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The study included the implementation of a factorial field experiment at the agricultural extension station affiliated with the Agricultural Extension Department in the Warka District, located north of Al-Muthanna Governorate, during the winter season 2022-2023. The soil texture of the field was loamy clay soil and the wheat variety was Research 22. The factorial experiment was designed according to the split-plot arrangement and (RCBD) design with three replications. The first factor represents the biological inoculum with B. subtilis and B. megaterium bacteria, with four levels, B0 without the addition of the inoculum, B1 with B. megaterium bacteria, and B2 with B. subtilis bacteria, and the fourth treatment, B3, included the double inoculum B1 + B2, and the second factor represents plowing depths with four levels, D1 represents zero plowing depth, D2 represents 10 cm plowing depth, D3 represents 20 cm plowing depth and D4 represents 30 cm plowing depth. The results showed the following. The results showed that the plowing depth D4 was superior to the control treatment and recorded the highest values in both plant height (100.74 cm) and moisture content was 41.26, 15.59 % in both flowering and harvesting stages respectively, while the depth D3 recorded a significant superiority in the weight of 1000 grains (49.14 gm). The B3 bacterial inoculum addition treatment was significantly superior to the control treatment.The highest values were recorded for plant height, weight of 1000 seeds, and moisture content in the harvest and flowering stages .The values were 100.26 cm, 46.63 g, 13.25%, 31.91% respectively. The results of the statistical analysis showed that the interaction treatment of the bacterial inoculum and plowing depth D4B1 was superior in plant height, the D3B2 treatment increased in the weight of 1000 seeds, and the D3B3 treatment was superior in moisture content for the flowering and harvesting stages. The values were 104.09 cm, 54.76 g, 44.35% and 17.50% respectively. [ABSTRACT FROM AUTHOR]

Harvester ants often selectively forage seeds, causing these ants to be viewed as pests in agricultural areas where they may forage on crop seeds. While little research has been done on harvester ant preferences for cover crop seeds, grower observations in the Lower Rio Grande Valley (LRGV) suggest that ants may remove these seeds before germination. We examined red harvester ant (Pogonomyrmex barbatus F. Smith) preferences for cover crop seeds (fescue, oat, sunn hemp, radish, vetch, and wheatgrass) and the effects of a commonly used bacterial seed inoculant. We evaluated relative preferences using seed depots presented to colonies with no prior exposure to the selected seeds or inoculants. After 24 h, ants had removed oat and radish seeds at the same rate as the preferred wheatgrass control. Fescue, sunn hemp, and vetch seeds were less preferred. The bacterial inoculation of wheatgrass and radish seeds did not alter the removal rates. Further, ant removal of seeds in both trials was dependent on the month and temperature, indicating potential interactions of colony activity levels, availability of seeds in the seed bank, and the intensity of cover crop seed removal. Together, these data indicate that harvester ant foraging preferences and seasonal activity should be considered to help mitigate potential ant predation of cover crops via planting less preferred seeds and at times of lower ant foraging intensity. [ABSTRACT FROM AUTHOR]

Inorganic arsenic (As) is a toxic and carcinogenic pollutant that has long-term impacts on environmental quality and human health. Pteris vittata plants hyperaccumulate As from soils. Soil bacteria are critical for As-uptake by P. vittata. We examined the use of taxonomically diverse soil bacteria to modulate As speciation in soil and their effect on As-uptake by P. vittata. Aqueous media inoculated with Pseudomonas putida MK800041, P. monteilii MK344656, P. plecoglossicida MK345459, Ochrobactrum intermedium MK346993 or Agrobacterium tumefaciens MK346997 resulted in the oxidation of 5–30% As(III) and a 49–79% reduction of As(V). Soil inoculated with P. monteilii increased extractable As(III) and As(V) from 0.5 and 0.09 in controls to 0.9 and 0.39 mg As kg−1 soil dry weight, respectively. Moreover, and P. vittata plants inoculated with P. monteilii, P. plecoglossicida, O. intermedium strains, and A. tumefaciens strains MK344655, MK346994, MK346997, significantly increased As-uptake by 43, 32, 12, 18, 16, and 14%, respectively, compared to controls. The greatest As-accumulation (1.9 ± 0.04 g kg−1 frond Dwt) and bioconcentration factor (16.3 ± 0.35) was achieved in plants inoculated with P. monteilii. Our findings indicate that the tested bacterial strains can increase As-availability in soils, thus enhancing As-accumulation by P. vittata. Novelty statementPteris vittata, a well-known As-hyperaccumulator, has the remarkable ability to accumulate higher levels of As in their above-ground biomass. The As-tolerant bacteria-plant interactions play a significant role in bioremediation by mediating As-redox and controlling As-availability and uptake by P. vittata. Our studies indicated that most of the tested bacterial strains isolated from As-impacted soil significantly enhanced As-uptake by P. vittata. P. monteilii oxidized 20% of As(III) and reduced 50% of As(V), increased As-extraction from soils, and increased As-uptake by 43% greater compared with control. Therefore, these strains associated with P. vittata can be used in large-scale field applications to remediate As-contaminated soil. [ABSTRACT FROM AUTHOR]

Survival niches for phytopathogenic bacteria are important for disease management. We study the survival of Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), the causal agent of bacterial wilt in common bean and bacterial tan spot in soybean, in the soil. While Cff strains from common bean already have several studies, the ecology of soybean strains needs more information. We used the strain Feij.2628A from common bean, and CffR1, Cff2R, and Cff4R from soybean. The soils were infested with bacterial suspension (107 CFU.mL−1) from each of the strains. For experiments under laboratory conditions, they were incubated in BOD incubator (biochemical oxygen demand) at 20 °C. Under natural field conditions, pots were maintained in the field without supplementary irrigation. The survival of Cff strains was evaluated every seven days until they were not detected. The identity of the bacterium was confirmed in all treatments by PCR. Under laboratory conditions, the survival period of Feij.2628A ranged from 140 to 154 days, and between 77 to 119 days for the soybean strains. Feij.2628A and Cff1R survived for a maximum of 91 days in soil with higher clay content, under natural field conditions. Cff survival was negatively influenced by high temperatures, low soil moisture, and precipitation in some treatments. These results demonstrated the potential survival of Cff strains from common bean and soybean in the soil, being potential inoculum sources for subsequent cultivations of these crops. Fallow periods ranging from three to four months may reduce the amount of inoculum in soils under these conditions. [ABSTRACT FROM AUTHOR]

Cellulolytic micro‐organisms are potent silage inoculants that decrease the fibrous content in silage and increase the fibre digestibility and nutritional value of silage. This study aimed to evaluate the effects of Bacillus subtilis CCMA 0087 and its enzyme β‐glucosidase on the nutritional value and aerobic stability of corn silage after 30 and 60 days of storage. We compared the results among silage without inoculant (SC) and silages inoculated with B. subtilis 8 log10 CFU per kg forage (SB8), 9 log10 CFU per kg forage (SB9) and 9·84 log10 CFU per kg forage + β‐glucosidase enzyme (SBE). No differences were observed in the levels of dry matter, crude protein and neutral detergent fibre due to the different treatments or storage times of the silos. Notably, the population of spore‐forming bacteria increased in the SB9‐treated silage. At 60 days of ensiling, the largest populations of lactic acid bacteria were found in silages treated with SB8 and SBE. Yeast populations were low for all silages, irrespective of the different treatments, and the presence of filamentous fungi was observed only in the SBE‐treated silage. Among all silage treatments, SB9 treatment resulted in the highest aerobic stability. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of the protein source in sugarcane silage-based diets on the ruminal pH and in situ dry matter digestibility (DMD). The treatments were: 1)- 60% sugarcane silage + 15% soybean meal (SBM); 2)- 60% sugarcane silage + 15% fish meal (FM); 3)- 55% sugarcane silage + 20% canola meal (CM); and T4)- 50% sugarcane silage + 30% coconut meal (CCM). In situ DMD was determined by the nylon bag technique using four cows equipped with ruminal cannula. Five grams of each experimental diet were weighted in nylon bags and incubated for 8, 12, 24, 48, 72 and 96 h. Dry matter digestibility for SBM, CM, and CCM showed higher values compared to FM. A similar pH among treatments was recorded; however, at 4 h decreases in SBM and FM were observed. Sugarcane silage in integral diets with the different protein sources used in this study, did not modify ruminal pH but showed lower DMD when fish meal was the protein source. Highlights The use of bacterial inoculum and an additive that promotes the silage process of sugarcane and improves its quality. Use of sugarcane silage and soybean meal as a protein source increase the ruminal digestibility of dry matter of the diet, and not change ruminal pH. Sugarcane silage can be used as an ingredient in an integral diet for ruminants.

Measuring bacterial growth potential (BGP) involves sample pre-treatment and inoculation, both of which may introduce contaminants in ultra-low nutrient water (e.g., remineralized RO permeate). Pasteurization pre-treatment may lead to denaturing of nutrients, and membrane filtration may leach/remove nutrients into/from water samples. Inoculating remineralized RO permeate samples with natural bacteria from conventional drinking water leads to undesired nutrient addition, which could be avoided by using the remineralized RO permeate itself as inoculum. Therefore, this study examined the effect of pasteurization and membrane filtration on the BGP of remineralized RO permeate. In addition, the possibility of using bacteria from remineralized RO permeate as inoculum was investigated by evaluating their ability to utilize organic carbon that is readily available (acetate, glucose) or complex (laminarin, gelatin, and natural dissolved organic carbon), as compared with bacteria from conventional drinking water. The results showed that membrane filtration pre-treatment increased (140–320%) the BGP of remineralized RO permeate despite the extensive soaking and flushing of filters (>350 h), whereas no effect was observed on the BGP of conventional drinking water owing to its high nutrient content. Pasteurization pre-treatment had insignificant effects on the BGP of both water types. Remineralized RO permeate bacteria showed limitations in utilizing complex organic carbon compared with bacteria from conventional drinking water. In conclusion, the BGP bioassay for ultra-low nutrient water (e.g., remineralized RO permeate) should consider pasteurization pre-treatment. However, an inoculum comprising bacteria from remineralized RO permeate is not recommended as the bacterial consortium was shown to be limited in terms of the compounds they could utilize for growth.

A crop rotation system can reduce phytopathogen inoculum, and consequently reduce the incidence and severity of disease. Bean bacterial wilt is an important disease and several crops can act as inoculum sources for Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff). The aim was to evaluate the influence of crop rotation systems on 10 common bean cultivars against bacterial wilt. Experiments were located in two different areas in Brazil (2012), cultivated under a no-tillage system and with a history of the disease. The evaluated rotation systems were black oat, wheat and fallow followed by common bean. After harvest, 10 dry bean cultivars were sown, together with a fallow area. Disease incidence and severity were assessed at 45, 60 and 80 days after sowing. Also evaluated were four agronomical parameters: pod numbers, grain numbers, total weight of grains per plant and weight of 100 grains. Epiphytic and endophytic colonization by Cff was evaluated in black oat and wheat, and in crop debris. The rotation systems significantly influenced the incidence and severity of bacterial wilt in common bean cultivars in both areas and negatively affected the four agronomic parameters. The cultivars BRS Campeiro, BRS Estilo, IPR Tuiuiú, IPR Tangará and IPR Campos Gerais presented low severity and incidence of the disease and higher productivity. Cff strains were recovered from black oat, wheat and crop debris. Our results reinforce the importance of planting non-Cff host crops in rotation systems with common bean, as well as planting cultivars with a level of resistance to bacterial wilt. [ABSTRACT FROM AUTHOR]

Kitchen waste is the best alternative for biogas production due to its high biodegradability and water content. These characteristics of kitchen waste make it a good candidate for anaerobic digestion with the concomitant benefit of biogas production. The aim of the study was to convert different categories of kitchen waste into biogas with a view to reducing environmental pollution and compare gas production among them. Two experiments were carried out to observe gas production in presence of rumen fluid and bacterial inoculum with cow manure and different categories of kitchen waste including vegetable, fish, chicken, rice, bread, paper, egg etc. SAU has seven residential hall and each of them contains individual dining, where daily a large amount of kitchen waste is obtained which can be utilized for better purpose. Since biogas production depends on the organic contents of substrate, therefore these wastes were categorized after collection. Carbohydrate and protein rich organic waste showed better biogas production result while the fat percentage on substrate lowered biogas yield. Gas production was higher in rumen fluid compared to bacterium inoculum at 48 hrs. For example, the volume of gas was higher for vegetable waste (21.75ml/g) as well as other carbohydrate source such as bread (31.25 ml/g), paper (25.5 g/ml), rice (22.25 ml/g) at 48hrs. On the other hand, gas production was lower in chicken (8.0 ml/g) and fish waste (3.0 ml/g) at 48 h. [ABSTRACT FROM AUTHOR]

This study was conducted in lath house of the Agricultural researches station (B)/College of Agricultural Engineering Sciences, University of Baghdad/Al-Jadriya for 2018 - 2019 year, to study the Effect of Bacterial inoculums, spraying with Calcium nitrate and Salicylic acid in Vegetative and flowery growth traits of Gerbera jamesonii cv Bighorn by injected 20 ml plant-1 bacteria Bacillus subtilus in Rhizospher area and foliar spraying of Calcium nitrate (Ca) was applied in two levels (500 and 1000 mg L-1) while salicylic acid (SA) with 75 and 150 mg L-1 levels at three times as foliar spraying during the vegetative period as well as control treatment. A field experiment was carried out according to Randomized Completely Block Design (RCBD). Results indicated that the combination (T15:BCa1SA1) distinguished in the most growth characteristics including number leaves (9.750 leaf plant-1), leaf area (680.2 cm²), total Chlorophyll (151.2), wet and dry weight of leaf (3.124, 0.489 gm), number of days required for the emergence of the flowery bud (113.3 Days), inflorescences number (4.083 flower plant-1), peduncle diameter (7.494 mm), vase life (11.08 Days), and bending Angle of peduncle (2.080°). [ABSTRACT FROM AUTHOR]

Measuring bacterial growth potential (BGP) involves sample pre-treatment and inoculation, both of which may introduce contaminants in ultra-low nutrient water (e.g., remineralized RO permeate). Pasteurization pre-treatment may lead to denaturing of nutrients, and membrane filtration may leach/remove nutrients into/from water samples. Inoculating remineralized RO permeate samples with natural bacteria from conventional drinking water leads to undesired nutrient addition, which could be avoided by using the remineralized RO permeate itself as inoculum. Therefore, this study examined the effect of pasteurization and membrane filtration on the BGP of remineralized RO permeate. In addition, the possibility of using bacteria from remineralized RO permeate as inoculum was investigated by evaluating their ability to utilize organic carbon that is readily available (acetate, glucose) or complex (laminarin, gelatin, and natural dissolved organic carbon), as compared with bacteria from conventional drinking water. The results showed that membrane filtration pre-treatment increased (140–320%) the BGP of remineralized RO permeate despite the extensive soaking and flushing of filters (>350 h), whereas no effect was observed on the BGP of conventional drinking water owing to its high nutrient content. Pasteurization pre-treatment had insignificant effects on the BGP of both water types. Remineralized RO permeate bacteria showed limitations in utilizing complex organic carbon compared with bacteria from conventional drinking water. In conclusion, the BGP bioassay for ultra-low nutrient water (e.g., remineralized RO permeate) should consider pasteurization pre-treatment. However, an inoculum comprising bacteria from remineralized RO permeate is not recommended as the bacterial consortium was shown to be limited in terms of the compounds they could utilize for growth. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of the protein source in sugarcane silage-based diets on the ruminal pH and in situ dry matter digestibility (DMD). The treatments were: 1)- 60% sugarcane silage + 15% soybean meal (SBM); 2)- 60% sugarcane silage + 15% fish meal (FM); 3)- 55% sugarcane silage + 20% canola meal (CM); and T4)- 50% sugarcane silage + 30% coconut meal (CCM). In situ DMD was determined by the nylon bag technique using four cows equipped with ruminal cannula. Five grams of each experimental diet were weighted in nylon bags and incubated for 8, 12, 24, 48, 72 and 96 h. Dry matter digestibility for SBM, CM, and CCM showed higher values compared to FM. A similar pH among treatments was recorded; however, at 4 h decreases in SBM and FM were observed. Sugarcane silage in integral diets with the different protein sources used in this study, did not modify ruminal pH but showed lower DMD when fish meal was the protein source. [ABSTRACT FROM AUTHOR]

An evaluation was conducted of the colonization of Pseudomonas protegens MP12, a plant-growth promoting and antagonistic strain, inoculated in vine plants during a standard process of grapevine nursery propagation. Three in vivo inoculation protocols (endophytic, rhizospheric, and epiphytic) were implemented and monitored by means of both culture-dependent and independent techniques. Endophytic treatment resulted in the colonization of the bacterium inside the vine cuttings, which spread to young leaves during the forcing period. Microscopy analysis performed on transformed dsRed-tagged P. protegens MP12 cells confirmed the bacterium’s ability to penetrate the inner part of the roots. However, endophytic MP12 strain was no longer detected once the plant materials had been placed in the vine nursery field. The bacterium also displayed an ability to colonize the rhizosphere and, when the plants were uprooted at the end of the vegetative season, its persistence was confirmed. Epiphytic inoculation, performed by foliar spraying of cell suspension, was effective in controlling artificially-induced Botrytis cinerea infection in detached leaves. The success of rhizospheric and leaf colonization in vine plants suggests potential for the future exploitation of P. protegens MP12 as biofertilizer and biopesticide. Further investigation is required into the stability of the bacterium’s colonization of vine plants under real-world conditions in vineyards.

Plants are often challenged by multiple abiotic stresses simultaneously. The inoculation of beneficial bacteria is known to enhance plant growth under these stresses, such as phosphorus starvation or salt stress. Here, for the first time, we assessed the efficiency of selected beneficial bacterial strains in improving tomato plant growth to better cope with double stresses in salty and P-deficient soil conditions. Six strains of Arthrobacter and Bacillus with different reservoirs of plant growth-promoting traits were tested in vitro for their abilities to tolerate 2–16% (w/v) NaCl concentrations, and shown to retain their motility and phosphate-solubilizing capacity under salt stress conditions. Whether these selected bacteria promote tomato plant growth under combined P and salt stresses was investigated in greenhouse experiments. Bacterial isolates from Cameroonian soils mobilized P from different phosphate sources in shaking culture under both non-saline and saline conditions. They also enhanced plant growth in P-deficient and salt-affected soils by 47–115%, and their PGP effect was even increased in higher salt stress conditions. The results provide valuable information for prospective production of effective bio-fertilizers based on the combined application of local rock phosphate and halotolerant phosphate-solubilizing bacteria. This constitutes a promising strategy to improve plant growth in P-deficient and salt-affected soils.

Objectives In developing a standardized drug susceptibility test for bedaquiline, it is very important to know which parameters might impact its activity in vitro and result in false resistance of the bacterium to bedaquiline. We aimed to assess the impact of different in vitro conditions on the minimal inhibitory concentration (MIC) of bedaquiline against Mycobacterium tuberculosis H37Rv reference strain. Methods The MIC of M . tuberculosis H37Rv strain was determined under different conditions such as inoculum size, pH, temperatures, log and stationary phase cultures, protein concentration, Tween 80 concentration, and labware plastics. Results Increases in bedaquiline MIC were observed with variations in inoculum size for M . tuberculosis H37Rv on agar or in broth, in protein concentration and labware plastics on agar, and with variations in pH and Tween 80 concentrations in broth. Conclusions In order to obtain reproducible MIC results, bedaquiline MIC should be assessed using polystyrene plates or tubes, at pH 7, with a Tween 80 concentration of 0.02%, without protein enrichment and with an inoculum size up to 10 7 colony-forming unit (CFU)/mL on 7H11 agar or with 10 5 CFU/mL in 7H9 broth. [ABSTRACT FROM AUTHOR]

Beta-glucanase enzyme can degrade β-glucan polysaccharide to saccharide oligomers and glucose monomers. The enzyme can be used as biological control to degrade β-glucan in cell wall of fungal pathogens. The objective of this study was to determine the optimum medium for bacterial β-glucanase production and to use the enzyme as biological control of oil palm pathogenic fungi. Medium optimization were carried out using Response Surface Methodology (RSM) with 18 experimental run of Central Composite Design (CCD) on three variables (oat β-glucan, yeast extract, and bacterial inoculum). The results showed that β-glucanase produced by Bacillus subtilis SAHA 32.6 was strongly influenced by bacterial inoculum size than oat β-glucan and yeast extract concentration. Beta-glucanase of optimized medium could inhibit the growth of oil palm pathogenic fungi, i.e Curvularia affinis and Colletotrichum gloeosporioides. The ammonium sulphate fractionation of the β-glucanase could inhibit the fungi better than crude enzyme. The bacterial β-glucanase of B. subtilis SAHA 32.6 can be used as bio-fungicide to attack of pathogenic fungi in the oil palm nursery. [ABSTRACT FROM AUTHOR]

The paper presents the interplay of the studied factors (absorbents, fertilizers, bacterial inoculum) upon the mobile phosphorus content of a soil polluted with 3% crude oil, 45 days from treatments application or 60 days from the pollution moment. The highest mobile phosphorus values were obtained in the variants fertilized with N200P200K200 mineral fertilizers against the application of 32 kg/ha Zeba absorbent; the values were also high in the variants in which the N200P200K200 mineral fertilizers were applied together with bacterial inoculum. From the applied new fertilizers AH-SG1 (potassium humates containing fertilizer in an NPK-type matrix with micro elements plus 50 g/l glucose) and AH-SG2 (potassium humates containing fertilizer in an NPK-type matrix with micro elements plus 100 g/l glucose) had the best effect on the soil mobile phosphorus level. [ABSTRACT FROM AUTHOR]

Revegetation of industrial landfills and mine tailing may restore key soil functions and reduce the environmental impacts of contaminants. These marginal sites are often characterized by phytotoxic levels of trace elements (TE) (Cu, Fe, Mn, and Zn) and low nutrient status (N, P, and K). The aim of this study was to test the effect of digestate and bacterial inoculation on soil physicochemical properties (pH, CaCl 2 extractable Mn, and microbial enzyme activities) and birch (Betula pendula) growth and physiology on a red gypsum substrate in a lab-to-field experimental approach. The biomass of birches amended with digestate (D0.05% N) was on average 2- and 6-fold greater than that of control birch in the laboratory and field experiments, respectively. A higher concentration of digestate (0.1% N) had an inhibitory effect on plant growth, and reduced the survival rates of amended plants by 40% as compared with controls. The digestate (D0.05% N) treatment significantly increased leaf P and K contents while decreasing leaf Ca, Fe and Mn contents. Digestate also increased some key soil enzyme activities of C, N, P and S metabolism by >10-fold compared with the control soil. In a phytomanagement scenario, digestate would be a preferred amendment resource for the production of clean birch leaf biomass on contaminated red gypsum landfill, as birch trees amended with digestate had lower leaf TE and higher leaf nutrient contents than control birches. [Display omitted] • Digestate and bacterial inoculum were used to improve birch growth on red gypsum. • The digestate significantly increased birch biomass as well as leaf P and K content. • The two amendments decreased the leaf Fe, Mn and Zn contents. • Soil functionalities were enhanced upon digestate amendments. [ABSTRACT FROM AUTHOR]

The present study aimed to isolate and select bacteria with cellulolytic capacity, having future application as inoculum in the fibrous organic waste composting. Five sampling environments were considered: organic agriculture (AO), conventional agriculture (AQ), forest (BM); sugarcane area (RC) and compost piles (AC). For bacterial isolation the nutrient agar medium was used changing the carbon source by cellulose. The main selection criterion of the bacterial isolates was the growth on above medium and its positive reaction to congo red test, showing clear zones around the colonies. The 93 bacterial isolates obtained were subjected to Gram staining, catalase test, presence of endospores and aerobically growth; having 70 bacteria Bacillus spp. like characteristics. Their cellulolytic activities were determined and 30 bacteria produced hydrolysis halo. Eight of these bacterial isolates were selected according to the largest halo production (AO-19, AO-28, AO-29, AQ-2, BM-7, RC-2, RC-6, CR-18) and their growth at different pH (3, 5, 7, 9) and temperatures (50 and 70 °C) were evaluated. The bacteria AO-19 showed higher hydrolysis halo with 12,33 mm and growth stability at different pH and temperature levels, for which its growth dynamic and amylolytic and pectinolytic capacity was determined. According to results the bacteria AO-19 has potential to be used as inoculum in composting. [ABSTRACT FROM AUTHOR]

Petroleum hydrocarbons in the bilge water of small fishing vessels are continuously released into the environment. The bilge water samples usually contained low amounts of oil-degrading bacteria; therefore, this study examines application of polyurethane foam (PUF)-immobilized Gordonia sp. JC11, a known lubricant-degrading bacterial inoculum, for the treatment of bilge water. Batch microcosm experiments showed that the PUF-immobilized bacteria were more efficient at removing oil than indigenous microorganisms and were able to remove approximately 40-50 % of the boat lubricant (1,000 mg L). The immobilized PUF samples rapidly adsorbed oil from the bilge water inside a small fishing vessel; however, the uninoculated PUF contained more oil than the inoculated PUF at most time points. The hydrocarbon components were also different when comparing inoculated and uninoculated PUF. These results indicate that the oil accumulated inside the PUF containing immobilized bacteria was being degraded by the Gordonia sp. JC11. However, these bacteria gradually die off after repeated oil exposure, and it is suggested that PUF-immobilized cells be replaced at timed intervals. This technique is considered simple and cheap; thus, it could be used to reduce chronic oil pollution from the release of bilge water. [ABSTRACT FROM AUTHOR]

Crude oil bioremediation of soils is limited by the bacteria activity in degrading the spills hydrocarbons. The aim of this study is to enhance the bioremediation of soils polluted with crude oil by adding the natural biodegradable product and bacterial inoculum. Biodegradation was quantified by total petroleum hydrocarbons (TPH) analyses. Petroleum hydrocarbon pollution is one of the main environmental problems, not only by the important amounts released but also because of their toxicity. The main objective of this work is to accelerate the biodegradation processes. The enhancement of petroleum hydrocarbons degradation was achieved under natural product treatment and bacterial inoculum. The bacterial inoculum was used to enrich indigenous microbes to enhance biodegradation rate in the green house experiment. [ABSTRACT FROM AUTHOR]

An evaluation was conducted of the colonization of Pseudomonas protegens MP12, a plant-growth promoting and antagonistic strain, inoculated in vine plants during a standard process of grapevine nursery propagation. Three in vivo inoculation protocols (endophytic, rhizospheric, and epiphytic) were implemented and monitored by means of both culture-dependent and independent techniques. Endophytic treatment resulted in the colonization of the bacterium inside the vine cuttings, which spread to young leaves during the forcing period. Microscopy analysis performed on transformed dsRed-tagged P. protegens MP12 cells confirmed the bacterium's ability to penetrate the inner part of the roots. However, endophytic MP12 strain was no longer detected once the plant materials had been placed in the vine nursery field. The bacterium also displayed an ability to colonize the rhizosphere and, when the plants were uprooted at the end of the vegetative season, its persistence was confirmed. Epiphytic inoculation, performed by foliar spraying of cell suspension, was effective in controlling artificially-induced Botrytis cinerea infection in detached leaves. The success of rhizospheric and leaf colonization in vine plants suggests potential for the future exploitation of P. protegens MP12 as biofertilizer and biopesticide. Further investigation is required into the stability of the bacterium's colonization of vine plants under real-world conditions in vineyards. [ABSTRACT FROM AUTHOR]

• Acclimatization increased 2-MBT removal efficiency of bacterial consortia. • The most efficient consortium degraded up to 300 mg L−1 2-MBT in medium. • It had higher efficiency than the previously reported bacterial strains. • The dominant populations were Pseudomonas and Stenotrophomonas. • When applied to rubber wastewater, it removed 79 % 2-MBT and 93 % COD. Benzothiazoles especially 2-mercaptobenzothiazole (2-MBT) in rubber industrial wastewater can be released into the environment. They can cause adverse health impacts. This study aimed to obtain efficient 2-MBT-degrading bacteria for wastewater application. The bacterial consortia were enriched by incubating rubber wastewater sludge in a medium containing 2-MBT for 28 days. Stepwise acclimatization was conducted with increasing 2-MBT concentrations from 50 to 200 mg L−1 in nitrogen-containing medium for 76 days. The process significantly increased the bacterial number and changed the dominant populations. Among these consortia, the EN consortium from benzothiazole-containing sludge had the highest specific 2-MBT biodegradation rate of 5.2 ± 0.5 mg L−1 day−1 mg protein-1 and could degrade up to 300 mg L−1 2-MBT. From 16S rRNA gene analysis, Pseudomonas was the dominant genus at approximately 70 % of the total population. S tenotrophomonas was the second most abundant populations and have never been reported for 2-MBT biodegradation. The EN consortium removed 65–79 % and 90–93 % of 112 mg L−1 2-MBT and ∼4000 mg L−1 COD in rubber wastewater, respectively, which were significantly higher than the values of natural attenuation. Therefore, the EN consortium could be an ideal inoculum for the post-treatment of benzothiazoles in rubber industrial wastewater. [ABSTRACT FROM AUTHOR]

Plants are often challenged by multiple abiotic stresses simultaneously. The inoculation of beneficial bacteria is known to enhance plant growth under these stresses, such as phosphorus starvation or salt stress. Here, for the first time, we assessed the efficiency of selected beneficial bacterial strains in improving tomato plant growth to better cope with double stresses in salty and P-deficient soil conditions. Six strains of Arthrobacter and Bacillus with different reservoirs of plant growth-promoting traits were tested in vitro for their abilities to tolerate 2–16% (w/v) NaCl concentrations, and shown to retain their motility and phosphate-solubilizing capacity under salt stress conditions. Whether these selected bacteria promote tomato plant growth under combined P and salt stresses was investigated in greenhouse experiments. Bacterial isolates from Cameroonian soils mobilized P from different phosphate sources in shaking culture under both non-saline and saline conditions. They also enhanced plant growth in P-deficient and salt-affected soils by 47–115%, and their PGP effect was even increased in higher salt stress conditions. The results provide valuable information for prospective production of effective bio-fertilizers based on the combined application of local rock phosphate and halotolerant phosphate-solubilizing bacteria. This constitutes a promising strategy to improve plant growth in P-deficient and salt-affected soils. [ABSTRACT FROM AUTHOR]