Astha Tripathi

Bio: Astha Tripathi is an academic researcher from Department of Biotechnology. The author has contributed to research in topics: Bjerkandera adusta & Ascorbic acid. The author has an hindex of 5, co-authored 13 publications receiving 66 citations.

Extracellular Ligninolytic Enzymes in Bjerkandera adusta and Lentinus squarrosulus.

Abstract: Extracellular ligninolytic enzyme activities were determined in two white-rot fungi, Bjerkandera adusta and Lentinus squarrosulus. To investigate the activity of extracellular enzymes, cultures were incubated over a period of 20 days in nutrient rich medium (NRM) and nutrient poor medium under static and shaking conditions. Enzymatic activity was varied with media and their incubation conditions. The highest level of Aryl alcohol oxidase (AAO) was detected under shaking condition of both medium while Manganese peroxidase (MnP) activity was best in NRM under both conditions. AAO is the main oxidases enzyme in B. adusta while laccase plays important role in L. squarrosulus. MnP is the main peroxidase enzyme in both varieties.

Mineralization of mono-nitrophenols by Bjerkandera adusta and Lentinus squarrosulus and their extracellular ligninolytic enzymes.

Abstract: Nitroaromatic compounds constitute a major class of widely distributed environmental contaminants. Fifty fungal strains were screened for their potential to tolerance with 2-nitrophenol, 3-nitrophenol and 4-nitrophenol on solid medium supplemented with 2% malt extract (MEA). Growth rate (mm/day) was determined at three concentrations (0.25, 0.5 and 1 mM) of all the three nitrophenols. From the fifty fungal strains only Bjerkandera adusta and Lentinus squarrosulus were able to tolerate all the three nitrophenols (NPs). These white-rot fungi (WRF) were chosen for liquid medium studies for the mineralization of mono-nitrophenols and ligninolytic enzyme activity at 0.25 mM concentration. Both varieties completely removed 2-NP and 3-NP while 4-NP was hard to mineralize. AAO (Aryl Alcohol Oxidase) is the main oxidase enzyme in B. adusta while laccase plays important role in L. squarrosulus. MnP (Manganese peroxidase) is the main peroxidase enzyme in both varieties. These fungal strains were capable to degrade nitrophenols and could be used for bioremediation applications on large scale. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Development and efficacy analysis of a Moringa oleifera based potable water purification kit

Abstract: The purpose of this study was to develop a water purification kit using seeds of Moringa oleifera (MO). For this purpose, aqueous extract of MO seeds was investigated for antibacterial activity against pathogenic bacterial strains viz. Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and MRSA (Methicillin-resistant Staphylococcus aureus). It was determined that 100 mg/mL of extract of MO seeds was effective against these bacterial strains resulting in 28.75 ± 0.707 mm of inhibition zone against E. coli, 26.0 ± 0.707 mm against S. aureus, 26.75 ± 0 mm against S. typhi, 29.75 ± 0.707 mm against P. aeruginosa and 25.5 ± 0.707 mm against MRSA. MIC (Minimum inhibitory concentration) of 12.5 ± 0 mg/mL against E. coli and 6.25 ± 0 mg/mL against S. aureus, P. aeruginosa, S. typhi, and MRSA was obtained. Accordingly, portable water purification kit in the form of a dip bag enclosing extremely safe and edible MO seed powder was developed as a key to drinking water problem. Water purification was performed using dip bag to treat pathogenic strains inoculated in water. The minimum time and seed quantity required for the anti-bacterial activity of seeds was optimized and was noted that a single dip bag containing 100 mg of MO seed powder was capable of eradicating 99.9% of the microbial load from 1 L of water in a time span of 5 min. Drinking water from natural water resources containing coliform bacteria was also tested using dip bag and was found to be equally effective.

Evaluation of antioxidant and anti-inflammatory properties of aqueous extract of wild mushrooms collected from himachal pradesh

Abstract: Objective: The objective of this study is to elucidate phytochemical contents, antioxidant, and anti-inflammatory activity of wild mushrooms collected from Himachal Pradesh. Methods: Quantitative analysis of phytochemical constituents was carried out using standard methods while 1,1 diphenylpicrylhydrazyl nitric oxide, hydrogen peroxide-free radical scavenging assay were used to evaluate the antioxidant properties of selected wild mushrooms. Anti-inflammatory capacity of samples was evaluated by human red blood cell membrane stabilization and albumin denaturation inhibition method. Results: The results obtained revealed that Pleurotus floridanus showed higher total phenol, flavonoid carotenoid, and ascorbic acid contents of 61.13±2.3 mg/g, 15.2±1.13 mg/g, 12.42±0.42 μg/g, 17.36±0.40 μg/g, and 14.55±0.58 mg/g. All the species showed antioxidant potential, but P. floridanus proved to be more active while Macrocybe sp. proved to be least one. Conclusion: The mushroom species analyzed have been showed to be good source of phytoconstituents, antioxidants, and also possess antiinflammatory properties, thus can be used in the management of oxidative stress-induced disease. Keywords: Wild mushrooms, Scavenging effect, Total phenol, Antioxidant, Anti-inflammatory.

Biological Management of Damping-Off, Buckeye Rot and Fusarial Wilt of Tomato (cv. Solan Lalima) under Mid-Hill Conditions of Himachal Pradesh

Abstract: Disease management is often complicated by the presence of multiple types of pathogens; in an organic system, it is appropriate to develop disease control strategies. The available literature so far reflects that the management of important disease of tomato is through the integrated approaches and very few organic approaches have been tried with various degree of success. Boiopriming of seeds with biocontrol agents (Trichoderma viridae, Trichoderma harzianum and Pseudomonas fluorescens) in combination with different biofertilizers (Azotobacter, Azospirillum and PSB) and organic manures (FYM and vermi-compost) were tested against disease incidence and health management of tomato seedling under nursery as well as field conditions. The studies were conducted during two successive years (2012-2013) at farmer’s field with the objective to combat with the increasing disease incidence of three major disease damping-off, fusarium wilt and buckeye rot from nursery stage to the final harvesting. The study focused on the use of biocontrol agents as the suitable alternative to chemical pesticides with sustainable disease management without pesticide residues in foodstuff. The bio priming of seeds with fungal antagonist Trichoderma viridae and harzianum and bacterial antagonist Pseudomonas fluorescens significantly improved the germination behavior of tomato seeds as compared to untreated control. Highest mean germination (93.1%) and seedling vigour (953.33) was recorded in Treatment 3 (FYM @ 200 q/ ha + Azospirillum + PSB + Trichoderma herzianum (4 kg/ha each) and lowest in control (60.3%) and (304.83), thus indicating a significant per cent increase in seedling emergence (54.4%) and seedling vigour (95.23%). A considerable reduction in disease incidence (pre and post) of damping off was observed in treatment T? and T? (VC @ 50 q/ha + Azospirillum + PSB + Trichoderma herzianum @ (4 kg/ha) with 45.6% and 35.4% respectively). Treatment T? proved highest in terms of yield (665 Kg/Ha), Hence these diseases can be managed by successful application of Biocontrol agents.

Cultivation of Mushrooms and Their Lignocellulolytic Enzyme Production Through the Utilization of Agro-Industrial Waste

Abstract: A large amount of agro-industrial waste is produced worldwide in various agricultural sectors and by different food industries The disposal and burning of this waste have created major global environmental problems Agro-industrial waste mainly consists of cellulose, hemicellulose and lignin, all of which are collectively defined as lignocellulosic materials This waste can serve as a suitable substrate in the solid-state fermentation process involving mushrooms Mushrooms degrade lignocellulosic substrates through lignocellulosic enzyme production and utilize the degraded products to produce their fruiting bodies Therefore, mushroom cultivation can be considered a prominent biotechnological process for the reduction and valorization of agro-industrial waste Such waste is generated as a result of the eco-friendly conversion of low-value by-products into new resources that can be used to produce value-added products Here, we have produced a brief review of the current findings through an overview of recently published literature This overview has focused on the use of agro-industrial waste as a growth substrate for mushroom cultivation and lignocellulolytic enzyme production

Production of thermo-alkali-stable laccase and xylanase by co-culturing of Bacillus sp. and B. halodurans for biobleaching of kraft pulp and deinking of waste paper

Abstract: To reduce pollution and cost of treatment for fresh and recycled paper, co-production of xylanase and laccase was carried out in the same production medium using two compatible species of Bacillus. These co-produced enzymes were used for deinking of old newsprint (ONP) and biobleaching of eucalyptus Kraft pulp. Solid-state co-cultivation of Bacillus sp. and B. halodurans FNP135 was optimized statistically by response surface methodology for the co-production of xylanase (X) and laccase (L). A significant increase in production of xylanase (2.1-fold, 1,685 IU/g) and laccase (2.04-fold, 2,270 nkat/g) was observed under optimized conditions viz. pH (10.5), inoculum size (10 + 10 %) and moisture:substrate ratio (0.8:1). Both the enzymes showed identical temperature and pH optima of 70 °C and 9, respectively, and were used for deinking of ONP pulp and biobleaching of kraft pulp. In case of ONP pulp deinking, the XL treatment increased brightness (11.8 %), freeness (17.8 %), breaking length (34.8 %), burst factor (2.77 %) and tear factor (2.4 %). In case of kraft pulp biobleaching, XL treatment showed a significant increase in brightness (13 %), whiteness (106.15 %) breaking length (49 %), burst factor (6.9 %), tear factor (23 %), and viscosity (11.68 %) and reduction in kappa number (15 %) after alkali extraction and peroxide stage. This enhancement of pulp properties revealed a synergistic effect of xylanase and laccase produced in one setup.

Lignocellulolytic enzymes from tropical fungi: Types, substrates and applications

Abstract: Lignocellulolytic enzymes constitute a large group of mainly extracellular proteins including ligninolytic enzymes (peroxidases and oxidases) and hydrolytic enzymes (cellulases, hemicellulases, pectinases, chitinases, amylases, proteases, esterases, and mannases). These enzymes have attracted a wide range of industrial and environmental applications including pulping, de-inking, decolourization and detoxification of textile wastes, wastewater treatment and bioremediation of polluted soils. This work gives an updated review and summarizes the main fungal strains, substrates, lignocellulosic enzymes and their applications with an emphasis on tropical fungi. The main groups of lignocellulolytic enzymes and their applications are summarized in a manner that provides a useful reference for both enzyme scientists and technologists. Moreover, current debates and significant gaps in the lignocellulolytic fungal enzymes’ research have been highlighted. Future prospects in lignocellulolytic enzymes research are directed towards bioprospecting of robust novel fungal enzymes to overcome the challenge of recalcitrant substrates, physiological regulations of enzymes, use of novel inducers to enhance production, use of multiple fungal strains or mixture of enzymes, gene cloning to screen for new generation of enzymes and nanobiotechnologal applications in enzymology. This review revealed that for the past seven years, lignocellulolytic enzymes research and development have been steadily advancing from cellular to molecular; and from micro- to nano- levels, and more efforts should be directed to new research frontiers including molecular cloning, sequencing and functional genomics. Key words: Biodegradation, lignocellulolytic enzymes activities, liquid culture, nanobiotechnology, solid state fermentation.