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Heavy metal toxicity affects aquatic plants and animals, disturbing biodiversity and ecological balance causing bioaccumulation of heavy metals. Industrialization and urbanization are inevitable in modern-day life, and control and detoxification methods need to be accorded to meet the hazardous environment. Microorganisms and plants have been widely used in the bioremediation of heavy metals. Sporosarcina pasteurii, a gram-positive bacterium that is widely known for its calcite precipitation property in bio-cementing applications has been explored in the study for its metal tolerance ability for the first time. S. pasteurii SRMNP1 (KF214757) can tolerate silver stress to form nanoparticles and can remediate multiple heavy metals to promote the growth of various plants. This astounding property of the isolate warranted extensive examinations to comprehend the physiological changes during an external heavy metal stress condition. The present study aimed to understand various physiological responses occurring in S. pasteuriiSRMNP1 during the metal tolerance phenomenon using electron microscopy. The isolate was subjected to heavy metal stress, and a transmission electron microscope examination was used to analyze the physiological changes in bacteria to evade the metal stress. S. pasteurii SRMNP1 was tolerant against a wide range of heavy metal ions and can withstand a broad pH range (5-9). Transmission Electron Microscopy (TEM) examination of S. pasteurii SRMNP1 followed by 5 mM nickel sulfate treatment revealed the presence of nanovesicles encapsulating nanosized particles in intra and extracellular spaces. This suggests that the bacteria evade the metal stress by converting the metal ions into nanosized particles and encapsulating them within nanovesicles to efflux them through the vesicle budding mechanism. Moreover, the TEM images revealed an excessive secretion of extracellular polymeric substances by the strain to discharge the metal particles outside the bacterial system. S. pasteurii can be foreseen as an effective bioremediation agent with the potential to produce nanosized particles, nanovesicles, and extracellular polymeric substances. This study provides physiological evidence that, besides calcium precipitation applications, S. pasteurii can further be explored for its multidimensional roles in the fields of drug delivery and environmental engineering.
Assuntos
Metais Pesados , Poluentes do Solo , Matriz Extracelular de Substâncias Poliméricas , Solo , Metais Pesados/toxicidade , Metais Pesados/química , Prata , Biodegradação Ambiental , Bactérias , Íons , Poluentes do Solo/toxicidadeRESUMO
In the present era of climate change and global warming, high temperatures have increased considerably, posing a threat to plant life. Heat stress affects the biochemistry, physiology and molecular makeup of the plant by altering the key processes, i.e., photosynthesis, respiration and reproduction which reduces its growth and development. There is a dire need to manage this problem sustainably for plant conservation as well as the food security of the human population. Use of phytohormones to induce thermotolerance in plants can be a sustainable way to fight the adversities of heat stress. Phytohormone-induced thermotolerance proves to be a compelling approach to sustainably relieve the damaging effects of heat stress on plants. Salicylic acid (SA) is an essential molecule in biotic and abiotic defense response signal transduction pathways. When supplied externally, it imparts heat stress tolerance to the plants by different means, viz., increased Heat Shock Proteins (HSP) production, Reactive oxygen species (ROS) scavenging, protection of the reproductive system and enhancing photosynthetic efficiency. The effect of SA on plants is highly dependent on the concentration applied, plant species, plant age, type of tissues treated, and duration of the treatment. The present review paper summarizes the mechanism of thermotolerance induced by salicylic acid in plants under heat stress conditions. It includes the regulatory effects of SA on heat shock proteins, antioxidant metabolism, and maintenance of Ca2+ homeostasis under heat stress. This review combines the studies conducted to elucidate the role of SA in the modulation of different mechanisms which lead to heat stress tolerance in plants. It discusses the mechanism of SA in protecting the photosynthetic machinery and reproductive system during high-temperature stress.
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Resposta ao Choque Térmico , Ácido Salicílico , Humanos , Ácido Salicílico/farmacologia , Fotossíntese , Antioxidantes/farmacologia , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/farmacologia , Estresse FisiológicoRESUMO
The agricultural sustainability concept considers higher food production combating biotic and abiotic stresses, socio-economic well-being, and environmental conservation. On the contrary, global warming-led climatic changes have appalling consequences on agriculture, generating shifting rainfall patterns, high temperature, CO2, drought, etc., prompting abiotic stress conditions for plants. Such stresses abandon the plants to thrive, demoting food productivity and ultimately hampering food security. Though environmental issues are natural and cannot be regulated, plants can still be enabled to endure these abnormal abiotic conditions, reinforcing the stress resilience in an eco-friendly fashion by incorporating fungal endophytes. Endophytic fungi are a group of subtle, non-pathogenic microorganisms establishing a mutualistic association with diverse plant species. Their varied association with the host plant under dynamic environments boosts the endogenic tolerance mechanism of the host plant against various stresses via overall modulations of local and systemic mechanisms accompanied by higher antioxidants secretion, ample enough to scavenge Reactive Oxygen Species (ROS) hence, coping over-expression of defensive redox regulatory system of host plant as an aversion to stressed condition. They are also reported to ameliorate plants toward biotic stress mitigation and elevate phytohormone levels forging them worthy enough to be used as biocontrol agents and as biofertilizers against various pathogens, promoting crop improvement and soil improvement, respectively. This review summarizes the present-day conception of the endophytic fungi, their diversity in various crops, and the molecular mechanism behind abiotic and biotic resistance prompting climate-resilient aided sustainable agriculture.
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Overwhelming anthropogenic activities lead to deterioration of natural resources and the environment. The microorganisms are considered desirable, due to their suitability for easy genetic manipulation and handling. With the aid of modern biotechnological techniques, the culturable microorganisms have been widely exploited for the benefit of mankind. Metagenomics, a powerful tool to access the abundant biodiversity of the environmental samples including the unculturable microbes, to determine microbial diversity and population structure, their ecological roles and expose novel genes of interest. This review focuses on the microbial adaptations to the adverse environmental conditions, metagenomic techniques employed towards microbial biotechnology. Metagenomic approach helps to understand microbial ecology and to identify useful microbial derivatives like antibiotics, toxins, and enzymes with diverse and enhanced function. It also summarizes the application of metagenomics in clinical diagnosis, improving microbial ecology, therapeutics, xenobiotic degradation and impact on agricultural crops.
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Toxic metal contamination in soils due industrialization is nowadays a concern to the scientists worldwide. The current study deals with the evaluation of response and tolerance by isolated metallophilic bacteria in different lead concentrations (100 ppm to 1000 ppm). By taking optical densities of the isolates, the minimum inhibitory concentration (MIC) of Pb2+ were determined.16S rRNA and MALDI-TOF MS were used for the identification of the bacteria. Total of 37 isolates were observed, among them 04 (Staphylococcus equorum, Staphylococcus warneri, Bacillus safensis and Bacillus thuringiensis), isolated were detected having efficacy of Pb2+tolerance and sequestration at varying MIC. Furthermore, B. thuringiensis was observed to have highest (900 ppm) tolerance for lead and lowest (500 ppm) for Staphylococcus warneri. Moreover, the highest (65.3%) sequestration potential has been observed for B. thuringiensis and least (52.8%) for S. warneri. The tolerance and sequestration potential properties of these isolated species can be utilised to exterminate heavy metals and reduce their toxicity from the contaminated environment.
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Pesticide residual persistence in agriculture soil selectively increases the pesticide-degrading population and transfers the pesticide-degrading gene to other populations, leading to cross-resistance to a wide range of antibiotics. The enzymes that degrade pesticides can also catabolize the antibiotics by inducing changes in the gene or protein structure through induced mutations. The present work focuses on the pesticide-degrading bacteria isolated from an agricultural field that develop cross-resistance to antibiotics. This cross-resistance is developed through catabolic gene clusters present in an extrachromosomal plasmid. A larger plasmid (236.7 Kbp) isolated from Bacillus sp. was sequenced by next-generation sequencing, and important features such as α-ß hydrolase, DNA topoisomerase, DNA polymerase III subunit beta, reverse transcriptase, plasmid replication rep X, recombination U, transposase, and S-formylglutathione hydrolase were found in this plasmid. Among these, the α-ß hydrolase enzyme is known for the degradation of organophosphate pesticides. The cloning and expression of the α-ß hydrolase gene imply nonspecific cleavage of antibiotics through a cross-resistance phenomenon in the host. The docking of α-ß hydrolase with a spectrum of antibiotics showed a high G-score against chloramphenicol (-3.793), streptomycin (-2.865), cefotaxime (-5.885), ampicillin (-4.316), and tetracycline (-3.972). This study concludes that continuous exposure to pesticide residues may lead to the emergence of multidrug-resistant strains among the wild microbial flora.
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Antibacterianos/farmacologia , Bacillus , Proteínas de Bactérias , Clonagem Molecular , Farmacorresistência Bacteriana/genética , Organofosfatos/metabolismo , Praguicidas/metabolismo , Monoéster Fosfórico Hidrolases , Plasmídeos , Bacillus/enzimologia , Bacillus/genética , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Organofosfatos/farmacologia , Praguicidas/farmacologia , Monoéster Fosfórico Hidrolases/biossíntese , Monoéster Fosfórico Hidrolases/genética , Plasmídeos/genética , Plasmídeos/metabolismoRESUMO
Arnebia benthamii of the family Boraginaceae is a critically endangered nonendemic plant of the Kashmir Himalayas and is used to treat a number of human diseases. The current study was based on developing an in vitro micropropagation protocol vis-à-vis induction of various secondary metabolites under in vitro conditions for the possible biological activity. A tissue culture protocol was developed for A. benthamii for the first time in the Himalayan region using varied combinations and proper media formulations, including various adjuvants: Murashige and Skoog (MS) media, growth hormones, sugars, agar, and so forth. The influence of different media combinations was estimated, and the MS + thidiazuron (TDZ) + indole 3-acetic acid (IAA) combination favors a higher regeneration potential. The higher amounts of chemical constituents were also recorded on the same treatment. The in vitro plant samples also showed a noteworthy effect of scavenging of hydroxyl radicals vis-à-vis protection from oxidative DNA damage. The in vitro raised plants are good candidates for the development of antioxidant molecules.
Assuntos
Antioxidantes/química , Boraginaceae/química , Dano ao DNA/efeitos dos fármacos , Composição de Medicamentos , Compostos Fitoquímicos/farmacologia , Animais , Antioxidantes/uso terapêutico , Bovinos , DNA/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Humanos , Ácidos Indolacéticos/química , Ácidos Indolacéticos/farmacologia , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologia , Compostos Fitoquímicos/química , Reguladores de Crescimento de Plantas/química , Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/química , Brotos de Planta/química , Plantas Medicinais/química , Regeneração/efeitos dos fármacos , Tiadiazóis/química , Tiadiazóis/farmacologia , Técnicas de Cultura de TecidosRESUMO
Multidrug-resistant (MDR) bacteria are a growing threat to humans across the world. Antibiotic resistance is a global problem that has developed through continuous antibiotic use, combinatorial antibiotic use, pesticide-antibiotic cross-resistance, and horizontal gene transfer, as well as various other modes. Pesticide-antibiotic cross-resistance and the subsequent expansion of drug-resistant bacteria are critically documented in this review, the primary focus of which is to assess the impact of indiscriminate pesticide use on the development of microbial communities with parallel pesticide and multidrug resistance. The consumption of pesticide-contaminated food products and the use of broad-spectrum antibiotics by humans and in livestock animals have favored the development of both antibiotic and pesticide-resistant bacterial flora via natural selection. Pesticide resistance mainly develops through defensive bacterial adaptations such as biofilm formation, induced mutations, and horizontal/vertical gene transfer through plasmids or transposons, as well as through the increased expression of certain hydrolytic enzymes. Pesticide resistance genes are always transferred as gene clusters, and they may also carry genes essential for antibiotic resistance. Moreover, for some induced mutations, the mutated active site of the affected enzyme may allow degradation of both pesticides and antibiotics, resulting in cross-resistance. A few studies have shown that the sub-lethal exposure of wild-type strains to herbicides induces antibiotic resistance. This review concludes that xenobiotic exposure leads to cross-resistance in wild microbial flora, which requires further study to develop therapeutic approaches to overcome the threats of MDR bacteria and superbugs.
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Bactérias/genética , Bactérias/metabolismo , Farmacorresistência Bacteriana Múltipla/genética , Farmacorresistência Bacteriana Múltipla/fisiologia , Transferência Genética Horizontal , Praguicidas/metabolismo , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/enzimologia , Fenômenos Fisiológicos Bacterianos , Proteínas de Bactérias/genética , Biodegradação Ambiental , Produtos Agrícolas/microbiologia , Elementos de DNA Transponíveis , Microbiologia Ambiental , Poluição Ambiental , Ligantes , Praguicidas/farmacologia , Plasmídeos/genética , Seleção GenéticaRESUMO
The antimicrobial properties of morel compounds from wild edible mushrooms (Morchella esculenta and Verpa bohemica) from Kashmir valley was investigated against different clinical pathogens. The butanol crude fraction of most popular or true morel M. esculenta showed highest 19 mm IZD against E.coli while as same fraction of Verpa bohemica exhibited 15 mm IZD against same strain. The ethyl acetate and butanol crude fractions of both morels also exhibited good antifungal activity with highest IZD shown against A. fumigates. The three morel compounds showed quite impressive anti bacterial and fungal activities. The Cpd 3 showed highest inhibitory activity almost equivalent to the synthetic antibiotics used as control. The MIC/MBC values revealed the efficiency of isolated compounds against the pathogenic strains. In the current study significant inhibitory activity of morel compounds have been obtained paying the way for their local use from ancient times.
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Agaricales/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Acetatos/química , Anti-Infecciosos/isolamento & purificação , Antifúngicos/farmacologia , Ascomicetos/química , Aspergillus fumigatus/efeitos dos fármacos , Butanóis/química , Escherichia coli/efeitos dos fármacos , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/isolamento & purificaçãoRESUMO
Impacts of pesticide exposure on the soil microbial flora and cross resistance to antibiotics have not been well documented. Development of antibiotic resistance is a common issue among soil bacteria which are exposing to pesticides continuously at sub-lethal concentration. The present study was focused to evaluate the correlation between pesticide exposures and evolution of multi drug resistance among isolates collected from soil applied with insecticides. Twenty five insecticide (Monochrotophos) degrading bacteria were isolated from contaminated agricultural soil. The bacterial isolates Bacillus Sps, Bacillus cereus, Bacillus firmus and Bacillus thuringiensis were found to be resistant against chloramphenical, monochrotophos, ampicillin, cefotaxime, streptomycin and tetracycline antibiotics used. Involvement of plasmid in drug as well as insecticide resistant was confirmed through plasmid curing among selected bacterial strains. Bacillus Sps (MK-07), Bacillus cereus (MK-11), Bacillus firmus (MK-13) and Bacillus thuringiensis (MK-24) lost their resistant against insecticides and antibiotics once after removal of plasmid by exposing to 2% sodium dodecyl sulphate. The plasmid was transformed back to bacteria which produced similar derivatives when cultured in Minimal Salt medium (pH 7.0) supplemented with 0.4% of insecticide. Homology modeling was used to prove that organophosphorus hydrolase and able to metabolize all the antibiotics showed positive interaction with high docking score. The present study revealed that persistent of insecticides in the agricultural soil may lead to increasing development of multidrug resistance among soil bacteria.
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Bactérias/efeitos dos fármacos , Inseticidas/farmacologia , Microbiologia do Solo , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Arildialquilfosfatase/química , Arildialquilfosfatase/metabolismo , Bacillus/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Proteínas de Bactérias/química , Cloranfenicol/farmacologia , Produtos Agrícolas/microbiologia , Farmacorresistência Bacteriana Múltipla , Inseticidas/farmacocinética , Testes de Sensibilidade Microbiana , Filogenia , Solo/químicaRESUMO
The primary aspiration in the microbial observatory is to advance the understanding of freshwater bacterioplankton, whose diversity and population dynamics are currently the least understood off all freshwater planktonic organisms. Through identification and characterization of bacterial populations in a suite of fresh water bodies, we are able to gain significant new insight into the ecological niches of bacteria in diverse freshwater ecosystems. Given the facts that lakes and other inland freshwaters play a more critical role in the global carbon budget and that lakes have been described as early indicators of both regional and global environmental change, the role of microbes in these processes is of renewed interest. In this review, general overview will be given highlighting the characteristic features of bacterial species thriving in different water bodies. In the following sections, different cultural approaches vis a vis the controlling factors of bacterial diversity have been elaborated. In the concluding sections, the prospects of aquatic microbial diversity are well mentioned.
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Bactérias/classificação , Biodiversidade , Água Doce/microbiologia , Microbiologia da Água , Ecossistema , Concentração de Íons de Hidrogênio , TemperaturaRESUMO
This study pertains to the radical scavenging potential of and DNA protection by Helvella lacunosa, an edible mushroom from Kashmir Himalaya (India). Different solvents, on the basis of their polarities, were used to extract all solvent-soluble bioactive compounds. Seven different antioxidant methods were also used to determine extensive radical scavenging activity. The mushroom ethanol extract and butanol extract showed effective scavenging activity of radicals at 95% and 89%, respectively. At 800 µg/mg, the ethanol extract was potent enough to protect DNA from degradation by hydroxyl radicals. It is evident from these findings that the presence of antioxidant substances signifies the use of H. lacunosa as food in the mountainous valleys of the Himalayan region.
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Antioxidantes/farmacologia , Ascomicetos/química , Dano ao DNA/efeitos dos fármacos , Carpóforos/química , Antioxidantes/química , Compostos de Bifenilo , Picratos , Superóxido DismutaseRESUMO
The aim of current research was to evaluate the physiological adjustment in three medicinal herbs viz., Atropa acuminata, Lupinus polyphyllus and Hyoscyamus niger to the winter period characterised by intense UV flux in Kashmir valley across the North Western Himalaya. Quinolizidine (QA) and tropane alkaloid (TA) concentrations were analysed in these herbs thriving at two different altitudes via GC-MS and correlated by PCA analysis. This study investigated the hypothesis that UV reflectance and absorbance at low temperatures are directly related to disparity in alkaloid accumulation. Among QAs in L. polyphyllus, ammodendrine and lupanine accumulated at higher concentration and exhibited significant variation of 186.36% and 95.91% in ammodendrine and lupanine respectively in both sites. Tetrahydrohombifoline displayed non-significant variation of about 9.60% irrespective of sites. Among tropane alkaloid (TA), hyoscyamine was recorded as the most abundant constituent irrespective of the plant and site while apotropine accumulated in lesser quantity in A. acuminata than H. niger. However, apotropine demonstrated significant variation of 175% among both sites. The final concentration of quinolizidine (QA) and tropane alkaloid (TA) reflects the interplay between reflectance and absorbance of UV radiation response field. These findings suggest that spectral response of UV light contributes directly to alkaloid biosynthesis.
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Alcaloides/análise , Atropa/química , Hyoscyamus/química , Lupinus/química , Raios Ultravioleta , Alcaloides/biossíntese , Atropa/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hyoscyamus/metabolismo , Lupinus/metabolismo , Piperidinas/análise , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo , Análise de Componente Principal , Piridinas/análise , Quinolizidinas/química , Esparteína/análogos & derivados , Esparteína/análise , Temperatura , Tropanos/químicaRESUMO
Herbs adapted to diverse climates exhibit distinct variability to fluctuating temperatures and demonstrate various metabolic and physiological adaptations to harsh environments. In this research, Rumex dentatus L. and Lavandula officinalis L. were collected before snowfall in September-November to evaluate variability in major phytoconstituents to diverse seasonal regime. LC-MS was used for simultaneous determination of eight anthraquinone derivatives in R. dentatus, i.e. emodin, physcion, chrysophanol, physcion glucoside, endocrocin, emodin glucoside, chrysophanol glucoside and chromone derivatives and monoterpenes in L. officinalis i.e. (Z)-ß-ocimene, (E)-ß-ocimene, terpene alcohol, terpin-4-ol, acetate ester-linalyl acetate and bicyclic sesquiterpene (E)-caryophyllene. The correlation analysis confirmed significant variation in anthraquinone glucoside and terpene content within Rumex and Lavender, respectively, and altitude was established as the determinant factor in secondary metabolism of both herbs. The study concludes the propagation of herbs in bioclimatic belts which favour accumulation of major constituents and validate their greater pharmacological activity.
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Antraquinonas/metabolismo , Lavandula/metabolismo , Rumex/metabolismo , Estações do Ano , Terpenos/metabolismo , Adaptação Fisiológica , Clima , Índia , TemperaturaRESUMO
A complete protocol for the saffron cormlet production under in vitro conditions and subsequent flowering under greenhouse conditions is described. Highest number of cormlets (70.0 ± 0.30) per corm slice (explant) could be regenerated on Murashige and Skoog (MS) half strength medium supplemented with thidiazuron (TDZ) (20 µM), Indole acetic acid (IAA) (10 µM), and sucrose (40 g/l). Maximum germination (90%) of these cormlets could be achieved on MS medium containing 6-benzyl amino purine (BAP) (20 µM) and α-naphthalene acetic acid (NAA) (15 µM). In order to increase the size of the in vitro raised cormlets, these were cultured on MS medium containing TDZ (15 µM) and IAA in the range of 1.5-30 µM. Maximum increase in cormlet size could be attained on TDZ (15 µM) + IAA (12.5 µM) + sucrose (30 g/l), and the average size of cormlets was 2.5g. In another experiment, apical vegetative buds of actively growing corms were cultured for cormlet development, and corms of size 2.5g could be developed on MS medium with NAA (15 µM), BAP (20 µM), and sucrose (30 g/l). The in vitro developed cormlets were dried under shade at 25 ± 2°C for 7 d. These were then planted in small cups containing clay loam soil and kept in green house at 20 ± 2°C. In vitro developed cormlets with mean weight 2.5 g showed maximum flowering (25%) as well as vegetative growth (55%), while only 19% cormlets of 2.0 g flowered. To our knowledge this is the first report on successful flowering from in vitro raised cormlets under greenhouse.