Natural dyes and pigments are emerged as an important alternative to potentially harmful syntheti... more Natural dyes and pigments are emerged as an important alternative to potentially harmful synthetic dyes. There is a growing demand for eco-friendly/non-toxic colourants specifically for textile dyeing because of its sustainability, green chemistry and improved eco-balances. The present study aimed to evaluate the dyeing potential of violet pigment from
Liquid pineapple waste, a novel nutritious low cost growth medium. Crude violet pigment shows bio... more Liquid pineapple waste, a novel nutritious low cost growth medium. Crude violet pigment shows bioactivity. This is the first report on the production of violet pigment using liquid pineapple waste medium.
Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has... more Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has been reported to have antimircobial activity. In the present study, antibacterial efficacy of leaf and fruit extracts on the growth and morphology of Staphylococcus aureus is evaluated. Both extracts display good antibacterial activity against S. aureus with a minimum inhibition concentration of 0.048 mg/mL. Both extracts are bacteriostatic at a minimum bacteriostatic concentration of 0.39 mg/mL. The bacteriostatic activity lasts for 24 h, and then cells start to grow as normal as shown in time-kill analysis. Scanning electron microscopy study indicated potential detrimental effect of the extracts of leaf and fruits of M. ferrea on the morphology of S. aureus. The treatment with the extracts caused extensive lysis of the cells, leakage of intracellular constituents, and aggregation of cytoplasmic contents forming an open meshwork of the matrix.
In this work we directed our inquiries to develop a stable flexirubin powder and to evaluate its ... more In this work we directed our inquiries to develop a stable flexirubin powder and to evaluate its properties and antioxidant activity. Flexirubin powders were produced by spray drying using two types of carrier agents: gum arabic (GA) and қ-carrageenan (KC) at different inlet air temperatures (140e220 C). The effect of encapsulation yield, moisture content, hygroscopicity, bulk density, solubility, particle morphology, storage stability and antioxidant activities were determined for both carrier agents. Encapsulation yield, moisture content and bulk densities were greatly influenced by the drying inlet air temperature. The stability test revealed that microencapsulation offered greater protection to flexirubin compared to its free form. Antioxidant activity is higher for microcapsules (687.5 g/kg wet basis) and the boosted properties of microcapsules with high colour stability indicate that this product, which currently has no commercial value, may be used as a natural pigment.
Ixora coccinea L. (Rubiaceae) has been used traditionally for a variety of ailments and also cult... more Ixora coccinea L. (Rubiaceae) has been used traditionally for a variety of ailments and also cultivated for ornamental purposes. The present study investigated antimicrobial activity of methanolic extracts of various parts of I. coccinea and determined the chemical groups of the active constituents. Antimicrobial activity was assessed using agar disc diffusion, microdilution and thin layer chromatography (TLC) bioautography assays. Methanolic extracts of leaf, flower and stem of I. coccinea displayed good antimicrobial activity, with inhibition zone in the range of 6.7 to 11.3 mm. minimum inhibitory concentration (MIC) values for all three extracts ranged from 0.78 to 3.125 mg/ml. Leaf and stem extracts of I. coccinea showed broad-spectrum antimicrobial activity. Of interest, stem extracts had MIC values against Staphylococcus aureus that were only 62.4 times less potent than the vancomycin. Likewise, leaf and stem extracts displayed good antimicrobial activity of 62.4 and 31.2 times, respectively lesser than gentamycin against Shigella flexneri. Minimum bactericidal/ bacteriostatic concentration (MBC) values for active extracts ranged from 0.78 to 6.25 mg/ml. TLC bioautography and phytochemical screening of the leaf and stem extracts showed that the antimicrobial activity of these extracts may be attributed to compounds belonging to terpenoid, flavonoid, coumarin, alkaloid and phenolic groups.
Bacterial pigments showed potential in various applications but the pigment production is limited... more Bacterial pigments showed potential in various applications but the pigment production is limited due to high cost. This study reports on the optimization of yellowish-orange pigment production by Chrys-eobacterium artocarpi CECT 8497 in liquid pineapple waste medium using response surface methodology (RSM). Culture conditions affecting pigment production were optimized statistically in shake flask experiments. Liquid pineapple waste (LPW), L-tryptophan and potassium phosphate (KH 2 PO 4) were the most significant variables affecting pigment production. Central composite design (CCD) and RSM analysis were adopted to investigate the interactions between variables and determine the optimal values for maximum pigment production. Evaluation of the experimental results signified that the optimum conditions for maximum production of pigment (152 mg l À1) in shake flasks were LPW 20% (v/v), L-tryptophan 125 g l 1 and KH 2 PO 4 12.5 g l À1. Production under optimized conditions is 3-folds higher than its production in nutrient broth. High pigment production was observed in 5 l (540 ± 14 mg l À1) and 50 l (200 ± 28 mg l À1) bioreactor under these optimized conditions. Two compounds from yellowish-orange pigment extracted from LPW were isolated and characterized using chromatography, ESI-MS and ATR techniques. Results showed that statistical optimization of medium composition influenced the yellowish-orange pigment production from C. artocarpi CECT 8497. The pigment was incorporated as natural colorant in soap making. Also, this is the first report optimizing the process parameters for yellowish-orange pigment production from C. artocarpi CECT 8497 in liquid pineapple waste.
Synthetic pigments have been utilized in numerous industries including textile, cosmetic, food an... more Synthetic pigments have been utilized in numerous industries including textile, cosmetic, food and pharmaceuticals. However, the drawbacks of these pigments, namely toxicity problems have kindled interest in natural pigments. In view of this, the use of natural pigments such as those from a bacterial origin offers an interesting alternative for industrial application. However, large scale applications of natural pigments are often hindered by the high production cost. This study evaluates the feasibility of using liquid pineapple waste for the production of violacein by a locally isolated Chromobacterium violaceum UTM5 both in a shake flask and a 50 L bioreactor. The use of optimized growth parameters including culture conditions, concentration of liquid pineapple waste and supplementation of L-tryptophan resulted in a violacein yield of 16 256 AE 440 mg L À1. Post treatment of the effluent effectively reduced the COD, turbidity and TSS contents to less than 1 mg L À1 , 1.57 AE 0.2 NTU and 2.7 AE 0.6 mg L À1 respectively. The violet pigment exhibited good stability during the entire storage period of 30 days at pH 7, temperature 25–30 C and under dark conditions. The violet pigment has a good antimicrobial activity against selected microorganisms. Of interest, the pigment was active against Staphylococcus aureus ATCC 29213 and methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 with a MIC value of 7.8 and 15.6 mg mL À1 , respectively. However, the pigment is toxic to the V79-4 Chinese hamster lung cells with low selectivity index. The purified compounds were determined as violacein and deoxyviolacein respectively using FT-IR, LC-MS and NMR. The results confirmed the feasibility of using liquid pineapple waste as a potential low cost growth medium for the large-scale cultivation of violet pigment using C. violaceum UTM5.
Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has... more Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has been reported to have antimircobial activity. In the present study, antibacterial efficacy of leaf and fruit extracts on the growth and morphology of Staphylococcus aureus is evaluated. Both extracts display good antibacterial activity against S. aureus with a minimum inhibition concentration of 0.048 mg/mL. Both extracts are bacteriostatic at a minimum bacteriostatic concentration of 0.39 mg/mL. The bacteriostatic activity lasts for 24 h, and then cells start to grow as normal as shown in time-kill analysis. Scanning electron microscopy study indicated potential detrimental effect of the extracts of leaf and fruits of M. ferrea on the morphology of S. aureus. The treatment with the extracts caused extensive lysis of the cells, leakage of intracellular constituents, and aggregation of cytoplasmic contents forming an open meshwork of the matrix.
Natural dyes and pigments are emerged as an important alternative to potentially harmful syntheti... more Natural dyes and pigments are emerged as an important alternative to potentially harmful synthetic dyes. There is a growing demand for eco-friendly/non-toxic colourants specifically for textile dyeing because of its sustainability, green chemistry and improved eco-balances. The present study aimed to evaluate the dyeing potential of violet pigment from
Liquid pineapple waste, a novel nutritious low cost growth medium. Crude violet pigment shows bio... more Liquid pineapple waste, a novel nutritious low cost growth medium. Crude violet pigment shows bioactivity. This is the first report on the production of violet pigment using liquid pineapple waste medium.
Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has... more Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has been reported to have antimircobial activity. In the present study, antibacterial efficacy of leaf and fruit extracts on the growth and morphology of Staphylococcus aureus is evaluated. Both extracts display good antibacterial activity against S. aureus with a minimum inhibition concentration of 0.048 mg/mL. Both extracts are bacteriostatic at a minimum bacteriostatic concentration of 0.39 mg/mL. The bacteriostatic activity lasts for 24 h, and then cells start to grow as normal as shown in time-kill analysis. Scanning electron microscopy study indicated potential detrimental effect of the extracts of leaf and fruits of M. ferrea on the morphology of S. aureus. The treatment with the extracts caused extensive lysis of the cells, leakage of intracellular constituents, and aggregation of cytoplasmic contents forming an open meshwork of the matrix.
In this work we directed our inquiries to develop a stable flexirubin powder and to evaluate its ... more In this work we directed our inquiries to develop a stable flexirubin powder and to evaluate its properties and antioxidant activity. Flexirubin powders were produced by spray drying using two types of carrier agents: gum arabic (GA) and қ-carrageenan (KC) at different inlet air temperatures (140e220 C). The effect of encapsulation yield, moisture content, hygroscopicity, bulk density, solubility, particle morphology, storage stability and antioxidant activities were determined for both carrier agents. Encapsulation yield, moisture content and bulk densities were greatly influenced by the drying inlet air temperature. The stability test revealed that microencapsulation offered greater protection to flexirubin compared to its free form. Antioxidant activity is higher for microcapsules (687.5 g/kg wet basis) and the boosted properties of microcapsules with high colour stability indicate that this product, which currently has no commercial value, may be used as a natural pigment.
Ixora coccinea L. (Rubiaceae) has been used traditionally for a variety of ailments and also cult... more Ixora coccinea L. (Rubiaceae) has been used traditionally for a variety of ailments and also cultivated for ornamental purposes. The present study investigated antimicrobial activity of methanolic extracts of various parts of I. coccinea and determined the chemical groups of the active constituents. Antimicrobial activity was assessed using agar disc diffusion, microdilution and thin layer chromatography (TLC) bioautography assays. Methanolic extracts of leaf, flower and stem of I. coccinea displayed good antimicrobial activity, with inhibition zone in the range of 6.7 to 11.3 mm. minimum inhibitory concentration (MIC) values for all three extracts ranged from 0.78 to 3.125 mg/ml. Leaf and stem extracts of I. coccinea showed broad-spectrum antimicrobial activity. Of interest, stem extracts had MIC values against Staphylococcus aureus that were only 62.4 times less potent than the vancomycin. Likewise, leaf and stem extracts displayed good antimicrobial activity of 62.4 and 31.2 times, respectively lesser than gentamycin against Shigella flexneri. Minimum bactericidal/ bacteriostatic concentration (MBC) values for active extracts ranged from 0.78 to 6.25 mg/ml. TLC bioautography and phytochemical screening of the leaf and stem extracts showed that the antimicrobial activity of these extracts may be attributed to compounds belonging to terpenoid, flavonoid, coumarin, alkaloid and phenolic groups.
Bacterial pigments showed potential in various applications but the pigment production is limited... more Bacterial pigments showed potential in various applications but the pigment production is limited due to high cost. This study reports on the optimization of yellowish-orange pigment production by Chrys-eobacterium artocarpi CECT 8497 in liquid pineapple waste medium using response surface methodology (RSM). Culture conditions affecting pigment production were optimized statistically in shake flask experiments. Liquid pineapple waste (LPW), L-tryptophan and potassium phosphate (KH 2 PO 4) were the most significant variables affecting pigment production. Central composite design (CCD) and RSM analysis were adopted to investigate the interactions between variables and determine the optimal values for maximum pigment production. Evaluation of the experimental results signified that the optimum conditions for maximum production of pigment (152 mg l À1) in shake flasks were LPW 20% (v/v), L-tryptophan 125 g l 1 and KH 2 PO 4 12.5 g l À1. Production under optimized conditions is 3-folds higher than its production in nutrient broth. High pigment production was observed in 5 l (540 ± 14 mg l À1) and 50 l (200 ± 28 mg l À1) bioreactor under these optimized conditions. Two compounds from yellowish-orange pigment extracted from LPW were isolated and characterized using chromatography, ESI-MS and ATR techniques. Results showed that statistical optimization of medium composition influenced the yellowish-orange pigment production from C. artocarpi CECT 8497. The pigment was incorporated as natural colorant in soap making. Also, this is the first report optimizing the process parameters for yellowish-orange pigment production from C. artocarpi CECT 8497 in liquid pineapple waste.
Synthetic pigments have been utilized in numerous industries including textile, cosmetic, food an... more Synthetic pigments have been utilized in numerous industries including textile, cosmetic, food and pharmaceuticals. However, the drawbacks of these pigments, namely toxicity problems have kindled interest in natural pigments. In view of this, the use of natural pigments such as those from a bacterial origin offers an interesting alternative for industrial application. However, large scale applications of natural pigments are often hindered by the high production cost. This study evaluates the feasibility of using liquid pineapple waste for the production of violacein by a locally isolated Chromobacterium violaceum UTM5 both in a shake flask and a 50 L bioreactor. The use of optimized growth parameters including culture conditions, concentration of liquid pineapple waste and supplementation of L-tryptophan resulted in a violacein yield of 16 256 AE 440 mg L À1. Post treatment of the effluent effectively reduced the COD, turbidity and TSS contents to less than 1 mg L À1 , 1.57 AE 0.2 NTU and 2.7 AE 0.6 mg L À1 respectively. The violet pigment exhibited good stability during the entire storage period of 30 days at pH 7, temperature 25–30 C and under dark conditions. The violet pigment has a good antimicrobial activity against selected microorganisms. Of interest, the pigment was active against Staphylococcus aureus ATCC 29213 and methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 with a MIC value of 7.8 and 15.6 mg mL À1 , respectively. However, the pigment is toxic to the V79-4 Chinese hamster lung cells with low selectivity index. The purified compounds were determined as violacein and deoxyviolacein respectively using FT-IR, LC-MS and NMR. The results confirmed the feasibility of using liquid pineapple waste as a potential low cost growth medium for the large-scale cultivation of violet pigment using C. violaceum UTM5.
Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has... more Mesua ferrea is traditionally used for treating bleeding piles, fever, and renal diseases. It has been reported to have antimircobial activity. In the present study, antibacterial efficacy of leaf and fruit extracts on the growth and morphology of Staphylococcus aureus is evaluated. Both extracts display good antibacterial activity against S. aureus with a minimum inhibition concentration of 0.048 mg/mL. Both extracts are bacteriostatic at a minimum bacteriostatic concentration of 0.39 mg/mL. The bacteriostatic activity lasts for 24 h, and then cells start to grow as normal as shown in time-kill analysis. Scanning electron microscopy study indicated potential detrimental effect of the extracts of leaf and fruits of M. ferrea on the morphology of S. aureus. The treatment with the extracts caused extensive lysis of the cells, leakage of intracellular constituents, and aggregation of cytoplasmic contents forming an open meshwork of the matrix.
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