الكاروتينويدية عند القياس بعد 24 ساعة من التعرض للأشعة على التوالي). كما لُحظ أن شرائح البولي ايثيلين تساهم في حماية الأصبغة اليخضورية تجاه الأشعة فوق البنفسجية. كان معدل الحماية أكثر وضوحاً تجاه أشعة UV-C ليصل إلى 7.78% بعد 24 ساعة من تعرض الأوغلينا لمدة 30 دقيقة وفق الشروط المخبرية للتجربة.
The study was conducted during 2017 in the laboratories of the department of Botany at Tishreen University, Lattakia, Syria. The effect of ultraviolet radiation (UV-C and UVB) for different periods (0.5, 1, 3, 5, 15, 15, 30, 45, 60 minutes) on the photosynthetic pigments of Euglena gracilis (with three stages of measurements) was studied. The results showed that chlorophyll pigments were more sensitive to UV-C compared to UV-B. These reductions were correlated with the increase in the exposure time, reaching the lowest value after 60 minutes exposure (97.83, 98.73, 99.18% for chlorophyll a, chlorophyll b and carotenoids when measured after 24 hours respectively). The polyethylene films protect the chlorophyll pigments against UV radiation. The protection rate was more evident against UV-C reaching .7.7% after 24 hours in the algae exposed for 30 minutes according to the experimental conditions.
References used
AGRAWAL, S.B. Effects of supplemental U.V.-B radiation on photosynthetic pigment, protein and glutathione contents in green algae. Environmental and Experimental Botany, Vol. 32, No. 2, 1992, 137 – 143
AYASH, A. S., RICHTER, P., HÄDER, D. P. Comparative study of the influence of UV on photosynthesis of Cryptomonas maculata and Cosmarium cucumis, Trends in Photochemistry & Photobiology, Vol. 10, 2003, 167 – 173
BHANDARI, R. & SHARMA, P. K. Effect of UV-B on photosynthesis, membrane lipids and MAAs in marine cyanobacterium Phormidium corium (Agardh) Gomont. Indian Journal of experimental biology, Vol. 44, 2006, 330 – 335
rate research
Read More
Young sun flower plants were exposed to ultraviolet radiation of the type UV-B (295
nm) for 3 days (2 hours per day) with or without excluding the UV-radiations using
polyethylene layers (blue and transparent) (0.5 mm thick). The amount of photosyn
thesis
pigments was measured whereby a variation in the chlorophyll contents. Chlorophyll a
(chl.a) was noticed at these rates (without covering 19.59%, transparent polyethylene
3.40%, blue polyethylene 1.66%), chlorophyll b (chl.b) at rates (7.81, 25.13, 22.79%) and
the total chlorophyll content (2.88, 21.76, 20.53%), while the amount of carotenoid
pigments has increased in the studied samples (24.45, 19.23, 17.32%). A decrease in the
rate of photosynthetic electron transport has also been noticed (88.04, 78.71, 58.81%) in
the plant samples exposed to ultraviolet radiation (on the third day) without UV excluding
and with transparent and blue polyethylene successively. All results were compared to the
sample which was not exposed to radiation.
All results indicate the negative effect of ultraviolet radiation on the chlorophyll
content and the rate of photosynthetic electron transport, therefore, on photosynthesis and
the productivity of sun flower plants. They also point out the importance of carotenoid
pigments in protecting chlorophyll pigments from the negative effects of this radiation.
Results showed the clear positive effect of polyethylene layers, specifically the blue one, in
protecting plants against this radiation.
This study includes an experimental work to determine the effect of ultraviolet radiation (uv-rays) on the mechanical behavior of the conveyor rubber vulcanizing, which used in various transport operations, and in the cement plant Tartus. In this wor
k, it has been prepared different samples of belts, and they were exposed to uv radiation at differente times, then they were tested to know its wear and tensile strength.
The results were compared with samples similar to the samples tested, which was not exposed to the rays of UV, and with other samples exposed to temperatures, and that in order to reach the ideal conditions for the use of these belts, which ensures longer period of use and safe conditions. This study showed that uv-rays increase the average of wear and the tensile strength of belts.
Photosynthetic transport was studied as an indicator of photosynthesis efficiency in
two bread wheat cultivars (ACSAD 899, ACSAD 1059) under the influence of one of the
salt stress.
This study was carried out in sand cultures irrigated with nutrie
nt solution in a
growth chamber, and 14 days seedlings were treated with 100 mM of sodium chloride.
Later the electron transport rates in those plants thylakoids were measured in 21, 28, 35
days of the experiment.
Electron transport rates decreased in ACSAD 899 and reached 57% in the last day of
the experiment, while it was 24.6% in ACSAD 1059.
The decrease in photosynthetic electron transport rate leads to a decrease in the
reduction rate of CO2 and the plant productivity as a consequence. Therefore, it could be
used as criterion to express photosynthesis.
This study discusses in-duct UVGI efficiency to disinfect O.R and ICU supplied air. Experiment
setup was designed using three ultraviolet lamps were placed at the upper side of experimental duct,
equipped with variable speed turbine to simulate flo
w rates of ICU and O.R. In order to determine
organism irradiance time, UV intensity distribution is measured at different levels in duct, Thenthese
parameters combined in simulation program executed under LABVIEW programming environment to
determine in-duct disinfection efficiency in relation to ICU and O.R designing requirement and sterility
level.
Five mixtures of ordinary concrete of dolomite aggregates were
prepared by changing the water to cement ratio. Thirty six cubic
concrete samples were prepared for every mixture.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
