Ametryne is an herbicide applied to sugar cane cultures to prevent the emergence of weeds. It is a persistent compound that percolates ground and surface water thus impacting aquatic communities. In this study, we evaluated microbial activity in soil with increased concentrations of ametryne solution and commercial Microgeo biofertilizer. The soil subject to analysis was obtained from a sugar cane cultivation area. The concentration used in the experiment was ametryne 12 μg/L and 1 % of biofertilizer. It was used with the Bartha and Pramer respirometric method to quantify CO₂production and determine microbial activity. Complimentary phytotoxicity tests with Lactuca sativa seeds after respirometry experiments were conducted in the soluble fraction of the soil. According to the results, the addition of biofertilizer promoted microbial activity in the presence of ametryne and reduced ametryne phytotoxicity for Lactuca sativa seeds. Thus, Microgeo biofertilizer can potentially improve biodegradation of ametryne through both bioaugmentation and bioestimulation.

This study aimed to identify the specific genes associated with plant growth promotion and cadmium tolerance in three bacteria strains associated with Pennisetum giganteum as well as to determine their biosafety levels in their potential use as biofertilizers for promoting plant growth and phytoremediation activities. The plant growth-promoting (PGP) abilities of Enterobacter cloacae strain RCB980 (A3), Klebsiella pneumonia strain kpa (A4), and Klebsiella sp. strain XT-2 (A7) were determined by a growth promotion trial and through testing for PGP traits such as 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme production, phosphorus solubilization, siderophore synthesis, and indole-3 acetic acid (IAA) production. The genes that potentially contribute to the beneficial activities of these three strains were identified through an analysis of their genomes. To establish the biosafety of the candidate PGPB, a pathological study was undertaken whereby 20 Kunming mice were injected intraperitoneally to study and analyze the effects of the strains on growth and lung paraffin sections of the mice. The strains had no obvious toxicity effect on the tested mice and were therefore not considered as highly virulent strains. These strains are thus considered non-toxic, safe, and highly recommended for use in environmental remediation strategies and agricultural production.

The use of soil conditioners as bovine biofertilizer associated with mineral fertilization affect the physical and physicochemical quality of passion fruit. For fruit growth, post-harvest quality is crucial for production chain development, as it is the characteristic most used by the fresh consumption market for this fruit. In this sense, an experiment was carried out to investigate the effects of doses of bovine biofertilizer in the soil with and without nitrogen fertilization in the cultivation of yellow passion fruit. A randomized block design was adopted, with three replications in a 5×2 factorial scheme, referring to five doses of liquid bovine biofertilizer (B) diluted in water (A): 0% − control (0B + 4A); 25% (1B + 3A); 50% (2B + 2A); 75% (3B + 1A); and 100% (4B + 0A) with and without nitrogen fertilization applied to the soil. Urea was the nitrogen source used in this study. A total of 10 g plant⁻¹ of N was applied monthly at 30 and 60 days after transplanting, and after that age, 20 g plant⁻¹ was applied until the end of harvest. During the final phase of production and ripening, twelve fruits were harvested from each treatment in physiological maturation for physical and physicochemical characterization. The following analyses were performed: longitudinal diameter, transversal diameter, number of seeds per fruit, peel firmness, pulp yield, fruit peel percentage, pulp pH, soluble solids content; titratable acidity and soluble solids content/titratable acidity ratio. Data underwent analysis of variance by the F test means for nitrogen were compared by Tukey’s test and means for bovine biofertilizer, by regression. Nitrogen enhances the positive effect of bovine biofertilizer on the postharvest quality of yellow passion fruit. The association of biofertilizer and nitrogen improves fruit quality in comparison to plants without these inputs, except for pulp yield and fruit peel percentage, which suffered isolated effects from the factors. High doses of biofertilizer, above 75 and 100%, reduce soluble solids content and increase titratable acidity. The bovine biofertilizer has promising effects, but it does not replace nitrogen fertilization on the postharvest quality of yellow passion fruit.

The present study aimed to investigate the elemental composition of the hard shell of the three-spot swimming crab, Portunus sanguinolentus, collected from the coasts of Pakistan. Thirty crab shells were collected and divided into three groups considering their size. The element detection was performed by energy-dispersive X-ray spectroscopy with scanning electron microscope (SIM/EDAX). The mean concentration of carbon, oxygen, calcium, copper, magnesium, and phosphorus observed in the shell of P. sanguinolentus was 13.63 ± 6.21%, 46.25 ± 12.62%, 34.39 ± 18.33%, 3.19 ± 1.25%, 1.15 ± 0.99%, and 1.39 ± 0.51%, respectively. The concentration pattern of these observed elements in P. sanguinolentus shells was found in the following order: O > Ca > C > Cu > P > Mg. To compare among the three groups of shells, the highest concentration of calcium (54.60%) was obtained in large-sized shell groups, which was significantly different from the other groups (p < 0.05). A high concentration of copper was found to be accumulated in the large-sized (3.55%) and medium-sized (4.21%) shell groups, which was significantly higher than in small-sized shell groups (p < 0.05). In the case of the large-sized shell group, the mean concentrations of magnesium and phosphorus were significantly lower than the medium-sized shell group (p < 0.05). The results indicate that crab shells could act as a good bio-sorbent for several minerals in its ecosystem. P. sanguinolentus shell is very rich in calcium, magnesium, and phosphorus. Extraction of calcium, magnesium, and phosphorus from P. sanguinolentus shells could be profitable for biofertilizer and pharmaceutical industries.

Crustacean shell waste disposal is considered as biggest problem in seafood processing centers. Incineration and landfilling are the commonest ways of disposal of the waste which causes environmental pollution. Microbial bio-conversion is one of the promising approaches to minimize the wastes by utilizing the same for deriving different value added metabolites. In this perspective, chitinase- and protease-producing bacterial strains were isolated from shrimp culture pond, and the potent isolate was subsequently identified as Alcaligenes faecalis SK10. Fermentative optimization of the production of chitinase (85.42 U/ml), protease (58.57 U/ml), and their catalytic products, viz., N-acetylamino sugar (84 μg/ml) and free amino acids (112 μg/ml), were carried out by utilizing shrimp and crab shell powder as principal substrate. The fermented hydrolysate (FH) was subsequently applied to evaluate its potential to be a candidate fertilizer for the growth of leguminous plant Pisum sativum and Cicer arietinum, and the results were compared with chitin, chitosan, and commercial biofertilizer amended group. The results revealed that FH have paramount potential to improve plants morpho-physiological parameters like stem and root length, chlorophyll, cellular RNA, protein content, and soil physico-chemical parameters like total nitrogen, magnesium, calcium, phosphorus, and potassium significantly (p < 0.05). Moreover, the application of FH also selectively encouraged the growth of free-living nitrogen-fixing bacteria, Rhizobium, phosphate-solubilizing bacteria in the soil by 4.82- and 5.27-, 5.57- and 4.71, and 7.64- and 6.92-fold, respectively, in the rhizosphere of P. sativum and C. arietinum, which collectively is a good sign for an ideal biofertilizer. Co-supplementation of FH with commercial PGPR-biofertilizer significantly influenced the morpho-physiological attributes of plant and physico-chemical and microbial attributes of soil. The study validated proficient and sustainable utilization of fermented hydrolysate of waste crustacean shell as biofertilizer.

This study evaluated the effect of applying biofertilizer in the soil on the cultivation of corn. Different doses of biofertilizer associated with chemical fertilizer were applied in the soil to meet the plants’ nutritional demand. Four months after sowing, plant samples were collected and evaluated, by measuring the height and productivity of biomass, dry matter, neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), and nitrogen (N). Soil samples were also collected to measure the concentrations of macronutrients, base saturation, and exchangeable acidity. The biofertilizer application did not alter the levels of dry matter, NDF, ADF, CP, and N in the plants, or the concentrations of nitrogen, phosphorus, magnesium, and copper in the soil. Besides this, the largest average values of the plant heights and levels of potassium in the soil were found in the treatment with the highest biofertilizer dose. Notably, there was a significant increase in the quantity of fresh and dry matter in the treatments that received biofertilizer in comparison with the controls. The results obtained indicated the potential of substituting conventional fertilization with fertirrigation using biofertilizer, an alternative procedure that can help reduce the environmental impacts caused by dairy farming, regarding the release of wastewater into watercourses.

In this study, different nitrogen doses (0, 16, 48, 64, 80, and 96 kg ha⁻¹) from two sources, biofertilizer (from anaerobic digestion of cattle wastewater) and urea, were applied to cultivate two sugarcane varieties (RB 867515 and SP 803280). °Brix values higher than 21% were obtained with application of 80 kg ha⁻¹ from biofertilizer. The mean productivity of the cultivar RB 867515 using biofertilizer was 147.5 ton ha⁻¹, while from urea it was 136.87 ton ha⁻¹. The cultivar SP 803280 produced an average yield of 152.25 ton ha⁻¹ when applying biofertilizer and 154.37 ton ha⁻¹ with use of urea. Significant differences (P ≤ 0.05) between the use of biofertilizer and urea were detected for cultivar RB 867515 in terms of crude protein concentration. The application of 80 kg of N ha⁻¹ was considered the ideal dose, corresponding to fertirrigation blades of 54 mm of biofertilizer. The experiment showed that the biofertilizer formulation analyzed can replace urea as a nitrogen source for growing sugarcane. Graphical Abstract ᅟ

This study evaluates the treatment efficacy and biogas yield of an integrated system composed of a plug-flow biodigester (with sludge recirculation) followed by polishing in a stabilization pond. The system was operated in real scale for 12 months at ambient temperature and under continuous flow. The volumetric yields of biogas varied according to the organic loads applied, between 114 and 294 Kg COD day⁻¹, reaching levels of 0.026 to 0.173 m³ m⁻³ day⁻¹, with concentrations of CH₄ between 56 and 70%. The monthly biogas productions were between 378.5 and 2186.1 m³ month⁻¹ equal to an energy potential of approximately 2070 to 19,168 KWh month⁻¹.The average yearly removals of BOD₅,₂₀ and COD by the integrated treatment system were 70 and 86%, respectively. The average annual removals of NH₄ and TKN were 88.5 and 85.5%, respectively. The pH values were always near neutral, and the alkalinity was in ranges propitious for anaerobic digestion. The results of this study indicate good efficacy in terms of removal of organic matter and nitrogen compounds, with the added benefits of generation of energy and use of the treated effluent as biofertilizer, enabling significant cost reductions to cattle farmers.

Wastewater (WW) for irrigation and application of biosolids in soil is becoming important as it is going to become very common in the near future. By 2050, the world is going to have four billion people living in water-scarce countries, making it a norm of freshwater for the cities and WW for agriculture. Further, biosolids might still be used as green biofertilizers for soils, if they are improved from an ecological point of view. However, application of biosolids in soil is argued because of the amount of organic pollutants that compromise the dynamic equilibrium of the biological systems. Therefore, information on the concentration, behavior, and cycling of organic pollutants as well as their possible degradation pathways is needed to predict, prevent, and remediate these pollutants from different sources including WW and biosolids. Among the group of organic pollutants, emerging contaminants (ECs) enter into the soil with the irrigation water from treated effluents and fertilization by biosolids. Quantification of ECs from WW and biosolids is of main importance to predict the toxic effects of WW effluents and sludge. Moreover, their incorporation into vegetables through irrigation and their magnification through natural food webs have been proved and must be monitored. This review presents information on the different sources of emerging contaminants and linking with the ecological effects they produced by reacting in the environment during various applications of WW and biosolids in soil. The available methods for analysis and quantification of ECs in different matrices, such as WW and biosolids, are also presented.

Heavy metal contamination plays a major role in water pollution. It needs remediation without raising the issues of secondary waste generation and their related issues. Heavy metal residues adversely affect soil and water quality. Their leachate would disturb the whole ecological system. It needs remediation to avoid the effect on soil and water. Azospirillium biofertilizer has the ability to reduce hazardous components without disturbing the growth of the plant. Hence, the use of low-cost biosorbent was proposed for heavy metal removal. The investigations showed excellent removal of heavy metals like copper (Cu) and chromium (Cr) using Azospirillium biofertilizer. These materials showed efficient removal of Cu and Cr at 94% and 70%, respectively. Separation was dependent upon the interaction between sorbent and sorbate, which makes separation tunable for the removal of the desired material from effluent or other streams. Parameter optimization like temperature, adsorbent dose, time, pH, and agitation speed was studied for both metals. At optimum parameters, Langmuir capacity was found to be 35.71 mg/g and 5.58 mg/g of copper and chromium. Experimental data was best fitted to Langmuir isotherm, and the pseudo-second-order kinetic model was suitable for the study of both metals.