Open Access Short communication

Comparative Evaluation of Antioxidant Properties of Methanolic Extract of Red and Green Custard Apple Fruits

Mahendran Sekar, Fathin Azara Muhamadul Bakir, Afikaah Shaan Ali, Suryani Hayati Mat Sha’ari, Rumaisak Amiruddin, Nur Iryani Ahmad Rizal, Mohd Syafiq Abdullah

Biotechnology Journal International, Page 1-6
DOI: 10.9734/BBJ/2015/19304

Annona squamosa (custard apple) or also called Sugar Apple. It is native to the tropical Americas and West Indies, but the exact origin is unknown. It is now the most widely cultivated of all the species of Annona, being grown for its fruit throughout the tropics and warmer subtropics, such as Indonesia, Thailand, and Taiwan; it was introduced to southern Asia before 1590. There are two varieties of custard apple which were available in the local Malaysian market. In the present study we aimed to carry out comparative antioxidant activity of methanolic extract of both custard apple fruits by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method. The results showed that the methanolic extract of red custard apple showed better antioxidant activity than methanolic extract of green custard apple. However, the standard ascorbic acid showed better antioxidant activity than both the extracts. In conclusion, the red custard apple is good candidate for further investigation.

Open Access Original Research Article

Mathematical Modeling of Macroscale Phenomena: Oxygen Transfer for Solid-state Fermentation in Static Tray Bioreactor

J. Sharon Mano Pappu, Tanmay Basak, Sathyanarayana N. Gummadi

Biotechnology Journal International, Page 1-14
DOI: 10.9734/BBJ/2015/20476

Aims: To develop a mathematical model for prediction of variation in oxygen concentration inside the bed of tray type bioreactor for solid state fermentation and comparison of oxygen profile of unsteady state and pseudo steady state approximation.

Place and Duration of Study: All the simulations were performed at the Applied and Industrial Microbiology laboratory, Indian Institute of Technology, Madras, from October 2013 to September 2014.

Methodology: Models for various reaction kinetics (zero order, first order and Monod’s kinetics) were derived from the general model. Ordinary differential equations (Pseudo steady state approximation) and partial differential equations (unsteady state assumption) were solved by numerical techniques – Finite difference method (FDM) and Runge-kutta method. Simulation runs were carried out for various parameters such as bed height gas phase oxygen concentration, saturation constant, and porosity of the bed.

Results: Oxygen profiles of unsteady state and pseudo steady state assumption were compared and results show lower oxygen concentration in case of unsteady state assumption. Concentration of oxygen was low for the organism following first order when compared to zero order and Monod kinetics. Results of simulation runs revealed that the oxygen concentration decreases as the bed height increases irrespective of the kinetics of the reaction. And it increases with increasing gas phase oxygen concentration, saturation constant and porosity.

Conclusion: Mathematical model with unsteady state assumption was reported and it can be employed in calculating the design and operational parameters for solid state fermentors to yield optimal productivity.

Open Access Original Research Article

Screening and Media Optimization for Enhancing L-asparaginase Production, an Anticancer Agent, from Different Filamentous Fungi in Solid State Fermentation

Ali Mohamed Elshafei, Dina Helmy El-Ghonemy

Biotechnology Journal International, Page 1-15
DOI: 10.9734/BBJ/2015/19728

Aim: The aim of present study was to screen new potent fungal isolates and microorganisms possessing extracellular L-asparaginase production capacity. In addition, optimization of cultural and environmental conditions required for enzyme production will be carried out for the highest L-asparaginase producer in solid state fermentation (SSF) technique using agro-industrial residues.

Study Design: Screening and physiological studies on the formation of L-asparaginase by Trichoderma viride F2 in order to obtain the optimum cultural and environmental conditions required for enzyme production.

Place and Duration of Study: Department of Microbial Chemistry, Genetic Engineering and Biotechnology Division, National Research Centre (NRC), Cairo, Egypt, between July 2013 and June 2015.

Methodology: Optimization of physical and nutritional parameters for enzyme production was investigated. Various locally available agro-industrial residues have been screened individually or as mixtures for L-asparaginase production. The combination of Rice husk (RH) with wheat bran (WB) (3:2) proved to be an efficient mixture for enzyme production as it gave the highest enzyme activity (71.87±3.19 U/g-ds) when compared to individual RH (66.71±2.76 U/g-ds) or WB (62.28±2.13 U/g-ds) substrates.

Results: Maximal L-asparaginase production (113.43±5.11 U/g-ds) by T. viride F2 was obtained with moisture content of 75%, an inoculums size of 1 x 108 spores/ml and an initial medium pH of 5.0 when incubated at 28ºC for four days. Presence of Tween 20 enhanced enzyme production by 1.19 folds. Glucose (1.0%), Casein (1.5%) and MgCl2 (0.05%) were found to be the best carbon, organic nitrogen and ion sources, respectively. Supplementation of the medium with NaNO3 (0.15%) as an inorganic nitrogen source further increased L-asparaginase production. Under these optimized conditions, L-asparaginase production by T. viride F2 was maximum with a yield of 276.5±13.4 U/g-ds in SSF, which was more than 19-fold enhancement in enzyme activity as compared to that obtained in the basal medium (SmF) (14.23±0.87 U/ml).

Conclusion: The results suggest that choosing a suitable substrate coupled with optimization of different parameters can improves enzyme production markedly. Moreover, the production of L-asparaginase from a process based on RH and WB as substrates in SSF is economically attractive due to abundant substrates availability in agriculture-based countries with cheaper cost.

Open Access Original Research Article

Investigating the In vitro Regeneration Potentiality of Three High Yielding Indica Rice (Oryza sativa L.) Varieties

Mohammd Rashed Hossain, Nazneen Akter, Upama Mondal, Ratan Candra Dey, Lutful Hassan

Biotechnology Journal International, Page 1-13
DOI: 10.9734/BBJ/2015/19258

Aims: An efficient and reproducible In vitro regeneration protocol is vital for varietal improvement research. The current research was conducted to optimize the callus induction, shoot and root regeneration of three indica rice varieties.

Place, Duration and Design of Study: The experiment was conducted in the tissue culture and biotechnology laboratory of the department of Genetics and Plant Breeding of Bangladesh Agricultural University using completely randomized experimental design.

Methodology: Dehusked mature seeds of three indica rice varieties namely, BRRI dhan28, BRRI dhan29 and BINA dhan6 were cultured In vitro in MS medium supplemented with different concentrations and combinations of phytohormones.

Results: The callus induction ranged from 14 - 84% which showed a general increasing trend with the increase in the concentration of 2,4-Dichlorophenoxyacetic acid (2,4-D) starting from 1.0 mg L-1 till 2.5 mg L-1. A further increase in the concentration of 2,4-D to 2.5 mg L-1, however, decreased the percentage of callus induction in all three varieties. MS medium supplemented with 2.5 mg L-1 2,4-D and 0.5 mg L-1 6-Benzylaminopurine (BAP) was better than any other composition for callus induction. For size of callus and nature of callus, however, MS medium supplemented with 2.0 mg L-1 2,4-D and 0.5 mg L-1 BAP was found to perfume best. The highest percentage of callus induction was observed in the variety BRRI dhan29 (84%) followed by BRRI dhan28 (74%). Almost all the varieties produced yellowish and compact calli except BINA dhan6 which produced creamy and friable calli. The desiccation treatment has shown to increase size but decrease the compactness of the callus. The differences are, however, not statistically significant. MS medium supplemented with 0.6 mg L-1 1-Naphthaleneacetic acid (NAA) and 6 mg L-1 Kinetin (Kn) showed highest shoot regeneration in BRRI dhan29 (85%) followed by BRRI dhan28 (60%). Higher frequency of root formation was observed in all three varieties using Indole-3-butyric acid (IBA). The survival rate of the plantlet in acclimatization chamber (96%) and in field condition (93.33%) was higher for BRRI dhan29. BINA dhan6 has shown the least regeneration potentiality for all the aforementioned traits.

Conclusion: Of the three varieties, BRRI dhan29 and BRRI dhan28 has shown higher regeneration potentiality. This optimized protocol will thus be useful in genetic improvement of these varieties using biotechnological manipulations.

Open Access Original Research Article

Synthesis, Characterisation, Antibacterial and Cytotoxic Assay of Zinc Oxide (ZnO) Nanoparticles

Richa Yadav, Madhurima Bandopadhyay, Aritra Saha, Abul Kalam Azad Mandal

Biotechnology Journal International, Page 1-10
DOI: 10.9734/BBJ/2015/20260

Aims: The objective of the present experiment was to synthesise ZnO nanoparticles by the environmental friendly process of bioreduction of ZnO salt with Camellia sinensis crop shoot extract and post synthesis to characterise and check their antibacterial potentiality and cytotoxicity.

Place and Duration of Study: Fermentation technology lab, School of biosciences and technology, VIT University, Vellore between July 2013 to December 2013.

Methodology: Green tea leaf extract (5%, 10% and 15%) and ZnO salt solution (0.1 M and 0.01 M) were prepared in different concentrations and mixed in three volumetric ratios (1:1, 1:2 and 1:3) to make a total of 18 combinations. The mixtures were incubated in a rotary shaker for 24-48 h. The synthesised nanoparticles were characterised subsequently by UV-Vis absorption spectroscopy, atomic force microscopy (AFM), particle size analysis, Fourier transfer infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. Upon characterization antibacterial activity of the nanoparticles were tested on three gram positive (Staphylococcus aureus, Salmonella sp., Bacillus sp.) and two gram negative (Escherichia coli, Pseudomonas sp.) bacteria. Finally haemolytic activity of the ZnO nanoparticles were compared with bulk ZnO salt and plant extract on RBC.

Results: The 370 nm peak obtained in UV-Vis spectrophotometer confirmed about the synthesis in case of only 15% extract. The AFM and particle size analysis revealed size of the nanoparticles at about 70 nm. FTIR analysis confirmed identical functional groups like tea leaf extract. Finally the crystalline nature of the nanoparticles were evident from XRD experiment. Antibacterial assay revealed inhibitory effect of the nanoparticles on all the five bacterial strains by producing prominent zone of inhibition. From the haemolytic assay the synthesised ZnO nanoparticles were found out to be biocompatible and non-toxic up to a conc. of 60 µg/ml.

Conclusion: The present experiment provided a simple, rapid and environmentally benign technique of synthesising spherical to elliptical ZnO nanoparticles having efficient antibacterial activity and non-toxicity which can be used for developing a successful drug delivery system.