Browsing by Author "Dharmendra Kumar"

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A new technique for monoconidial culture of the most aggressive isolate in a given population of Bipolaris sorokiniana, cause of foliar spot blotch in wheat and barley
(2007) Dharmendra Kumar; Ramesh Chand; Lal C. Prasad; Arun K. Joshi
We developed a new technique for monoconidial culture of the most aggressive isolate in a given population of Bipolaris sorokiniana, to facilitate the evaluation of spot blotch resistance in wheat and barley. Blotched portions of infected barley leaves were placed on a glass slide in a moist chamber for production of conidia by associated fungal hyphae. Conidia were collected separately and grown on water agar discs. Individual water agar discs having conidium growth were inoculated on barley leaves. The conidium producing the earliest symptom with the largest lesion was considered most aggressive. This lesion was incubated in a moist chamber and the conidial offspring were tested for pathogenicity. When a uniform infection was observed, a small piece of the lesion was cut using a sterilized scalpel, surface sterilized with NaOCl, and inoculated in the centre of Petri dishes containing potato dextrose agar medium. The inoculated Petri dishes were incubated at 25 ± 1°C to yield monoconidial cultures of the most aggressive isolate. Variability in symptom expression caused by the most aggressive isolate of a given population was much less than variability in symptom expression caused by all isolates collectively. The techniques will be useful for plant pathologists and breeders in screening for spot blotch resistance in wheat and barley. © 2007 Springer Science+Business Media B.V.
Advances in extraction technologies: Isolation and purification of bioactive compounds from biological materials
(Elsevier, 2020) Nishi Srivastava; Arti Singh; Puja Kumari; Jay Hind Nishad; Veer Singh Gautam; Monika Yadav; Rajnish Bharti; Dharmendra Kumar; Ravindra N. Kharwar
Natural bioactive compounds (NBCs) are receiving more popularity because of their various medicinal properties and huge exploitation in various commercial sectors such as food, chemical, and pharmaceutical industries. The extraction of NBCs begins with the selection of a suitable protocol, sample preparation, and extensive literature survey. During the extraction of NBCs from biological materials, the major concern of researchers is on minimizing the interference of unwanted compounds that may coextract with the focused compounds. Numerous extraction procedures have been introduced along with existing classical extraction methodology (conventional extraction methodology), but still, scientists are in search of the development of a standard single method for extracting NBCs from biological materials. There are several critical parameters such as understanding the nature of the plant matrix and chemistry of bioactive compounds and scientific expertise that impact efficiencies of conventional and nonconventional extraction. This chapter focuses on the mechanism of different extraction techniques, extraction instrumentation, and common problems encountered and their elimination. For efficient extraction of NBCs from biological materials, there is an urgent need for advancement in selective extraction procedures, from extraction to fractionation and subsequent purification that will speed up and scale up the isolation of purified compounds from biological materials. © 2021 Elsevier Inc.
Algae Polysaccharides (Carrageenan and Alginate)—A Treasure-Trove of Antiviral Compounds: An In Silico Approach to Identify Potential Candidates for Inhibition of S1-RBD Spike Protein of SARS-CoV2
(Multidisciplinary Digital Publishing Institute (MDPI), 2023) Dikshansha Rohilla; Akhileshwar Kumar Srivastava; Rahul Prasad Singh; Priya Yadav; Sandeep Kumar Singh; Dharmendra Kumar; Nikunj Bhardwaj; Mahipal Singh Kesawat; Kapil Deo Pandey; Ajay Kumar
For the last three years, the world has faced the unexpected spread of the pandemic of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The high mortality rate and ever-changing shape of the virus are the challenging factors in the effective management of SARS-CoV-2. However, in last three years, research communities have made significant progress in developing vaccines and controlling the spread of the pandemic to a certain extent. These vaccines contain the attenuated pathogens, which after application did not kill the virus but protected the human by enhancing the immune system response during pandemic exposure. However, the negative side effects and the high cost of the synthetic vaccines are always of concern for researchers, consumers, and the government. Therefore, as an alternative to synthetic drugs, natural medicines or natural plant products have piqued researchers’ interest. Algae are considered as a treasure house of bioactive compounds such as carotenoids, vitamins, polysaccharides, proteins, etc. These bioactive compounds have been well documented for the treatments of various human ailments such as cancer and cardiovascular diseases. Furthermore, sulfated polysaccharides such as alginate and carrageenan have been reported as having antiviral and immunomodulating properties. Therefore, this review addresses algal polysaccharides, especially alginate and carrageenan, and their application in the treatment of COVID-19. In addition, in silico approaches are discussed for the inhibition of the S1-RBD (receptor-binding domain) of SARS-CoV-2, which attaches to the host receptor ACE2 (angiotensin-converting enzyme 2), and the interaction with the network of relative proteins is also explored, which will help in drug discovery and drug design. © 2023 by the authors.
An overview of integrated management of Leucinodes orbonalis in brinjal crop in eastern Uttar Pradesh, India
(Plant Archives, 2014) Dharmendra Kumar; M. Raghuraman
The present studies on the Integrated Pest Management (IPM) for brinjal fruit and shoot borer (Leucinodes orbonalis) in the field trial was conducted at Banaras Hindu University at Vegetable Research Farm during 2011 and 2012. In strategy of IPM for the control of brinjal fruit and shoot borer (Leucinodes orbonalis) consists of resistant cultivar, sex pheromone, cultural, mechanical and biological control methods. Brinjal cultivars such as Krishna, Pusa anmol, Pusa purple cluster, Navkiran and Pusa purple long-74 possess appreciable levels of resistance to Leucinodes orbonalis. For the control of Leucinodes orbonalis the use of sex pheromone traps based on (E)-11-hexadecenyl acetate and (E)-11-hexadecen-1-ol to continuously trap the adult males significantly reduced the pest damage on brinjal. In addition, prompt destruction of pest damaged brinjal shoots and fruits at regular intervals and withholding of pesticide use to allow proliferation of local natural enemies especially the parasitoid, Trathala flavoorbitalis reduced the Leucinodes orbonalis population. The IPM strategy was profit margins and production area significantly increased whereas pesticide use and labor requirement decreased for those farmers, who adopted this IPM technology. The effort also made to expand the Leucinodes orbonalis is management with the help of production and management practices such as the remove the infected parts. © 2014, Plant Archives. All rights reserved.
Candidemia-induced pediatric sepsis and its association with free radicals, nitric oxide, and cytokine level in host
(W.B. Saunders, 2015) Dharmendra Kumar; Abhai Kumar; Smita Singh; Ragini Tilak
Candida species has become the seventh most frequent causal microorganisms of nosocomial sepsis. Prematurity and low birth weights are strongly associated with the development of neonatal nosocomial bloodstream infections. Candida albicans has been the species most often associated with neonatal infections, but recently, there has been a changing pattern in the isolates recovered from neonates with invasive candidiasis, which poses resistance to the existing class of azoles such as fluconazole antifungals along with cross resistance to newer triazoles, which results in a therapeutic challenge in invasive fungal infections causing high incidence of mortality. Candida species was isolated from blood of neonates and children younger than 15 years admitted to hospital and susceptible for Candida-induced sepsis. Polymerase chain reaction-based identification and confirmation of individual Candida species were done using DNA sequencing. Antibiotic susceptibility assay and resistance pattern for fluconazole, voriconazole, and amphotericin were done for all the isolates. Furthermore, the change in free radical, cytokine release, and nitric oxide synthase expression and nitric oxide release from polymorphonuclear leukocytes isolated from control and pediatric sepsis cases were also performed.The present study probably for the first time reports the change in increasing incidence of nonalbicans Candida-induced sepsis in neonates and children admitted to the intensive care unit of hospital, and current antibiotics load posing resistance for antifungal treatment strategy and provide serious threats in future treatment. The increase in free radicals in polymorphonuclear leukocytes and increase in expression of nitric oxide synthase expression and nitric oxide release in Candida-infected pediatric sepsis cases underlie the role of host factor in dissemination and invasiveness of infection from exogenous sources and pathogenesis of systemic inflammation during sepsis. © 2014 Elsevier Inc.
Comparative in vitro antimicrobial and phytochemical evaluation of methanolic extract of root, stem and leaf of Jatropha curcas linn
(Pharmacognosy Network Worldwide, 2012) Amit Kumar Sharma; Mayank Gangwar; Ragini Tilak; Gopal Nath; Akhoury Sudhir Kumar Sinha; Yamini Bhusan Tripathi; Dharmendra Kumar
Background: Earlier researchers have reported antibacterial activity of different specific parts, but none of the reports show the comparative microbial and phytochemical studies of root, stem and leaf extract. Objective: To compare and investigate antimicrobial, qualitative phytochemical studies, phenol, flavonoid and TLC analysis of root, stem bark, leaf extracts of Jatropha curcas Linn family Euphorbiaceae. Methods: The dried plant powder was subjected to Soxhlet extraction with methanol. These solvent extracts were subjected to a preliminary phytochemical screening to detect the different chemical principles present viz., carbohydrates, proteins, amino acids, steroids, glycosides, alkaloids, flavonoids, tannins and phenolic compounds, fixed oils. Antimicrobial activity was evaluated by disc diffusion method and minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum fungicidal concentration (MFC) was calculated by micro dilution method. Thin layer chromatography was also performed using solvent system chloroform, benzene, hexane, and ethyl acetate for the analysis of a number of constituents in the plant extract. The content of the total phenolics in the extract was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as catechol equivalent. The content of total flavonoids in the extract was determined and calculated as quercetin equivalent. Result: These extracts showed antibacterial, antifungal activities against gram-positive and gramnegative bacteria with varying magnitudes. The phytochemical analysis showed the presence of alkaloid, saponin, tanins, terpenoids, steroids, glycosides, phenols and flavonoids. Maximum phenolic content (38.8) was found in leaf extract and flavonoid content (18.14) in latex of plant. Discussion: It is concluded that the antimicrobial activity showed by the plant was due to the presence of these phytochemicals. Further studies are highly needed for drug development.
Density and efficacious stages of some predator against two spotted spider mite, tetranychus urticae Koch
(Plant Archives, 2015) Dharmendra Kumar; M. Raghuraman
The two spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is a one of the most important mite pests of vegetable and ornamentals crops in greenhouses as well as several other agricultural outdoor/indoor crops. It is well adapted to various environmental conditions, causing qualitative and quantitative losses in yield or death of plants by sucking the contents of cells sap. A number of natural enemies were reported to predate on the spider mites. Among these predator coccinellid genus; Stethorus, Staphylinid, Oligota sp. and phytoseiid mite, Amblyseius longispinosus (Evans) contributing the chief predatory fauna on spider mites. Hence, present investigations were carried out to study the influence of different predator prey densities on the efficacy of predators viz., the predatory coccinellid, Stethorus pauperculus Weise, staphylinid, Oligota sp. and phytoseiid mite, Amblyseius longispinosus (Evans) against T. urticae on brinjal. The results of the study revealed that the predator prey ratio of suitable for both Stethorus pauperculus and Oligota sp. Among the predators, S. pauperculus recorded the highest consumption of 17.97 ± 4.13, 39.57 ± 6.27, 118.03 ± 10.23, 124.73 ± 11.00 and 147.87 ± 10.98 number of T. urticae adults per day against first, second, third, fourth instar grubs and adults, respectively at a predator prey ratio of 5:150. The predatory staphylinid, Oligota sp. grubs fed significantly more T. urticae (133.93 ± 11.76 per day) than adults (49.42 ± 7.12 per day). Similarly, maximum consumption was recorded in 5:50 ratio of A. longispinosus and T. urticae where nymph fed were 13.93 ± 3.99 per day and adult fed were 16.32 ± 4.12 per day.
Diversity of springtails (collembola: Insecta) in different tree ecosystems of Varanasi, India
(Ecological Society of India, 2016) Tsering Toldan; Santeshwari; M. Raghuraman; Dharmendra Kumar
Diversity of collembola in different tree ecosystems, were investigated in Varanasi, Uttar Pradesh. A total of 2568 specimens of 10 genera belonging to 8 families viz., Isotomidae, Entomobryidae, Paronellidae, Cyphoderidae, Onychiuridae, Hypogastruridae, Sminthurididae, and Katiannidae were recorded. Collembola genera viz., Lepidocyrtus sp., Entomobrya sp., Hypogastrurasp., Sminthurinus sp, Sminthurides sp, were most common among almost all the ecosystems followed by Isotomurus sp., Crytopygus sp., Cyphoderus sp., Onychiurus sp, and Folsomia sp. A Maximum population of 17.71% was recorded during the month of September in Bael ecosystem and minimum in the Aonla ecosystem. In the abundance of collembola in general, there were pronounced seasonal fluctuations of different genera in all the ecosystems. Two peaks in September and October and a fall in December was observed in the population fluctuation. The distribution and abundance of soil fauna was more during monsoon period. These organisms play a functional role in soil ecosystem and there is lack of enough records of these beneficial insects from different ecosystems.
Effect of Arsenic on Growth, Arsenic Uptake, Distribution of Nutrient Elements and Thiols in Seedlings of Wrightia arborea (Dennst.) Mabb
(Taylor and Francis Inc., 2015) Dharmendra Kumar; Vijay Pratap Singh; Durgesh Kumar Tripathi; Sheo Mohan Prasad; Devendra Kumar Chauhan
Hydroponic experiments were conducted to investigate the effect of arsenic on seedlings of Wrightia arborea and Holoptelea integrifolia. Results revealed that W. arborea could tolerate much higher arsenic concentration than H. integrifolia. Therefore, further investigations were focused on W. arborea using higher arsenic concentrations (0.2–2.0 mM). Seedlings of W. arborea accumulated about 312–2147 and 1048–5688 mg/kg dry weight of arsenic in shoots and roots, respectively, following treatments with 0.2–1.5 mM of arsenic without exhibiting arsenic toxicity signs. However, arsenic at 2.0 mM caused decline in growth. Macronutrients content such as Ca, S (except at 2.0 mM), and K (only in root) increased while Mg, P, and K (shoot) decreased by arsenic treatments. However, the content of micronutrients was enhanced under arsenic treatments. Non-protein thiols (NP-SH) showed positive correlations with arsenic doses up to 0.2–1.5 mM but at 2.0 mM there was a decline in NP-SH thus suggesting important role of NP-SH in imparting arsenic tolerance. This study demonstrated that W. arborea that could tolerate arsenic concentrations up to 0.2–1.5 mM may be useful in arsenic phytoremediation programs. © 2015, Taylor & Francis Group, LLC.
Endophytes of Medicinal Plants: Diversity and Bioactivity
(Springer Nature, 2022) Sandeep Kumar Singh; Vipin Kumar Singh; Dharmendra Kumar; Dinesh Prasad Gond; Ajay Kumar
Plants are home to a diverse range of microbial communities. These microbes are present either on the epiphytic regions or inside the plant tissue as endophytes and play an integral role in growth promotion, phytopathogen control, and the management of various biotic and abiotic stresses. In this chapter, we summarized the diversity pattern of endophytic microorganisms associated with medicinal plants and their potential role in metabolite synthesis within the host plant. Medicinal plants harbor a plethora of bioactive compounds that are directly or indirectly used for the treatments of various human ailments. The endophytic diversity pattern of medicinal plants will provide insight into their potential and beneficial use, especially for the modulation of bioactive compounds. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.
Endophytic Fungi: A Cryptic Fountainhead for Biodiversity, Functional Metabolites, Host Stress Tolerance, and Myco-mediated Nanoparticles (Nps) Synthesis
(Springer Science and Business Media B.V., 2019) Jay Hind Nishad; Arti Singh; Veer Singh Gautam; Dharmendra Kumar; Jitendra Kumar; R.N. Kharwar
The view on association of higher plants and fungi from past few decades confirms the belief that all plants foster their own endophytic fungal diversity as a host, and all plant species studied till date are found to harbor one or more endophytes. The diversity of endophytic fungi can have deep impressions on plant communities through adding fitness to their concerned host conferring tolerance against abiotic and biotic stresses. While endophytes have been outlined to biosynthesize a wide array of molecules, genome sequencing of such organisms has revealed that these have the potential to provide many more secondary metabolites than usual. Recently, various methods have been advanced to aid in the activation of cryptic biosynthetic pathways. Since the most important medicinal compound taxol (paclitaxel) has been isolated from the endophytic fungus therefore, more plant mimetic compounds may be expected from this hidden microbial source. Various enzymes (amylase, lipase, cellulase, protease, lactase, pectinases, peroxidase, catalase, and penicillinase) and toxins (aflatoxin, zearalenone, ochratoxin, citrinin, T-2 toxin, and fumonisins) may be isolated from this repertoire. Cell-free extract of many endophytic fungal isolates may also be utilized to synthesize the nanoparticles like copper (Cu), silver (Ag), platinum (Pt), and gold (Au) from respective metal salt solutions. This chapter also discusses different approaches such as co-culture of microbes, altering growth media and culture conditions, genetic as well as epigenetic strategies for obtaining the biochemical treasure hidden within these unique microbes. © 2019, Springer Nature Switzerland AG.
Evaluation of antimicrobial activity and bronchodialator effect of a polyherbal drug-Shrishadi
(Asian Pacific Tropical Biomedicine Press, 2012) Divya Kumari Kajaria; Mayank Gangwar; Dharmendra Kumar; Amit Kumar Sharma; Ragini Tilak; Gopal Nath; Yamini Bhusan Tripathi; J.S. Tripathi; S.K. Tiwari
Objective: To investigate antimicrobial and bronchodialator effect of hydroalcholic extract of polyherbal drug Shirishadi containing Shirisha (Albezzia lebbeck), Nagarmotha (Cyprus rotandus) & Kantakari (Solanum xanthocarpum). Methods: Antimicrobial activity was evaluated by disc diffusion method and MIC, MBC, MFC were calculated by micro dilution method. Hydroalcholic extract of this preparation was investigated for its phytochemical analysis, phenol and flavonoid were determined by spectrophotometric method and in vivo bronchodilator effect was analysed by convulsion time. Results: The phytochemical tests revealed presence of alkaloids, anthraquinones, carbohydrates, flavonoids, saponins and tannins. The antimicrobial result showed the MIC of 6.25 mg/mL against Staphylococcus aureus and 12.5 mg/mL for Escherichia coli and 12.5 mg/mL against remaining bacteria tested, with strong antifungal activity. The maximum inhibition zone is found against Pseudomonas aeruginosa with MIC 16 mg/mL. Drug showed significant bronchodilator effect with 27.86% & 36.13% increase in preconvulsion time of guinea pigs pretreated with 100 & 200 mg/kg body weight of extract. Conclusions: The study reveals that the extracts possess antibacterial activity and antifungal activity in a dose dependent manner. This antimicrobial property may be due to presence of several saponins, further studies are highly needed for the drug development. © 2012 Asian Pacific Tropical Biomedical Magazine.
Exploring Potent Fungal Isolates from Sanitary Landfill Soil for In Vitro Degradation of Dibutyl Phthalate
(MDPI, 2023) Shriniketan Puranik; Livleen Shukla; Aditi Kundu; Deeba Kamil; Sangeeta Paul; Govindasamy Venkadasamy; Rajna Salim; Sandeep Kumar Singh; Dharmendra Kumar; Ajay Kumar
Di-n-butyl phthalate (DBP) is one of the most extensively used plasticizers for providing elasticity to plastics. Being potentially harmful to humans, investigating eco-benign options for its rapid degradation is imperative. Microbe-mediated DBP mineralization is well-recorded, but studies on the pollutant’s fungal catabolism remain scarce. Thus, the present investigation was undertaken to exploit the fungal strains from toxic sanitary landfill soil for the degradation of DBP. The most efficient isolate, SDBP4, identified on a molecular basis as Aspergillus flavus, was able to mineralize 99.34% dibutyl phthalate (100 mg L−1) within 15 days of incubation. It was found that the high production of esterases by the fungal strain was responsible for the degradation. The strain also exhibited the highest biomass (1615.33 mg L−1) and total soluble protein (261.73 µg mL−1) production amongst other isolates. The DBP degradation pathway scheme was elucidated with the help of GC-MS-based characterizations that revealed the formation of intermediate metabolites such as benzyl-butyl phthalate (BBP), dimethyl-phthalate (DMP), di-iso-butyl-phthalate (DIBP) and phthalic acid (PA). This is the first report of DBP mineralization assisted with A. flavus, using it as a sole carbon source. SDBP4 will be further formulated to develop an eco-benign product for the bioremediation of DBP-contaminated toxic sanitary landfill soils. © 2023 by the authors.
First record of Texas citrus mite, Eutetranychus banksi (McGregor) infesting neem (Azadirachta indica A. Juss) from India
(Malhotra Publishing House, 2021) Ramesh Singh Yadav; Gopal Prasad Painkra; Dharmpal Kerketta; Dharmendra Kumar; Mahadevan Raghuraman
During the present investigation a series of samples of an unusual spider mite were collected from the Neem, Azadirachta indica A. Juss in the Zamania, Ghazipur of Uttar Pradesh, India. The collected mite fauna was identified as the Texas citrus mite, Eutetranychus banksi (McGregor) (Trombidiformes: Tetranychidae) causing notable harms to the overall plant in the early stage of this naturally grown early aged plants in the field condition during the cold winter season of 2018-2020. It has emerged as a new pest of neem, Azadirachta indica A. Juss plants in India and first time reported for the country during present study © 2021, Journal of Entomological Research.All Rights Reserved.
In vitro antimicrobial activity of o-phenylenediamine-tert-butyl-N-1,2,3-triazole carbamate analogs
(Birkhauser Boston, 2014) Manavendra Kumar Singh; Mayank Gangwar; Dharmendra Kumar; Ragini Tilak; Gopal Nath; Alka Agarwal
In an attempt to design and synthesize effective antimicrobial agents using click chemistry, mono- and di-alkyne-substituted monoboc protected o-phenylenediamines were reacted with different substituted aryl azides which yielded 18 new compounds (4a-4k and 5a-5f, 5l). Structures of all newly synthesized compounds were established by 1H and 13C NMR analysis. The intermediate compound 1 was also confirmed by X-ray crystallography. The title compounds were screened for their antibacterial activity against Gram +ve bacteria (Staphylococcus aureus and Enterococcus faecalis), Gram -ve bacteria (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa), and their antifungal profile were tested on (Candida tropicalis , Candida albicans, Candida krusei, and Cryptococcus neoformans) as well as on molds such as (Aspergillus niger, Aspergillus fumigatus). The compounds 4k and 5f both showed maximum potency against S. aureus (ATCC 25323) strain with MIC value of 6.25 μg/ml, which is comparable with standard drug ciprofloxacin (MIC 6.25 μg/ml) while remaining compounds showed moderate to weak activity. Further, all compounds showed average antifungal activity in the range of 100-200 μg/ml. © Springer Science+Business Media New York 2014.
Insect-pests complex of cabbage, Brassica Oleracea var. Capitata in Varanasi, Uttar Pradesh
(2014) Ramesh Singh Yadav; Dharmendra Kumar; D.K. Singh; S.K. Singh
During the intensive survey in rabi season of 2007 and 2008 in Varanasi, Uttar Pradesh of cabbage, Brassica oleracea var. capitata fields, 23 different insect-pests' species with seven different orders were recorded. Out of which maximum 31% insect-pests species of order Lepidoptera and minimum 5% insect-pests species of order Diptera and Isoptera were found in the investigation. Diamond back moth, Plutella xylostella (L.) and cabbage head borer, Hellula undalis Fab recorded high in population. Among natural enemies, predators were rove beetle, Paederus sp. and lady bird beetle, Coccinella septumpunctata L.; parasitoids, Diaeretiella rapae and Cotesia plutellae were also recorded.
Itraconazole-resistant Candida auris with phospholipase, proteinase and hemolysin activity from a case of vulvovaginitis
(Journal of Infection in Developing Countries, 2015) Dharmendra Kumar; Tuhina Banerjee; Chandra Bhan Pratap; Ragini Tilak
Since the emergence of pathogenic non-albicans Candida species, a number of new isolates have been added to the list. One such unusual species is Candida auris (C. auris), recently isolated and studied in few reports. In this study, a case of vulvovaginitis caused by Candida auris incidentally identified by molecular methods using internal transcribed spacer polymerase chain reaction (ITS PCR) is described. Antifungal susceptibility testing revealed the isolate to be resistant to itraconazole (MIC ≥ 2 μg/ml) and expressed important virulence factors including phospholipase, proteinase and hemolysin activity. The patient was successfully treated with oral fluconazole and did not have any invasive fungemia. Very few cases of this emerging pathogen have been reported. However, its isolation from clinical specimens reveals the significance of non-albicans candida species over C. albicans and the diversity of Candida spp causing infections. © 2015, Kumar et al.
Mechanisms of Stress Tolerance in Cyanobacteria under Extreme Conditions
(Multidisciplinary Digital Publishing Institute (MDPI), 2022) Priya Yadav; Rahul Prasad Singh; Shashank Rana; Diksha Joshi; Dharmendra Kumar; Nikunj Bhardwaj; Rajan Kumar Gupta; Ajay Kumar
Cyanobacteria are oxygen-evolving photoautotrophs with worldwide distribution in every possible habitat, and they account for half of the global primary productivity. Because of their ability to thrive in a hostile environment, cyanobacteria are categorized as “extremophiles”. They have evolved a fascinating repository of distinct secondary metabolites and biomolecules to promote their development and survival in various habitats, including severe conditions. However, developing new proteins/enzymes and metabolites is mostly directed by an appropriate gene regulation system that results in stress adaptations. However, only few proteins have been characterized to date that have the potential to improve resistance against abiotic stresses. As a result, studying environmental stress responses to post-genomic analysis, such as proteome changes using latest structural proteomics and synthetic biology techniques, is critical. In this regard, scientists working on these topics will benefit greatly from the stress of proteomics research. Progress in these disciplines will aid in understanding cyanobacteria’s physiology, biochemical, and metabolic systems. This review summarizes the most recent key findings of cyanobacterial proteome study under various abiotic stresses and the application of secondary metabolites formed during different abiotic conditions. © 2022 by the authors.
Microbial biosurfactant: A new frontier for sustainable agriculture and pharmaceutical industries
(MDPI, 2021) Ajay Kumar; Sandeep Kumar Singh; Chandra Kant; Hariom Verma; Dharmendra Kumar; Prem Pratap Singh; Arpan Modi; Samir Droby; Mahipal Singh Kesawat; Hemasundar Alavilli; Shashi Kant Bhatia; Ganesh Dattatraya Saratale; Rijuta Ganesh Saratale; Sang-Min Chung; Manu Kumar
In the current scenario of changing climatic conditions and the rising global population, there is an urgent need to explore novel, efficient, and economical natural products for the benefit of humankind. Biosurfactants are one of the latest explored microbial synthesized biomolecules that have been used in numerous fields, including agriculture, pharmaceuticals, cosmetics, food processing, and environment-cleaning industries, as a source of raw materials, for the lubrication, wetting, foaming, emulsions formulations, and as stabilizing dispersions. The amphiphilic nature of biosurfactants have shown to be a great advantage, distributing themselves into two immiscible surfaces by reducing the interfacial surface tension and increasing the solubility of hydrophobic compounds. Furthermore, their eco-friendly nature, low or even no toxic nature, durability at higher temperatures, and ability to withstand a wide range of pH fluctuations make microbial surfactants preferable compared to their chemical counterparts. Additionally, biosurfactants can obviate the oxidation flow by eliciting antioxidant properties, antimicrobial and anticancer activities, and drug delivery systems, further broadening their applicability in the food and pharmaceutical industries. Nowadays, biosurfactants have been broadly utilized to improve the soil quality by improving the concentration of trace elements and have either been mixed with pesticides or applied singly on the plant surfaces for plant disease management. In the present review, we summarize the latest research on microbial synthesized biosurfactant compounds, the limiting factors of biosurfactant production, their application in improving soil quality and plant disease management, and their use as antioxidant or antimicrobial compounds in the pharmaceutical industries. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Morpho-anatomical and biochemical adapting strategies of maize (Zea mays L.) seedlings against lead and chromium stresses
(Elsevier Ltd, 2015) Swati Singh; Prabhat Kumar Srivastava; Dharmendra Kumar; Durgesh Kumar Tripathi; Devendra Kumar Chauhan; Sheo Mohan Prasad
This study was aimed to investigate an impact of different concentrations of lead (Pb: 50-300μM) and chromium (Cr: 50-300μM) on maize seedlings (Zea mays L.). Results revealed that Pb and Cr at their 300μM concentrations showed significant (P<0.05) reduction in growth, photosynthetic pigments, protein and mineral contents (except S), which were accompanied by a significant increase in the accumulation of Pb and Cr, lipid peroxidation (measured as malondialdehyde; MDA) and hydrogen peroxide (H2O2). Mineral distribution and anatomical traits were also severely affected at 300μM of Pb and Cr concentration. Moreover, in comparison to Pb, different Cr treatments up to 200μM showed severe toxicity responses and significantly hampered the growth, photosynthetic pigments, minerals (except S) and anatomical features of the maize seedlings due to an increase in the accumulation of Cr in tissues and oxidative stress.Shoot and root anatomy of maize seedlings was severely affected up to 200. μM concentration of Cr while Pb showed trivial impact on anatomical features. Interestingly, the thickness of leaf midrib increased which could be correlated with the increased level of Pb and Cr in the cell wall, representing an approach to avoid their translocation to photosynthetic tissues. Epiblema and endodermis of the root were thickened while cortical cells were degraded. An increase in the number of protoxylem, perhaps had increased the availability of water in roots under different concentrations of Pb and Cr which could have protected the plants under the stress conditions. © 2015 Elsevier Ltd.