Effect of growth conditions on production of green fluorescent protein from escherichia coli fermentation

Effect of growth conditions (temperature, agitation rate and working volume) on production of enhanced green fluorescent protein (EGFP) from Escherichia coli (E.coli) fermentation was studied in this research. An improved growth conditions are needed to maximize the functional EGFP production. Preparation of cell culture was done by transferring E. coli strain BL21 (DE3) carrying plasmid pRSETEGFP to agar plate by streaking method and incubated at 30°C for 18 hr. Inoculum was prepared from a single colony of E.coli from agar plate. Fermentation of batch cultures were carried out in Erlenmeyer flasks inoculated with inocula [5% (v/v)]. The process variables include temperature, agitation rate and working volume were varied throughout the batch fermentation by using one factor at a time method. During the cultivation process, samples were taken from Erlenmeyer flask to measure cell biomass and EGFP concentrations. Cell biomass concentration was determined based on the culture absorbance using spectrophotometer and EGFP concentration was determined using gel-based imaging method. The results obtained shows that EGFP production by E.coli decreases as the working volumes was increased from 20 to 50%. However, when the agitation rate was increased from 100 to 250 rpm, it subsequently increases the yield of EGFP and cell concentration. Suitable temperature (30°C) enables E.coli to grow well and produce higher amount of functional EGFP. Consequently, functional EGFP production decreased at low temperature ( 30°C) also resulted in a decrease of EGFP and biomass production due to protein aggregation into inclusion bodies. In conclusion, the yield of functional EGFP was highest in shake flask fermentation under condition, working volume of 20%, agitation rate of 200 rpm and temperature of 30°C with 0.04, 0.061 and 0.06 g/L respectivel

STUDY OF DIFFERENT TREATMENT METHODS ON CHICKEN FEATHER BIOMASS

The chicken feathers (CFs)  consist of up to 10 % of total chicken dry mass and they have many potential industrial applications. CFs contains protein fibers named as keratin, which is an insoluble protein. Primary sanitization phases are complex because of the presence of lots of blood born microbes, pathogens and parasites in raw biomass. The extraction process of keratins from the unprocessed feathers is also a challenging task. Prior to the extraction cleaning/sanitization of feathers is a very necessary step. Thus, the present work was conducted to optimize  an efficient surfactant  for the cleaning process of the  CFs by using ionic and non-ionic surfactants. The experiment was conducted by the washing of feathers with double distilled water (ddH2O), detergents, ether and lastly with boiling water. The washed feathers treated with surfactants and the effect of each surfactant was analyzed by a microbiological test which tells about the extent of  the presence of different bacteria on the treated feathers. SEM, EDX, FTIR were used to study the morphology and composition of  untreated and treated CFs. SEM showed there was no detectable fiber damage after treatment. Cetrimonium bromide (CTAB) (t3) was one of the best surfactant for the treatment of CFs among all the surfactant used. The present study described the best treatment method  for the CFs.

Simulating self-similar vbr traffic / Malini Subramaniam

Studies on the nature of VBR traffic have shown that VBR traffic has self-similar characteristics. However, most traditional network traffic models that are used in the simulation of VBR traffic are unable to capture these self-similar qualities. As VBR traffic is forecasted to be a substantial portion of network traffic, it is imperative that the self-similarity of VBR traffic be taken into account whilst designing both network simulators and real networks. The aim of this project is to implement a module that will simulate self-similar VBR traffic. The module will be implemented in an existing network simulator: the UMJaNetSim network simulator. Users of the simulator will then be able to generate self-similar VBR traffic

Preparation and characterization of rice starch and transition metal stearates filled polypropylen

The high versatility of synthetic plastics in terms of mechanical properties and durability has become a deteriorating factor of natural environment. In response to these issues, this study has been directed towards development and application of degradable plastics as an alternative to replace commodity non degradable plastics. Untreated rice starch (URS), treated rice starch (TRS) and transition metal stearates (TMS) were used as fillers and incorporated with polypropylene (PP). URS, TRS and TMS filled PP samples were prepared through extrusion and injection molding technique. URS and TRS were mixed with PP with a concentration of 10, 20, 30, 40 and 50 wt % respectively. Composition of TMS (CoSt3 and FeSt3) of 0.1, 0.3, 0.5, 0.7 and 0.9 phr was blended with PP. The prepared blends were characterized by tensile properties such as tensile strength (TS), tensile modulus (TM) and percentage of elongation at break (EB). The thermo-oxidative properties were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Degradability of blends was studied by using enzymatic degradation and accelerated weathering test. The degradation properties and surface morphologies were observed using fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analysis. The results indicated that TS and TM of URS and TRS filled PP samples reduced as the composition of starch increases. The results indicated that maximum TS and TM of both CoSt3 and FeSt3 at concentration of TMS of 0.5 phr. DSC analysis showed that enthalpy and crystallinity of URS and TRS filled PP samples dropped as the composition of URS and TRS increased from 10- 50 wt % meanwhile crystallinity of PPFe5 samples were much higher than PPCo5 samples. Furthermore, higher Tmax in PP/TRS compared to PP/URS signified that the incorporation of TRS improved the thermal stability of the blends with the increase in the composition of starch (10-50 wt %). TGA results showed that PPCo5 has a higher Tmax as compared to PPFe5 and CoSt3 exhibits higher decomposition temperature as compared to FeSt3. During enzymatic degradation, URS and TRS filled PP samples experienced highest weight reduction after the 10, 20 and 30 days for 50 wt % URS and TRS. The weight loss in both PPCo5 and PPFe5 samples are almost negligible after enzymatic degradation. Significant discoloration was observed in both URS and TRS filled PP samples after accelerated weathering test. Same test showed that the ability of CoSt3 as pro-oxidant is more deteriorating than FeSt3 as observed in visual observation and SEM analysis of samples. The incorporation of URS, TRS and TMS into PP matrices exhibits some significant changes on the properties of plastic blends been produced. In all the formulation, it was observed decrease in mechanical and thermal properties but a significant improvement in the degradability of samples can be observed. Substitution of PP matrix with fillers can improve its susceptibility towards degradation. From the data analysis, TMS acts as best filler among all the three fillers been blended with PP followed by TRS and URS. Conclusively, filling of natural filler and pro-oxidants into synthetic plastics can be a great solution to solve the environmental issues caused by non-degradable plastic wastes

Natural Rubber Latex (NRL) and Rice Starch as an Alternative Binder in Wood Composite Industry

Medium density fiberboards (MDF) was produced in laboratory using bio-adhesives synthesized using natural rubber latex (NRL) and rice starch (RS) with pressing time of 3 minutes, temperature of 180°C and pressure of 5MPa. This present study is aimed on increasing and improving the physical and mechanical performances of MDF by application of bio-based adhesives which comprises NRL and rice starch solution. The effects of bio-adhesives used on the physical and mechanical properties of boards produced were investigated accordingly and compared with the MDF prepared using urea-formaldehyde according to the specific ASTM standards. In the composite preparation, bio- adhesives were used as manipulated variable, where they were split into 5 further weight proportions as follows: 1) 20g NRL; 2) 15g NRL + 5g RS; 3) 10g NRL + 10g RS; 4) 5g NRL + 15g RS and 5) 20g RS. The samples were also subjected to mechanical testing such as modulus of rupture (MOR), internal bonding (IB) and thickness swelling (TS). Based on the mechanical testing done on the specimens, it is clearly indicated that bioadhesives comprising of 15g of natural rubber latex and 5 g of rice starch blend improves the modulus of rupture (MOR) and internal bonding strength (IB) of MDF significantly, where the mechanical strength value obtained were better and comparable than MDF made with UF alone. Hence, it strongly indicates the promising feasibility of NRL and rice starch to replace conventional UF in wood composite industry, and eventually highlights the success of this research

Evaluation on the Thermo-Oxidative Degradation of PET using Prodegradant Additives

Objectives: Transition metal stearates are example of potent pro-degradants reported to work at trace levels. They speed up the oxidative reaction leading to polymeric chain cleavage and reduction in molecular mass causing bio-assimilation of plastic waste. In this paper, attempt to analyze the effect of different loading amounts of cobalt stearate (CS) on the polymeric matrix of polyethylene terephthalate (PET) has been reported. Methods/Statistical Analysis: Formulated compounds were melt blended using an extruder and the extrudates were pelletized prior to molding into bone shaped specimens using an injection molding machine for characterization purpose. Findings: The effects on the incorporation of CS on the mechanical properties revealed that CS influences its tensile strength and elongation at break (%) at processing stage and studies based on Fourier Transform Infrared Spectroscopy (FTIR) spectra and carbonyl index (CI) measurements indicate that blends’ consisting of 0.25CS contributes to thermal degradation of PET. Application/Improvements: The outcome of this study would assist in the production of biodegradable materials which could decompose in shorter time frame as well as reduces plastic waste in environment

Enhanced Degradation Properties Of Polypropylene Integrated With Iron And Cobalt Stearates And Its Synthetic Application

Synthetic plastic leads to environmental contamination, and a promising solution to this problem is to use prooxidants as fillers within them to speed up the photooxidation and thermooxidation processes. This makes plastics more susceptible to biodegradation. In this study, the degradation properties of the widely used polymer polypropylene (PP) were improved by integration with cobalt stearate (CoSt2) and iron stearate (FeSt3) as prooxidants with accelerating weathering degradation. The metal stearates were blended with PP in the concentration range 0.1–0.9% w/w. The properties of the blends were studied by mechanical properties testing, thermogravimetric analysis, differential scanning calorimetry, and water absorption measurement. We performed the degradation properties and thermooxidative studies by conducting an accelerated weathering test on PP–metal salt blends. Fourier transform infrared spectroscopy and scanning electron microscopy analysis of the samples before and after the accelerated weathering test were performed to study the extent of degradation in PP-based metal salt blends. The results indicate that the tensile strength was inversely proportional to the concentration of metal stearates, and the samples showed an increased degree in polymer crystallinity (PPFe5 > PPCo5), and this led to the degradation of PP in less time. CoSt2 predominantly enhanced the degradation of PP in comparison to FeSt3. Food containers and pots were constructed with the tailored polymers of PP in the injection-molding machine. Thus, metal-stearate-integrated polymers have great industrial potential to generate value-added products

Preparation of bioplastic using polypropylene and starch as filler

The main objective of this contract research is to prepare bioplastic using polypropylene as matrix and other biobased materials as filler. Different categories of starch and other biodegradable materials will be used to prepare it

Isolation of Nano Cellulose from Rubber Wood Fibre and Fibrillation Effects on Nano Cellulose Reinforced Poly (Ethylene Oxide)

Wood and plants are cellular hierarchical bio-composites produced by nature, and are essentially semicrystalline cellulose microfibrilreinforced amorphous matrices made of hemicellulose, lignin, waxes, extractive and trace elements. Cellulose acts as a structural reinforcing agent that provides mechanical strength as well as chemical stability to plants. The development of low-cost, sustainable and renewable resources is critical to meet the growing environmental concerns and energy demands; the use of rubber wood is extremely beneficial to Malaysia as it is one of the main commodities. The current study aims to extract cellulose nanofibres from rubber wood (Heveabrasiliensis) fibers via high pressure homogenisation combined with enzymatic and chemical pretreatments. In this study the application of enzymes in fiber processing has been mainly directed towards the modification of hemicelluloses and lignin while preserving the cellulosic fraction .The diameter distributions of the resulting nanofibers were dependent on the number of times of cellulose solution is passing. The extent of dispersion improved significantly with increasing when number of passes through the high pressure homogenised. Fe-SEM study showed that the diameters of the nanofibersisolated ranged from 37 to 85 nanometer(nm) and estimated length is several micrometers (µm). The nanocellulosefibres were studied further by examining with Fourier Transform Infrared Spectroscopy (FTIR). There was a disappearance of vibration peaks at 1730.28 and 1234 cm-1 from spectra of treated fibres which shows the removal of hemicellulose and lignin components respectively. XRD results showed an increase in crystalline which resulted from the removal of lignin and hemicellulose. Moreover, the isolated cellulose nanofibres were used to reinforce poly(ethylene oxide) (PEO). PEO was dissolved in isolated nanocellulose liquid suspension followed by casting. The nanocomposites were characterized by using FTIR analysis and X-Ray diffractometry