Geobacillus sp. WSUCF1 is a Gram-positive, spore-forming, aerobic and thermophilic bacterium, isolated from a soil sample obtained from a compost facility. Strain WSUCF1 demonstrated EPS producing capability using different sugars as the carbon source. The whole-genome analysis of WSUCF1 was performed to disclose the essential genes correlated with nucleotide sugar precursor biosynthesis, assembly of monosaccharide units, export of the polysaccharide chain, and regulation of EPS production. Both the biosynthesis pathway and export mechanism of EPS were proposed based on functional annotation. Additionally, the genome description of strain WSUCF1 suggests sophisticated systems for its adaptation under thermophilic conditions. The presence of genes associated with CRISPR-Cas system, quorum quenching lactonase, polyketide synthesis and arsenic resistance makes this strain a potential candidate for various applications in biotechnology and biomedicine. The present study indicates that strain WSUCF1 has promise as a thermophilic EPS producer for a broad range of industrial applications. To the best of our knowledge, this is the first report on genome analysis of a thermophilic Geobacillus species focusing on its EPS biosynthesis and transportation, which will likely pave the way for both enhanced yield and tailor-made EPS production by thermophilic bacteria.
A xanthan gum matrix controlled release tablet formulation containing diclofenac sodium was evaluated in vitro and was found to release the drug at a uniform rate. The gastrointestinal transit behaviour of the formulation as determined by gamma scintigraphy, using healthy male volunteers under fasted and fed conditions, indicated that gastric emptying was delayed with food intake. In contrast, the small intestinal transit remained practically unchanged under both food statuses. Therefore, the delay in caecal arrival observed in the fed state can be attributed to the delay in gastric emptying. Rate of diclofenac sodium absorption was generally higher in the fed state compared to the fasted state, however the total amount absorbed under both food statuses remained practically the same. The rate of in vivo dissolution of the drug in the fed state was faster compared to that in the fasted state. Thus, at the time of caecal arrival, in vivo dissolution was complete in the fed state, unlike in the fasted state, where almost 60% of the drug was delivered to the colon.
The purpose of this study is to evaluate the in vitro and in vivo performance of gastro-retentive matrix tablets having Metformin HCl as model drug and combination of natural polymers. A total of 16 formulations were prepared by a wet granulation method using xanthan, tamarind seed powder, tamarind kernel powder and salep as the gel-forming agents and sodium bicarbonate as a gas-forming agent. All the formulations were evaluated for compendial and non-compendial tests and in vitro study was carried out on a USP-II dissolution apparatus at a paddle speed of 50 rpm. MOX2 formulation, composed of salep and xanthan in the ratio of 4:1 with 96.9% release, was considered as the optimum formulation with more than 90% release in 12 hours and short floating lag time. In vivo study was carried out using gamma scintigraphy in New Zealand White rabbits, optimized formulation was incorporated with 10 mg of (153)Sm for labeling MOX2 formulation. The radioactive samarium oxide was used as the marker to trace transit of the tablets in the gastrointestinal tract. The in vivo data also supported retention of MOX2 formulation in the gastric region for 12 hours and were different from the control formulation without a gas and gel forming agent. It was concluded that the prepared floating gastro-retentive matrix tablets had a sustained-release effect in vitro and in vivo, gamma scintigraphy played an important role in locating the oral transit and the drug-release pattern.
The purpose of this research was to study processing variables at the laboratory and pilot scales that can affect hydration rates of xanthan gum matrices containing diclofenac sodium and the rate of drug release. Tablets from the laboratory scale and pilot scale proceedings were made by wet granulation. Swelling indices of xanthan gum formulations prepared with different amounts of water were measured in water under a magnifying lens. Granules were thermally treated in an oven at 60 degrees C, 70 degrees C, and 80 degrees C to study the effects of elevated temperatures on drug release from xanthan gum matrices. Granules from the pilot scale formulations were bulkier compared to their laboratory scale counterparts, resulting in more porous, softer tablets. Drug release was linear from xanthan gum matrices prepared at the laboratory scale and pilot scales; however, release was faster from the pilot scales. Thermal treatment of the granules did not affect the swelling index and rate of drug release from tablets in both the pilot and laboratory scale proceedings. On the other hand, the release from both proceedings was affected by the amount of water used for granulation and the speed of the impeller during granulation. The data suggest that processing variables that affect the degree of wetness during granulation, such as increase in impeller speed and increase in amount of water used for granulation, also may affect the swelling index of xanthan gum matrices and therefore the rate of drug release.
Xanthan integrated graphene oxide functionalized by titanium dioxide was successfully prepared through facile, eco-friendly and cost effective ice-templating technique. The three-dimensional (3D) graphene composite demonstrated relatively high temperature stability, chemical functionalities and porous sponge-like structure. The adsorption of lead was favored by high initial concentration and shaking speed at the operational solution pH. The process equilibrium and kinetic adhered to the Langmuir and pseudo-second-order correlations, respectively. The biomass integrated graphene composite showed maximum adsorption capacities ranging from 132.18 to 199.22 mg/g for 30-70 °C. Moreover, it was highly regenerable under mild conditions (0.1 M hydrochloric acid, 30 °C) and used repeatedly while retaining 84.78% of its initial adsorption capacity at the fifth adsorption-regeneration cycle. With comparatively high lead adsorption capacities, adequate recyclability and environmentally friendliness, the as-prepared 3D graphene composite has high application potential in heavy metal-wastewater separation for protection of the environment and human health.
Olive oil-entrapped diethanolamine-modified high-methoxyl pectin (DMP)-gellan gum (GG)-bionanofiller composites were developed for controlled intragastric delivery of metformin HCl (MFM). DMP had a degree of amidation of 48.7% and was characterized further by FTIR, XRD and DSC analyses. MFM-loaded composites were subsequently accomplished by green synthesis via ionotropic gelation technique using zinc acetate as cross-linker. The thermal, X-ray and infrared analyses suggested an environment in the composites compatible with the drug, except certain degree of attenuation in drug's crystallinity. Scanning electron microscopy revealed almost spherical shape of the composites. Depending upon the mass ratios of GG:DMP, types of nanofiller (neusilin/bentonite/Florite) and oil inclusion, the composites exhibited variable drug encapsulation efficiency (DEE, 50-85%) and extended drug release behaviours (Q8h, 69-94%) in acetate buffer (pH 4.5). The optimized oil-entrapped Florite R NF/GG: DMP (1:1) composites eluted MFM via case-II transport mechanism and its drug release data was best fitted in zero-order kinetic model. The optimized formulation demonstrated excellent gastroretentive properties and substantial hypoglycemic effect in streptozotocin-induced diabetic rats. These novel hybrid matrices were thus found suitable for controlled intragastric delivery of MFM for the management of type 2 diabetes.
Volumetric mass transfer coefficient (kLa) is an important parameter in bioreactors handling viscous fermentations such as xanthan gum production, as it affects the reactor performance and productivity. Published literatures showed that adding an organic phase such as hydrocarbons or vegetable oil could increase the kLa. The present study opted for palm oil as the organic phase as it is plentiful in Malaysia. Experiments were carried out to study the effect of viscosity, gas holdup, and kLa on the xanthan solution with different palm oil fractions by varying the agitation rate and aeration rate in a 5 L bench-top bioreactor fitted with twin Rushton turbines. Results showed that 10% (v/v) of palm oil raised the kLa of xanthan solution by 1.5 to 3 folds with the highest kLa value of 84.44 h(-1). It was also found that palm oil increased the gas holdup and viscosity of the xanthan solution. The kLa values obtained as a function of power input, superficial gas velocity, and palm oil fraction were validated by two different empirical equations. Similarly, the gas holdup obtained as a function of power input and superficial gas velocity was validated by another empirical equation. All correlations were found to fit well with higher determination coefficients.
A locally isolated Acinetobacter sp. Strain AQ5NOL 1 was encapsulated in gellan gum and its ability to degrade phenol was compared with the free cells. Optimal phenol degradation was achieved at gellan gum concentration of 0.75% (w/v), bead size of 3 mm diameter (estimated surface area of 28.26 mm(2)) and bead number of 300 per 100 ml medium. At phenol concentration of 100 mg l(-1), both free and immobilized bacteria exhibited similar rates of phenol degradation but at higher phenol concentrations, the immobilized bacteria exhibited a higher rate of degradation of phenol. The immobilized cells completely degrade phenol within 108, 216 and 240 h at 1,100, 1,500 and 1,900 mg l(-1) phenol, respectively, whereas free cells took 240 h to completely degrade phenol at 1,100 mg l(-1). However, the free cells were unable to completely degrade phenol at higher concentrations. Overall, the rates of phenol degradation by both immobilized and free bacteria decreased gradually as the phenol concentration was increased. The immobilized cells showed no loss in phenol degrading activity after being used repeatedly for 45 cycles of 18 h cycle. However, phenol degrading activity of the immobilized bacteria experienced 10 and 38% losses after the 46 and 47th cycles, respectively. The study has shown an increased efficiency of phenol degradation when the cells are encapsulated in gellan gum.
Extensive use of carbofuran insecticide harms the environment and human health. Carbofuran is an endocrine disruptor and has the highest acute toxicity to humans than all groups of carbamate pesticides used. Carbofuran is highly mobile in soil and soluble in water with a lengthy half-life (50 days). Therefore, it has the potential to contaminate groundwater and nearby water bodies after rainfall events. A bacterial strain BRC05 was isolated from agricultural soil characterized and presumptively identified as Enterobacter sp. The strain was immobilized using gellan gum as an entrapment material. The effect of different heavy metals and the ability of the immobilized cells to degrade carbofuran were compared with their free cell counterparts. The results showed a significant increase in the degradation of carbofuran by immobilized cells compared with freely suspended cells. Carbofuran was completely degraded within 9 h by immobilized cells at 50 mg/L, while it took 12 h for free cells to degrade carbofuran at the same concentration. Besides, the immobilized cells completely degraded carbofuran within 38 h at 100 mg/L. On the other hand, free cells degraded the compound in 68 h. The viability of the freely suspended cell and degradation efficiency was inhibited at a concentration greater than 100 mg/L. Whereas, the immobilized cells almost completely degraded carbofuran at 100 mg/L. At 250 mg/L concentration, the rate of degradation decreased significantly in free cells. The immobilized cells could also be reused for about nine cycles without losing their degradation activity. Hence, the gellan gum-immobilized cells of Enterobacter sp. could be potentially used in the bioremediation of carbofuran in contaminated soil.
The purpose of this study was to simultaneously predict the drug release and skin permeation of Piroxicam (PX) topical films based on Chitosan (CTS), Xanthan gum (XG) and its Carboxymethyl derivatives (CMXs) as matrix systems. These films were prepared by the solvent casting method, using Tween 80 (T80) as a permeation enhancer. All of the prepared films were assessed for their physicochemical parameters, their in vitro drug release and ex vivo skin permeation studies. Moreover, deep learning models and machine learning models were applied to predict the drug release and permeation rates. The results indicated that all of the films exhibited good consistency and physicochemical properties. Furthermore, it was noticed that when T80 was used in the optimal formulation (F8) based on CTS-CMX3, a satisfactory drug release pattern was found where 99.97% of PX was released and an amount of 1.18 mg/cm2 was permeated after 48 h. Moreover, Generative Adversarial Network (GAN) efficiently enhanced the performance of deep learning models and DNN was chosen as the best predictive approach with MSE values equal to 0.00098 and 0.00182 for the drug release and permeation kinetics, respectively. DNN precisely predicted PX dissolution profiles with f2 values equal to 99.99 for all the formulations.
The effects of xanthan gum (XG) and hydroxypropyl methylcellulose (HPMC) in sponge cakes were studied. Hydrocolloids enhanced the thickening effect in batter that affected the textural attributes of sponge cakes. During storage, the structural changes in XG-cake resulted in higher hardness compared to HPMC-cake. Similar to XG, HPMC also contributed moistness to cake. The moisture loss of cake containing XG was slower than HPMC-cake. FTIR study showed absorption of OH at region of 3600-2900 cm-1 that explained the strong interaction of water in cake containing XG compared to other cake formulations.
The aim of this study was to determine the effects of xanthan gum and carrageenan on the
oil uptake and acceptability of banana (Musa acuminate) fritters during repeated deep fat
frying. Banana namely ‘Pisang Awak’ at maturity stage 6 were peeled, cut and dipped into 3
batter formulations containing 1% carrageenan, 1% xanthan gum and a control. The bananas
were deep fried at 170±5°C for 3 minutes in 2.5L cooking oil without oil replenishment for
3 consecutive days. The moisture, oil content, texture, colour and acceptability of the banana
fritters were evaluated at first and every 10th frying cycles. Results indicated that the oil and
moisture content of fried bananas were dependent on frying cycles. The oil content increased
while the moisture decreased with increased in frying cycles. There was significant reduction
(p0.05) in terms of overall acceptance between
treated and untreated. Hence, 1% xanthan gum was effective in reducing oil absorption of
banana fritters without affecting the overall sensory acceptability
The ability of gellan gum-immobilised cells of the heavy metal-tolerant bacterium Alcaligenes sp. AQ05-001 to utilise both heavy metal-free and heavy metal-polluted feathers (HMPFs) as substrates to produce keratinase enzyme was studied. Optimisation of the media pH, incubation temperature and immobilisation parameters (bead size, bead number, gellan gum concentration) was determined for the best possible production of keratinase using the one-factor-at-a-time technique. The results showed that the immobilised cells could tolerate a broader range of heavy metal concentrations and produced higher keratinase activity at a gellan gum concentration of 0.8% (w/v), a bead size of 3 mm, bead number of 250, pH of 8 and temperature of 30 °C. The entrapped bacterium was used repeatedly for ten cycles to produce keratinase using feathers polluted with 25 ppm of Co, Cu and Ag as substrates without the need for desorption. However, its inability to tolerate/utilise feathers polluted with Hg, Pb, and Zn above 5 ppm, and Ag and Cd above 10 ppm resulted in a considerable decrease in keratinase production. Furthermore, the immobilised cells could retain approximately 95% of their keratinase production capacity when 5 ppm of Co, Cu, and Ag, and 10 ppm of As and Cd were used to pollute feathers. When the feathers containing a mixture of Ag, Co, and Cu at 25 ppm each and Hg, Ni, Pb, and Zn at 5 ppm each were used as substrates, the immobilised cells maintained their operational stability and biological activity (keratinase production) at the end of 3rd and 4th cycles, respectively. The study indicates that HMPF can be effectively utilised as a substrate by the immobilised-cell system of Alcaligenes sp. AQ05-001 for the semi-continuous production of keratinase enzyme.
The aim of this work is to study the effect of hydrocolloids (guar gum, xanthan gum and carboxymethyl cellulose (CMC) on the physical properties and sensory evaluation of ice cream produced in order to investigate the potential of applying fermented glutinous rice (tapai pulut) as a value-added ingredient. The addition of 25% fermented glutinous rice was the most reliable amount to enhance the physical and sensory properties of ice cream when incorporating hydrocolloids. The addition of hydrocolloids significantly (p < 0.05) increased the pH, firmness, overrun, and melting rate of fermented glutinous rice ice cream. The addition of guar gum scored the highest firmness value (5403 g) followed by CMC (4630 g) and xanthan gum (3481g). Fermented glutinous rice ice cream with xanthan gum added, induced a noticeable change in overrun value (62%) while the addition of CMC decreased the melting rate compared to the control. The FTIR spectrum of fermented glutinous rice ice cream with different hydrocolloids containing carboxyl, amide and carbonyl group was appeared at 3362-3379 cm-1 , 1639-1640 cm-1 and 1026-1064 cm-1, respectively. In conclusion, the addition of xanthan gum presented great potential to improve the quality of fermented glutinous rice ice cream produced in terms of its firmness, overrun and melting rate.
The aim of this work is to study the effect of hydrocolloids; guar gum (GG), xanthan gum (XG) and carboxymethyl cellulose (CMC) on the physicochemical properties, microbiological quality and sensory properties in order to investigate the potential of applying fermented cassava (tapai ubi) in ice cream. Fermented cassava ice cream (FCI) incorporated with the three types of hydrocolloid was prepared and the protein content, pH value, overrun, colour, hardness, microstructure, FTIR spectrum and sensory acceptance of all samples were determined. Fermented cassava ice cream incorporated with XG showed the highest protein content (14.88%), pH value (pH 6.07), and overrun value (4.27%) as compared to the fermented cassava ice cream incorporated with GG and CMC. Meanwhile, ice cream incorporated with GG possessed the highest L* (94.43) and hardness (3693.15 g) value as compared to XG and CMC. The microstructure study showed that the difference in uniformity at the interface obtained with different types of the hydrocolloids added demonstrated the effect of fat absorption at the air interfaces. The FTIR spectrum investigated indicated that the addition of the fermented cassava to FCI had increased the OH group in the ice cream as compared to the control. All samples were microbial safe as the total plate counts in all samples were below the standard as prescribed in Food Act 1983 with no presence of E. coli . In conclusion, fermented cassava ice cream with XG showed the good quality in terms of its pH value, overrun, total plate count and overall acceptability.
Dough mixing and thermal properties including the pasting profiles of various commercial wheat flour (WF)-banana pseudostem flour (BP)-hydrocolloid blends were determined using a farinograph, differential scanning calorimetry (DSC) and a rapid-visco analyser (RVA). The prepared blends were WF, WF substituted with 10% BP (10BP) and 10BP with added 0.8% w/w (flour weight basis) xanthan gum (XG) or sodium carboxymethylcellulose (CMC) (10BPX and 10BPC, respectively). The dough of 10BP and the doughs containing XG or CMC reduced stability and breakdown time compared with the WF dough. All dough containing BP demonstrated greater water absorption and mixing tolerance index values than the WF dough. The substitution of 10% BP into WF and the addition of hydrocolloids did not significantly affect the conclusion temperature (Tc) of the mixture, but did increased the onset temperature (To), peak temperature (Tp) and decreased the gelatinisation enthalpy change (ΔHg) of the blends. Samples of 10BP, 10BPX and 10BPC significantly decreased (p
Klebsiella pneumoniae is a pathogen associated with various infection types, which often exhibits multiple antibiotic resistance. Phages, or bacterial viruses, have an ability to specifically target and destroy K. pneumoniae, offering a potential means of combatting multidrug-resistant infections. Phage enzymes are another promising therapeutic agent that can break down bacterial capsular polysaccharide, which shields K. pneumoniae from the immune response and external factors. In this study, Klebsiella phage K5 was isolated; this phage is active against Klebsiella pneumoniae with the capsular type K21. It was demonstrated that the phage can effectively lyse the host culture. The adsorption apparatus of the phage has revealed two receptor-binding proteins (RBPs) with predicted polysaccharide depolymerising activity. A recombinant form of both RBPs was obtained and experiments showed that one of them depolymerised the capsular polysaccharide K21. The structure of this polysaccharide and its degradation fragments were analysed. The second receptor-binding protein showed no activity on capsular polysaccharide of any of the 31 capsule types tested, so the substrate for this enzyme remains to be determined in the future. Klebsiella phage K5 may be considered a useful agent against Klebsiella infections.
Impacts and relationships on physicochemical properties in dark chocolate produced from different substitution for cocoa butter by Xanthan gum (XG) and Guar gum (GG) blends were determined using D-optimal mixture design. This study involved three levels of substitution which are 5%, 10% and 15% with constrained cocoa butter content and random blend of gums. Linear design models were applied to analyze parameters including texture (hardness) measurement and melting profile of fat crystal. Products experienced undesirable raises of hardness jointly with the increment of gums incorporation across the level of cocoa butter replacement from 5% to 15%. Similar trend was also agreed with the melting behavior of products as their melting point increased with the gradual diminution of cocoa butter. After all, the replacement of cocoa butter using hydrocolloids was deemed possible as there were products whose melting point and hardness fell in the acceptable range.
The vulnerability of probiotics at low pH and high temperature has limited their optimal use as nutraceuticals. This study addressed these issues by adopting a physicochemical driven approach of incorporating Lactobacillus plantarum LAB12 into chitosan (Ch) coated alginate-xanthan gum (Alg-XG) beads. Characterisation of Alg-XG-Ch, which elicited little effect on bead size and polydispersity, demonstrated good miscibility with improved bead surface smoothness and L. plantarum LAB12 entrapment when compared to Alg, Alg-Ch and Alg-XG. Sequential incubation of Alg-XG-Ch in simulated gastric juice and intestinal fluid yielded high survival rate of L. plantarum LAB12 (95%) at pH 1.8 which in turn facilitated sufficient release of probiotics (>7 log CFU/g) at pH 6.8 in both time- and pH-dependent manner. Whilst minimising viability loss at 75 and 90 °C, Alg-XG-Ch improved storage durability of L. plantarum LAB12 at 4 °C. The present results implied the possible use of L. plantarum LAB12 incorporated in Alg-XG-Ch as new functional food ingredient with health claims.