Search or add a thesis

Advanced Search (Beta)
Home > Strategies for the Production of Commercially Important Secondary Metabolites in Cell Cultures of Fagonia Indica

Strategies for the Production of Commercially Important Secondary Metabolites in Cell Cultures of Fagonia Indica

Thesis Info

Access Option

External Link

Author

Khan, Tariq.

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Biotechnology

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/9431/1/Tariq%20Khan_Biotech_2018_QAU_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727242650

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Fagonia indica, commonly known as “true herb”, is famous for its variety of medicinal activities especially anti-cancer potential. It is a member of the genus Fagonia and family Zygophyllaceae. The species of the genus Fagonia, especially, F. indica is famous for its diverse class of medicinally important compounds including terpenoids, flavonoids, and other polyphenolic compounds. The medicinal activities of F. indica especially antioxidant and anticancer activities may be attributed to its phenolic compounds. However, isolation only from wild grown F. indica does not guarantee sustainable production of these metabolites. This is because of limitations with wildgrown plants such as over-harvesting, endangerment, seasonal and geographic dependence and variations in metabolic profiles of the plant. In vitro cultures promise to deal with these limitations as they are independent of seasons and geography. Especially, cell cultures promise sustainable, uniform and homogeneous production of secondary metabolites. The present work was aimed to devise various strategies for the enhancement of phenolic compounds through the establishment of feasible cell cultures of F. indica. The following experiments were performed for setting up in vitro cultures of F. indica. The first set of experiments was set to handle the microbial contamination we observed during seed germination in vitro. The microbial growth was affecting normal plantlet growth in vitro conditions. Once the type and endophytic nature of the contaminants were confirmed through different tests, they were characterized as bacteria on a molecular level through polymerase chain reaction and sequencing techniques. Eight different bacterial strains; most of them belonging to the Bacillus genus were isolated and characterized from in vitro grown plantlets of F. indica. Nine different antibiotics were applied to eliminate this bacterial growth during seed germination and plantlet development. Tobramycin showed the lowest minimum inhibitory concentration (<8 mg/L) and the highest efficacy in terms of plantlet development. In the subsequent experiments, callus cultures were established for applications of further strategies to enhance secondary metabolite production. To obtain the ideal cell line, two different explant types (stem and leaf) from a 50 days old F. indica plantlet were used. Callus induction was observed in response to different plant growth regulators (PGRs). Among the explants and PGRs tested, the highest fresh biomassproduced was for stem explants in response to 1.0 mg/L of Thidiazuron (TDZ) after 6 weeks of culture. The highest total phenolic content (TPC) and total flavonoid content (TFC) were recorded in stem derived callus cultures compared to control cultures (lacking TDZ). The highest antioxidant potential (69.45 %) was recorded in stemderived callus treated with 1.0 mg/L of TDZ. Similarly, important polyphenolic compounds like gallic acid, quercetin, apigenin, catechin were detected in elevated levels and were quantified through high-performance liquid chromatography (HPLC) in the optimized callus lines. In further experiments, callus cultures were elicited through manipulation in the carbohydrate source. Carbohydrate source provided in the medium has a significant effect on the growth and metabolism of cell cultures. Different carbohydrate sources (sucrose, glucose, fructose, and maltose) were used in different concentrations (1, 3 and 5 %) in the medium for their effects on biomass accumulation, TPC, antioxidant activity and photosynthetic activity of callus cultures. In accordance with the previous study, the optimum level of sucrose was the highest driver of biomass accumulation followed by maltose which means that disaccharides were feasible for biomass formation. However, glucose proved to be the key elicitor of TPC [1.677 mg gallic acid equivalent (GAE)/g DW] and antioxidant activity (82.11%) of callus cultures. Like glucose, the other monosaccharide (fructose) also significantly elicited the total phenolic compound (1.625 mg GAE/g DW) in comparison to sucrose. Later, these callus cultures were used to produce adventitious roots. Different elicitation strategies such as transient and prolonged elicitation were used with adventitious roots grown on solid as well as a liquid medium as suspension cultures. Interestingly, explants treated with 0.5 mg/L Methyl Jasmonate (Me-J) for 2 hours and incubated on Murashige and Skoog (MS) medium supplemented with 1.0 mg/L α-naphthalene acetic acid (NAA) produced the highest adventitious root induction frequency (88%) and biomass accumulation (6.9 g/L DW). The growth kinetics of roots in suspension cultures showed that maximum biomass was produced on the 27th day in log phase of culture supplemented with 1.0 mg/L NAA. The secondary metabolites were produced in significantly enhanced quantities compared to our previous experiments on TDZ and carbohydrate-induced elicitation. The highest TPC (6.0 mg GAE/g of DW) and TFC [5.0 mg Quercetin Equivalent (QE)/g of DW] were produced by 0.5 mg/L Me-J in roots from the lag phase of growth. This finding was further justified by the quantification of important phenolic compounds through HPLC. In the final set of experiments, the interplay between light, PGRs, and elicitors during cell cultures of F. indica was evaluated. Different PGRs (auxins and cytokinin) and elicitors were applied to cell cultures on solid medium grown in three light regimes (continuous light; photoperiod of 16 hours light/8 hours dark; continuous darkness). The results revealed that 1.0 mg/L benzyl aminopurine (BA), 0.5 mg/L Me-J and 1.0 mg/L Phenylacetic acid (PAA) were the optimum regulators in terms of biomass, production of phenolic compounds and antioxidant activity. Similarly, the continuous light produced the highest biomass (13.2 g/L DW) in cell cultures provided with 1.0 g/L BA. Me-J-treated dark-grown cultures responded with the highest TPC and TFC in both solid medium and cell suspension cultures. Furthermore, the TPC and TFC in cell suspension cultures were higher (6.8 mg GAE/g of DW and 5.2 mg QE/g of DW, respectively) compared to our previous findings. The antioxidant activity was found dependent on TPC and TFC and thus higher activity (88%) was produced in cell suspension cultures grown in Me-J. Conclusively, different elicitation strategies in the form of PGRs, carbohydrate sources, elicitors and different light regimens proved worthy of the enhancement of phenolic compounds in cell cultures of F. indica.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

المبحث الثالث: فلسفة الحیاۃ

المبحث الثالث: فلسفة الحیاۃ

قصیدۃ (أغنية للحیاة) ([1]) لنازک الملائکۃ

سألوا في غدٍ([2]) عن ھوانا([3])

ونحنُ ترابٌ مع الذکريات

وراحَ یُجیبُھم العابرون([4])

بأنّا مررنا بھذي الحیاۃ([5])

وذقنا الھوی والمُنی والعذاب

ثمّ عدنا رُفات([6]) کأسلافنا([7])

علی أثرینا([8]) الریاحُ وعفّت([9])

وعدنا([10]) ضباباً([11]) تلاشی([12]) ومات

وقال لھم قائلٌ: إنّنا

شربنا الأسی([13]) في ثنایا([14]) الکؤوس

وإنّ ا بتساماتنا کنّ لوناً

یغلّف([15]) شیئا طوتہ([16]) النفوس

وإنّا دفعنا أنا شیدنا

وأحلامنا للرّجاء العبوس([17])

وکنّا کمن قبلنا غرباءَ([18])

علی الأرض ثم طوتَنا الرّموس([19])

فمن سوف یخبرھم أنّنا

شربنا العذوبۃ حتی سکرِنا([20])

وأنّا ملکنا([21]) ضیاء([22]) النجوم

ودجلۃ([23]) والفجرَ فیما ملَکنا

وکانت لنا من خدودِ النسیم([24])

وسائدُ([25]) تسندُنا([26]) إن کلنا...

Akuntansi Terintegrasi Islam : Alternatif Model Dalam Penyusunan Laporan Keuangan Islamic Integrated Accounting : Alternative Models in Preparing Financial Statements

Akuntansi merupakan suatu sistem informasi yang krusial dalam menggambarkan kinerja keuangan suatu entitas. Dalam konteks global yang semakin kompleks dan multikultural, terdapat kebutuhan untuk mengembangkan pendekatan akuntansi yang mencerminkan nilai-nilai dan prinsip-prinsip Islam. Penelitian ini bertujuan untuk mengusulkan alternatif model penyusunan laporan keuangan yang terintegrasi dengan prinsip-prinsip Islam sebagai respons terhadap kebutuhan akan transparansi, etika, dan keadilan dalam pelaporan keuangan.Dengan menggabungkan prinsip-prinsip akuntansi konvensional dengan nilai-nilai Islam, model ini menawarkan kerangka kerja yang holistik untuk menerapkan konsep akuntansi terintegrasi Islam. Model ini mendasarkan penyusunan laporan keuangan pada prinsip-prinsip syariah, termasuk larangan riba, gharar (ketidakpastian yang berlebihan), dan maysir (spekulasi). Selain itu, model ini menekankan pada tanggung jawab sosial dan lingkungan, serta aspek etis dalam pelaporan keuangan.Dalam konteks praktis, penelitian ini mengkaji penerapan model akuntansi terintegrasi Islam dalam berbagai jenis entitas, mulai dari perusahaan skala kecil hingga perusahaan skala besar. Implikasi dari penggunaan model ini terhadap transparansi, keadilan, dan keberlanjutan keuangan dianalisis melalui studi kasus dan perbandingan dengan pendekatan akuntansi konvensional.Hasil penelitian menunjukkan bahwa model akuntansi terintegrasi Islam ini mampu memberikan pandangan yang lebih komprehensif dan berkelanjutan terhadap kinerja keuangan entitas, dengan mengakomodasi prinsip-prinsip syariah dan nilai-nilai etis. Implikasi dari penelitian ini akan memberikan kontribusi bagi pengembangan praktek akuntansi yang lebih inklusif, berkelanjutan, dan sesuai dengan prinsip-prinsip agama Islam, sehingga memberikan pandangan yang lebih holistik terhadap aspek keuangan dan non-keuangan dalam penyusunan laporan keuangan.

Ardl Model As a Remedy for Spurious Regression: Problems, Performance and Prospects

The most important feature that directed to the development of new time series econometrics was the spurious regression. It is a phenomenon known to econometricians since the times of Yule (1926) who attributed this problem to missing variable. A spurious regression occurs when two independent series come up with significant regression results. For a long time, missing variables were considered as root cause of spurious regression. However, Granger and Newbold (1974) challenged this wisdom and presented unit root as one of the causes of spurious regression. The extensive literature considers the nonstationarity as the only cause of spurious regression. The researchers frequently employed unit root and co-integration procedures for the treatment of spurious regression in case of nonstationarity but these procedures are equally unreliable because of uncertainty about various specification decisions like choice of the deterministic part, structural breaks, choice of autoregressive, lag length and distribution of error term. On the other hand Granger et al. (2001) show that unit root is not the only reason for spurious regression. They show the possibility of spurious regression in stationary time series. Whereas unit root and cointegration are unable to deal with this problem because they deal only nonstationary series. Such amount of conventional econometric literature is inadequate to deal with the problem of spurious regression in stationary time series. The objective of this study is to provide an alternative solution of spurious regression for both stationary and nonstationary time series. So, this study makes two contributions in this particular setup. First, spurious regression occurs due to missing variable and can be avoided by including missing lag values. Therefore, an alternative way to look at the problem of spurious regression takes us back to the missing variable (lag values) which further leads to ARDL model. Second, it significantly reduces the probability of spurious regression in both stationary and nonstationary time series case. This study mainly focusing on Monte Carlo simulations and real data is also used for performance comparison of ARDL model and conventional procedures. Our results indicate that conventional methods are significantly suffering in size and there is power problems but the performance of ARDL in both cases is far better than conventional methods. ARDL model significantly reduced the probability of spurious regression in stationary and nonstationary time series case.