The experimental assessment and study of ubi kayu starch as fluid loss control agent in water based drilling fluids

The efficiency of a drilling mud, particularly the additives is valued by standard measurement of specific characteristics of the formation. This study presents an investigation on ubi kayu starch as a fluid loss control agent in water-based drilling mud (WBM) formation. The rheological and fluid loss behavior of ubi kayu-WBM (in 75, 100 and 150pcf of mud weight) was studied in various drilling condition (250, 275 and 300℉). The rheological values of samples were increased by mud weight, while decreased by temperature increment, Mud samples were found in a mild-acidic to neutral stated after drilling process (pH 6.1 to 7.4). Ubi kayu displayed an adequate fluid loss (under light, average and heavy mud weights with the values of 1.4, 0.8 and 0.4ml, respectively. only average weight mud samples exposed an acceptable fluid loss volume (0.4ml). Similar to cassava derivatives (fufu and ijebu garri) which were investigated in authors pervious papers, ubi kayu starch also failed as a fluid loss control agent (with volume ranging from 60 to 250ml). This study indicates the prospective of ubi kayu starch as a fluid loss additive in WBM formation

Removal of poly-histidine fusion tags from recombinant proteins purified by expanded bed adsorption

Enzymatic methods have been used to cleave the C- or N-terminus polyhistidine tags from histidine tagged proteins following expanded bed purification using immobilized metal affinitychromatography (IMAC). This study assesses the use of Factor Xa and a genetically engineered exopeptidase dipeptidyl aminopeptidase-1 (DAPase-1)for the removal of C-terminusand N-terminus polyhistidine tags, respectively. Model proteins consisting of maltose binding protein (MBP) having a C- or N-terminal polyhistidine tag were used. Digestion of the hexahistidinetagofMBP-His6 by Factor Xa and HT 15-MBP by DAPase-1 was successful. The time taken to complete the conversion of MBP-HiS6 to MBP was 16 h, as judged by SDS-PAGE and Western blots against anti-His antibody. When the detagged protein was purified using subtractive IMAC, the yield was moderate at 71% although the overall recovery was high at 95%. Likewise, a yield of 79% and a recovery of 97% was obtained when digestion was performed with using "on-column" tag digestion. Oncolumn tag digestion involves cleavage of histidine tag from polyhistidine tagged proteins that are still bound to the IMAC column. Digestion of an N-terminal polyhistidine tag from HT15-MBP (1 mg/mL) by the DAPase-1 system was superiorto the results obtained with Factor Xa with a higher yield and recovery of 99% and 95%, respectively. The digestion by DAPase-1 system was faster and was complete at 5 h as opposed to 16 h for Factor Xa. The detagged MBP proteins were isolated from the digestion mixtures using a simple subtractive IMAC column procedure with the detagged protein appearing in the flowthrough and washing fractions while residual dipeptides and DAPase-1 (which was engineered to exhibit a poly-His tail) were adsorbed to the column. FPLC analysis using a MonoS cation exchanger was performed to understand and monitor the progress and time course of DAPase-1 digestion of HT15-MBP to MBP. Optimization of process variables such as temperature, protein concentration, and enzyme activity was developed for the DAPase-1 digesting system on HT15-MBP to MBP. In short, this study proved that the use of either Factor Xa or DAPase-l for the digestion of polyhistidine tags is simple and efficient and can be carried out under mild reaction conditions

Optimizing supercritical antisolvent process parameters to minimize the particle size of paracetamol nanoencapsulated in L-polylactide

Background: The aim of this study was to optimize the different process parameters including pressure, temperature, and polymer concentration, to produce fine small spherical particles with a narrow particle size distribution using a supercritical antisolvent method for drug encapsulation. The interaction between different process parameters was also investigated. Methods and results: The optimized process parameters resulted in production of nanoencapsulated paracetamol in L-polylactide with a mean diameter of approximately 300 nm at 120 bar, 30°C, and a polymer concentration of 16 ppm. Thermogravimetric analysis illustrated the thermal characteristics of the nanoparticles. The high electrical charge on the surface of the nanoparticles caused the particles to repel each other, with the high negative zeta potential preventing flocculation. Conclusion: Our results illustrate the effect of different process parameters on particle size and morphology, and validate results obtained via RSM statistical software. Furthermore, the in vitro drug-release profile is consistent with a Korsmeyer–Peppas kinetic model

Isolation and Characterization of Coprophilous Cellulolytic Fungi from Asian Elephant (Elephas maximus) Dung

A lot of work has been done on isolation of cellulolytic fungi from the natural environment, but no such work was done on Asian elephant dung in Malaysia. Fungi that grow on elephant dung which is full of fibres may serve as a source of potential cellulase enzymes. Commercial cellulase enzymes used for the hydrolysis of lignocellulose biomass are not only expensive, but may as well hinder progress in the bioethanol industry. In this study, eight new fungi were isolated from Asian elephant dung sourced from Malaysian forest reserve. The fungi were identified morphologically and by molecular assay. The sequences of the fungi were deposited in the Gen Bank NCBI and were assigned accession numbers. Phylogenetic tree of the fungi was constructed to show similarities of the new fungi to known strains. The fungi were tested for cellulolytic potential using carboxymethyl cellulose (CMC). Trichoderma aureoviride strain UPM 09 (JN811061) and Fusarium equiseti strain UPM 09 (JN811063) proved to be potential cellulolytic fungi. This study shows that nature harbors the best cellulolytic fungi for biotechnological applications yet to be exploited. Keywords: cellulolytic, fungi, cellulase, lignocelluloses, biomass, Trichoderma aureoviride, Fusarium equiset

Numerical method on drug release from Nanoparticles using CFD.

Nowadays, there are many ways to administer the huge variety of drugs that are on the market. A drug is a chemical substance, that when applied to a living creature, alters its body function. Many drugs are used daily, such as caffeine in coffee and aspirin for pain. A route of drug administration in pharmacology and toxicology is the path by which a drug is brought into contact with the body. The most critical issue is some drugs are not significantly absorbed into the bloodstream. There are thousands of questions on the drug diffusion in the bloodstream and the most common issue is how long will these micro particles drug be released from the tablet? Thus, to identify the rate of the drug release and to control the drug release in our body is important, where to meet the target and not to become a waste. The Computational Fluid Dynamics method was used to investigate the drug design and diffusion profiles with time during the process of degradation and diffusion in water

Preparation and characterization of Poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles loaded with linamarin for controlled drug release

Poly (D,L-lactide-co-glycolide) nanoparticles loaded with linamarin as a model drug were successfully prepared using the double emulsion solvent evaporation technique. The physicochemical characterization of the formulated nanoparticles revealed that they were spherical, nonaggregated, and negatively charged, with good drug encapsulation efficiencies (>50%) and average particle sizes <200 nm. Interestingly, all the nanoparticles exhibited dibasic release profiles with a starting burst release within the first 8 h, followed by a controlled release phase lasting four days. Thus, linamarin-loaded nanoparticles indicate a promising candidate for controlled drug release applications

Detoxification of sago trunk hydrolysate using activated charcoal for xylitol production.

Xylitol is one of the alternative natural sweeteners; belong to a group of sugar alcohol. It can be derived from D- xylose which mainly contains in lignocellulose materials. In this study sago trunk cortex was chosen as lignocellulose source due to its availability and abundant in the sago starch processing industry. The production of xylitol includes hydrolysis which breaks the cellulose and hemicellulose polymers to fermentable sugar, mainly xylose, followed by fermentation process which converts the sugars to xylitol. However, some by-products such as furfural and phenolic are released during chemical hydrolysis and inhibit fermentation process. Detoxification procedures were carried out over sago trunk hydrolysates. Powdered activated charcoal was mixed with the hydrolysate at 1% and 2.5% (w/v) and stirred for 30 and 60 minutes at room temperature. The recovery of xylitol was performed using yeast Candida tropicalis in sago trunk cortex hydrolysate. This study describes detoxification methods of sago trunk cortex hydrolysates to improved xylitol production by Candida tropicalis. The effects of 1% and 2.5% (w/v) activated charcoal were identified to the growth and xylitol concentration. This study found that with the application of activated charcoal method, it enabled a reduction of furfural (58%) and total phenolics (78%) compounds. The best conditions was achieved with 2.5% activated charcoal at adsorption time of 60 minutes and the maximum xylitol concentration, xylitol yield and volumetric productivity obtained were 19.53 g l-1, 0.78 g g-1 and 0.37 g l-1 h-1. The value of xylitol yield using the detoxification hydrolysate medium was higher when compared to non-treated medium (0.307 g g-1). This strongly suggests that detoxification method using activated charcoal has a significant impact in xylitol production

Potential of Trichoderma harzianum as cellulose biodegrade in biocomposting of paddy straw

The present study was conducted to screen the significant cellulase (cellulolytic enzyme) produced by locally isolated fungi, Trichoderma harzianum using submerged culture system. Screening of the cellulase was conducted using carboxylmethylcellulase (CMC) plate assay to assist in determining of the microorganism potential as biodegrader. The highest diameter of inhibition zone around the T.harzianum colony which was grown on CMC agar was recorded at 1.9cm from a culture that used CMC supplemented with instant yeast. The culture with the best morphology was observed after 6 days incubation at temperature of 28°C and agitation speed of 150rpm. The biocomposting study on paddy straw showed that the waste is suitable for biocompost production with the lowest C:N ratio of 17.5 after 90 days of composting period

Evaluation of Fermentation Conditions by Candidatropicalis for Xylitol Production from Sago Trunk Cortex.

Xylitol production from sago trunk cortex hydrolysate using Candida tropicalis was evaluated in shake flasks and a bioreactor. The fermentation and kinetic behaviours of this microorganism were investigated using sago trunk cortex hydrolysate and commercial xylose as substrate. Results obtained for sago trunk hydrolysate were close to the commercial xylose with xylitol yield of 0.82 gg-1 and productivity of 0.39 gL-1h-1. The maximum specific growth rate, µmax for sago trunk cortex was higher (0.24 h-1) compared to commercial xylose (0.17 h-1). The bioreactor study showed an increase of about 6% (w/v) of xylitol concentration and 10% (v/v) of volumetric productivity when compared to the results obtained under the shake flasks, keeping xylitol yield above 0.8 g g-1

The prophylactic effect of probiotic enterococcus lactis IW5 against different human cancel cells

Enterococcus lactis IW5 was obtained from human gut and the potential probiotic characteristics of this organism were then evaluated. Results showed that this strain was highly resistant to low pH and high bile salt and adhered strongly to Caco-2 human epithelial colorectal cell lines. The supernatant of E. lactis IW5 strongly inhibited the growth of several pathogenic bacteria and decreased the viability of different cancer cells, such as HeLa, MCF-7, AGS, HT-29, and Caco-2. Conversely, E. lactis IW5 did not inhibit the viability of normal FHs-74 cells. This strain did not generate toxic enzymes, including β-glucosidase, β-glucuronidase, and N-acetyl-β-glucosaminidase and was highly susceptible to ampicillin, gentamycin, penicillin, vancomycin, clindamycin, sulfamethoxazol, and chloramphenicol but resistant to erythromycin and tetracyclin. This study provided evidence for the effect of E. lactis IW5 on cancer cells. Therefore, E. lactis IW5, as a bioactive therapeutics, should be subjected to other relevant tests to verify the therapeutic suitability of this strain for clinical applications