Compost Soil Research Articles

Jackfruit Starch Based Blends with Polyvinylpyrrolidone: Preparation, Structural Characterization, and Biodegradable Properties

AbstractStarch is extracted from the seeds of ripen jackfruit (Artocarpus heterophyllus) cultivated in Nepal by treating with distilled water and alkali solution. The properties of extracted starch are evaluated by measuring ash content, moisture content, and amylose content. A series of starch‐based biodegradable blends with polyvinylpyrrolidone (PVP) are prepared through solution casting method and their biodegradable properties are studied. The blend is characterized by thickness measurement, water solubility test, Fourier transform infrared spectroscopy (FTIR), optical microscopy, and biodegradability test. The thickness measurement shows the linear increase in thickness of the blend with the addition of starch. The water solubility test reveals the higher solubility of PVP in water than that of the starch. FTIR spectra of PVP/thermoplastic starch (PVP/TPS) blends exhibit the existence of relevant functional groups of both starch and PVP, the peaks shifting, and the change in nature of the peaks after degradation. Optical microscopy reveals the nonuniform dispersion of starch particles in the PVP matrix and the appearance of holes and fractures in composite subjected to compost soil for degradation. The biodegradability study proves that the loading of starch to PVP accelerates the degradation process.

Extraction and characterization of cellulase from forest and compost soil fungal isolates for the application of straw degradation

Cellulases are complex hydrolytic enzymes working synergistically on the hydrolysis of cellulolytic materials for the production of simple sugars. These enzymes have tremendous environmental, industrial and agricultural applications including enhancement of the degradability of lignocellulosic materials for cattle’s feed. The aim of this study was to isolate fungus and extract cellulose enzyme from forest and compost soil samples and examine the extent to which these enzymes enhance the degradability of finger millet and oat straw for making palatable cattle’s feed. Accordingly, a total of 53 fungal isolates were isolated from forest and compost soil. On 1% CMC media resulted 40% were cellulolytic fungal species. Six were selected based on their clear zone. These isolates belonged to the genera Trichoderma, Aspergillus and Penicillium based on their morphological characteristics. Cultivation of fungal isolates for cellulase production using submerged fermentation and Solid-state fermentation was undertaken through make the variation on their levels of different growth conditions such as temperature, pH, minerals and substrates. The results showed that the highest cellulase production i.e CMCase 83.12 ± 3.18 U/dL and FPase 44.51± 0.391FPU/dL were obtained from FSI6 in FMS supplemented SSF at 280C and a pH of 6.

Incorporation of engineered nanoparticles of biochar and fly ash against bacterial leaf spot of pepper

In agriculture, the search for higher net profit is the main challenge in the economy of the producers and nano biochar attracts increasing interest in recent years due to its unique environmental behavior and increasing the productivity of plants by inducing resistance against phytopathogens. The effect of rice straw biochar and fly ash nanoparticles (RSBNPs and FNPs, respectively) in combination with compost soil on bacterial leaf spot of pepper caused by Xanthomonascampestris pv. vesicatoria was investigated both in vitro and in vivo. The application of nanoparticles as soil amendment significantly improved the chili pepper plant growth. However, RSBNPs were more effective in enhancing the above and belowground plant biomass production. Moreover, both RSBNPs and FNPs, significantly reduced (30.5 and 22.5%, respectively), while RSBNPs had shown in vitro growth inhibition of X.campestris pv. vesicatoria by more than 50%. The X-ray diffractometry of RSBNPs and FNPs highlighted the unique composition of nano forms which possibly contributed in enhancing the plant defence against invading X.campestris pv. vesicatoria. Based on our findings, it is suggested that biochar and fly ash nanoparticles can be used for reclaiming the problem soil and enhance crop productivity depending upon the nature of the soil and the pathosystem under investigation.

Brightness Values-Based Discriminant Functions for Classification of Degrees of Organic Matter Decomposition in Soil Thin Sections

The decomposition of organic matter represents a fundamental pedogenetic process, since it impacts the carbon cycle and the release of nutrients to the soil. However, quantitative research aimed at micro-scale in situ analysis is scarce, despite its relevance in the decomposition process. Therefore, the objectives of this research were to generate discriminating functions of the degrees of organic matter decomposition, based on the brightness values associated with each morphological stage, and from this step, to generate thematic maps. Soil thin sections of forest and compost soils were selected, and petrographic microscope images with three light sources were taken: plane polarized light (PPL), crossed-polarized light (XPL), and crossed polarizers and a retardation plate (gypsum compensator) inserted (XPLλ). Subsequently, the RGB (red, green, blue) image was broken down into three bands, resulting in nine bands for each image. Two thousand sampling points were generated for each band, obtaining brightness values for each decomposed organic matter stage. The points were classified into four categories based on their degree of decomposition: no (A), light (B), moderate (C), and strong (D), in addition to porosity (P). Linear discriminant analysis was performed to obtain classification models for each level of decomposition. The results show that each degree of organic matter decomposition can be highlighted through specific light sources and a set of bands, with an overall accuracy of >94% and kappa coefficients of >0.75 for all classes. In addition, the resulting functions were validated in training images and high-resolution mosaics to create final thematic maps. The use of linear models automated the production and quality of thematic maps at the microscopic level, which can be useful in monitoring the organic matter decomposition process.

Co-applying biochar and manganese ore can improve the formation and stability of humic acid during co-composting of sewage sludge and corn straw

This study examined the effects of corn straw biochar (CSB) and manganese ore (MO) on the abiotic formation and stability of humic acid (HA) during sewage sludge composting. Co-applying CSB and MO (106%) induced a higher increase in HA content of final compost product than those of no or single applications (32.6–85.1%). This positive change was achieved by promoting the conversion of humus precursors and fulvic acid to HA through abiotic pathway, respectively, in the early and later stages of composting. The co-application of CSB and MO also exhibited a higher capacity to improve HA stability than those of single applications. In sum, this study confirmed a clear synergistic effect of CSB and MO on improving the formation and stability of HA in compost product, which could further enhance the multi-benefits (e.g., carbon sequestration and soil quality improvement) of compost soil application.

Changes in physical and chemical properties of saline soil amended with municipal solid waste compost and chemical fertilizers in a mustard–pearl millet cropping system

AbstractSoil salinity is a severe threat in arid and semiarid agro‐ecosystem of India, and it is directly influenced by soil physical properties. Therefore, understanding the dynamic nature of salinity is the key to implementing suitable management options for re‐builing the fertility of saline soils. In this context, we conducted field experiments in saline soil, comprising five treatments (1‐5 following) and a control (C). These are: C) no amendments and chemical fertilizer; T1) recommended dose nitrogen, phosphorus, and potassium (N‐P‐K) fertilizers @60:30:30 kg ha−1; T2) 100% recommended dose of chemical fertilizers (RDF).; T3) rice straw compost (RSC) @14 Mg ha−1; T4) gypsum enriched compost (GEC) @14 Mg ha−1; and T5) municipal solid waste compost @16 Mg ha−1 (MSWC) applied for three consecutive years (2012 to 2015). Our results revealed that compost and chemical fertilizer had significant effect on soil organic carbon, soil aggregate stability indices, soil water retention, transmission characteristics, and pore size distribution. This improvement in soil physical properties imparted into better soil physical environment and significant reduction in soil salinity (75%) was apparent with application of MSWC. Multivariate analysis indicated that mean weight diameter (MWD) and retension pores (RP) were the two main soil physical properties that help to reduce soil salinity. Our results revealed that, MWD increased by 49.1% in MSWC and 37.7% in GEC over control (C) (0.53 mm). Improvement in soil environment under composted soil produced significantly higher grain yield of mustard (2.22 Mg ha−1) and pearl millet (2.29 Mg ha−1) with MSWC as compared to control (C). Organic amendments significantly improved the soil physical environment.

Effect of Feldspar, Compost and Biochar on Cultivating Cowpea (Vigna unguiculata ssp. unguiculata) Plant and Soil Sandy Clay Loam Properties

The crop production in Egypt relies completely on imports to meets its annual requirement of potash fertilizers besides; the high cost of conventional, water soluble K fertilizers constrains their use by most of the farmers in the country. This work was conducted cowpea (Vigna unguiculata ssp. unguiculata) plants cv. Dokki 126 at Ismailia Research Station, Agricultural Research Center (A.R.C), Egypt, during the two summer seasons of 2020 and 2021 to study the effect of some treatments as potassium feldspar, biochar and compost on soil sandy clay loam properties and the physical and chemical contents of cowpea. A randomized complete block design was used. The results show that the potassium feldspar + biochar + Compost significantly increased the vegetative growth expressed as plant length, number of leaves, number of branches, pod length, Pod diameter, Pod fresh weight, Pod dry weight, Plant fresh weight, Plant dry weight. Also the results indicated that soil pH and EC was not significantly affected in the soil treated with potassium feldspar + biochar + compost. There are positive significant effects on nutrient availability (NPK) in both seasons by using potassium feldspar + biochar + compost in soil. The application of OMW can improve soil quality indices (nutrients (N, P, and K), organic matter, pH, total porosity, bulk density.

High Power Generation with Reducing Agents Using Compost Soil as a Novel Electrocatalyst for Ammonium Fuel Cells.

Ammonium toxicity is a significant source of pollution from industrial civilization that is disrupting the balance of natural systems, adversely affecting soil and water quality, and causing several environmental problems that affect aquatic and human life, including the strong promotion of eutrophication and increased dissolved oxygen consumption. Thus, a cheap catalyst is required for power generation and detoxification. Herein, compost soil is employed as a novel electrocatalyst for ammonium degradation and high-power generation. Moreover, its effect on catalytic activity and material performances is systematically optimized and compared by treating it with various reducing agents, including potassium ferricyanide, ferrocyanide, and manganese dioxide. Ammonium fuel was supplied to the compost soil ammonium fuel cell (CS-AFC) at concentrations of 0.1, 0.2, and 0.3 g/mL. The overall results show that ferricyanide affords a maximum power density of 1785.20 mW/m2 at 0.2 g/mL fuel concentration. This study focuses on high-power generation for CS-AFC. CS-AFCs are sustainable for many hours without any catalyst deactivation; however, they need to be refueled at regular intervals (every 12 h). Moreover, CS-AFCs afford the best performance when ferricyanide is used as the electron acceptor at the cathode. This study proposes a cheap electrocatalyst and possible solutions to the more serious energy generation problems. This study will help in recycling ammonium-rich wastewaters as free fuel for running CS-AFC devices to yield high-power generation with reducing agents for ammonium fuel cell power applications.

Fungal key players of cellulose utilization: Microbial networks in aggregates of long-term fertilized soils disentangled using 13C-DNA-stable isotope probing

Long-term compost application accelerates organic carbon (C) accumulation and macroaggregate formation in soil. Stable aggregates and high soil organic C (SOC) content are supposed to increase microbiota activity and promote transformation of litter compounds (i.e., cellulose) into SOC. Here, we used 13C-DNA-stable isotope probing with subsequent high-throughput sequencing to characterize fungal succession and co-occurrence trends during 13C-cellulose decomposition in aggregate size classes in soils subjected to no fertilizer (control), nitrogen‐phosphorus‑potassium (NPK) fertilizers, and compost (Compost) application for 27 years. Ascomycota (mostly saprotrophic fungi) were always highly competitive for cellulose in all aggregate size classes at the early stages of cellulose decomposition (20 days). Compost-treated soil was enriched with Ascomycota compared to the control soil, wherein Sordariomycetes, the majority, strongly dominated the cellulose utilization (13C incorporation in DNA). 13C-labeled fungal communities converged in the Compost soil, with lower abundance and diversity compared with the NPK and control soils. Such convergence led to greater cellulose decomposition, indicating that compost amendment increased the capacity of a few dominant fungal taxa to decompose litter. Compost soil had more 13C-labeled fungal decomposers in microaggregates and lower fungal decomposers in macroaggregates when compared with the levels in the NPK and control soils. This implies that compost application facilitates fungal colonization towards smaller aggregates. Fungal interactions were reinforced in microaggregates (<250 μm), with more positive associations than those in macroaggregates (>250 μm), indicating greater fungal synergism for recalcitrant resource utilization in microaggregates. The keystone taxa in the co-occurrence networks were not related to cellulose decomposition in microaggregates, but did in macroaggregates. The findings advance a process-based understanding of cellulose utilization by fungal key players based on C and energy availability and the regulation of microbial activity at the aggregate level.

Fungal biosorption of the heavy metals chromium(VI) and nickel from industrial effluent-contaminated soil

Heavy metals are ubiquitous contaminants that have accompanied man since the earliest ancient times, and unlike other environmental pollutants, they are chemical elements that man does not create or destroy. In the present study, the aim was to determine the biosorption potential of heavy metal-tolerant fungi that were isolated from compost soil samples contaminated by industrial effluents. The isolation was performed on potato dextrose agar (PDA) media supplemented with heavy metals. Chromium-Cr(VI) and nickel-Ni. The most dominant fungal species were found to be Penicillium spp. This fungus was screened for its ability to tolerate heavy metals by the plate diffusion and broth method and was highly tolerant to fungal species. The fungi were assessed for their ability to remove heavy metals from the culture media, and the culture conditions for the fungus were experimentally optimized. The isolated Penicillium species was found to show maximum growth at 35°C with media pH 6 for an incubation period of 168 hours. The isolate was able to tolerate 60-70 ppm concentrations of heavy metals under normal conditions. The ability of the isolate to take up metal was very effective, as after 96 hrs of incubation, it was capable of removing approximately 93.8% of Cr(VI) and 95.6% of Ni from the culture media, and complete uptake was observed after a 144 hr incubation period. The molecular characterization revealed the only isolate to be Penicillium rubens (Accession no. LC536286). The morphological characteristics of this fungus make it capable of biosorption of heavy metals, imparting its bioremediation potential and economic importance.

PERCEPATAN PERTUMBUHAN BIBIT SENGON (Paraserianthes falcataria L.) DENGAN APLIKASI PERENDAMAN BENIH PADA MEDIA TANAM KOMPOS

The purpose of this study was to determine the acceleration of the growth of Sengon Seedlings with a long treatment time of soaking the seeds planted in compost soil media. This research was conducted in the experimental garden of the Agrotechnology Study Program, Faculty of Science and Technology, Tabanan University. The study was conducted from July 2020 to October 2020, using the basic design of a factorial randomized block design (RAK) which was repeated three times. The treatment that was tried consisted of two factors, namely the immersion time factor and the compost planting media factor.The results showed that the interaction between the soaking time of Sengon seeds and the composition of the compost growing media had a very significant effect (P&lt;0.01) on the wet weight parameters of the underground plant parts and the oven-dry weight of the underground plant parts, significantly (P &lt; 0 0.05) on the parameters of the total wet weight of the plant and the total dry weight of the plant, while the other parameters had no significant effect (P &gt; 0.05). The highest total oven dry weight of the plant was produced by the interaction between the composition of the growing media: soil: sand: compost (1:1:2) and the soaking time of 12 hours (K2P2), which was 2.89 g, while the lowest was produced by the interaction between the composition of the growing media. soil:sand (1:1) with no soaking (K0P0) which is 0.25 g or an increase of 1056%.

Compost Soil Amendment: An Approach to Enhance Crop Productivity by Improving Soil Physiology

Compost Soil Amendment: An Approach to Enhance Crop Productivity by Improving Soil Physiology

Utilization of Compost as a Soil Amendment to Increase Soil Health and to Improve Crop Yields

Compost amendments have remarkable potential for improving soil structure, porosity and water holding capacity. Soil health is the ability to function as a living system, to sustain plant and animal productivity, to enhance water and air quality, and to promote plant and animal health. Soil health can be estimated by measuring the total living microbial biomass, retained carbon, odor, and texture. Poor or deteriorating soil health is threatening food security. The potential for compost to reverse these negative trends is transformative if means and methods for large scale composting and compost amendments can be developed. A field-scale compost soil amendment project was implemented in Rapid City, South Dakota. The compost was added to a soil plot at 5 wt% and 10 wt% and the results were compared with an adjacent untreated plot without any compost addition. Measurements of soil health characteristics indicate that compost amendments improve soil health, crop yields, and soil water content. Treating soils with compost has the potential to reverse global deteriorating soil health.

Value of Water Based upon Retail Sales Tax Revenue

In quantifying the benefits of compost amendments to soils for agricultural and urban use in terms of water conservation, there are many difficulties in conveying “value” of water due to the many different aspects of value to individuals and organizations. Perhaps the most universal metric for value is through the net monetary impact of water. Therefore, it is necessary to quantify the benefits by placing a dollar value on the amount of water conserved by amending soils with compost. In most of the literature, the value of water is rarely defined, and when it is the value presented is actually the “cost” of water production or reclamation. However, to truly understand the impacts of water conservation, a fuller vision of the value of water is needed beyond the costs of water. In this paper, the value of water is developed for the Rapid City, South Dakota area. With a value of water established, the benefits of soil compost amendments are calculated by evaluating the reduction of irrigation water needed for comparable crops and the value of the conserved water. In developing a value of water for Rapid City, South Dakota, the direct costs for water production are compared with the retail value of water and the economic activity enabled by a water supply. The average cost of water production for South Dakota cities averaged $0.004 per gallon ($0.001/Liter). The analysis of retail value and economic impact showed that water is valued at $0.71 per gallon ($0.19/Liter) for Rapid City and nine other South Dakota communities when calculated using the community’s retail sales records and economic reports. Efforts to find similar findings for the US were not found. With the value of water established for Rapid City and other South Dakota communities, the value benefits of compost amendments on water conservation are shown in direct monetary terms.

Effect of Biochar and Manual Vegetation Control on Early Growth and Survival of Planted Jack Pine (Pinus banksiana Lamb.) Seedlings in Northern Minnesota

Abstract Survival of planted seedlings following a regeneration harvest can be challenging and early interventions through silvicultural treatments may be required for successful stand establishment. We tested the influence of soil amendment (biochar plus compost, compost-only, or control) and vegetation control (VC; applied either initially or annually for five years using brush saws) on the growth and survival of jack pine at three sites in northern Minnesota. Application of the biochar plus compost soil amendment increased seedling survival by 30% relative to the control in the first year, but there was no significant difference in survival among soil amendment treatments after five years. Both soil amendments increased diameter growth relative to the control (14% increase with biochar plus compost, 10% increase with compost only), with most of the biochar plus compost effect attributed to the compost. Annual VC increased diameter growth by 17% relative to initial VC, but overall effects on survival and growth were generally small relative to reported effects of VC via herbicide. The limited short-term influence of biochar and manual VC on growth and survival of jack pine indicates that these practices are likely not an effective means to increase jack pine establishment, but other benefits (e.g., increased carbon storage) may become apparent with time.

Sewage sludge from Taxco de Alarcón wastewater treatment plant as substrate to cultivate Panicum maximum

The management and disposal of the sewage sludge (SS) generated by a wastewater treatment plant (WWTP) as part of the municipal wastewater (MWW) treatment process is one of the main socio-environmental issues faced by this type of system. Taxco de Alarcón, Guerrero, in southern Mexico has had a WWTP operating since 2016, and the SS disposal is a task that must be addressed by the WWTP. Thus, the aim of this work was to evaluate the growth capacity of Panicum maximum, also known as mombaza grass (MG), by using SS generated within the "Taxco de Alarcón wastewater treatment plant" as substrate. To do so, 4 g of MG seeds were scattered over 5 kg (dry basis) of SS. As a control, a commercial compost soil was used, hereafter called pattern soil (PS). The experiment was carried out in triplicates for three months and drinking water (water used for human consumption) was used for crop irrigation. Each month a MG harvest was carried out. The response variables analyzed for MG were germination time (one month after plant emergence), height (HMG), growth rate GrMG, and yield (YMG), whereas in the SS and PS the content of organic matter was analyzed. Furthermore, the chemical composition was analyzed using scanning electron microscopy and X-ray energy dispersion spectroscopy (SEM-EDS) on the MG, SS, and PS. The results showed that MG germinated faster on PS (5 days) than germination on SS (7 days). However, the MG grown on SS reached a considerably higher height (45 cm) compared to the height reached on PS (17 cm). Furthermore, the maximum GrMG over SS was also higher than the maximum GrMG observed on the PS, 3.64 and 1.40 cm∙day-1, respectively. In terms of YMG, it was observed that on SS it reached an average monthly YMG of 416 g∙m-2, whereas in PS it reached a YMG of 72 g∙m-2. The chemical analysis detected P, K, Ca, Mg, and S, considered macronutrients in both substrates. Besides, some micronutrients identified in SS were Cu, Fe, Mn, and Zn, whereas in PS it was also possible to detect micronutrients except Mn and Zn. All the macronutrients detected in the substrates were observed in the harvested MG. However, in the MG harvested in PS, Mn and Zn were not detected. Hence, a feasible disposal strategy for the SS generated by the Taxco de Alarcón WWTP is as a substrate for grass forage MG by its high organic matter content, the significant presence of macro and micronutrients, and the performance shown by MG cultivated in SS. Furthermore, the SS characteristics provide added value and can be considered as organic amendments of agricultural soils.

Effects of Plastic Pollution of Soil on the Growth and Survival of Bacteria and Fungi

&#x0D; &#x0D; &#x0D; The study examined the effect of plastic waste on soil bacteria and fungi. The test soil samples were collected from Lokoja international market waste dump site and the control soil sample was collected from non plastic contaminated garden in Salem University, Lokoja. The samples were analysed using Gas chromatography with mass spectrometer. The test soil sample soil sample had high quantity of plastic contaminant which were Methylene chloride 17.45mg/kg, hexane 10.05mg/kg, chloroform 1.56mg/kg, toluene 5.87mg/kg, tetrachloroethylene 1.48mg/kg as compared to the control garden soil sample, which had methylene chloride 0.54mg/kg, hexane 0.26mg/kg, chloroform 0.31mg/kg, toluene 5.87mg/kg and tetrachloroethylene 0.01mg/kg. The result showed the presence of plastic in the soil and it effect on bacteria and fungi. The totals of 11 bacteria were isolated from both soil samples using nutrient agar. The bacteria isolated are; Corynebacterium spp. (12%), Enterobacter spp. (8%), Acinetobacter spp. (6%), Escherichia coli (16%), Epidermis, Bacillus subtilis (15%), Serratia sp. (8%), Proteus spp. (4%), Micrococcus luteus (7%), Flavobacterium spp. (10%), Pseudomonas aeruginosa (15%). Micrococcus luteus, Flavobacterium spp. and Pseudomonas aeruginose were not isolated in plastic composted soil sample due to the presence of plasticizers. The total of 6 fungi were isolated, namely Penicilliun expansion (12%), Sacchromyces sp. (24%), Aspergillus niger (19%), Fusarium spp. (20%), Rhizopus stolonifer (10%) and Mucor piriformis (15%). This study reveals the effect of plastic waste, as it inhibits the growth of microorganism that is important for soil activities, thereby reducing the soil nutrients, fertility and productivity.&#x0D; &#x0D; &#x0D;

Isolation and Identification of Cellulase Producing and Sugar Fermenting Bacteria for Second-Generation Bioethanol Production

Over the last decades, the negative impacts of fossil fuel on the environment and increasing demand for energy due to the unavoidable depletion of fossil fuels, has transformed the world’s interests towards alternative fuels. In particular, bioethanol production from cellulosic biomass for the transportation sector has been incrementing since the last decade. The bacterial pathway for bioethanol production is a relatively novel concept and the present study focused on the isolation of potential “cellulase-producing” bacteria from cow dung, compost soil, and termite gut and isolating sugar fermenting bacteria from palm wine. To select potential candidates for cellulase enzyme production, primary and secondary assays were conducted using the Gram’s iodine stain in Carboxy Methyl Cellulose (CMC) medium and the Dinitrosalicylic acid (DNS) assays, respectively. Durham tube assay and Solid-Phase Micro-Extraction (SPME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS) was used to evaluate the sugar fermenting efficiency of the isolated bacteria. Out of 48 bacterial isolates, 27 showed cellulase activity where Nocardiopsis sp. (S-6) demonstrated the highest extracellular crude enzyme activity of endoglucanase (1.56±0.021 U) and total cellulase activity (0.93±0.012 U). The second-highest extracellular crude enzyme activity of endoglucanase (0.21±0.021 U) and total cellulase activity (0.35±0.021 U) was recorded by Bacillus sp. (T-4). Out of a total of 8 bacterial isolates, Achromobacter sp. (PW-7) was positive for sugar fermentation resulting in 3.07% of ethanol in broth medium at 48 h incubation. The results of the study revealed that Nocardiopsis sp. (S-6) had the highest cellulase enzyme activity. However, the highest ethanol percentage was achieved with by having both Bacillus sp. (T-4) and Achromobacter sp. (PW-7) for the simultaneous saccharification and fermentation (SSF) method, as compared to separate hydrolysis and fermentation (SHF) methodologies.

Innovative Polycomposite Fertilizer Obtained by Recycling and Processing Three Organic Wastes

The paper aims at testing an innovative organic fertilizer obtained from waste by processing a mixture of marine algae biomass, sewage municipal sludge and farmyard manure. Design of this polycomposite fertilizer is based on adequate conceptual and experimental models by taking into account the complex interactions among these three biomasses. In the first step a detail physico-chemical analysis has been performed on the composition of the three raw materials and also on the soil. In the second phase similar analyses have been carried out on representative samples of soil treated with the compost as compared with untreated soil samples. Analytical methods applied were FT-IR spectroscopy in correlation with organic/inorganic and total carbon (TOC/TIC/TC) analysis. The efficiency of applying this compost on the field at large scale has been assessed by means of fatty acid content of the oleaginous plants cultivated. Based on correlation between production quality and chemical composition of the composted soil, the optimal proportions of the mixture of the three organic wastes will be selected for designing an eco-friendly fertilizer able to improve agrochemical properties of the soil.

Exploration for Thermostable β-Amylase of a Bacillus sp. Isolated from Compost Soil to Degrade Bacterial Biofilm.

ABSTRACTIn an attempt to explore biofilm degradation using extracellular amylase, a potent amylase-producing bacterium of compost origin, B. subtilis B1U/1, was found to grow suitably in a simple medium of pH 7.5 for 48 h at 37°C under agitation of 140 rpm. This bacillary amylase was recovered by ammonium sulfate precipitation and purified to near homogeneity by membrane filtration and DEAE cellulose column chromatography. The amylase was purified to 4.5-fold with almost 50% yield and 26 kDa of molecular weight. Stable enzyme activity was found in a pH range of 5.2 to 9.0, while 90% residual activity was recorded at 90°C, indicating its thermostable nature. In the presence of 1 mM Fe++ and Ca++, the activity of amylase improved; however, it is inhibited by 1 mM Cu++. In the presence of 5% NaCl concentration, amylase showed 50% residual activity. The end product analysis identified the enzyme as β-amylase, and a crystal violet assay ensured that it can degrade Pseudomonas aeruginosa (78%) and Staphylococcus aureus biofilm efficiently (75%). The experiments carried out with the compost soil isolate were promising not only for biotechnological exploitation due to its pH flexibility during growth but also for high efficiency in the degradation of biofilms, which makes the organism a potent candidate in the fields of food industries and biomedical engineering, where it can be used as a prosthetic and hip joint cleaner. The β-amylase is highly thermostable since it withstands an elevated temperature for a prolonged period with a minimum loss of activity and is also moderately salt and metal tolerant.IMPORTANCE More than 85% of nosocomial infections are due to the development of bacterial biofilms. Recent research proposed that biofilm-like structures are not only visible in autopsies, biopsies, patients with chronic wounds, and exudates in animal models but are also present in biomedical devices, implants, prosthetic valves, urinary catheters, etc. Because complete eradication of biofilm is highly challenging, alternative methods, such as enzymatic damage of extracellular matrix and mechanical removal, are being implemented due to their easy availability, low cost, and high yield. Organisms from compost piles are rich sources of diverse extracellular enzymes with a high level of stability, which makes them able to withstand the different conditions of their environments. Under diverse environmental conditions, the enzymes are active to continue degradation processes, making them potential candidates in waste management, medicine, and the food and agriculture industries.