Current Biotechnology - Volume 8, Issue 2, 2019

Stevia rebaudiana is a vital medicinal plant of the genus Stevia and family Asteraceae. It is commonly used as a natural sweetener plant and its products are 300 times sweeter than the commonly used sugarcane. The sweetening potential is due to the presence of calorie-free steviol glycosides (SGs). The plant species has been extensively profiled to identify steviol glycosides (SGs) with intensity sweetening properties. However, the limited production of plant material is not fulfilling the higher market demand worldwide. Researchers are working worldwide to enhance the production of important SGs through the intervention of different biotechnological approaches in S. rebaudiana. In this review, the research work conducted in the last twenty years, on the different aspects of biotechnology to enhance the production of SGs has been precisely reviewed. Biotechnological methods such as micropropagation, callus and cell cultures, elicitation and the metabolomics and transcriptomic elucidation of the biosynthetic metabolic pathways for the production of steviol glycosides have been concisely reviewed and discussed.

The review summarizes the recent (2016-2019) practical applications of novel extraction methods for Citrus metabolite extraction, such as microwave-assisted (MAE), ultrasound-assisted (UAE), super-critical carbon dioxide (SC-CO2) and enzyme-assisted extraction (EAE) with the aim to compare efficiencies based on the criteria of enhanced (%) yield, cost-effectiveness, reproducibility, eco-friendliness, time/energy consumed and industrial scale application. It was found that supercritical carbon dioxide extraction (SC-CO2) is the most successful and scaled-up technique when compared to MAE, UAE, Soxhlet and EAE, following the trend: SC-CO2 > EAE > UAE > MAE. However, other novel approaches, including pulse-electric field (PEF), sub-critical water extraction (SWE), solarenergy assisted extraction (SE) and molecularly imprinted polymers (MIPs), that have not been well explored for Citrus bioactives extraction, have the potential to be coupled with conventional as well as contemporary methods leading to an innovative hypothetical scaled-up design.

Under-utilized and abundant plants found in Africa are endowed with a lot of potentials, which can be coupled and channeled to aid environmental, economic and social development. Tamarind (Tamarindus indica) is one of the most commonly under-utilized plant materials with some reported biological and environmental relevance. In this communication, we reported on antioxidant potentials and environmental role associated with T. indica, which might be due to its vast phytochemical constituents, to unravel the applicability of antioxidant properties of T. indica for environmental health and remediation. Numerous researchers revealed antioxidant capacity, phenolics and ascorbic acid content of different parts of Tamarind to be significantly appreciative. These properties show a strong association with the vast amount of phytochemicals confined in this plant. The presence of phytocompounds in Tamarind such as luteolin, catechin, apigenin, lupeol and terpenoids has been implicated in the treatment and management of different diseases such as diabetes, cancer, hypertension and cardiovascular disorders. These highlighted medicinal roles were associated with their antioxidant capacities. This property in T. indica might serve as a driving force in many of its displayed biological potentials. The plant also demonstrated robust abilities for environmental uses. Thus, T. indica could also serve reasonably, in the field of environmental science such as bioremediation, biosorption, coagulation and waste water treatment due to its abundance and limited utilization. This review, therefore, highlights the applicability of antioxidant properties of T. indica for environmental health and remediation.

Background: Standardization of herbal formulation is mandatory for the quality check of drugs for assurance of their therapeutic value. According to the World Health Organization reports, about 80% of the world’s population relies on traditional medicine. Dhatryadi Ghrita, a polyherbal preparation containing eleven ingredients, has a sweet taste, cold potency and sweet post-digestive effects. Objective: In this research article, quality control for ghrita has been assessed for some of the ingredients of Dhatryadi Ghrita. Materials & Methods: Quality control assessment was done with the aid of the HPTLC method. Precoated silica gel GF 254 was used as the stationary phase and the developed method used benzene:ethyl alcohol (9:1v/v). Scanning and quantification of the plates were performed at 254 nm and 366 nm. Result: The study confirms the presence of different constituents of Ghrita. Conclusion: The routine analysis of Ghrita was facilitated with simple, accurate and cost-effective HPTLC method. Data has been provided to demonstrate the present and future applicability of the methods of quality control assessment of Dhatryadi Ghrita.

Background: One of the critical challenges of cost-effective bioethanol production from lignocellulosic biomass is the decreasing yield of reducing sugars caused by increasing substrate loading. Hence, it is crucial to determine the best substrate concentration for efficient saccharification of lignocellulosic wastes. Objective: This paper reports the saccharification of corn cob by two lignocellulolytic fungi (Fusarium oxysporum and Sporothrix carnis) and concurrent production of lignocellulolytic enzymes at varying substrate concentrations. Methods: F. oxysporum and S. carnis were cultivated on corn cob based media at 30°C and 160 rpm for 144 h. The lignocellulosic composition of corn cob was determined. Saccharification of varying concentrations of substrate was determined by evaluating the release of reducing sugar while the production of cellulase and xylanase was monitored. Results: Cellulose, hemicellulose and lignin contents of corn cob were 37.8±1.56%, 42.2±1.68% and 12.7±1.23%, respectively. Yields of reducing sugar by F. oxysporum and S. carnis were 5.03 μmol/mL and 6.16 μmol/mL; and 6.26 μmol/mL and 6.58 μmol/mL at 10.0 and 25.0% substrate concentration, respectively. The production of cellulase and xylanase was exponential as corn cob concentration increased from 0.5% to 10.0% yielding 586.93 U/mL and 1559.18 U/mL from F. oxysporum, with 590.7 U/mL and 1573.95 U/mL from S. carnis, respectively. Conclusion: The study shows that the most efficient saccharification of corn cob by F. oxysporum and S. carnis was achieved at 10.0% substrate concentration. This suggests that two separate saccharification processes at this concentration will result in higher yields of enzyme and reducing sugars than a single process involving higher concentration.

Background: Forward osmosis is a sustainable membrane process employed for concentrating thermo-sensitive compounds to minimize storage and transportation costs with improved shelf life. Objective: In this study, the intervention of high molecular weight osmotic agents in the concentration of Opuntia betacyanin using forward osmosis was studied. Furthermore, the statistical model was used to estimate the probabilistic behavior of the forward osmosis process during concentration. Methods: By using 2k-full factor analysis, the hydrodynamic variables, such as flow rate (50 and 150 mL/min) and temperature (20 and 50ºC) of the feed solution and osmotic agent solution (OAS) were selected. The study focused on inquiring and developing a statistically significant mathematical model using four independent variables on transmembrane flux, concentration factor and concentrate recovery. Results: Betacyanin feed flow rate of 50 mL/min at 28ºC, and OAS flow rate of 150 mL/min at 50ºC were determined as optimal conditions with a 2.5-fold increase in total soluble solids for a processing time of 4 h. Furthermore, forward osmosis enhanced the betacyanin concentration from 898 to 1004 mg/L and 98.7% recovery with 0.40 L/m2h transmembrane flux with comparable improvement in its physicochemical characteristics. The lower p-value of the main effects on the responses validated the significance of the process parameters on betacyanin concentration. Conclusion: The study suggested that a high molecular weight sucrose could be used as an osmotic agent for the concentration of Opuntia betacyanin during forward osmosis.

Background: Borivilianoside H is a naturally occurring anti-cancer compound with known cytotoxicity against human colorectal cancer cell line (HCT-116) and human adenocarcinoma cell line (HT-29). The present study describes the pharmacophore modelling, molecular docking, and molecular dynamics simulation approaches to predict the target proteins of borivilianoside H along with its binding affinity to the selected proteins. Methods: A 3-dimensional structure of borivilianoside H was constructed using Avogadro from its 2-D coordinates retrieved from the Pubchem Compound database. Target proteins associated with cancers were identified based on the 95% normalized fit score of PharmMapper. The crystal structures of the targets were retrieved from Protein Data Bank and molecular docking was performed with Autodock Vina 1.1.2. MD simulations were carried out via Google Cloud Platform. ADMET characteristics for borivilianoside H were determined using admetSAR web server. Results: Among the selected 7 top-ranked target proteins, fibroblast activation protein (FAP) exhibited the highest binding affinity followed by serum albumin (ALB), bone morphogenetic protein 2 (BMP2) and kinesin-like protein 11 (KIF11). However, the best fit was found with KIF11, where both the steroidal and oligosaccharide moieties of borivilianoside H were involved in interacting with the protein cavity. KIF11 was thus found to be the most suitable target for the anti-cancer effect of borivilianoside. ADMET analysis revealed its suitability as an intravenous drug. Conclusion: The targets predicted using this approach will serve as leads for the possible use of borivilianoside H, one of the active ingredients of Chlorophytum borivilianum as an anti-cancer drug.