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A hexagonal mesoporous molecular sieve-like structure of MCM41 and SBA15 with a large surface area was used to immobilize protein L-ribose isomerase (L-RI) through covalent linkages. The amino group of APTES functionalized nanosilica support MCM41 and SBA15 interacted with glutaraldehyde to promote bidentate linkage and on other side with amino group of enzyme. The use of mesoporous silica matrix for immobilization was observed to conserve the distinctive properties of the protein. The various operational conditions optimized for covalent conjugation of protein with the silica support were found to be dependent on enzyme support ratio, immobilization temperature and time. The immobilization yield of L-RI on MCM41 and SBA15 was achieved to be 60 % (600 mg enzyme /g matrix) and 45 % (450 mg enzyme/g matrix), respectively under the optimized conditions. The immobilized biocatalyst was characterized by various analytical techniques like HR-TEM, EDS, FTIR, TGA and BET. Effects of different experimental conditions were optimized to study enzyme kinetics, pH, temperature, bioconversion, reusability, metal ion effect and storage stability. The biocatalytic efficiency (k

The present study aims to develop functional composite edible films using varied film formulations containing pectin (P), corn flour (CF), beetroot powder (BP), orange peel powder + sodium alginate (OPS), muesli root powder (MRP) and rice flour (RF) along with their structural, mechanical and functional characterization. Strong intermolecular attachment evolved between starch and pectin molecules due to hydrogen bonding of their hydrophilic groups, confirmed through scanning electron micrographs and FTIR spectra. Also, P-CF ratio (1:1) might retained some crystalline regions of starch which has significantly enhanced structural integrity and functionality of films in terms of tensile strength (TS), water solubility (WS), water vapour permeability (WVP) and thermal stability. In accordance with Herschel-Bulkley model, the predicted consistency index and flow behaviour values were affected by film formulation and the model was of good fit with R2 = 0.81 (PC3), R2 = 0.74 (PCB3) and R2 = 0.99 (for rest formulations). Although, higher proportions of hydrophilic polymers (P, OPS & BP) due to higher molecular mobility resulted in less rigid, highly soluble, moisture permeable and thermally unstable films. Furthermore, RF films possessed cracks over the surface and insoluble fractions due to insufficient starch gelatinization which decreased their TS and barrier properties. The ATR-FTIR spectra confirmed the presence of functional groups corresponding to starch and pectin in range of 500–4000 cm−1. The variation among different films underlies only in peak intensities due to some molecular changes. Overall, the films made of P-CF ratio (1:1) were more functional and structurally stable as compared to rest of the films, thus, they would make a better alternative for synthetic packaging.

The aim of the study was to develop a tomato-based beverage and to investigate the effect of thermal (pasteurization) and non-thermal (ultrasonication, ultra-violet (UV), atmospheric cold plasma (ACP)) processing on the quality of a tomato-based beverage. The ultrasonication and ACP processing for 10 min put significant effect on L* and a* color values of the tomato beverage. All the processing techniques applied degraded ascorbic acid but maximum retention (95%) of ascorbic acid was found in ACP processed beverage. Furthermore, ACP processing of 10 min also had significant (p ≥ 0.05) effect on bioactive compounds like chlorogenic acid, sinapic acid and gallic acid in comparison to thermal and other non-thermal processing. Moreover, ACP for 10 min and ultrasonication for 15 min was found equivalent to thermal processing in microbial reduction and ACP processing for 10 min was found equivalent to pasteurization in reduction of yeast and mold count. Both thermal and non-thermal processing had insignificant (p ≥ 0.05) effects on pH, TSS and sugars of developed beverage. In summary, ACP processing for 10 min has emerged as the best processing method for retaining as well as improving the quality of the developed beverage.

The biocatalysts are broadly explored in the biological transformation processes. The enzyme cascade catalysis involves various catalytic activities in a sequential process to produce the desired product including the formation of reaction intermediates. Enzyme immobilization is a method in which enzymes are confined within a support or matrix either physically or chemically to enhance their relative stability and catalytic activity in the enzyme cascade catalysis. In view of this, L-arabinose isomerase (L-AI) and L-ribose isomerase (L-RI) were immobilized on zeolite based metal framework as a micro-composite construct (DEMC@L-AI+L-RI) using linker, and metal ions. Such immobilization could be of great significance and provide several advantages like mesoporous surface for enzyme adsorption, desirable functionality in the production of products in enzyme cascade reaction, high storage stability and enhanced recyclability. The developed DEMC@L-AI+L-RI was characterized using SEM, FTIR, CLSM and TGA. The immobilization yield was 32% and loading of enzyme was 22% on the surface of micro-composite. The DEMC@L-AI+L-RI showed relatively stable catalytic activity at pH 5-6 and temperature 40 °C. The catalytic efficiency (k

The gene encoding protease from Acinetobacter sp. IHB B 5011(MN12) was cloned and expressed in Escherichia coli BL21(DE3). The nucleotide sequence revealed 1323bp ORF encoding 441 amino acids protein with molecular weight 47.2kDa. The phylogenetic analysis showed clustering of Alp protease with subtilisin-like serine proteases of S8 family. The amino acid sequence was comprised of N-terminal signal peptide 1-21 amino acids, pre-peptide 22-143 amino acids, peptidase S8 domain 144-434 amino acids, and pro-peptide 435-441 amino acids at C-terminus. Three constructs with signal peptide pET-Alp, without signal peptide pET-Alp1 and peptidase S8 domain pET-Alp2 were prepared for expression in E. coli BL21(DE3). The recombinant proteins Alp1 and Alp2 expressed as inclusion bodies showed ∼50kDa and ∼40kDa bands, respectively. The pre-propeptide ∼11kDa removed from Alp1 resulted in mature protein of ∼35kDa with 1738Umg-1 specific activity. The recombinant protease was optimally active at 40°C and pH 9, and stable over 10-70°C and 6-12pH. The activity at low-temperature and alkaline pH was supported by high R/(R+K) ratio, more glycine, less proline, negatively charged amino acids, less salt bridges and longer loops. These properties suggested the suitability of Alp as additive in the laundry.

Addition of low-methoxyl pectin (LMP) was observed to reduce whey loss, improve firmness, rheology, quality and overall liking of low-fat set-yoghurt. LMP addition increased soluble solids content and resulted in higher bacterial counts (≥10 log CFU/g), acidity, bioactivity (DPPH• & ABTS+ μM Trolox/g), and lower pH of set yoghurts. A significant (p

Pectin from black carrots pomace was extracted in hot acidic water (2.5 pH) using microwave (MW) at 110 °C/5 min, ultrasound (US) at 70 °C/30 min and conventional heating (CH) at 110 °C/90 min. CH showed highest yield (0.22 kg/kg pomace), followed by MW and US treatments. However, from kinetic modelling, MW extraction was found to exhibit the highest rate of extraction among the three approaches. Pectin extracted via CH resulted in maximum retention of anthocyanins (1213 mg/l), phenolics (1832 mg/l) and antioxidant activity (180 μM/ml). MW extraction resulted in pectin with a higher water holding capacity and larger particle size than US. Pectin from CH and MW also evinced higher DE and GalA than from US. FTIR, 1H NMR and XRD spectra confirmed the presence of characteristic functional groups in MW, CH and US pectin and these agreed with chemical analysis. Images from scanning electron microscopy revealed a cellular structure in dried pomace while the pectin powder has a particulate structure. In terms of thermal stability, CH and MW resulted in pectin with less residues indicating higher phenolic content as compared to pomace and US pectin. Overall, MW extraction was found to be most cost effective, followed by CH and finally, US. Therefore, it is concluded that MW processing integrated with CH could result in rapid extraction and higher yield of pectin without impacting its functionality.

This work deals with the development of an improved process for xylitol production from corn cob hydrolysate by biotechnological routes emphasizing the detoxification of corncob acid hydrolysate. The acid hydrolysate obtained by acid hydrolysis of corn cob was concentrated and detoxified by activated charcoal, membrane process and ion exchange resin process. The resultant partially purified corncob hydrolysate was used in fermentation. The fermentation of acid hydrolysate containing 56.5 g/L xylose was carried out in a 14 L fermenter at pH 4.5 for 48 h with 150 rpm stirring rate at 30 °C. A xylitol yield of 62% was achieved from the partially purified acid hydrolysate medium during fermentation using Candida tropicalis MTCC 6192. The purity of xylitol was increased to 92–94% upon downstream processing of carbonation, subsequently ion exchange process and activated charcoal.

Small RNAs (sRNAs) are 18-30 nt non-coding regulatory elements found in diverse organisms, which were initially identified as small double-stranded RNAs in Caenorhabditis elegans. With the development of new and improved technologies, sRNAs have also been identified and characterized in plant systems. Among them, micro RNAs (miRNAs) and small interfering RNAs (siRNAs) are found to be very important riboregulators in plants. Various types of sRNAs differ in their mode of biogenesis and in their function of gene regulation. sRNAs are involved in gene regulation at both transcriptional and post-transcriptional levels. They are known to regulate growth and development of plants. Furthermore, sRNAs especially plant miRNAs have been found to be involved in various stress responses, such as oxidative, mineral nutrient deficiency, dehydration, and even mechanical stimulus. Therefore, in the present review, we focus on the current understanding of biogenesis and regulatory mechanisms of plant sRNAs and their responses to various abiotic stresses.

Glyoxalase II, one of the enzymes of the glyoxalase pathway, cDNA cloned from rice (OsglyII) consists of 1623 nucleotides with an open reading frame of 1010 bp encoding a polypeptide of 336 amino acids and an estimated isoelectric point of 8.08. The recombinant protein purified from Escherichia coli using Ni-NTA affinity chromatography showed molecular mass of approximately 37 kDa. Catalytic parameters of the protein were determined using S-D-lactoylglutathione as a thioester substrate. The K(m) (61 microM) and K(cat) (301 s(-1)) values were lower than those reported for Arabidopsis, human and yeast and showed pH optima at 7.2. The E. coli overexpressing OsglyII were able to grow on higher concentration of methylglyoxal. Transcript analysis in rice showed that OsglyII gene expression is stimulated within 15 min in response to various abiotic stresses as well as treatment with abscisic acid or salicylic acid. This multistress response of OsglyII gene documents its future utility in developing tolerance to various stresses in crop plants.

Methylglyoxal (MG), a cytotoxic by-product produced mainly from triose phosphates, is used as a substrate by glyoxalase I. In this paper, we report on the estimation of MG level in plants which has not been reported earlier. We show that MG concentration varies in the range of 30-75 microM in various plant species and it increases 2- to 6-fold in response to salinity, drought, and cold stress conditions. Transgenic tobacco underexpressing glyoxalase I showed enhanced accumulation of MG which resulted in the inhibition of seed germination. In the glyoxalase I overexpressing transgenic tobacco, MG levels did not increase in response to stress compared to the untransformed plants, however, with the addition of exogenous GSH there was a decrease in MG levels in both untransformed and transgenic plants. The exogenous application of GSH reduced MG levels in WT to 50% whereas in the transgenic plants a 5-fold decrease was observed. These studies demonstrate an important role of glyoxalase I along with GSH concentration in maintaining MG levels in plants under normal and abiotic stress conditions.