Papers by Prabhat Nath Jha
Frontiers in Microbiology
Bacterial biofilms are clinically admissible and illustrate an influential role in infections, pa... more Bacterial biofilms are clinically admissible and illustrate an influential role in infections, particularly those related to the implant of medical devices. The characterization of biofilms is important to understand the etiology of the diseases. Enterobacter cloacae are known for causing infections by forming biofilms on various abiotic surfaces, such as medical devices. However, a detailed characterization in terms of morphology and the molecular composition of the formed biofilms by this bacterium is sparse. The present study provides insights into the biofilm formation of E. cloacae SBP-8, an environmental isolate, on various surfaces. We performed assays to understand the biofilm-forming capability of the SBP-8 strain and characterized the adhering potential of the bacteria on the surface of different medical devices (foley latex catheter, enteral feeding tube, and glass) at different temperatures. We found that medical devices exhibited strong colonization by E. cloacae SBP-8....
Frontiers in Microbiology
Polychlorinated biphenyls (PCBs) are persistent organic pollutants widely distributed in the envi... more Polychlorinated biphenyls (PCBs) are persistent organic pollutants widely distributed in the environment and possess deleterious health effects. The main objective of the study was to obtain bacterial isolates from PCB-contaminated soil for enhanced biodegradation of PCB-77. Selective enrichment resulted in the isolation of 33 strains of PCB-contaminated soil nearby Bhilai steel plant, Chhattisgarh, India. Based on the prominent growth using biphenyl as the sole carbon source and the confirmation of its degradation by GC-MS/MS analysis, four isolates were selected for further study. The isolates identified by 16S rRNA gene sequencing were Pseudomonas aeruginosa MAPB-2, Pseudomonas plecoglossicida MAPB-6, Brucella anthropi MAPB-9, and Priestia megaterium MAPB-27. The isolate MAPB-9 showed a degradation of 66.15% biphenyl, while MAPB-2, MAPB-6, and MAPB-27 showed a degradation of 62.06, 57.02, and 56.55%, respectively in 48 h. Additionally, the degradation ability of these strains was...
PLOS ONE
Plant growth promoting rhizobacterium (PGPR) designated as ZNP-4, isolated from the rhizosphere o... more Plant growth promoting rhizobacterium (PGPR) designated as ZNP-4, isolated from the rhizosphere of Ziziphus nummularia, was identified as Enterobacter cloacae following 16S rRNA sequence analysis. The isolated strain exhibited various plant growth promoting (PGP) traits. The 1-aminocyclopropane-1-carboxylic acid deaminase (ACCD) activity was evaluated under diverse physiological conditions that could be useful for minimizing the abiotic stress-induced inhibitory effects on wheat plants. The strain showed resistance to salt (NaCl) and metal (ZnSO4) stress. The effect of E. cloacae ZNP-4 on the augmentation of plant growth was studied under salinity stress of 150 mM (T1 treatment) & 200 mM (T2 treatment) NaCl. The inoculation of strain ZNP-4 significantly improved the various growth parameters of wheat plant such as shoot length (41%), root length (31%), fresh weight (28%), dry weight (29%), photosynthetic pigments chlorophyll a (62%) and chlorophyll b (34%). Additionally, the strain ...
Iron and steel industries are the major contributors to persistent organic pollutants (POPs). The... more Iron and steel industries are the major contributors to persistent organic pollutants (POPs). The microbial community present at such sites has potential to remediate these contaminants. The present study highlights the metabolic potential of resident microbial community of PAHs and PCB contaminated soil nearby Bhilai steel plant, Chhattisgarh (India). The GC-MS/MS analysis of soil samples MGB-2 (sludge) and MGB-3 (dry soil) resulted in identification of different classes of POPs including PAHs {benzo[a]anthracene (nd; 17.69%), fluorene (15.89%, nd), pyrene (nd; 18.7%), benzo(b)fluoranthene (3.03%, nd), benzo(k)fluoranthene (11.29%; nd), perylene (5.23%; nd)} and PCBs (PCB-15, PCB-95, and PCB-136). Whole-genome metagenomic analysis by Oxford Nanopore GridION Technology revealed Proteobacteria (44.3%; 50.0%) to be the prominent phylum followed by Actinobacteria (22.1%; 19.5%) in MBG-2 and MBG-3, respectively. The sample MGB-3 was richer in terms of macronutrients (C, N, P) supporting...
Critical assessment of five eutrophicated ponds of Varanasi city (India) revealed the presence of... more Critical assessment of five eutrophicated ponds of Varanasi city (India) revealed the presence of heavy blooms of cyanobacteria consisting mainly of Microcystis aeruginosa. Crude aqueous extracts of blooms as well as laboratory grown M. aeruginosa isolated from three ponds, namely Lakshmikund, Durgakund and Adityanagar showed toxicity in mouse bioassay test. Crude aqueous extracts from these samples caused death of test mice within 1h of administration (i.p.) with a LD50 of 60 mg/kg body weight and the treated animals showed clinical signs of hepatotoxicity. However such an effect was not associated with the blooms from Laatbhairov and Surajkund ponds suggesting that not all strains of M. aeruginosa are toxic. Based on spectral properties (λmax 230 nm), and comparison with standard microcystin-LR, the toxin is tentatively identified as microcystin-LR. The purified toxin caused death of test mice within 40 min of its administration with a LD50 of 100 µg/ kg body weight and induced gr...
Land
Diazotrophic endophytic bacteria (DEB) are the key drivers of nitrogen fixation in rainfed soil e... more Diazotrophic endophytic bacteria (DEB) are the key drivers of nitrogen fixation in rainfed soil ecosystems and, hence, can influence the growth and yield of crop plants. Therefore, the present work investigated the structure and composition of the DEB community at different growth stages of field-grown pearl millet plants, employing the cultivation-dependent method. Diazotrophy of the bacterial isolates was confirmed by acetylene reduction assay and amplification of the nifH gene. ERIC-PCR-based DNA fingerprinting, followed by 16S rRNA gene analysis of isolates recovered at different time intervals, demonstrated the highest bacterial diversity during early (up to 28 DAS (Days after sowing)) and late (63 DAS onwards) stages, as compared to the vegetative growth stage (28–56 DAS). Among all species, Pseudomonas aeruginosa was the most dominant endophyte. Assuming modulation of the immune response as one of the tactics for successful colonization of P. aeruginosa PM389, we studied the ...
Bioorganic & medicinal chemistry letters, Jul 1, 2016
A series of bis(indolyl)glyoxylamides 10a-n has been designed and synthesized. In situ generated ... more A series of bis(indolyl)glyoxylamides 10a-n has been designed and synthesized. In situ generated indole-3-glyoxalylchloride from the reaction of readily available indole 9 with oxalyl chloride was treated with tryptamine to produce bis(indolyl)glyoxylamides 10a-n in 82-93% yields. All the synthesized bis(indolyl)glyoxylamides were well characterized and tested for their antibacterial activity against Gram-positive and Gram-negative bacterial strains. Compounds 10d, 10g and 10i were found to display potent antibacterial activity against Gram-negative strain. Further, the cytotoxicity of bis(indolyl)glyoxylamides 10a-n were evaluated against a panel of human cancer cell lines. Of the screened analogues, compound 10f (IC50=22.34μM; HeLa, 24.05μM; PC-3, 21.13μM; MDA-MB-231 and 29.94μM; BxPC-3) was identified as the most potent analogue of the series. Exposure of PC-3 cells to either 10a or 10f resulted in increased levels of cleaved PARP1, indicating that bis(indolyl)glyoxylamides induc...
Anti-Infective Agents, 2016
Background: AIDS continues to be a major public health issue worldwide. In 2014, an estimated 36.... more Background: AIDS continues to be a major public health issue worldwide. In 2014, an estimated 36.9 million people were living with HIV, in the same year, around 1.2 million people died due to AIDS-related illnesses. Due to global efforts particularly made in the last decade has reduced mortality rate due to AIDS and associated diseases. But still many people living with HIV/AIDS particularly in the low and middle income countries do not have access of anti-HIV drugs. Moreover, still there is no permanent cure of disease and rapid emergence of drug resistance by HIV towards the current available therapy further drive the need for the search of new potential anti-HIV drugs. Methods: In the present study, fifteen novel 2-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)-N-phenylpropanamide derivatives (5a-o) were designed as HIV-1 Reverse Transcriptase (RT) inhibitors, in-silico evaluated for drug likeness behaviour, synthesized and characterized. Compounds were evaluated in-vitro for inhibition of HIV-1 RT activity. Three compounds (5a, 5f and 5o) as representative of the series were evaluated for cytotoxicity studies on human T lymphocytes (C8166 cells). All the synthesized compounds were also evaluated for in-vitro antibacterial (E. coli, P. putida, S. aureus and B. cereus) and antifungal (C. albicans and A. niger) activity. Results: All compounds (5a-o) possessed drug-likeness behavior based upon their in-silico predicted drug-likeness properties. Five compounds 5f, 5h, 5i, 5k and 5n exhibited more than 50% inhibition of HIV-1 RT, in which compound 5h showed highest inhibition (61%). Cytotoxicity studies of compounds 5a, 5f and 5o on T lymphocytes revealed that, all three exhibited CC 50 >200 µg/ml. Four compounds 5f, 5i, 5j and 5n showed significant inhibition against the tested G(-) ve (E. coli and P. putida) bacterial strains while one compound 5f significantly inhibited the growth of all tested bacterial strains. Among the series, four compounds (5e, 5f, 5i and 5m) significantly inhibited the growth of A. niger, while compound 5m exhibited significant inhibition of both the tested fungal strains. Conclusion: Titled compounds (5a-o) exhibited weak to significant inhibition of HIV-1 RT, particularly 5h. Four compounds showed significant anti-bacterial activity against the both tested G(-)ve bacterial strains, moreover compound 5f significantly inhibited the growth of all four tested bacterial strains. Four compounds significantly inhibited the growth of A. niger, in which compound 5m exhibited significant inhibition of both the tested fungal strains.
Genomics Data, 2017
Here, we report the draft genome sequence and annotation of plant growth promoting rhizobacterium... more Here, we report the draft genome sequence and annotation of plant growth promoting rhizobacterium Enterobacter cloacae SBP-8 isolated from the rhizosphere of Sorghum bicolor L. growing in desert region of Rajasthan, India. From the genome sequences, we identified the genes encoding plant growth promoting properties such as 1-aminocyclopropane-1-carboxylate deaminase (AcdS), phosphate solubilisation, siderophore, and IAA (indole acetic acid) production. The genes encoding different functions required for colonization including motility, chemotaxis, adherence, and secretion system (I, II, IV, VI) were also identified. The complete genome sequence of this bacterium consists of one chromosome (48,54,065 bp) and one plasmid (85,398). The genome sequence of Enterobacter cloacae SBP-8 was deposited in the Genbank with the accession number CP016906 (chromosome) and CP017413 (plasmid).
A vast increase in population, urbanization and industrialization has shrunken agriculture land a... more A vast increase in population, urbanization and industrialization has shrunken agriculture land and thus, affected demand vs. food supply ratio. Exploitation and manipulation of beneficial bacteria-plant association can be most effective and eco-friendly to enhance plant growth and productivity in sustainable manner. Various bioinoculants tested in several crops are found to be effective under laboratory conditions but showed inconsistencies in field studies. Therefore, present study aimed to adopt a systematic approach from lab to natural conditions for providing better and stable bioinoculants. In addition, to broaden the application of selected bacterial inoculants, cross infection studies were performed. Ability of endophytic bacteria to promote growth of pearl millet plant was tested at laboratory, greenhouse and field condition. They were screened and sorted out for various levels on the basis of various plant growth parameters. Bioinoculants of field trial were inoculated to ...
A B S T R A C T Erwinia carotovora, an important gram-negative, rod-shaped bacteria (Family Enter... more A B S T R A C T Erwinia carotovora, an important gram-negative, rod-shaped bacteria (Family Enterobacteriaceae), causes soft rot diseases on wide variety of crop species, chiefly potato which is characterized by blackleg of potato plants and soft rot of its tubers during the storage condition, thus causing extreme yield losses worldwide. The aim of proposed review is to depicts the current status and analyze the molecular diversity of E. carotovora, recovered from potato and highlighting the various techniques or methods used for Erwinia diseases management.
Microbial Interventions in Agriculture and Environment
Plants face various biotic and abiotic environmental stresses in their lifetime. These environmen... more Plants face various biotic and abiotic environmental stresses in their lifetime. These environmental impacts reduce plant growth and productivity. Out of abiotic stressors, drought, salt, heat, and heavy metal ion contamination are the major challenges faced by plants. For overcoming these challenges, plants adopt certain physiological and biochemical changes. These changes include a variation in an aspect ratio of root-shoot length, leaf wilting, leaf abscission, generation of reactive oxygen species (ROS), altered relative water content, and accumulation of free radicals that can disrupt cellular homeostasis, thereby affecting cell viability. Plants also produce stress hormones, namely, abscisic acid and stress ethylene which induce closure of leaf stomata leading to reduced water loss from the plants and withstand various molecular and metabolic changes. Plants undergo physiological and metabolic changes, activating signal transduction mechanism to re-establish cellular homeostasis to generate tolerance against various abiotic stressors. The expression of stress-responsive genes is regulated not only by protein regulators but also by various regulatory RNAs.
Welcome to Current Topics in Biotechnology and Microbiology. This book provides the basics as wel... more Welcome to Current Topics in Biotechnology and Microbiology. This book provides the basics as well as new ideas in Biotechnology and Microbiology in a narrative and lucid style. The modern techniques employed in Nano-biotechnology, Genetic Engineering, Biotechnology and Microbiology are discussed in a comprehensive manner which will update the readers of Biotechnology and Microbiology field. This book is aimed to develop scientific and research skill along with the basic knowledge in the undergraduate and postgraduate students.
Transactions of the IMF
The purpose of this study was to test the effectiveness of group guidance based on Javanese chara... more The purpose of this study was to test the effectiveness of group guidance based on Javanese character to improve student resilience. This type of research was a quantitative research with one group Pre-test-Post-test design. The data collection technique was in the form of a resilience scale. The research subjects were 7 students who were taken randomly. The data analysis technique used non-parametric statistics with the Wilcoxon technique. The result of the Wilcoxon test showed the value of Z =-2,371 with asymp sid (2-tailed) 0.018. It's means that there was a significant difference of student resilience level between Pre-test and Post-test. So this means that there was significant difference between before and after the application of group guidance. For further research can be done by develop a group guidance guide or the other experimental research design.
International Journal of Phytoremediation
Abstract This study focused on isolation of bacteria with biphenyl/polychlorinated biphenyl (PCB)... more Abstract This study focused on isolation of bacteria with biphenyl/polychlorinated biphenyl (PCB) degrading ability from the rhizosphere of Morus alba (mulberry plant). Repetitive enrichment of rhizospheric soil samples with biphenyl resulted in the isolation of Rhodococcus sp. MAPN-1, identified by 16S rRNA gene sequence analysis. The bacterium showed growth on five different aromatic compounds (naphthalene, salicylic acid, benzoic acid, dibenzofuran and anthracene). Benzoic acid was detected as the major metabolite during biphenyl degradation using high-performance thin-layer chromatography (HPTLC) with Rf 0.42 at 254 nm. Further GC-MS/MS study showed 95% and 15% degradation of biphenyl and dichlorobiphenyl, respectively. A pot study was conducted to evaluate the effect of presence of biphenyl on M. alba and the role of biphenyl degrader Rhodococcus sp. MAPN-1 in relation to phytoremediation. Morus alba twigs in biphenyl spiked soil (100 mg/kg and 300 mg/kg) inoculated with Rhodococcus sp. MAPN-1 showed growth, whereas, growth of plants (control) was adversely affected in biphenyl-spiked uninoculated soil. It is the first report of isolation of Rhodococcus sp. MAPN-1 from the rhizosphere of Morus alba, its capability to degrade biphenyl, thereby showing a positive effect on the plant growth grown in biphenyl spiked soil.
Microbial Pathogenesis
Enterobacter cloacae, an opportunistic nosocomial pathogen, is reported to possess different viru... more Enterobacter cloacae, an opportunistic nosocomial pathogen, is reported to possess different virulence factors that could potentially influence its pathogenesis. Generally, the E. cloacae infections are of endogenous origin occurring in immunocompromised patients. The mechanisms of pathogenicity remain elusive, possibly due to the absence of established model hosts. Thus, we explored the utility of Caenorhabditis elegans as a model host to test the pathogenicity of E. cloacae SBP-8, a soil isolate. E. cloacae SBP-8 progressively colonized the intestine of C. elegans. It induced cell death (as assessed through DNA damage), reproductive defect and reduction of lifespan, comparable to a clinical isolate, E. cloacae (MTCC 509). Observation with Nomarski microscopy revealed significant anterior pharyngeal distention, and altered egg arrangement with internal egg hatching in 70% infected worms. The internal egg hatching was observed as early as 48 h post infection. E. cloacae SBP-8 infection reduced the brood size by 16%. A 2',7'-dichlorodihydrofluorescein diacetate staining confirmed the 10-fold induction of reactive oxygen species implicating either mitochondrial damage or septic shock in infected worms. Expression analysis through RT-PCR indicated stimulation of immune response by E. cloacae SBP-8 in worms by upregulating tol-1, a Toll-like receptor, within 6 h of exposure. During the initial phase of infection (up to 24 h) the nematodes exhibited protective immune response by upregulating antimicrobial peptide genes, lys-1, clec-60, clec-85, and clec-87. However, these genes were downregulated at later hours (48 h), indicating the nematodes surrendered to the infection. A similar trend was observed for reproductive genes (lin-29 and let-23), suggesting a struggle to maintain functional reproduction by the nematodes. These results clearly demonstrate the pathogenic potential of E. cloacae SBP-8 and suggest the suitability of C. elegans as a model organism to study its pathogenesis. This is the first study indicating that E. cloacae infections could potentially originate from an exogenic source (here soil).
Symbiosis
A halotolerant plant-growth-promoting rhizobacteria (PGPR) can ameliorate salt stress in associat... more A halotolerant plant-growth-promoting rhizobacteria (PGPR) can ameliorate salt stress in associated plants by various mechanisms. Therefore, the present study aimed to characterize a PGPR Klebsiella sp. SBP-8 for its ability to tolerate salt stress and to study the mechanism of PGPR-mediated mitigation of salt stress in the wheat plant. The abiotic stressors result in multiple changes in the fatty acid composition of Klebsiella sp. SBP-8, helping the membrane to keep its integrity, fluidity, and function for its growth under salt (NaCl) stress conditions. The changes in fatty acid composition of test organism were analyzed by fatty acid methyl ester (FAME) analysis under varying saline conditions. The spectroscopy (GC-MS) profile of cell extract at different salt concentrations was comprised of hydrocarbons, and fatty alcohols with varying carbon chain length. Inoculation of Klebsiella sp. SBP-8 to wheat seedling showed increase in proline, total soluble sugar, and total protein content of treated plants. Bacterial inoculation also decreased the concentration of salinity-induced malondialdehyde (MDA) content. In addition, bacterial inoculation also increased the various antioxidative enzymes like superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) in treated plants. It is likely that bacterial inoculation alleviated the salt stress to wheat plant by co-ordination of antioxidative machinery, and improvement in osmolyte contents. Therefore, the present study suggests that bacterial-inoculated wheat plants were able to cope better with salt stress than uninoculated control, therefore it can serve as a promising bio-inoculant for enhancing the growth of wheat like cereal crops under saline stress.
Environmental Sustainability
Plant-microbe and soil interactions are one of the oldest muse for multidisciplinary researchers.... more Plant-microbe and soil interactions are one of the oldest muse for multidisciplinary researchers. Plant growth promoting microorganisms influence the host physiology by secreting regulatory chemical signals in the vicinity of plant roots and play a key role in the enhancement of plant growth and expansion. The present review deals with the in-depth understanding of steps involved in host tissues colonization by bacterial endophytes. The molecular insights of these events, particularly for endophytic bacteria, are poorly documented till date. The endophytic bacteria must coexist with the host plant and capable of colonizing the internal plant tissues without being recognized as a pathogen. A proper understanding of exchange of signals between the host plant and bacterial communities is required which may facilitate the development of new strategies to promote beneficial interactions between them. This knowledge can be instrumental in agricultural practices as well as for phytoremediation of pollutants. Keeping these facts in mind, the present review attempts to explore the systematic understanding of steps involved and molecular insights of plant colonization events by endophytic bacteria. We conclude that molecular mechanisms and factors affecting endophytic bacterial colonization deserve more research attention in order to exploit their beneficial aspects for sustainable agriculture and environment.
Ecological Engineering
A metal resistant bacterium was isolated from the rhizosphere of Kair ‘Capparis decidua’ and scre... more A metal resistant bacterium was isolated from the rhizosphere of Kair ‘Capparis decidua’ and screened for its phytoextraction ability under gradient metal stress conditions. Based on 16S rDNA analysis, the strain was identified as Enterobacter ludwigii. Among the plant growth promoting traits, isolate showed the ACC (1-aminocyclopropane-1-carboxylate) deaminase activity, production of indole-3-acetic acid in tryptophan supplemented medium and solubilize the inorganic phosphate. The isolate was resistant to heavy metals like zinc (Zn), nickel (Ni), copper (Cu), and cadmium (Cd). The fatty acid adaptation of isolate growing at different concentration of Zn (100–300 mg kg−1) was also studied, which indicated that metal concentration strongly influenced the fatty acid composition of bacterium, particularly by increasing the unsaturated fatty acids. Furthermore, inoculation with the test isolate was found to significantly (p < 0.01) increase the various growth parameters of wheat plants and also improve the photosynthetic pigments. In addition, inoculation with isolate resulted in significant (p < 0.01) increase in the Zn content in wheat plant under metal stress. Moreover, bacterial application significantly (p < 0.01) increased the various compatible solutes such as proline content (30–65%), total soluble sugar (9–49%), and decreased the malondialdehyde (MDA) content (38–47%) as compared to control, illustrating its protective effect under metal induced oxidative stress. Inoculation with test isolate also increased the total protein content in range of 16–52%. Our work revealed that metal resistant plant growth promoting rhizobacterium could be exploited as microbial mediated phytoremediation of metal polluted soils.
Letters in Organic Chemistry
The paper describes the synthesis of quinoline-4-carboxylic acid derivatives employing completely... more The paper describes the synthesis of quinoline-4-carboxylic acid derivatives employing completely green methods such as the use of water as solvent and of microwave irradiation for heating. The prepared molecules were examined for bactericidal and antifungal behavior and two of the tested compounds showed reasonably good antimicrobial activity. The biological activity results were further corroborated by fluorescence microscopy and by evaluating their time-dependent bactericidal behavior. Two of the most potent compounds were then subjected to docking against DNA gyrase protein (PDB ID: 2XCT) showing possible interactions responsible for the potency of these compounds. Also, an SAR analysis was proposed based on the results obtained.
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Papers by Prabhat Nath Jha