Enzymatic removal of flatulence-inducing sugars in chickpea milk using free and polyvinyl alcohol immobilized α-galactosidase from <Emphasis Type="Italic">Aspergillus oryzae</Emphasis>

The treatment of chickpea milk was carried out in batch, repeated batch and continuous reaction by soluble and polyvinyl alcohol (PVA) immobilized Aspergillus oryzae alpha-galactosidase for the removal of raffinose family oligosaccharides (RFOs). In the batch mode of treatment 96 and 92% of RFOs hydrolysis was observed by soluble and immobilized enzyme, respectively. In repeated batch experiments, immobilized enzyme showed 70% RFOs hydrolysis up to sixth cycle. Polyvinyl alcohol immobilized alpha-galactosidase in fluidized bed reactor showed highest reduction of 94% at a flow rate of 30 ml/h. The results obtained from the present study are very interesting for industrial use of PVA-immobilized enzyme.     

Immobilization of <Emphasis Type="Italic">Aspergillus oryzae</Emphasis> α-galactosidase in gelatin and its application in removal of flatulence-inducing sugars in soymilk

Raffinose oligosaccharides (RO) are the major factors responsible for flatulence following ingestion of soybean-derived products. Removal of RO from seeds or soymilk would then have a positive impact on the acceptance of soy-based foods. In this study, α-galactosidase from Aspergillus oryzae was entrapped in gelatin using formaldehyde as the hardener. The immobilization yield was 64.3% under the optimum conditions of immobilization. The immobilized α-galactosidase showed a shift in optimum pH from 4.8 to 5.4 in acetate buffer. The optimum temperature also shifted from 50°C to 57°C compared with soluble enzyme. Immobilized α-galactosidase was used in batch, repeated batch and continuous mode to degrade RO present in soymilk. In the repeated batch, 45% reduction of RO was obtained in the fourth cycle. The performance of immobilized α-galactosidase was tested in a fluidized bed reactor at different flow rates and 86% reduction of RO in soymilk was obtained at 25 ml h⁻¹ flow rate. The study revealed that immobilized α-galactosidase in continuous mode is efficient in reduction of RO present in soymilk.     

Hydrolysis of Galacto-oligosaccharides in Soymilk by κ-carrageenan-entrapped α-galactosidase from Aspergillus Oryzae

Summary α-Galactosidase was immobilized in κ-carrageenan. The optimum pH of the soluble enzyme and immobilized enzyme was 4.8. The optimum temperature of the soluble enzyme was 50 °C and that of the immobilized enzyme was increased to 53 °C. The immobilized enzyme was used in batch, repeated batch, and in the continuous mode to degrade the raffinose family sugars present in soymilk. Two hours incubation with free and immobilized α-galactosidase resulted in 88 and 75% reduction in raffinose family oligosaccharides in soymilk respectively. In the repeated batch, 61% reduction was obtained in the fourth cycle. A fluidized bed reactor was designed to treat soymilk continuously. The performance of immobilized α-galactosidase was also tested in a fluidized bed reactor at different flow rates and 92% reduction of raffinose family oligosaccharides in soymilk was obtained at 25 ml h⁻¹ flow rate. The study revealed that immobilized α-galactosidase in continuous mode is efficient in reducing the oligosaccharides present in the soymilk.     

Isolation and identification of alpha-amylase producing Bacillus sp. from dhal industry waste

A bacterial strain was isolated from dhal industry red gram waste and identified as Bacillus. A thermostable extracellular amylase was partially purified from the strain. Optimum temperature and pH for the enzyme were found to be 60 degrees C and 6.5, respectively. The maximum amylase production was achieved with maltose as carbon source. Among the nitrogen sources, peptone and yeast extract produced maximum amylase.     

<Emphasis Type="Italic">In vivo</Emphasis> assessment of the impedance ratio method used in electronic foramen locators

Background  

The results of an in vivo study on the "ratio method" used in electronic foramen locators (EFL) are presented. EFLs are becoming widely used in the determination of the working length (WL) during the root canal treatment. The WL is the distance from a coronal reference point to the point at which canal preparation and filling should terminate. The "ratio method" was assessed by many clinicians with the aim of determining its ability to locate the apical foramen (AF). Nevertheless, in vivo studies to assess the method itself and to explain why the "ratio method" is able to locate the apical foramen and is unable to determine intermediate distances were not published so far.     

Interaction and energy transfer studies between bovine serum albumin and CdTe quantum dots conjugates: CdTe QDs as energy acceptor probes

In this paper, a systematic investigation of the interaction of bovine serum albumin (BSA) with water‐soluble CdTe quantum dots (QDs) of two different sizes capped with carboxylic thiols is presented based on steady‐state and time‐resolved fluorescence measurements. Efficient Förster resonance energy transfer (FRET) was observed to occur from BSA donor to CdTe acceptor as noted from reduction in the fluorescence of BSA and enhanced fluorescence from CdTe QDs. FRET parameters such as Förster distance, spectral overlap integral, FRET rate constant and efficiency were determined. The quenching of BSA fluorescence in aqueous solution observed in the presence of CdTe QDs infers that fluorescence resonance energy transfer is primarily responsible for the quenching phenomenon. Bimolecular quenching constant (k_q) determined at different temperatures and the time‐resolved fluorescence data provide additional evidence for this. The binding stoichiometry and various thermodynamic parameters are evaluated by using the van ‘t Hoff equation. The analysis of the results suggests that the interaction between BSA and CdTe QDs is entropy driven and hydrophobic forces play a key role in the interaction. Binding of QDs significantly shortened the fluorescence lifetime of BSA which is one of the hallmarks of FRET. The effect of size of the QDs on the FRET parameters are discussed in the light of FRET parameters obtained.     

Salicylic acid and salicylic acid sensitive and insensitive catalases in different genotypes of chickpea against Fusarium oxysporum f. sp. ciceri

Differential expression of catalase isozymes in different genotypes of chickpea resistant genotypes- A1, JG-315, JG-11, WR-315, R₁-315, Vijaya, ICCV-15017, GBS-964, GBM-10, and susceptible genotypes- JG-62, MNK, ICCV-08321, ICCV-08311, KW-104, ICCV-08123, ICC-4951, ICC-11322, ICC-08116 for wilt disease caused by Fusarium oxysporum. f. sp. ciceri (Foc) was analyzed. Salicylic acid (SA) and H₂O₂ concentrations were determined in control as well as in plants infected with F. ciceri and found that the high and low levels of salicylic acid and H₂O₂ in resistant and susceptible genotypes of chickpea respectively. Catalase isozyme activities were detected in the gel and found that no induction of new catalases was observed in all the resistant genotypes and their some of the native catalase isozymes were inhibited; whereas, induction of multiple catalase isozymes was observed in all the screened susceptible genotypes and their activities were not inhibited upon Foc or SA treatments. The above results support the possible role of these isozymes as a marker to identify which genotype of chickpea is expressing systemic acquired resistance.     

Circular dichrotic probes for aspects of chromatin structure: aromatic polycationic ionen probes

Two ionens (II and X) formed complexes with DNA and chromatin with extrinsic CD bands and reduced intrinsic bands. The salt and urea sensitive, AT-specific probe (II) gave Δε > 100 L-(residue II)^?1-cm^?1 with DNA and Δε=0–14 with chromatin; II reduced the intrinsic bands from Δε≈0.7 to Δε≈0.5. Ionen X gave Δε₃₄₅=30 with DNA, and Δε₃₄₅=15–20 with chromatin. X reduced the intrinsic band to ?1.6. X show less base specificity. Extrinsic Δε_λ of X increased linearly to r (residue/phosphate) = 0.5 for DNA and only 0.3 in chromatin. DNA in chromatin may have ～10% of the II and 50–60% of the X binding sites and those in an altered conformation.