مقالههای Ahmad Majd
توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقالههای نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده میشوند.
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال ۱۳۸۶
تعداد صفحات: ۷
Production of enzymes is a well studied subject however, simultaneous optimization of production of two or more enzymes and trying to develop a single condition for their optimum production, is not well documented in the literatures. Taguchi method was used for optimization of such a culture condition. In the preliminary tests, maximum production of cellulase, pectinase and amylase was determined, using wheat bran, citrus pectin and corn starch flour as substrates, respectively. Media with mixed carbon sources, containing different ratios of wheat bran, citrus pectin and corn starch were designed and the best condition for highest amount of production of these enzymes was detected. As a result, after performing the Taguchi method, an increase of 209.28%, 287.13%, 282.61% and 271.43% in the amount of produced amylase, pectinase, CMCase and FPase was showed, respectively. As the next step, a combinatory optimum point, which was an arithmetic average point of the previous points, was chosen, in which in relation to the initial conditions, the production of the mentioned enzymes was increased 185.79%, 201.32%, 160.87% and 242.86%, respectively.<\div>
اطلاعات انتشار: کنفرانس بین المللی توسعه پایدار، راهکارها و چالش ها با محوریت کشاورزی ، منابع طبیعی، محیط زیست و گردشگری، سال ۱۳۹۳
تعداد صفحات: ۱۰
In this paper, we show how regenerated plantlets were obtained from Safflower (Carthamus tinctorius L.) plants through indirect and direct somatic embryogenesis, for the first time in Iran. After a week,the callus was observed on the hypocotyl of explants obtained from seedlings that was grown on theMurashige and Skoog (MS) basal medium supplemented with 0.1–1 mg\L α–naphthalene acetic acid (NAA) and 6–benzylaminopurine (BAP). Embryogenic calli developed within 4 weeks after transferring to MS medium with different concentrations of auxins like 2,4–D, NAA, IAA; and cytokinins like BAP and KN, separately and in combination with auxins. MS medium supplemented with 0.5 mg\L NAA and 2 mg\L IAA was the most effective medium for indirect emberyogenesisinduction, that has the highest embryogenesis frequency per explants. About 30–40% of regeneratedsomatic embryos germinated into complete plantlets. Direct somatic embryogenesis without an intervening callus phase was conducted from intact seedlings on MS medium supplemented withgrowth regulators like: 2,4–D, NAA, IAA and Kin at different concentrations. After a week, embryosfrom cotyledon explants in a medium contain1 and 1.5 mg\L 2,4–D was observed. 13 embryos was the highest number of observed embryos for each explant and almost 40% of embryos from cotyledons developed to perfect plants; rooting procedure was performed in MS medium supplemented by 0.5 NAA. Also, histological observations revealed different stages of embryogenesis in Safflower such as globular, heart and torpedo stages.<\div>
۳Comparing cytogenetic effects of extremely low frequency electromagnetic fields in Brassica napus L and Zea mays L
اطلاعات انتشار: Journal of Pharmaceutical & Health Sciences، اول،شماره۳، summer ۲۰۱۲، سال ۰
تعداد صفحات: ۸
Many biological effects of exposure to extremely low frequency electromagnetic fields (ELF–EMFs) have been documented, but little work carried out on plants. A meiotic study was performed on Brassica napus L as C3 plant and Zea mays L as a C4 plant exposed to electromagnetic fields. Our investigations were focused on plants grown from wet pretreated seeds with 3 and 10 mT for a 4 h exposure time and compared with the control plants of maize. Also our investigation used plants grown from dry pretreated seeds with 10 mT for 4 h, wet pretreated seeds with 10 mT for 2 h, and a control line of canola. A significant difference was observed for meiotic characters studied among treatments. In canola the mean value of total, terminal, and intercalary chiasmata reduced significantly in plants grown from exposed seeds, indicating that EMFs caused reduction in the mean value of the genetic recombination. Other meiotic characteristics including ring bivalent and quadrivalent formation reduced significantly as well. In maize the mean value of total, terminal and intercalary chiasmata changed significantly in the plants grown from exposed seeds to 3 mT intensity, indicating increase in genetic recombination. Moreover, formation of ring bivalent and quadrivalent increased significantly. All results suggested these plants react differently in some aspects against EMFs as abiotic stress.
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