Biochemical substitution of fungal xylanases for prebleaching of hardwood kraft pulp

Xylanase enzymes of three fungi, Aspergillus indicus, A. flavus and A. niveus, were purified and characterized. The enzymes are used in the pretreatment of Hardwood kraft pulp prior to conventional alkali extraction and conventional chlorine extraction sequence (EDED process) normally used forbleaching of pulp. In the enzyme pretreated pulp when subjected to alkali extraction process the kappa number was reduced to a maximum of 5.0, 6.2 and 6.8 from 18.60 and the brightness was increased to a maximum of 43.12, 42.20 and 45.19 ISO units, respectively, from 19.83 by xylanases of A. indicus, A. flavus and A. niveus. Whereas, in the enzyme pretreated pulp, when subjected to EDED process, the maximum reduction in kappa number of 6.7, 7.2 and 7.1 and a maximum increase in brightness of 41.28, 41.06 and 41.07 ISO units, respectively, were observed in case of A. indicus, A. flavus and A. niveu

Antibacterial Activity of \u3cem\u3ePunica granatum\u3c/em\u3e L. Against Gastro Intestinal Tract Infection Causing Organisms

The pericarp of Punica granatum Linn. has been commonly employed as a crude drug in Indian traditional medicine for the treatment of diarrhoea as well as for use as an astringent, antihelminthic, asphrodisacs, laxative, diuretic, stomachic, cardiotonic and refrigerant. Antibacterial activity of P. granatum pericarp extracts was evaluated against ten Gastro Intestinal Tract (GIT) infection causing bacterial strains using paper disc agar diffusion method. The result indicated that the extracts obtained from P. granatum pericarp exhibited antimicrobial activity against all organisms except the crude extract used against Pseudomonas aeruginosa. The methanol extract has exhibited maximum antibacterial activity against Salmonella typhimurium, Salmonella typhi and Shigella dysenteriae Serotype 1. Methanol extract shows significant activity against tested bacterial strains when compared to other extracts used in the study. Our findings suggest that an appropriate bioactive compound(s) may be developed from P. granatum pericarp as complementary alternative medicine for the treatment of GIT infection causing bacterial strains

Optimised production of L-glutaminase: A tumour inhibitor from Aspergillus flavus cultured on agroindustrial residues

L-Glutaminase, an amidohydrolase enzyme has been a choice of interest in the treatment of lymphoblastic leukemia. This study investigates the production and optimization of extracellular glutaminase enzyme using several agro-industrial residues by Aspergillus flavus KUGF009 using SSF (solid state fermentation). Effect of process variables namely substrates, incubation period, temperature, moisture content, initial pH, supplementary carbon and nitrogen sources and metal ions on the production of L-glutaminase was studied and accordingly, optimum conditions were determined. A. flavus KUGF009 was cultured in tea dust to produce L-glutaminase. The organism produced high levels of glutaminase under optimized culture conditions on the 5th day of incubation at an optimum pH 4.0, temperature 30°C and moisture content 50% by SSF. Enhanced production occurred on the addition of dextrose, yeast extract and MgSO4 as nutritional factors.Key words: L-Glutaminase, anti-leukemic agent, Aspergillus flavus, solid state fermentation

Phytochemical screening and antibacterial evaluation of stem bark of Mallotus philippinensis var. Tomentosus

Mallotus philippinensis var. Tomentosus is a medicinal plant, which was tested against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi and Bacillus subtilis. Phytochemicalscreening of the stem bark of M. philippinensis indicates the presence of secondary metabolites. From the results obtained, eluted fractions of chloroform and methanolic extracts showed excellent zone of inhibition comparable to the standard drug used. However, the hexane extract did not show any appreciable activity. The results of the study showed the justification of the use of the plant against the bacterial pathogens

Association Behavior of Poly(methacrylic acid)-block-Poly(methyl methacrylate) in Aqueous Medium: Potentiometric and Laser Light Scattering Studies

Atom transfer radical polymerisation (ATRP) technique was used to synthesize poly(methacrylic acid-block-methyl methacrylate) (P(MAA₁₀₂-b-MMA₁₀)) copolymer in order to study the aggregation behavior in aqueous solution over the course of neutralization. A combination of static and dynamic light scattering (SLS, DLS) and potentiometric titration techniques were used to investigate the size and shape of the micelle at various degrees of neutralization. The hydrodynamic radius (Rh) determined from dynamic light scattering increases from ~26nm (for unneutralized) to ~42nm (for completely neutralized sample). Both potentiometric and laser light scattering studies indicate the formation of a core shell micelle. The weighted average molecular weights of the polymer and micelle are 1.18x10⁴ and 2.25 x 10⁵ g/mol respectively, which suggests that the aggregation number of the micelle is ~20.Singapore-MIT Alliance (SMA

Association Behavior of Poly (methyl methacrylate-b-methacrylic acid-b-methyl methacrylate) in Aqueous Medium

ABA type tri-block amphiphilic polyelectrolyte consisting of poly(methyl methacrylate-block-methacrylic acid-block-methyl methacrylate) (P(MMA-b-MAA-b-MMA)) was synthesized by atom transfer radical polymerization technique (ATRP) and the self-assembly behavior of the polymers in aqueous solution was studied over the course of neutralization. Combination of potentiometric and conductometric titrations along with dynamic light scattering (DLS) techniques were used to investigate the size and shape of aggregates at various degrees of neutralization. The effect of hydrophobic-hydrophilic (MMA-MAA) ratio and polymer chain length on the aggregation behavior during neutralization was studied. P(MMA-b-MAA-b-MMA) with longer MMA segment self-assembles via the close association mechanism through stronger self-entanglement of MMA chains, whereas P(MMA-b-MAA-b-MMA) with shorter MMA chain self-assembles via the open association mechanism, as confirmed by transmission electron microscopy (TEM). Conductometric titration was used to determine the counterion condensation during the course of neutralization. When the charge density of micelle approaches a critical value as neutralization progresses, counterion condensation of Na+ ions on the polymer chains occurs. The effect of counterion condensation on the aggregation behavior during neutralization was elucidated.Singapore-MIT Alliance (SMA

Novel pH Responsive Amphiphilic Diblock Copolymers with Reversible Micellization Properties

Di-block copolymer of poly[methacrylic acid-block-2-(diethylamino)ethyl methacrylate] [P(MAA-b-DEA)] with narrow molecular weight distribution was synthesized using the atom transfer radical polymerization (ATRP) technique. The micellization behavior of the P(MAA-b-DEA) copolymer in aqueous solution at room temperature and different pH values were examined by potentiometric and conductivity titration, UV-Visible spectrophotometry, ¹H-NMR, static and dynamic laser light scattering. At low pH ( 9.5), core-shell like micelles consisting of hydrophobic DEA core and ionized MAA shell were re-established.Singapore-MIT Alliance (SMA

PRODUCTION AND PURIFICATION OF ANGIOTENSIN-CONVERTING ENZYME INHIBITOR BY SELECTED BACTERIAL STRAIN FOR CANCER THERAPY

Objective: The present study was planned to explore safer, innovative and economic Angiotensin-converting enzyme inhibitors (ACEi) from beef extract by the action of a proteolytic Micrococcus luteus. Cytotoxicity of the stable peptide was predicted using MCF-7 cell line in vitro.Methods: ACEi was purified by sequential steps of ethanol precipitation, ion exchange column chromatography (MonoQ) and gel filtration column chromatography (Sephadex G25). The apparent molecular mass was determined by SDS-PAGE. The anticancer property was analyzed by studying the cytotoxicity effects of angiotensin converting enzyme inhibitor using Breast cancer MCF-7 cell linesResults: The peptide was purified and molecular mass was determined as 4.5 kDa. The IC50 value of peptide was found to be 59.5 µg/ml. The DNA fragmentation was not observed in the treated cells. The purified peptide has demonstrated to induce apoptosis of cancer cell. The results proved that the peptide has the ability to be used for cancer therapy.Conclusion: The presence of ACE inhibition activities in the fermentation of beef extract using Micrococcus luteus has been investigated. The Peptide has been determined as an active compound that inhibited the activity of ACE. These properties indicate the possibilities of the use of purified protein as a potent anticancer agent.Keywords: Angiotensin-converting enzyme inhibitors, Micrococcus luteus, Anti-proliferative, Anti-metastatic, MCF-7 cell line, Anticancer activity

ISOLATION OF ANGIOTENSIN-CONVERTING ENZYME INHIBITOR PRODUCING BACTERIA FROM COW MILK

Objective: To evaluate the potential of protease producing organism for the production of Angiotensin I–converting enzyme (ACE) inhibitor by fermentation of various protein substrates.Methods: Bacterial strains were isolated from cow milk collected in Coimbatore, Tamil Nadu, India by using serial dilution technique, plated on nutrient agar medium. The identity of the strain was ascertained by 16s rRNA gene sequencing method and was submitted to the NCBI GenBank nucleotide database. Various substrates were screened for ACE inhibitor production by the fermentation with the isolated strain.Results: The isolated coded as BUCTL09, which showed a significant zone of clearance was selected and identified as Micrococcus luteus (KF303592.1). Among the seven substrates, only beef extract fermented broth showed an inhibition of 79% and was reported as the best substrate.Conclusion: In the search for non-toxic, and economic ACE inhibitors as an alternative to the synthetic drugs, many natural ACE inhibitors have been isolated from a microbial source. In the present study, isolate BUCTL09 was selected for the production of ACE inhibitor from the beef extract. Findings from this study lead us to investigate this potent ACE inhibitor further for its biological properties and to explore the impending efficacy of the ACE inhibitor which may conceivably be developed into a prospective drug

SCREENING AND PRODUCTION OF ANTICARCINOGENIC ENZYME FROM ESCHERICHIA COLI CTLS20: L - ASPARAGINASE

Objective: The objective of this study was attempted to screen the production of L-asparaginase from bacteria isolated from soil samples and its enzymatic activity.Methods: Screening of L-asparaginase was performed using phenol red indicator growth medium from which the positive strains were chosen based on the colour change. The enzyme production of L-asparaginase was established by submerged fermentation followed by the molecular detection of the efficient bacterial strains.Results: The enzyme production was undertaken by submerged fermentation with the evaluation of enzymatic activity and protein content. This revealed that the strain Escherichia coli CTLS20 produced a higher yield of L-asparaginase (30.22 IU/mg), 16.91 µg/ml of protein with the specific activity of 1.787 IU/mg when compared with other bacterial strains. The efficient bacterial strains were also confirmed by 16S rRNA sequence as Escherichia coli, Acinetobacter baumnnii, Klebsiella pneumoniae and the phylogenetic tree construction revealed the evolutionary relationship of the bacterial strains.Conclusion: This study indicated that the bacterial strain E. coli CTLS20 had the ability for the higher production of L-asparaginase. This novel higher yielding bacterial asparaginase is highly desirable as better alternatives in cancer therapy.Keywords: Soil, L-asparaginase, Submerged fermentation, E. coli, Phylogenetic tre