Natural gums and their derivatives based hydrogels: in biomedical, environment, agriculture, and food industry.

The hydrogels based on natural gums and chemically derivatized natural gums have great interest in pharmaceutical, food, cosmetics, and environmental remediation, due to their: economic viability, sustainability, nontoxicity, biodegradability, and biocompatibility. Since these natural gems are from plants, microorganisms, and seaweeds, they offer a great opportunity to chemically derivatize and modify into novel, innovative biomaterials as scaffolds for tissue engineering and drug delivery. Derivatization improves swelling properties, thereby developing interest in agriculture and separating technologies. This review highlights the work done over the past three and a half decades and the possibility of developing novel materials and technologies in a cost-effective and sustainable manner. This review has compiled various natural gums, their source, chemical composition, and chemically derivatized gums, various methods to synthesize hydrogel, and their applications in biomedical, food and agriculture, textile, cosmetics, water purification, remediation, and separation fields.

Antitumor Activity of Choerospondias axillaris Fruit Extract by Regulating the Expression of SNCAIP and SNCA on MDA-MB-231 Cells.

OBJECTIVE: Cancer is a huge problem of disease globally. Today, the percentage of people die from cancer is more than a combination of various diseases. In females, most common types of malignancies that occur are breast and cervical. The present focus has been shifted on medicinal plants as a form of therapy and there is a constant need to identify new therapeutic agents. Choerospondias axillaris (C. axillaris), an underutilized fruit, has been used in the remedy of various diseases. In the present communication, we evaluated the molecular mechanism of C. axillaris methanol extract in regulating cell death in human breast cancer cells (MDA-MB-231). METHODS: Methanol extract of C. axillaris was prepared and compounds were screened by Gas chromatography-mass spectrometry. The effect of fruit extract was determined on MDA-MB-231 cells by MTT ((3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay and to analyse the molecular mechanism of human breast cancer cells after treating with fruit extract, protein profiling study was performed by two-dimensional gel electrophoresis. RESULTS: A total 9 differentially expressed proteins were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS/MS) analysis. Among 9 identified proteins, synphilin-1 protein was found to be significantly downregulated, validated by western blot and RT-qPCR analysis. Possible interacting partners of synphilin-1 (SNCAIP) were analyzed for their possible role in cancer by the in-silico method. CONCLUSION: Our data implicate that the presence of bioactive compound(s) in C. axillaris fruits might play an important role in inhibiting the proliferation of breast carcinoma cells and Synphilin-1 protein may play a role of apoptotic function.

DNA barcoding: a modern age tool for detection of adulteration in food.

Globalization of the food trade requires precise and exact information about the origin, methods of production, transformation technologies, authentication, and the traceability of foodstuffs. New challenges in food supply chains such as deliberate fraudulent substitution, tampering or mislabeling of food and its ingredients or food packaging incapacitates the market and eventually the national economy. Currently, no proper standards have been established for the authentication of most of the food materials. However, in order to control food fraud, various robust and cost-effective technologies have been employed, like a spectrophotometer, GC-MS, HPLC, and DNA barcoding. Among these techniques, DNA barcoding is a biotechnology advantage with the principle of using 400-800 bp long standardized unique DNA sequences of mitochondrial (e.g. COI) or plastidial (e.g. rbcL) of nuclear origin (e.g. ITS) to analyze and classify the food commodities. This review covers several traded food commodities like legumes, seafood, oils, herbal products, spices, fruits, cereals, meat, and their unique barcodes which are critically analyzed to detect adulteration or fraud. DNA barcoding is a global initiative and it is being accepted as a global standard/marker for species identification or authentication. The research laboratories and industries should collaborate to realize its potential in setting standards for quality assurance, quality control, and food safety for different food products.

Gold nanomaterials for optical biosensing and bioimaging.

Gold nanoparticles (AuNPs) are highly compelling nanomaterials for biomedical studies due to their unique optical properties. By leveraging the versatile optical properties of different gold nanostructures, the performance of biosensing and biomedical imaging can be dramatically improved in terms of their sensitivity, specificity, speed, contrast, resolution and penetration depth. Here we review recent advances of optical biosensing and bioimaging techniques based on three major optical properties of AuNPs: surface plasmon resonance, surface enhanced Raman scattering and luminescence. We summarize the fabrication methods and optical properties of different types of AuNPs, highlight the emerging applications of these AuNPs for novel optical biosensors and biomedical imaging innovations, and discuss the future trends of AuNP-based optical biosensors and bioimaging as well as the challenges of implementing these techniques in preclinical and clinical investigations.

Heat-induced endoplasmic reticulum stress in soleus and gastrocnemius muscles and differential response to UPR pathway in rats.

The present study aimed to investigate the differential response of oxidative (soleus) and glycolytic (gastrocnemius) muscles to heat-induced endoplasmic reticulum (ER) stress. It was hypothesized that due to compositional and functional differences, both muscles respond differently to acute heat stress. To address this, male Sprague Dawley rats (12/group) were subjected to thermoneutral (25 °C) or heat stress (42 °C) conditions for 1 h. Soleus and gastrocnemius muscles were removed for analysis post-exposure. A significant increase in body temperature and free radical generation was observed in both the muscles following heat exposure. This further caused a significant increase in protein carbonyl content, AOPP, and lipid peroxidation in heat-stressed muscles. These changes were more pronounced in heat-stressed soleus compared to the gastrocnemius muscle. Accumulation of unfolded, denatured proteins results in ER stress, causing activation of unfolded protein response (UPR) pathway. The expressions of UPR transducers were significantly higher in soleus as compared to the gastrocnemius muscle. A significant elevation in resting intracellular calcium ion was also observed in heat-stressed soleus muscle. Overloading of cells with misfolded proteins in soleus muscle activated ER-induced apoptosis as indicated by significant upregulation of C/EBP homologous protein and Caspase12. The study provides a detailed mechanistic representation of the differential response of muscles toward UPR under heat stress. Data suggests that soleus majorly being an oxidative muscle is more prone to heat stress-induced insult indicated by enhanced apoptosis. This study may aid in devising mitigation strategies to improve muscle performance under heat stress.

Subclinical elevated B-type Natriuretic Peptide (BNP) indicates endothelial dysfunction contributing to hypoxia susceptibility in healthy individuals.

AIMS: Baseline elevated B-type Natriuretic Peptide (BNP) has been found in high altitude pulmonary edema susceptible population. Exaggerated pulmonary vascular response to hypoxia may be related to endothelial dysfunction in hypoxia susceptible. We hypothesize that baseline BNP levels can predict hypoxia susceptibility in healthy individuals. MAIN METHODS: The pulmonary vascular response to hypoxia was compared in 35 male healthy individuals divided into two groups based on BNP levels (Group 1 ≤ 15 and Group 2 > 15 pg/ml). Acute normobaric hypoxia was administered to both the groups, to confirm hypoxia susceptibility in Group 2. KEY FINDINGS: Unlike Group 1, Group 2 had elevated post hypoxia BNP levels (26 vs 33.5 pg/ml, p = 0.002) while pulmonary artery pressure was comparable. A negative correlation with tissue oxygen consumption (delta pO2) and compartmental fluid shift was seen in Group 1 only. Endothelial dysfunction in Group 2 resulted in reduced vascular compliance leading to elevation of mean blood pressure on acute hypoxia exposure. BNP showed a positive correlation with endothelial dysfunction in Group 2 and has been linked to pre-diabetic disorder (HbA1c 6 ± 0.44%) and may additionally represent a lower cross-sectional area of vascular bed related to vascular remodeling mediated by chronic hypoxia. SIGNIFICANCE: Hypoxia susceptibility in healthy individuals may be related to endothelial dysfunction that limits vascular compliance during hypoxic stress. BNP level showed positive correlation with HbA1c (r = 0.49, p = 0.04) and negative correlation with delta pO2 (r = -0.52, p = 0.04) can predict reduced microvascular compliance due to endothelial dysfunction contributing to hypoxia susceptibility in healthy individuals. BNP levels≤15 pg/ml at sea level is indicative of hypoxia resistance.

Emerging Trends in Microfluidics Based Devices.

One of the major challenges for scientists and engineers today is to develop technologies for the improvement of human health in both developed and developing countries. However, the need for cost-effective, high-performance diagnostic techniques is very crucial for providing accessible, affordable, and high-quality healthcare devices. In this context, microfluidic-based devices (MFDs) offer powerful platforms for automation and integration of complex tasks onto a single chip. The distinct advantage of MFDs lies in precise control of the sample quantities and flow rate of samples and reagents that enable quantification and detection of analytes with high resolution and sensitivity. With these excellent properties, microfluidics (MFs) have been used for various applications in healthcare, along with other biological and medical areas. This review focuses on the emerging demands of MFs in different fields such as biomedical diagnostics, environmental analysis, food and agriculture research, etc., in the last three or so years. It also aims to reveal new opportunities in these areas and future prospects of commercial MFDs.

Evaluation of Anti-inflammatory Effects of Choerospondias axillaris Fruit's Methanolic Extract in Synoviocytes and CIA Rat Model.

BACKGROUND: Rheumatoid Arthritis (RA) is an autoimmune, systemic disease mainly affecting joints. Presently, there is no specific treatment/ drug available for curing RA except few supportive medicines. Therefore, the focus has been shifted to medicinal plants for the treatment of such diseases. Choerospondias axillaris commonly known as Lupsi/Lapsi and has been reported to have several properties for the treatment of various diseases. OBJECTIVE: The present study has been conducted to explore the anti-inflammatory effects of Choerospondias axillaris fruit extract on Synoviocytes (FLS) and Collagen-Induced Arthritis (CIA) rat model. METHODS: Methanolic extract of the Choerospondias axillaris fruit was used for determining phytochemical, antioxidant and anti-inflammatory properties. Antioxidant activity of Choerospondias axillaris fruit was determined by free radicals scavenging assays and bioactive compounds were identified via LC-MS/MS analysis. Anti-inflammatory effect was investigated in RA and Osteo Arthritis (OA) primary cells and also in Collagen Induced Arthritis (CIA) rat models. Further, the medicinal properties of anti-inflammatory bioactive compounds were supported by docking studies. RESULTS: In-vitro and in-vivo studies showed significant decrease in the levels of inflammatory cytokines. Docking analysis revealed that quercetin inhibits TNF-α having -9.1 kcal/mol binding energy and 10.13 µM inhibitory constant. Quercetin also inhibits IL-6 having -6.6 kcal/mol binding energy and 21.9 µM inhibitory constant. CONCLUSION: Observed results suggest that the underutilized fruit Choerospondias axillaris can be used to reduce the inflammation of inflammatory diseases like RA.

Mitochondrial DNA sequencing reveals association of variants and haplogroup M33a2'3 with High altitude pulmonary edema susceptibility in Indian male lowlanders.

High Altitude Pulmonary Edema (HAPE) is a threatening disorder caused due to acute exposure to high altitude above 3000 m. Apart from multiple factors involved, the genetic factors also play an important function in the pathogenesis of HAPE. This study aims to evaluate the role of mtDNA polymorphism and their association with haplogroup in understanding the etiology of HAPE. In this study, all the HAPE susceptible and acclimatized control subjects could be classified into nine haplogroups pertaining mostly to Macrohaplogroup M and U. The frequency of haplogroup M was significantly higher in HAPE susceptibles whereas the haplogroup M33a2'3 was found only in HAPE susceptibles. The variant G4491A and A4944G of MT-ND2, A14002G of MT-ND5, and C8562T of MT-ATP8, were definition site of haplogroup M33a2'3. The frequency of A10398G of MT-ND3, A8701G of MT-ATP6 and C14766T of MT-CYB genes were significantly higher in HAPE susceptibles. mtDNA copy number also plays a significant synergistic role in HAPE susceptibility. Our findings suggests that variants in MT-ND2 and MT-ND5 were predicted to confer decreased protein stability in HAPE susceptibles and in particular, highly conserved variants G4491A, A4944G and A14002G associated with haplogroup M33a2'3 may be the primary cause of susceptibility to HAPE in Indian male lowlanders.

Subclinical pulmonary dysfunction contributes to high altitude pulmonary edema susceptibility in healthy non-mountaineers.

HAPE susceptible (HAPE-S, had HAPE episode in past) subjects may have subclinical cardio-pulmonary dysfunction. We compared the results of pulmonary function tests in 25 healthy HAPE-S non-mountaineers and 19 matched HAPE resistant (HAPE-R, no HAPE episode in past). Acute normobaric hypoxia (FIo2 0.12) was administered at sea level to confirm hypoxia intolerance in HAPE-S. Unlike HAPE-R, HAPE-S subjects had elevated baseline and post-hypoxia systolic pulmonary arterial pressures (20.9 ± 3 vs 27.3 ± 5 mm Hg during normoxia and 26.2 ± 6 vs 45.44 ± 10 mm Hg during hypoxia, HAPE-R vs HAPE-S). Forced vital capacity (FVC) and single breath alveolar volume (SBVA) were significantly lower in HAPE-S compared to HAPE-R (FVC: 4.33 ± 0.5 vs 4.6 ± 0.4; SBVA: 5.17 ± 1 vs 5.6 ± 1 Lt; HAPE-S vs HAPE-R). Two subgroups with abnormal pulmonary function could be identified within HAPE-S; HAPE-S1 (n = 4) showed DLCO>140% of predicted, suggestive of asthma and HAPE-S2 (n = 12) showed restrictive pattern. Each of these patterns have previously been linked to early small airway disease and may additionally represent a lower cross-sectional area of the pulmonary vascular bed, related to lower lung volumes. HAPE susceptibility in healthy non-mountaineers may be related to sub-clinical pulmonary pathology that limits compensatory rise in ventilation and pulmonary circulation during hypoxic stress.

Natural gums of plant origin as edible coatings for food industry applications.

Natural plant-based gums and their derivatives are widely utilized in food industries, however, their applications as edible coatings to extend fresh fruits and vegetable shelf-life has been explored recently. These natural polymeric polysaccharides have many advantages as compared to synthetic polymers, because they are biodegradable, nontoxic, economical and easily available in the environment. Natural gums can also be semi synthetically modified to produce derivatives, which can easily compete with the synthetic preservatives available on the food market. In this review, the recent developments in the use of natural gums and their derivatives as edible coatings have been explored and discussed.

Raised HIF1α during normoxia in high altitude pulmonary edema susceptible non-mountaineers.

High altitude pulmonary edema (HAPE) susceptibility is associated with EGLN1 polymorphisms, we hypothesized that HAPE-susceptible (HAPE-S, had HAPE episode in past) subjects may exhibit abnormal HIF1α levels in normoxic conditions. We measured HIF1α levels in HAPE-S and HAPE resistant (HAPE-R, no HAPE episode) individuals with similar pulmonary functions. Hemodynamic responses were also measured before and after normobaric hypoxia (Fi02 = 0.12 for 30 min duration at sea level) in both groups. . HIF1α was higher in HAPE-S (320.3 ± 267.5 vs 58.75 ± 33.88 pg/ml, P < 0.05) than HAPE-R, at baseline, despite no significant difference in baseline oxygen saturations (97.7 ± 1.7% and 98.8 ± 0.7). As expected, HAPE-S showed an exaggerated increase in pulmonary artery pressure (27.9 ± 6 vs 19.3 ± 3.7 mm Hg, P < 0.05) and a fall in peripheral oxygen saturation (66.9 ± 11.7 vs 78.7 ± 3.8%, P < 0.05), when exposed to hypoxia. HIF1α levels at baseline could accurately classify members of the two groups (AUC = 0.87). In a subset of the groups where hemoglobin fractions were additionally measured to understand the cause of elevated hypoxic response at baseline, two of four HAPE-S subjects showed reduced HbA. In conclusion, HIF 1 α levels during normoxia may represent an important marker for determination of HAPE susceptibility.

Elevated pulmonary artery pressure and brain natriuretic peptide in high altitude pulmonary edema susceptible non-mountaineers.

Exaggerated pulmonary pressor response to hypoxia is a pathgonomic feature observed in high altitude pulmonary edema (HAPE) susceptible mountaineers. It was investigated whether measurement of basal pulmonary artery pressure (Ppa) and brain natriuretic peptide (BNP) could improve identification of HAPE susceptible subjects in a non-mountaineer population. We studied BNP levels, baseline hemodynamics and the response to hypoxia (FIo2 = 0.12 for 30 min duration at sea level) in 11 HAPE resistant (no past history of HAPE, Control) and 11 HAPE susceptible (past history of HAPE, HAPE-S) subjects. Baseline Ppa (19.31 ± 3.63 vs 15.68 ± 2.79 mm Hg, p < 0.05) and plasma BNP levels (52.39 ± 32.9 vs 15.05 ± 9.6 pg/ml, p < 0.05) were high and stroke volume was less (p < 0.05) in HAPE-S subjects compared to control. Acute hypoxia produced an exaggerated increase in heart rate (p < 0.05), mean arterial pressure (p < 0.05) and Ppa (28.2 ± 5.8 vs 19.33 ± 3.74 mm Hg, p < 0.05) and fall in peripheral oxygen saturation (p < 0.05) in HAPE-S compared to control. Receiver operating characteristic (ROC) curves showed that Ppa response to acute hypoxia was the best variable to identify HAPE susceptibility (AUC 0.92) but BNP levels provided comparable information (AUC 0.85). BNP levels are easy to determine and may represent an important marker for the determination of HAPE susceptibility.

Antifungal potential of actinomycete isolate Streptomyces exfoliates MT9 against wood-rotting fungi.

An actinomycete isolate, Streptomyces exfoliatus MT9 was assessed for in vitro antagonism against wood-rotting fungi. Strain MT9 showed strong antagonistic activity (ZOI ? 25 mm) towards various tested wood-rotting fungi. Extracellular production of antifungal metabolite(s) including primary and secondary was monitored up to 10 days of submerged fermentation. Antagonist S. exfoliatus MT9 produces fungal cell-wall lytic enzymes, namely chitinase (3.098 U ml-1), b-1,3 glucanase (2.4 U ml-1) and protease (144.0 U ml-1) and also showed antifungal activity towards tested P. chrysosporium MTCC 787 (12.0 mm) and P. placenta MTCC 144 (16.0 mm). Extracellular culture filtrate (ECF) of S. exfoliatus MT9 also exhibited strong antifungal activity (ZOI ≥ 25 mm) towards tested wood-rotting fungi and n-butanol was found to be the suitable solvent for complete extraction of antifungal metabolite(s) from ECF. Reduced antifungal activity of n-butanol extract against P. chrysosporium MTCC 787 (11.00 mm) and P. placenta MTCC 144 (10.00 mm) on ergosterol agar plate, no activity against bacteria and characteristic UV spectra at 224 nm revealed the polyene nature of antifungal metabolite(s) present in the n-butanol extract. A novel actinomycete isolate, S. exfoliatus MT9 is producing antifungal metabolite(s) that makes it suitable for biotechnological processes and has the potential to be used as a bioactive agent for controlling wood-rotting fungi.

Identification and molecular docking analysis of active ingredients with medicinal properties from edible Baccaurea sapida.

Underutilized plant species has started changing the conception of plants by expanding the use well beyond from foods and fibers to rich source of medicinally important secondary metabolites. Bioactive compounds from natural sources are gaining importance as potential drug candidates towards many inflammatory conditions like Rheumatoid Arthritis (RA). The focus of the present study has been centred to reveal the anti-inflammatory potential of an underutilized fruits of B. sapida. Further efforts towards its medicinal significance may provide relieve from symptoms of RA by reducing the side effects that are observed in available medications. Total 10 compounds in fruit crude methanol extract were identified and quantified by LC-MS/MS analysis followed by the agar well diffusion method for their anti microbial activity. Among all studied micro organism S. aureus was found to surmount the inflammation in RA through domain B of surface protein A (Staphylococcal surface protein A). Identified compounds (having anti-inflammatory properties) were scrutinized for their toxicity and quantitative structure-activity relationship (QSAR) using lazer toxicity and Molinspiration servers respectively. Further, docking studies have been carried out between domain B and studied compounds using AutoDock. Out of 6 anti-inflammtory compounds, quercetin has been identified as the most potent compound in reference to its inhibitory constant (47.01) and binding energy (-5.90 kcal/mol) to bacterial protein. Our data suggest that methanol extract of B. sapida fruit posses medicinally significant anti-inflammatory compounds and thus justifies the use of this fruit as folklore medicine for preventing inflammation related diseases.

Biological control of toxigenic citrus and papaya-rotting fungi by Streptomyces violascens MT7 and its extracellular metabolites.

An Indian indigenous, Loktak Lake soil isolate Streptomyces violascens MT7 was assessed for its biocontrol potential both in vitro and in vivo against toxigenic fruit-rotting fungi. Strain MT7 exhibited broad-spectrum antifungal activity against various pathogenic postharvest fungi of citrus and papaya. In shake-flask fermentation, antagonist S. violascens MT7 highly produced extracellular antifungal metabolites in early stationary growth phase in glucose-yeast extract-malt extract (M93) broth. Both extracellular culture fluid (ECF) and its n-butanol extract showed significant broad-spectrum fungal mycelial inhibition of several tested fruit-rotting fungi. Antifungal metabolite was found to be heat stable, nonpeptidic, and polyene type antibiotic. The lowest minimum inhibitory concentration (MIC) of n-butanol extract against Colletotrichum gloeosporioides MTCC 9664 and Aspergillus niger MTCC 281 was 0.0312 and 0.0625 mg/ml, respectively. Purification of n-butanol extract through silica gel chromatography resulted in partial purification of bioactive metabolite and the TLC autobiography revealed the presence of single antifungal metabolite with Rf value of 0.755. In vivo bioassays demonstrated the biocontrol potential of tested biocontrol agents on fruit-rotting fungi. Use of cell suspension of S. violascens MT7, extracellular metabolite(s), and n-butanol extract significantly (p < 0.05) reduced sour-rot development on Citrus reticulata Blanco (oranges) and soft-rot development on papaya fruits. Therefore, these results strongly suggest a high potential for application of S. violascens MT7 and its extracellular metabolites as an effective eco-friendly alternative to synthetic fungicides for controlling toxigenic citrus and papaya-rotting fungi.

Fungal cell-wall lytic enzymes, antifungal metabolite(s) production, and characterization from Streptomyces exfoliatus MT9 for controlling fruit-rotting fungi.

An antifungal actinomycete strain MT9 was isolated from Loktak Lake, Manipur, India and its cultural characteristics, fatty acid methyl ester, 16S rRNA gene analysis suggests that strain MT9 is identical to Streptomyces exfoliatus. Strain MT9 displayed strong and broad-spectrum antagonism towards several fruit-rotting fungi by mycelial growth suppression. Crude fungal cell-wall lytic enzymes, i.e., chitinase, ß-1,3-glucanase, and protease produced by S. exfoliatus MT9 were optimally active at pH 8.0 and 50 °C, pH 5.0 and 60 °C, pH 9.0 and 70 °C, respectively. All three mycolytic enzymes had good stability over a wide pH range of 5.0-10.0, with protease being more thermostable than both chitinase and ß-1,3-glucanase. Interestingly zymogram analysis revealed that S. exfoliatus MT9 secretes six distinct chitinase isoenzymes with approximate molecular weights of 9.42, 13.93, 27.87, 36.43, 54.95, 103.27 kDa, six active protease isoenzymes with apparent molecular weights of 12.45, 30.20, 37.45, 46.32, 52.46, 131.46 kDa, and an active band of 119.39 kDa as ß-1,3-glucanase enzyme. Extracellular fluid and its organic solvent extracts also exhibited inhibitory activity to various fruit-rotting fungi. The MIC value of n-butanol extract was 2-25 µg/ml against tested fruit-rotting fungi. Antifungal secondary metabolite(s) was found to be polyene in nature. To the best of our knowledge, this is the first report on extracellular production of fungal cell-wall lytic enzymes and antifungal metabolites by bioactive S. exfoliatus MT9 under submerged fermentation.

Mycolytic enzymes produced by Streptomyces violaceusniger and their role in antagonism towards wood-rotting fungi.

Extracellular mycolytic enzymes produced under submerged fermentation by the fungal antagonist Streptomyces violaceusniger MTCC 3959 were characterized. This streptomycete produced higher amounts of extracellular chitinase and protease during late exponential phase, whereas ß-1,3-glucanase production was at peak in mid-stationary phase. Cell-free culture filtrate (CCF) exhibited a broad range of antifungal activity against both white rot and brown rot fungi. The inhibitory activity was completely lost after treatment with proteinase K and heat, indicating that extracellular antifungal metabolites are heat labile and proteinaceous in nature. Optimum pH and temperature for enzyme activity were: 9.0 and 60 °C for chitinase; 6.0 and 60 °C for ß-1,3-glucanase; and 9.0 and 70 °C for protease. Mycolytic enzymes were moderately thermostable, and had a wide pH stability range extending from pH 5.0 to 10.0. The zymogram analysis of CCF revealed five chitinase isoenzymes with an apparent molecular weight of 20.8, 33.3, 45.6, 67.4, and 114.8 kDa, one ß-1,3-glucanase appeared as a single band of ∼131.8 kDa and four protease isoenzymes with approximate molecular weights of 22.8, 62.52, 74.64, and 120.5 kDa. S. violaceusniger MTCC 3959 produced mycolytic enzymes that can be effectively used for suppression of phytopathogenic basidiomycetes. It has the potential to be an effective biofungicide.

Chitinases: in agriculture and human healthcare.

Biological control of phytopathogenic fungi and insects continues to inspire the research and development of environmentally friendly bioactive alternatives. Potentially lytic enzymes, chitinases can act as a biocontrol agent against agriculturally important fungi and insects. The cell wall in fungi and protective covers, i.e. cuticle in insects shares a key structural polymer, chitin, a ß-1,4-linked N-acetylglucosamine polymer. Therefore, it is advantageous to develop a common biocontrol agent against both of these groups. As chitin is absent in plants and mammals, targeting its metabolism will signify an eco-friendly strategy for the control of agriculturally important fungi and insects but is innocuous to mammals, plants, beneficial insects and other organisms. In addition, development of chitinase transgenic plant varieties probably holds the most promising method for augmenting agricultural crop protection and productivity, when properly integrated into traditional systems. Recently, human proteins with chitinase activity and chitinase-like proteins were identified and established as biomarkers for human diseases. This review covers the recent advances of chitinases as a biocontrol agent and its various applications including preparation of medically important chitooligosaccharides, bioconversion of chitin as well as in implementing chitinases as diagnostic and prognostic markers for numerous diseases and the prospect of their future utilization.

Purification and characterization of an extracellular chitinase from antagonistic Streptomyces violaceusniger.

The actinomycetes Streptomyces violaceusniger showed strong antagonistic activity against various tested wood rotting fungi. An extracellular chitinase, produced by antagonistic S. violaceusniger MTCC 3959, was purified as follows: ammonium sulfate precipitation, chitin affinity and chromatographic separation of Q Sepharose. The molecular mass of the purified chitinase was estimated as 56.5 kDa by SDS-PAGE. Chitinase was optimally active at pH of 5.0 and 50 °C. It retained almost 100% activity at pH 5.0 and also had high thermal tolerance at 50 °C. Enzyme activity was inhibited by Hg(2+) and Ag(+) cations, but was neither substantially inhibited by K(+) cation nor by chelating agent EDTA. The apparent Km and Vmax at 37 °C were 0.1426 mM and 6.6 U/mg, respectively using pNP-(GlcNAc)2 as substrate. The 56.5 kDa chitinase of strain MTCC 3959 represented an exo-type activity. The purified chitinase was further identified by MALDI-TOF. The results of peptide mass fingerprinting showed that 10 tryptic peptides of the chitinase were identical to the chitinase C from Streptomyces albus J1074 (GenBank Accession No. gi|239982330). The sequence of N-terminal amino acid (AA) of the chitinase was determined to be G-D-G-T-G-P-G-P-G-P.