Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Biopolymers ; : e23603, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38888353

RESUMO

Globally sustainable disease management ensuring high quality in grapes is in demand as it holds significant importance as a versatile fruit for consumption, winemaking, and production of various products such as grape juice, raisin, and grape-seed oil. The present paper reports a combination of nano-biotechnology as a promising strategy for enhancing plant health and fruit productivity in grapes combining Irradiated chitosan nanoparticles and bio-control agents. The Irradiated Chitosan with Bacillus subtilis and Trichoderma viridae and pesticides were evaluated for disease management. Percent disease index, percent disease control, and percent yield enhancement in Cymoxanil 8% + Mamcozeb 64% WP @ 0.2% treatment were as 17. 24%, 67.97% and 33.91% in 150 ppm Irradiated chitosan+B. subtilis were 19.83, 63.16, 30.41 and in Trichoderma 150 ppm Irradiated chitosan were 24.58, 54.33, and 27.40, respectively as compared to untreated crop with disease severity 53.84% PDI. Thus, irradiated chitosan and Bacillus subtilis elucidated a synergistic combination for residue-free efficient phytosanitary measures, which harnessed the strength of chitosan and bio-control agents for sustainable grape productivity. These findings will also pave the way for a deeper understanding of the synergistic interaction between Irradiated nanochitosan and bio-control agents for an eco-friendly and economically viable disease management strategy. The minimum temperature and morning relative humidity (RH I) had positive significance, with correlation coefficients of 0.484 and 0.485, respectively. The evening relative humidity (RH II) had a positive highly significant positive correlation coefficient of 0.664. Chitosan merits as a multiple stress tolerance enhancing agent that will further help in mitigating climate change adaptations in grapevines reducing reliance on chemical agro-inputs.

2.
Crit Rev Microbiol ; 48(4): 428-449, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34595998

RESUMO

Almost sixty years ago, Bdellovibrio and like organisms (BALOs) were discovered as the first obligate bacterial predators of other bacteria known to science. Since then, they were shown to be diverse and ubiquitous in the environment, and to bear astonishing ecological, physiological, and metabolic capabilities. The last decade has seen important strides made in understanding the mechanistic basis of their life cycle, the dynamics of their interactions with prey, along with significant developments towards their use in medicine, agriculture, and industry. This review details these achievements, identify current understanding and knowledge gaps to encourage and guide future BALO research.


Assuntos
Bdellovibrio , Bactérias/genética , Bdellovibrio/fisiologia
3.
Int Microbiol ; 25(4): 831-838, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35857219

RESUMO

Bjerkandera adusta can decompose polycyclic aromatic hydrocarbons including cellulose and lignin, but its roles in inhibiting plant pathogens are unclear. Here, the confrontation culture and greenhouse pot experiments were employed to study the control effect of B. adusta M1 on Fusarium graminearum and wheat scab. The results showed that B. adusta M1 fermentation broth (FB) inhibited the growth of F. graminearum, with an inhibition rate of 52.7-89.17%. FB had a significant control effect (72.14 ± 1.42%) on wheat scab, which was slightly lower than that of the chemical fungicide carbendazim (77.34 ± 1.76%). The growth rate was significantly higher in B. adusta M1 than in F. graminearum, indicating a strong competitiveness by B. adusta M1. The images from a scanning electron microscope showed substantial deformations of the hyphae of F. graminearum being penetrated by the hyphae of B. adusta M1, indicating a strong mycoparasitism by B. adusta M1. In addition, FB increased the activity of catalase, peroxidase, and phenylalanine ammonia-lyase in wheat leaves related to disease resistance and decreased the malondialdehyde production and cell membrane permeability. We conclude that B. adusta M1 is a promising fungal agent to control the detriment of F. graminearum to cereal growth in the field.


Assuntos
Coriolaceae , Fungicidas Industriais , Hidrocarbonetos Policíclicos Aromáticos , Catalase , Fungicidas Industriais/farmacologia , Lignina , Malondialdeído , Fenilalanina Amônia-Liase , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Triticum/microbiologia
4.
Pestic Biochem Physiol ; 187: 105199, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127070

RESUMO

Biocontrol microbes are environment-friendly and safe for humans and animals. To seek biocontrol microbes effective in suppressing tomato gray mold is important for tomato production. Therefore, serial experiments were conducted to characterize the antagonism of Bacillus velezensis HY19, a novel self-isolated biocontrol bacterium, against Botrytis cinerea in vitro and the control on tomato gray mold in greenhouse. This bacterium produced extracellular phosphatase, protease, cellulose and siderophores, and considerably inhibited the growth of B. cinerea. A liquid chromatography-mass spectrometry (LC-MS) detected salicylic acid and numerous antifungal substances present in B. velezensis HY19 fermentation liquid (BVFL). When B. cinerea was grown on potato glucose agar, BVFL crude extract remarkably suppressed the fungal growth and reduced protein content and the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD). Transcriptome studies showed that BVFL crude extract significantly induced different expression of numerous genes in B. cinerea, most of which were down-regulated. Theses differently expressed genes were involved in the biological process, cell compartment, molecular functions, and metabolisms of glycine, serine, threonine, and sulfur in pathogen hyphae. Thus, this biocontrol bacterium antagonized B. cinerea in multiple ways due to the production of numerous antifungal substances that acted on multiple targets in the cells. BVFL significantly increased antioxidant enzyme activities in tomato leaves and decreased the incidence of tomato gray mold, with the control efficacies of 73.12-76.51%. Taken together, B. velezensis HY19 showed a promising use potential as a powerful bioagent against tomato gray mold.


Assuntos
Solanum lycopersicum , Ágar/farmacologia , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Bacillus , Catalase , Celulose/farmacologia , Misturas Complexas/farmacologia , Glucose/farmacologia , Glicina/farmacologia , Solanum lycopersicum/microbiologia , Peptídeo Hidrolases/farmacologia , Monoéster Fosfórico Hidrolases/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Ácido Salicílico/farmacologia , Serina/farmacologia , Sideróforos/farmacologia , Enxofre/farmacologia , Superóxido Dismutase , Treonina/farmacologia
5.
Arch Microbiol ; 203(6): 3257-3268, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33837802

RESUMO

This study aimed to identify four isolates of Trichoderma sp. (Ufra.T06, Ufra.T09, Ufra.T12, and Ufra.T52) and characterize their interaction with Magnaporthe oryzae in vitro and in vivo conditions. The four isolates of Trichoderma sp. were sequenced, investigated as an antagonist against M. oryzae in five Petri plate assays, and as an inhibitor of conidial germination appressoria formation. Finally, were quantified the lytic activity of chitinase (CHI), glucanase (GLU), and protease (PRO) during co-cultivation of Trichoderma sp. and M. oryzae. In vivo, leaf blast suppression was evaluated in two assays: simultaneous and curative application. Both in vitro and in vivo assays were scanned by electron microscopy (SEM). All isolates were identified as Trichoderma asperellum. All in vitro Petri plates assays reduced M. oryzae colony growth (paired-91.18% by Ufra.T09, volatile metabolites-all isolates equally reduced, non-volatile-68.33% by Ufra.T06, thermostability-99.77% by Ufra.T52 and co-cultivate-64.25% by Ufra.T52). The filtrates and conidia suspensions for T. asperellum isolates inhibited the conidia germination and appressoria formation significantly. In co-cultivate (mycelial or cell wall), all enzymes (GLU, CHI, and PRO) and times (24, 48, and 72 h) showed increased activity. In vivo, reduced leaf blast severity until 94.64% (Ufra.T52cs) in a simultaneous and until 85% (Ufra.T09 24 and 48 hasi) in a curative application. T. asperellum isolates showed efficient control of M. oryzae by mycoparasitism, and antibiosis mechanisms were interfered with by the M. oryzae infection process.


Assuntos
Antibiose , Ascomicetos , Hypocreales , Oryza , Ascomicetos/fisiologia , Ascomicetos/ultraestrutura , Hypocreales/genética , Hypocreales/ultraestrutura , Oryza/microbiologia , Doenças das Plantas/microbiologia
6.
BMC Microbiol ; 20(1): 299, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33008296

RESUMO

BACKGROUND: Root-knot nematode is one of the most significant diseases of vegetable crops in the world. Biological control with microbial antagonists has been emerged as a promising and eco-friendly treatment to control pathogens. The aim of this study was to screen and identify novel biocontrol agents against root-knot nematode, Meloidogyne incognita. RESULTS: A total of 890 fungal isolates were obtained from rhizosphere soil of different crops and screened by nematicidal activity assays. Snef1910 strain showed high virulence against second stage juveniles (J2s) of M. incognita and identified as Trichoderma citrinoviride by morphology analysis and biomolecular assay. Furthermore, T. citrinoviride Snef1910 significantly inhibited egg hatching with the hatching inhibition percentages of 90.27, 77.50, and 67.06% at 48, 72, and 96 h after the treatment, respectively. The results of pot experiment showed that the metabolites of T. citrinoviride Snef1910 significantly decreased the number of root galls, J2s, and nematode egg masses and J2s population density in soil and significantly promoted the growth of tomato plants. In the field experiment, the biocontrol application showed that the control efficacy of T. citrinoviride Snef1910 against root-knot nematode was more than 50%. Meanwhile, T. citrinoviride Snef1910 increased the tomato plant biomass. CONCLUSIONS: T. citrinoviride strain Snef1910 could be used as a potential biological control agent against root-knot nematode, M. incognita.


Assuntos
Agentes de Controle Biológico , Hypocreales/crescimento & desenvolvimento , Controle Biológico de Vetores/métodos , Doenças das Plantas/prevenção & controle , Solanum lycopersicum/parasitologia , Tylenchoidea/microbiologia , Animais , Produtos Agrícolas/parasitologia , Humanos , Doenças das Plantas/parasitologia , Raízes de Plantas/parasitologia , Rizosfera , Solo/parasitologia , Tylenchoidea/crescimento & desenvolvimento , Tylenchoidea/patogenicidade
8.
Braz J Microbiol ; 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39083222

RESUMO

The use of yeast to biologically control the production of ochratoxin A, which is caused by filamentous fungal growth, in coffee farms is a promising alternative to conventional methods. However, yeast strains, environmental field conditions, and the chemical composition of grains / fruits can influence the effectiveness of biological control agents. We tested the efficiency of different yeast strains in controlling three species of ochratoxigenic fungi in a coffee-based medium. The reasons and mechanisms behind the varying sensitivities of different Aspergillus species to biological control remains unclear. Aspergillus carbonarius rapidly assimilated carbon sources, giving it an advantage over yeasts in substrate colonisation. Saccharomyces cerevisiae CCMA 0159 inhibited all three fungal species, achieving efficiencies of 74.4%, 100%, and 80.9% against A. carbonarius, A. westerdijkiae, and A. ochraceus, respectively. The strategies employed by S. cerevisiae CCMA 0159 to inhibit the growth of ochratoxigenic fungi included competition, production of fungicidal volatile compounds, and alteration of the substrate's physicochemical properties. Our results indicate that among the yeast isolates tested, S. cerevisiae CCMA 0159 is the most effective in inhibiting ochratoxigenic fungi in coffee, including the more resistant A. carbonarius.

9.
J Spec Oper Med ; 23(1): 92-95, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36753717

RESUMO

Crimean-Congo Hemorrhagic Fever (CCHF) is the most widespread tickborne virus causing human disease. CCHF wields a mortality rate up to 30% and was responsible for the death of a US Soldier in 2009. The virus is spread by the Hyalomma species of hard tick found across Central Europe, the Middle East, Africa, and Asia south of the 50° parallel. Infection typically consists of a 1-7-day non-specific viral prodrome, followed by onset of hemorrhagic disease on days 7-10. Severe disease may cause thrombocytopenia, transaminitis, petechial hemorrhage, hematemesis, and death typically by day 10 of illness. Education and insect control are paramount to disease prevention. Treatment is predominantly supportive care, though evidence suggests a benefit of early ribavirin administration. CCHF has caused multiple nosocomial outbreaks, and therefore consideration should be given to safe transport and evacuation of infected and exposed patients. Given the wide area of distribution, transmissibility, innocuous arthropod vectors, and high mortality rate, it is imperative that Special Operations Forces (SOF) providers be aware of CCHF and the existing countermeasures.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Humanos , Febre Hemorrágica da Crimeia/diagnóstico , Febre Hemorrágica da Crimeia/epidemiologia , Febre Hemorrágica da Crimeia/prevenção & controle , África , Oriente Médio , Surtos de Doenças
10.
AMB Express ; 13(1): 119, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37870667

RESUMO

The protection of post-harvest infection by Fusarium spp. is a major worldwide demand, especially using effective natural alternatives to chemical fungicides. In this respect, selenium nanoparticles (SeNPs) were biosynthesized using Fenugreek seeds aqueous extract. Bio-mediated SeNPs were characterized using XRD, FTIR, UV-Vis, TEM, and EDX. XRD confirmed the crystalline nature with six characteristic peaks corresponding to Se-nanocrystals. TEM showed spherical-shaped SeNPs with 34.02-63.61 nm diameter. FTIR verified the presence of different bio-functional groups, such as, N-H, O-H, C-N, and C-NH2 acting as stabilizing/reducing agents during the biosynthesis. Bio-mediated SeNPs exhibited excellent biocidal activity against F. oxysporum and F. moniliforme, with MIC of 0.25 and 1.7 mg/mL, respectively. Direct treatment of F. oxysporum with SeNPs led to significant deformation and lysis of the fungal hyphae within 18 h. The treatment of infected fruits with MIC of SeNPs reduced the infection signs by 100% and preserved the fresh-like appearance of treated fruits for 25 and 35 days when stored at 25 °C and 5 °C, respectively. Therefore, SeNPs is considered efficacious fungicidal against Fusarium spp. in-vitro and in-vivo. The treatment of tomato fruits with MIC of SeNPs positively affected its chemical properties, as well as decreased weight loss %, confirming the barrier effect of SeNPs, thus increasing fruits' shelf-life. Bio-mediated SeNPs appeared safe towards normal HSF and OEC cell lines with IC50> 300 µg/mL. Overall results recommend the usage of bio-mediated SeNPs as safe powerful bioagent against Fusarium infection, maintaining tomato quality, and providing protection from post-harvest invasion and/or destroying existing infections.

11.
Life (Basel) ; 13(6)2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37374140

RESUMO

The utilization of beneficial endophytic microorganisms presents a promising and innovative strategy for attaining environmental sustainability and fostering development. The majority of microbial bioagents are unsuitable for preparation in a suitable granular formula, and few are prepared in complicated formulas. In this work, Trichoderma viride was simply prepared in a marketable granular formula to manage Rhizoctonia solani and improve common bean growth. The GC-MS analysis showed several antimicrobial compounds in the fungal filtrate. T. viride was able to suppress the phytopathogenic R. solani in the laboratory. The formula had up to 6 months of shelf-life viability. Under greenhouse conditions, the formula improved plant resistance against R. solani. Moreover, the vegetative plant growth and physiological performance (peroxidase, polyphenol, total phenols, phenylalanine ammonia-lyase, and photosynthetic pigments) of the common bean showed obvious promotion. The formula reduced the disease incidence by 82.68% and increased the yield by 69.28%. This work may be considered a step in the right direction for producing simple bioactive products on a large scale. Moreover, the study's findings suggest that this method can be considered a novel approach to enhancing plant growth and protection, in addition to reducing costs, improving handling and application, and maintaining fungal viability for enhancing plant growth and protecting against fungal infections.

12.
Pathogens ; 11(2)2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35215152

RESUMO

Cell culture systems have greatly expanded our understanding of how bacterial pathogens target signaling pathways to manipulate the host and cause infection. Advances in genetic engineering have allowed for the creation of fluorescent protein readouts within signaling pathways, but these techniques have been underutilized in pathogen biology. Here, we genetically engineered a lung cell line with fluorescent reporters for extracellular signal-related kinase (ERK) and the downstream transcription factor FOS-related antigen 1 (Fra1) and evaluated signaling after inoculation with pathogenic and non-pathogenic bacteria. Cells were inoculated with 100 colony-forming units of Acinetobacter baylyi, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus agalactiae, or Staphylococcus epidermidis and imaged in a multi-mode reader. The alamarBlue cell viability assay was used as a reference test and showed that pathogenic P. aeruginosa induced significant (p < 0.05) cell death after 8 h in both wild-type and engineered cell lines compared to non-pathogenic S. epidermidis. In engineered cells, we found that Fra1 signaling was disrupted in as little as 4 h after inoculation with bacterial pathogens compared to delayed disruption in signaling by non-pathogenic S. epidermidis. Overall, we demonstrate that low levels of pathogenic versus non-pathogenic bacteria can be rapidly and sensitively screened based on ERK-Fra1 signaling.

13.
Front Med (Lausanne) ; 9: 847620, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35492309

RESUMO

The interdiction of restricted and hazardous biological agents presents challenges for any detection method due to the inherent complexity of sample type and accessibility. Detection capabilities for this category of agents are limited and restricted in their mobility, adaptability and efficiency. The potential for identifying biological agents through a volatile organic compound (VOC) signature presents an opportunity to use detection dogs in a real-time mobile capacity for surveillance and screening strategies. However, the safe handling and access to the materials needed for training detection dogs on restricted or hazardous biological agents prevents its broader application in this field. This study evaluated the use of a polymer-based training aid in a viral detection model using bovine viral diarrhea virus mimicking biosafety level 3+ agent conditions. After the biological agent-based odor was absorbed into the polymer, the aid was rendered safe for handling through a rigorous sterilization process. The viral culture-based training aid was then used to train a cohort of detection dogs (n = 6) to discriminate agent-based target odor in culture from relevant distractor odors including non-target biological agent-based odors. Following culture-based training, dogs were tested for generalization to aids with infected animal sample-based odors across five sample types (fecal, blood, nasal, saliva, and urine). Within the context of the polymer-based training aid system, dogs were successfully trained to detect and discriminate a representative biological viral agent-based odor from distractor odors with a 97.22% (±2.78) sensitivity and 97.11% (±1.94) specificity. Generalization from the agent-based odor to sample-based odors ranged from 65.40% (±8.98) to 91.90 % (±6.15) sensitivity and 88.61% (±1.46) to 96.00% (±0.89) specificity across the sample types. The restrictive nature for mimicking the access and handling of a BSL 3+ agent presented challenges that required a strict study design uncommon to standard detection dog training and odor presentation. This study demonstrates the need to further evaluate the utility and challenges of training detection dogs to alert to biological samples using safe and manageable training aids.

14.
Pathogens ; 10(11)2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34832652

RESUMO

As of 2021, the biothreat policy and research communities organize their efforts around lists of priority agents, which elides consideration of novel pathogens and biotoxins. For example, the Select Agents and Toxins list is composed of agents that historic biological warfare programs had weaponized or that have previously caused great harm during natural outbreaks. Similarly, lists of priority agents promulgated by the World Health Organization and the National Institute of Allergy and Infectious Diseases are composed of previously known pathogens and biotoxins. To fill this gap, we argue that the research/scientific and biodefense/biosecurity communities should categorize agents based on how they impact their hosts to augment current list-based paradigms. Specifically, we propose integrating the results of multi-omics studies to identify bioagent-agnostic signatures (BASs) of disease-namely, patterns of biomarkers that accurately and reproducibly predict the impacts of infection or intoxication without prior knowledge of the causative agent. Here, we highlight three pathways that investigators might exploit as sources of signals to construct BASs and their applicability to this framework. The research community will need to forge robust interdisciplinary teams to surmount substantial experimental, technical, and data analytic challenges that stand in the way of our long-term vision. However, if successful, our functionality-based BAS model could present a means to more effectively surveil for and treat known and novel agents alike.

15.
Front Bioeng Biotechnol ; 9: 642760, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33996779

RESUMO

A recent study on the immunotherapy treatment of renal cell carcinoma reveals better outcomes in obese patients compared to lean subjects. This enigmatic contradiction has been explained, in the context of the debated obesity paradox, as the effect produced by the cell-cell interaction network on the tumor microenvironment during the immune response. To better understand this hypothesis, we provide a computational framework for the in silico study of the tumor behavior. The starting model of the tumor, based on the cell-cell interaction network, has been described as a multiagent system, whose simulation generates the hypothesized effects on the tumor microenvironment. The medical needs in the immunotherapy design meet the capabilities of a multiagent simulator to reproduce the dynamics of the cell-cell interaction network, meaning a reaction to environmental changes introduced through the experimental data.

16.
Insects ; 11(11)2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33158029

RESUMO

A trend towards environmentally friendly chemicals for use in termite management has been occurring globally. This study examined three naturally occurring plant extracts from Lavandula latifolia (Spike lavender), Origanum vulgare (Marjorum), and Syzygium aromaticum (Clove) against the termite Microcerotermes eugnathus. Plant extract results were compared to two commercially used termite pesticides, the bio-insecticide, Bacillus thuringiensis var. kurstaki (Protecto 9.4% WP) and Dursban (Chlorpyrifos 48%). Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the main compounds in the three plant extracts. The main compounds in Lavandula Latifolia were linalool (21.49%), lavandulol (12.77%), ß-terpinyl acetate (10.49%), and camphor (9.30%). Origanum vulgare extract contained thymol (14.64%), m-cymene (10.63%), linalool (6.75%), and terpinen-4-ol (6.92%) as main compounds. Syzygium aromaticum contained eugenol (99.16%) as the most abundant identified compound. The extract of O. vulgare caused the highest termite death rate, with an LC50 of 770.67 mg/L. Exposure to lavender extract showed a high death rate with an LC50 of 1086.39 mg/L. Clove extract did not show significant insecticidal activity with an LC50 > 2000 mg/L. Significant termiticide effects were found, with LC50 values of 84.09 and 269.98 mg/L for soldiers and workers under the application of Dursban and Protecto, respectively. The LC50 values reported for nymphs were <120, <164.5, and 627.87 mg/L after exposure to Dursban, Protecto, and O. vulgare extract, respectively. The results of the study show that some of the extracts have low toxicity compared to the bioagent and Dursban, and may show promise as natural termiticides, particularly as extracts from O. vulgare.

17.
J Anim Sci Biotechnol ; 10: 15, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30886709

RESUMO

BACKGROUND: Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets. However, the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA. Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes. Hence, the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements. RESULTS: All the studied LAB isolates were versatile extracellular protease producers, whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5, pH 6.5, pH 8) using qualitative and quantitative proteolytic assays. The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14, while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5. As for the results of AA production conducted in de Man, Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system, all LAB isolates were capable of producing an array of AA. Generally, Pediococcus sp. showed greater ability for AA production as compared to Lactobacillus sp. Moreover, the studied LAB were able to produce a few major feed supplement AA such as methionine, lysine, threonine and tryptophan. P. pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively. However, L. plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h, while P. acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity. CONCLUSION: All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine, lysine, threonine and tryptophan. Despite AA production was strain dependent, the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.

19.
Environ Sci Pollut Res Int ; 24(3): 2956-2965, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27844322

RESUMO

Microorganisms are considered a genetic resource with great potential for achieving sustainable development of agricultural areas. The objective of this research was to determine the effect of microorganism application forms on the production of biomass, gas exchange, and nutrient content in upland rice. The experiment was conducted under greenhouse conditions in a completely randomized design in a factorial 7 × 3 + 1, with four replications. The treatments consisted of combining seven microorganisms with three application forms (microbiolized seed; microbiolized seed + soil drenched with a microorganism suspension at 7 and 15 days after sowing (DAS); and microbiolized seed + plant sprayed with a microorganism suspension at 7 and 15 DAS) and a control (water). Treatments with Serratia sp. (BRM32114), Bacillus sp. (BRM32110 and BRM32109), and Trichoderma asperellum pool provided, on average, the highest photosynthetic rate values and dry matter biomass of rice shoots. Plants treated with Burkolderia sp. (BRM32113), Serratia sp. (BRM32114), and Pseudomonas sp. (BRM32111 and BRM32112) led to the greatest nutrient uptake by rice shoots. Serratia sp. (BRM 32114) was the most effective for promoting an increase in the photosynthetic rate, and for the greatest accumulation of nutrients and dry matter at 84 DAS, in rice shoots, which differed from the control treatment. The use of microorganisms can bring numerous benefits of rice, such as improving physiological characteristics, nutrient uptake, biomass production, and grain yield.


Assuntos
Biomassa , Conservação dos Recursos Naturais , Oryza/crescimento & desenvolvimento , Agricultura , Sementes/crescimento & desenvolvimento
20.
Environ Sci Pollut Res Int ; 24(32): 25233-25242, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28929284

RESUMO

Microorganisms can promote plant growth by increasing phytomass production, nutrient uptake, photosynthesis rates, and grain yield, which can result in higher profits for farmers. However, there is limited information available about the physiological characteristics of lowland rice after treatment with beneficial microorganisms in the tropical region. This study aimed to determine the effects of different beneficial microorganisms and various application forms on phytomass production, gas exchange, and nutrient contents in the lowland rice cultivar 'BRS Catiana' in a tropical region. The experiment was performed under greenhouse conditions utilizing a completely randomized design and a 7 × 3 + 1 factorial scheme with four replications. The treatments consisted of seven microorganisms, including the rhizobacterial isolates BRM 32113, BRM 32111, BRM 32114, BRM 32112, BRM 32109, and BRM 32110 and Trichoderma asperellum pooled isolates UFRA-06, UFRA-09, UFRA-12, and UFRA-52, which were applied using three different methods (microbiolized seed, microbiolized seed + soil drenched with a microorganism suspension at 7 and 15 days after sowing (DAS), and microbiolized seed + plant spraying with a microorganism suspension at 7 and 15 DAS) with a control (water). The use of microorganisms can provide numerous benefits for rice in terms of crop growth and development. The microorganism types and methods of application positively and differentially affected the physiological characteristics evaluated in the experimental lowland rice plants. Notably, the plants treated with the bioagent BRM 32109 on the seeds and on seeds + soil produced plants with the highest dry matter biomass, gas exchange rate, and N, P, Fe, and Mg uptake. Therefore, our findings indicate strong potential for the use of microorganisms in lowland rice cultivation systems in tropical regions. Currently, an additional field experiment is in its second year to validate the beneficial result reported here and the novel input sustainability.


Assuntos
Oryza/crescimento & desenvolvimento , Rhizobiaceae/fisiologia , Microbiologia do Solo , Trichoderma/fisiologia , Inoculantes Agrícolas/fisiologia , Biomassa , Oryza/microbiologia , Sementes/microbiologia , Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA