Bacillus Megatherium Research Articles

Growth, nutrient removal, and lipid productivity promotion of Chlorella sorokiniana by phosphate solubilizing bacteria Bacillus megatherium in swine wastewater: Performances and mechanisms

Effects of a phosphorus-solubilizing bacteria (PSB) Bacillus megatherium on growth and lipid production of Chlorella sorokiniana were investigated in synthesized swine wastewater with dissolved inorganic phosphorus (DIP), insoluble inorganic phosphorus (IIP), and organic phosphorus (OP). The results showed that the PSB significantly promoted the algal growth in OP and IIP, by 1.10 and 1.78-fold, respectively. The algal lipid accumulation was also greatly triggered, respectively by 4.39, 1.68, and 1.38-fold in DIP, IIP, and OP. Moreover, compared with DIP, OP improved the oxidation stability of algal lipid by increasing the proportion of saturated fatty acids (43.8 % vs 27.9 %), while the PSB tended to adjust it to moderate ranges (30.2–41.6 %). Further, the transcriptome analysis verified the OP and/or PSB-induced up-regulated genes involving photosynthesis, lipid metabolism, signal transduction, etc. This study provided novel insights to enhance microalgae-based nutrient removal combined with biofuel production in practical wastewater, especially with complex forms of phosphorus.

Temperature, microbiological and chemical composition of broiler chickens’ excrement with litter after its composting with different doses of biodestructor

The rapid growth of production volumes of broiler chicken products both in our country and in most countries of the world is combined with an increase in industry waste. A significant percentage of this waste is poultry droppings with litter. In the absence of implemented technologies for rational disposal of broiler chicken droppings, economic and ecological problems arise locally. Considering the above, the search for effective methods of disposal of broiler chicken droppings is of scientific and practical importance. Composting poultry droppings with litter (sawdust of non-coniferous trees) can be an alternative method of rational disposal of this waste. To accelerate the fermentation of broiler litter, there is a practice of using various microbiological preparations. The effectiveness of using a biodestructor containing bacteria: Bacillus spp., Bacillus subtilis, Bacillus megatherium, Bacillus mesentericus, Bacillus mycoides during composting of broiler chicken excrement and its effect on the microbiological, chemical and physical parameters of fermented biomass remains unexplored. To conduct an experiment, 30 kg samples were formed from the excrement with the litter taken from the poultry house after broiler chickens had been reared for 42 days. In the control group, excrement samples were treated with water without a biodestructor. In the 1st, 2nd, and 3rd research groups, broiler chicken droppings were moistened with biodestructor solutions providing its doses of 143, 1430, and 2860 mg/t, respectively. Temperature and microbiological indicators were determined in the litter of broiler chickens during composting. In non-fermented litter of broiler chickens and litter composted for 150 days using a biodestructor, the crude protein content, mass fraction of Calcium, total Nitrogen and Phosphorus were determined. It has been established that the introduction of a biodestructor at a dose of 2860 mg/t of manure with a moisture content of 60.0 % leads to an increase in the activity of biochemical processes, which is confirmed by an increase in the temperature of the compost during the first hundred days of fermentation. The higher the dose of biodestructor was added to the litter of broiler chickens, the higher the KMAFAnM indicator and the numbers of Bacillus spp. bacteria in compost were higher. A regularity has been established that with the increase in the amount of biodestructor in the litter of broiler chickens, the number of Staphylococcus and Clostridium bacteria in the latter decreases. The use of a biodestructor at a dose of 2860 mg/t of broiler chicken droppings contributes to the increase of Nitrogen, crude protein, and Phosphorus in the compost and accelerates its mineralization compared to the control.

Non-contact bacterial identification and decontamination based on laser-induced breakdown spectroscopy.

As a new kind of modern military biological weapon, bacterial agents pose a serious threat to the public health security of human beings. Existing bacterial identification requires manual sampling and testing, which is time-consuming, and may also introduce secondary contamination or radioactive hazards during decontamination. In this paper, a non-contact, nondestructive and "green" bacterial identification and decontamination technology based on laser-induced breakdown spectroscopy (LIBS) is proposed. The principal component analysis (PCA) combined with support vector machine (SVM) based on radial basis kernel function is used to establish the classification model of bacteria, and the two-dimensional decontamination test of bacteria is carried out using laser-induced low-temperature plasma combined with a vibration mirror. The experimental results show that the average identification rate of the seven types of bacteria, including Escherichia coli, Bacillus subtilis, Pseudomonas fluorescens, Bacillus megatherium, Pseudomonas aeruginosa, Bacillus thuringiensis and Enterococcus faecalis reaches 98.93%, and the corresponding true positive rate, precision, recall and F1-score reaches 0.9714, 0.9718, 0.9714 and 0.9716, respectively. The optimal decontamination parameters are laser defocusing amount of -50mm, laser repetition rate of 15-20kHz, scanning speed of 150mm/s and number of scans of 10. In this way, the decontamination speed can reach 25.6mm2/min, and the inactivation rates for both Escherichia coli and Bacillus subtilis are higher than 98%. In addition, it is confirmed that the inactivation rate of plasma is 4 times higher than that of thermal ablation, meaning that the decontamination ability of LIBS mainly relies on the plasma rather than the thermal ablation effect. The new non-contact bacterial identification and decontamination technology does not require sample pretreatment, and can quickly identify bacteria in situ and decontaminate the surfaces of precision instruments, sensitive materials, etc., which has potential application value in modern military, medical and public health fields.

Inference of Rock Phosphate, Phosphorus Solubilizing Bacteria and Lime on Phosphorus Content and Economic Yield of Green Gram

Aim: To study the effect of Rock Phosphate, Phosphorus Solubilizing Bacteria, and Lime on phosphorus content in the soil, Phosphorus Uptake, and Economic yield of green gram (var. DGGS-4).
 Study Design: This experiment was conducted through a completely randomized design with 10 treatments and 3 replications.
 Place and Duration of Study: The research was conducted at the Department of Soil Science and Agricultural Chemistry, Central Agricultural University, Imphal between February 2019- November 2019.
 Methodology: Available phosphorus content in soil was estimated spectrophotometrically by Bray and Kurtz No. 1 method, the Active Phosphorus was determined by the addition of Saloid-bound phosphate, Aluminum phosphate, iron phosphate, and calcium phosphate, and total Inorganic P is the summation of all the inorganic forms of P. Total Phosphorus (Total P) in Soil was estimated by using Murphy-Riley solution and 5M NaOH and the intensity of yellow color was read at 730 nm in a spectrophotometer, organic P was calculated from the difference between total phosphorus and total mineral P, and the uptake of phosphorus was computed from the data on P concentration and dry matter yield.
 Results: The release and fixation pattern of different forms of phosphorus, its uptake, and the economic yield of green gram were significantly affected by the application of rock phosphate singly or combination with PSB and lime. Comparing among the different treatments, significantly higher accumulation of available Phosphorus, Phosphorus uptake, and economic yield were recorded in soil treated with Rock phosphate in combination with Phosphocare, Bacillus megatherium, and lime which is at par with treatment with Rock phosphate in combination with Bacillus megatherium and lime.
 Conclusion: The investigation revealed that the release and fixation pattern of different forms of phosphorus, its uptake, and the yield of green gram are significantly affected by the application of RP singly or combination with PSB and lime.

Screening and Optimization Consortium Technique of the Bacillus megatherium and Saccharomyces cerevisiae Microbial Consortium for Ethanol Detection

Determination of alcohol content is very important in the food and beverage industry. Biosensor is an alternative to measuring ethanol content. Alcohol biosensors with a single microbe still have a narrow measurement area at ethanol concentrations, so a microbial consortium is needed to widen the range of measured ethanol concentrations. Therefore, it is necessary to screen the microbes from Bacillus sp and S. cerevisiae which have the potential to produce alcohol dehydrogenase (ADH) enzymes and optimize the consortium technique that can provide the best response to oxidation currents. In the yeast microbial screening of 14 S. cerevisiae isolates and 5 Bacillus sp isolates, it can be concluded that for the 14 yeast S. cerevisiae isolates that have the potential to produce ADH enzymes, there is one isolate with the SCRF code. For the 5 bacterial isolates of Bacillus sp that have the potential to produce ADH enzymes, all Bacillus isolates with the code Bacillus megatherium 29/9/14, Bacillus megatherium 23/6/22, Bacillus 6, Bacillus 53, and Bacillus 55. Based on the oxidation current data, Bacillus megatherium 23 /6/22 produces the highest current compared to other Bacillus isolates. The consortium technique that provides the highest current is the method of mixing 1:1 (µL) microbial suspension in an Eppendorf container. Optimization of the consortium's biofilms using the Response Surface Method was produced at 10 days of age, pH 7.5, and 75 µL of microbial suspension dripping volume.

Study on the mechanism of biochar affecting the effectiveness of phosphate solubilizing bacteria.

Low phosphorus utilization and phosphorus fertilizer pollution are serious issues primarily affecting soil health. To investigate the effects of biochar on the growth, phosphorus solubilization, and metabolites of phosphorus-solubilizing bacteria (PSB), rice husk biochar (RH) and rice straw biochar (RS) were incubated with Bacillus megatherium (BM1) and Bacillus mucilaginosus (BM2), respectively. The highest phosphorus solubilization was observed in BM2 following the addition of RS. The dissolved amount of phosphorus was 244.99mg/L, which was 43.86% higher than that of the control group. Hence, biochar can improve the phosphorus solubilization capacity of PSB by affecting the organic acid and polysaccharide contents, and phosphatase activity secreted by the PSB, as the porous structure and surface characteristics of biochar ensured the adsorption of PSB. This study can help improve the functional activity of PSB and provide basis for improving the utilization of soil phosphorus, which in turn, aid in the development of biochar-based microbial fertilizers.

Effect of Rock Phosphate, Single Super Phosphate and Phosphorus Solubilizing Bacteria on Phosphorus Concentration and Dry Matter Yield of Paddy

The majority of tropical and subtropical soils are acidic which are mostly deficient in phosphorus and have strong phosphorus sorption capacity. Exploring different phosphorus inputs is essential not only to increase crop production but also to improve soil phosphorus status to avoid further soil degradation. Acidic nature of the soils of these regions help to solubilize the rock phosphate and increases the amount of phosphorus that is made available to the plants. A pot experiment was conducted in Department of Soil Science and Agricultural Chemistry of College of Agriculture, Central Agricultural University, Imphal (Manipur) during kharif season of 2021 to study the effect of rock phosphate, single super phosphate and phosphorus solubilizing bacteria on phosphorus concentration and dry matter yield of paddy. To each experimental pot, recommended dose of 60 kg of N ha-1 in the form of urea and 30 kg K2O ha-1 in the form of muriate of potash were applied as basal and thoroughly mixed with the soil. Rock phosphate and single super phosphate were administered to the pots as phosphorus sources according to different sets of treatment based on the recommended amount of 40 kg P2O5 ha-1 for paddy. Seeds were treated with Bacillus megatherium. Result revealed that the changes in soil phosphorus concentration and dry matter yield of paddy were significantly affected by rock phosphate applied either singly or in combination with single super phosphate and phosphorus solubilizing bacteria. All the parameters showed different trend of changes during the whole crop growth stages till harvest. Among the treatments higher values were recorded in soil treated with T10 (50% recommended dose of P2O5 from single super phosphate + 50% recommended dose of P2O5 from rock phosphate + phosphorus solubilizing bacteria). Addition of phosphorus solubilizing bacteria enhances release of less soluble and fixed forms into easily available form as well as reduces phosphorus fixation. Efficiency of rock phosphate as phosphorus source for crop production is improved by the solubility effect of phosphorus solubilizing bacteria.

RESPONSE OF SOYBEAN (GlycinemaxL. Merrill) PRODUCTIVITY TO BIOFERTILIZER INOCULANTS COMBINED WITH ORGANIC FERTILIZERUNDER SANDY SOIL CONDITIONS

One of the most important food sources for humans is the soybean crop because it is an important source ofprotein and oil, which makes it important to improve its productivity under stress conditions, especially in sandy lands.Therefore, the study aimed to improve soybean productivity by using biological fertilizers in the presence of organicfertilizer and low concentration of mineral fertilizer under new sandy soil conditions.The experiment was carried out intwo summer seasons of 2020 and 2021 at the Ismailia Research Station, Ismailia Governorate. The used inoculates inthe experiment were,an identified Streptomyces strain,Bacillus megatherium, (SEWRI) and Bradyrhizobiumjaponicum(Okaden) as,biofertilizer agents.Activated dose of N-fertilizer was used in seven different treatments. Results showedthat Bradyrhizobia+Bacillus+actinomycetes+20 kg nitrogen fertilizer/fed was effective in the presence of organicfertilizer compared to organic fertilizer-free soil or un-inoculated+70 kg N/fed. Bradyrhizobia+ Bacillus+Actino+20 kgN/fed (T14) was the most effective treatment in the presence of organic fertilizer compared to organic fertilizer-free soilor uninoc.+70 kg N/fed. Promising expected yields of each of seeds and straw (Ton/fed) of soybean plants cultivatedunder different fertilizers and biofertilizers conditions expected was clear from increasing the yield seed up to1.8400Ton/fed in the presence of organic fertilizer (T14) compared to 1.4565 when soybean was cultivated in theabsence of organic fertilizer (T01). This could be supported by the amounts of NPK, N-percentage, and protein content,numbers of branches and pods and dehydrogenase activity in soil. Significant differences between the straw yield in thepresence and absences of organic fertilizer as well as biofertilizers were recorded. Organic fertilizer applicationrecorded the highest significant increases in nodulation status, growth and straw nitrogen content as well as harvestparameter of soybean compared with those un-received organic fertilizer

A comprehensive study on population dynamics of microbial enrichment of Organic manures

An experiment was conducted in Department of Agriculture, Karunya Institute of Technology and Sciences,Coimbatore to study the population dynamics of microbially enriched organic manures and their nutrientcomposition. Organic manures such as vermicompost, FYM, and coir pith compost were enriched with thelignite based microbial strains of Rhizobium leguminosorum, Bacillus megatherium and its combined inoculumat a rate of 1 kg per ton of manure and its moisture content was maintained at 50 per cent and incubated for180 days. After their enrichment, the microbial load in the organic manures was enumerated using thestandard plate count technique. The microbial results revealed that the maximum microbial populationwas attained on the 90th day after enrichment. The total microbial population in combined bio fertilizers(Rhizobium and Phosphobacteria) inoculated vermicompost was high during the initial phases and thentotal microbial population declined towards the end. Among the enriched organic manures, the highestpopulation was observed in combined microbial strains enriched with vermicompost (6.52 log10 CFU g-1)whereas, after 3 months the enriched organic manure shows the very less population density.

Effect of Bio_fertilizers on Growth and Medicinal active compounds Content of Olive Transplants

A study was carried out in central nursery in Kut affiliated to Wasit Agriculture Directorate on 18/09/2020 to study effect of adding Azotobacter chroococcum and Bacillus megatherium on growth, leaf mineral content and medicinal compounds of “Qaisi” olive transplants. This experiment was carried out on 81 olive transplants with homogeneous vegetative growth as much as possible. Two factors were used in experiment; first factor is addition Azotobacter chroococcum bacteria (A) with three levels: no addition (A0), addition of 30 ml.pot-1 (A30) and addition of 60 ml.pot-1 (A60) and second factor is three levels of Bacillus megatherium (P) is without addition (P0), adding 30 ml.pot-1 (P30) and adding 60 ml.pot-1 (P60).Treatments were replicated three times (three transplants in experimental unit) at factorial experiment in a RCBD. experimental results showed; adding Azotobacter chroococcum to soil at 60 ml.pot-1 (A60) significantly increased in transplant height of 5.78 cm, highest leaf area of 8.99 cm2, highest Branches number of 10.67 branches transplant-1, highest Leaves Carbohydrates content of 4.54 %, highest leaf Caffeic acid content of 14.63 mg.g-1 and highest leaf Vanillic Acid content of 16.90 mg.g-1, also results shows that adding Bacillus megatherium to soil at 60 ml.pot-1 (P60) gave highest increased in transplant height of 5.64 cm, highest leaf area of 8.84 cm2, highest Branches number of 9.78 branches transplant-1, highest Leaves Carbohydrates content content of 4.62 %, highest leaf Caffeic acid content of 15.59 mg.g-1 and highest leaf Vanillic Acid content of 17.89 mg.g-1,

Biologization of growing grain crops technology

The use of biologics and preparations based on amino acids (Krokus universal) for protection against diseases, as well as entomopathogenic microorganisms against pests is one of the main directions in the biologization of technology for growing cereal crops. The research was carried out in 2018-2020 on the basis of the Kuban State Agrarian University. The object of the study was the wheat and barley varieties, as well as oats. As microbiological agents, cultures of microorganisms from the collection were used: Trichoderma viride and T. lignorum, Beauveria bassiana, Metarhizium anisopliae, Azotobacter chroococcum, Bacillus megatherium, Bacillus thuringiensis, Pseudomonas fluorescens. To suppress the pathogens of bacteriosis and stimulate the growth processes of plants, the preparation based on the essential amino acids Crocus universal was used. The results of research have shown that this method is not inferior in biological effectiveness to chemical protection and even have advantages. The systematic use of biologics on cereal crops turned out to be appropriate. It provided the increase in the suppressiveness and fertility of the soil, the suppression of various pathogens and pests on winter wheat crops, the reduction in the amount of pesticides introduced, as well as high economic efficiency.

Removal and potential mechanisms of Cr(Ⅵ) contamination in phosphate mining wasteland by isolated Bacillus megatherium PMW-03

Inappropriate mining strategies have led to the development of an increasing number of phosphate mining wastelands containing a large amount of rock phosphate (RP) contaminated with hexavalent chromium (Cr (Ⅵ)). Although bioremediation has been investigated as an effective strategy for Cr (Ⅵ) removal, few studies have focused on microbial remediation coupled with RP. In this study, a strain of Bacillus megatherium named PMW-03 isolated from a phosphate mining wasteland was used to remediate Cr (Ⅵ) contamination. The liquid medium experiment showed that strain PMW-03 exhibited significant insoluble phosphate solubilization and Cr (Ⅵ) resistance. The maximum release of soluble phosphate and removal rate of Cr (Ⅵ) reached 319.941 mg/L and 94.8%, respectively. The activities of antioxidation enzymes and chromate reductase reached 145.08, 153.71 and 40.07 U/min/gm, which indicated that the bioreduction process participated in the Cr (Ⅵ) removal of strain PMW-03. Furthermore, FTIR and XRD studies showed that Cr (Ⅵ) removal in RP coupled with PMW-03 was also attributed to the biosorption of functional groups on the surface of the strain and the formation of Cr-phosphate precipitates. Finally, the evolution of microbial community structures and functional gene abundance were analyzed to reveal the reduction of Cr (Ⅵ) by microbial remediation. These findings provide some reference and new insights for microbial remediation of Cr (Ⅵ) contamination in phosphate mining wastelands.

Productivity of Paddies as Influenced by Varied Rates of Recommended Nutrients in Conjunction with Biofertilizers in Local Landraces

This research work explores the productive performance of local paddy landraces under different fertility levels as well as the role of microbial inoculants in improving the yields of paddy landraces and reducing nutrient additions by increasing nutrient use efficiency under changing climatic scenarios in coastal areas. The landrace Padmarekha recorded taller plants, more tillers per hill, higher total dry matter accumulation other than grain and straw yields besides better uptake of N, P2O5, K2O, S and Zn. Further, nutrient management with the application of 100% of the recommended doses of fertilizers combined with biofertilizers including Azospirillum + Bacillus megatherium var. Phosphoticum + Frateuria quaratia + Thiobacillus thiooxidans + Vesicular Arbuscular Mycorrhiza recorded higher growth and yield traits in addition to improving the uptake of nutrients and partial factor productivity. Thus, it can be concluded that the application of 100% of the recommended dose of fertilizer, inoculated with biofertilizers, would be helpful in increasing the efficiency of applied nutrients in addition to improving yield and nutrient use efficiency.

INTEGRATED MANAGEMENT OF RICE ROOT-KNOT NEMATODE, MELOIDOGYNE GRAMINICOLA UNDER THE DIRECT-SEEDED CONDITION

The present field experiment was conducted to determine the efficacy of consortium of different bio-agents viz., Psuedomonas fluorescens + Trichoderma harzianum + Bacillus megatherium, organic amendments viz., neem cake, poultry manure and nematicides viz., carbosulfan, carbofuran and fluensulfone for the management of M. graminicola under direct-seeded condition during kharif 2019-20 at the University of Agricultural and Horticultural Sciences, Shivamogga. The results revealed that all the treatments were significantly superior over the untreated check with respect to plant growth parameters and nematode population. However, the plots treated with fluensulfone at 3g/plot was found to be the best treatment as it recorded highest plant height (78.87 cm), root length (18.90 cm) with lowest RKI (2.0), maximum grain yield (36.87 q/ha) and least nematode population (199.00/200g soil) followed by the consortium of bioagents P. fluorescens + T. harzianum + B. megatherium at 20g/m2, carbofuran 3G at 9.9g/ m2, carbosulfan 25 EC at 0.1%, neem cake at 100g/m2 and poultry manure at 100g/m2 respectively.

REMOVAL OF NUTRIENTS AS INFLUENCED BY VARIED RATES OF RECOMMENDED NUTRIENTS IN CONJUNCTION WITH BIOFERTILIZERS IN LOCAL LANDRACES OF PADDY IN COASTAL AREA OF KARNATAKA, INDIA

The uptake of nutrients by the paddy crop better indicative of the fertility, productivity, and plant nutrient status. The main objective of this investigation was that the rate of nutrient application can influence the removal of nutrients into formsavailable to the soil with different landraces in conjunction with the application of different microbial inoculants under different fertility levels. The yield of landraces was significantly influenced by the microbial inoculants under different fertility levels.Significantly higher uptake of N, P and K was observed in the landrace padmarekha compared to other landraces. The nutrient removal from the soil was in the range of 81.57 – 104.08 kg N, 19.55 -33.96 kg P and 88.15 – 111.81 kg/ha Kamong landraces. Similarly, the higher uptake was seen with the application of 100 per centRDF along with the azospirullum, Bacillus megatherium var. Phosphoticum Frateuria quaratia,Thiobacillus thiooxidans and Vesicular ArbescularMycorrizae.The nutrient removal was in the range of 47.11-122.0 kg N, 10.71-36.7 kg P2O5 and 34.22- 141.21 kg/ha K2O among fertility levels in different paddy landraces used in the study. The different microbial inoculants application with the recommended dose of fertilizers in different levels helped in the acquisition of the nutrients from the soil solution illustrating the effects of microbial applications through the increased supply of biologically fixed nitrogen, mobilizing the phosphorus towards plant roots, and potassium availability to the crop. Thus, our investigations acclaim that there is a need to inoculate the crop with different microbial inoculants to increase the use and uptake of the nutrients by the crop and improvement in soil nutrient status.

The Effect of Organic and Bio-Fertilization on some Physical and Chemical Properties of Calendula officinalis L. Plant

The effect of organic fertilization (using three rates of poultry manure) and biological fertilization (using a nitrogen-fixing bacterial strain Azospirillum brasilense, mycorrhizal (VAM) fungi and another bacterial strain dissolving phosphate(Bacillus megatherium) on Calendula officinalis L. plant during two consecutive seasons were studied. The results showed that all organic and biological fertilization treatments improved different vegetative growth characteristics and enhanced flowering factors. The various chemical components (Chlorophyll A&B) and carotenoids, as well as an increase in carbohydrates, minerals percentage and oleanolic acid. Hence, organic and biological fertilizers can be used as an alternative to chemical fertilization, which reduces production costs and pollution the agricultural environment and leads to improvement of the natural and chemical properties.

Effect of foliar and soil application of plant growth promoting bacteria on growth, physiology, yield and seed quality of maize under Mediterranean conditions

The use of plant growth promoting bacteria (PGPB) as biostimulants favors the increase of crop productivity and the improvement of yield quality. The main objective of the present study was to investigate the effect of the PGPB biostimulants (Azotobacter chroococcum, Bacillus subtilis, Bacillus megatherium and their mixes) and the application method (foliar and soil) on the growth, the physiology, the yield and the quality of maize. The obtained results showed that A. chroococcum treatment increased the chlorophyll content up to 6.1%, the photosynthetic rate up to 18.4% and the transpiration rate up to 34.3%. The highest maize yields were performed by the treatments B. megatherium (244.67 g) and the mix of A. chroococcum and B. subtilis (1:1) (243.67 g) when applied on the soil. The Soil application of the PGPB resulted in increased yield of maize from 5.5 to 13.4% compared to control treatment. Concerning quality characteristics, B. subtilis treatment increased total solids content in harvested maize seeds by 92%, as well as crude fiber content by 46% compared to control. The results confirmed that the use of PGPB could contribute as a new cultivation practice for sustainable growth, productivity and quality of grain crops.

Impact of Trichoderma harzianum and bacterial strains against Striga hermonthica in Sorghum

A series of laboratory and green house experiments were conducted to investigate the efficacy of Trichoderma harzianum fungi, bacteria ( Flavobacterium, Bacillus megatherium var. phosphaticum (BMP) and Azomonas ) on Striga hermonthica early developmental stages , incidence and sorghum growth under laboratory and greenhouse conditions. The first laboratory experiment results showed that application of BMP + Flavobacterium significantly inhibited S. hermonthica seeds germination during and after conditioning in response to GR24 concentrations as compared to medium control. In the second laboratory experiment, application of the filtrate of T. harzianum alone or in combinations with bacteria significantly inhibited S. hermonthica germination and haustorium initiation as compared to the corresponding control. From greenhouse experiment results, S. hermonthica emergence significantly reduced by T. harzianum and insignificantly by the combination of Flavobacterium + BMP + T. harzianum . T. harzianum followed by the combination of Flavobacterium + BMP gave the highest increment in plant height. T. harzianum significantly increased sorghum number of leaves as compared to the infested control. The combination of Flavobacterium + BMP + T. harzianum gave the highest number of leaves. The combination Flavobacterium + BMP gave the highest sorghum shoot dry weight, followed by T. harzianum . While the highest sorghum root dry weight was obtained from the combination of Flavobacterium + BMP + T. harzianum . Generally, the combination of T. harzianum + Flavobacterium + BMP reduced S. hermonthica infestation and enhanced sorghum growth in comparison to the infested control.

Bioremediation of Cd-spiked soil using earthworms (Eisenia fetida): Enhancement with biochar and Bacillus megatherium application

In this study, we evaluated the influence of biochar and Bacillus megatherium on Cd removal from artificially contaminated soils using earthworms (Eisenia fetida). Within a 35-days remediation period, over 30% of Cd was removed by earthworms from the contaminated soil (with Cd at ∼ 2.5 mg kg−1), and both additives facilitated Cd removal. Additionally, over 22% reduction in the extractable Cd contents was also achieved by earthworms. Cd accumulated in earthworms steadily increased through remediation, and the accumulated Cd decreased in the order of earthworm + biochar (T3) > earthworm + Bacillus megatherium (T4) > earthworm alone (T2). The bioaccumulation factors (BCF) were above 1, indicating the enrichment of Cd in earthworms, and there were higher BCF for both T4 (944%) and T3 (845%). The ingestion of metal-bonded biochar particle and the elevated Cd mobility would be the main reason for the enhanced Cd-remediation by earthworms under T3 and T4, respectively. Through remediation, microbiota communities in both, soil and earthworm guts, demonstrated high similarity, while a lower level of bacterial abundance was observed in earthworm guts compared with that in soils. Eventually, soils became more fertile and demonstrated higher enzyme activities after remediation. Therefore, we concluded that earthworm, alone or combined with biochar or Bacillus megatherium could be an alternative method for Cd-contaminated soil remediation.

Response of black cumin (Nigella sativa L.) plants to the addition of natural fertilizers and the inoculation by bacteria mix and seaweed liquid extract

This experiment was carried out duringthe two successive seasons of 2017/2018 and 2018/2019 aiming to study the effect of natural fertilizers namely mixed minerals ores; control, 200, 400 and 600 Kg/fed. (fed. = feddan = 0.420 hectares = 1.037 acres) and half recommended dose of NPK fertilizers and the inoculation of mixed of bacteria namely (Azotobacter chroococcum, Bacillus megatherium var Phosphaticum and Bacillus circulans) alone or with seaweed liquid extract , as well as, their interactions on vegetative growth, yield, fixed oil (percentage & yield) and fixed oil components of black cumin (Nigella sativa L.) plants. The highest values of all parameters were observed when the plants received the high rate of mixed minerals ores (600 kg /fed.). In regard to the inoculation with bacteria alone or with seaweed liquid extract, it was noticed that all treatments led to a significant increase in plant height, branch number, shoot dry weight, capsules number, seed yield , fixed oil (percentage & yield). The highest values of these previous characters were obtained when the inoculation with bacteria plus seaweed liquid extract. Generally, the combined effect among mixed minerals ores, the inoculation with bacteria and seaweed liquid extract treatments on Nigella sativa L., plants parameters was statistically significant. In most cases, the addition of the high rate of mixed minerals ores (600 kg /fed.) plus the inoculation with bacteria plus seaweed liquid extract was the most effective treatment in increasing these parameters. Results of GC-MS analysis of fixed oil revealed that the main fatty acids offered were myristic acid, palmatic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and arachidic acid. The elevated percentages between the previous components were oleic acid followed by Stearic acid and arachidic acid. The treatments of mixed mineral ores and the inoculation with bacteria with seaweed liquid extract increased the former fatty acids in the fixed oil paralleled to untreated control.