Selective reduction of the pathogenic load of cow manure in an industrial-scale continuous-feeding vermireactor

Bioconversion of cow manure through vermicomposting: effects of tylosin concentration on the weight of worms and manure quality

This study investigated batch-fed vermicomposting of cow manure, with a specific focus on assessing the effects of tylosin on the weight of earthworms and the overall quality of the resulting manure. Five reactors, including three concentrations of tylosin (50, 100, and 150 mg/kg) and two control reactors, were employed. Residual tylosin concentrations were measured using high-performance liquid chromatography (HPLC). Quality parameters such as pH, temperature, volatile solids (VS), organic carbon content (OCC), electrical conductivity (EC), ash content, C/N ratio, total Kjeldahl nitrogen (TKN), and microbial content were evaluated. The toxicity and maturity of vermicompost were assessed by determining the germination index (GI). The study also monitored variations in the earthworm's weight. The results demonstrated a decreasing trend in VS, OCC, C/N, and fecal coliforms, along with increased pH, EC, ash content, and TKN during the vermicomposting process. Furthermore, investigations revealed significant reductions in the reactors with tylosin concentrations of 50, 100, and 150 mg/kg, resulting in the removal of 98%, 90.48%, and 89.38% of the initial tylosin, respectively. This result confirms the faster removal of tylosin in reactors with lower concentrations. Degradation of tylosin also conforms to first-order kinetics. The findings showed a significant influence of tylosin on the weight of Eisenia fetida earthworms and the lowest antibiotic concentration led to the highest weight gain. Finally, the high percentage of germination index (90-100%) showed that the quality and maturity of vermicompost is by national and international standards.

New insights into vermiremediation of sewage sludge: The effect of earthworms on micropollutants and vice versa

Vermicomposting represents an environmentally friendly method for the treatment of various types of biowastes, including sewage sludge (SS), as documented in numerous studies. However, there are few papers providing insights into the mechanisms and toxicity effects involved in SS vermicomposting to present a comprehensive overview of the process. In this work, the vermiremediation of SS containing various micropollutants, including pharmaceuticals, personal care products, endocrine disruptors, and per/polyfluoroalkyl substances, was studied. Two SSs originating from different wastewater treatment plants (WWTP1 and WWTP2) were mixed with a bulking agent, moistened straw, at ratios of 0, 25, 50, and 75% SS. Eisenia andrei earthworms were introduced into the mixtures, and after six weeks, the resulting materials were subjected to various types of chemical and toxicological analyses, including conventional assays (mortality, weight) as well as tissue- and cell-level assays, such as malondialdehyde production, cytotoxicity tests and gene expression assays. Through the vermiremediation process significant removal of diclofenac (90%), metoprolol (88%), telmisartan (62%), and triclosan (81%) was achieved. Although the concentrations of micropollutants were substantially different in the original SS samples, the micropollutants vermiaccumulated to a similar extent over the incubation period. The earthworms substantially eliminated the present bacterial populations, especially in the 75% SS treatments, in which the average declines were 90 and 79% for WWTP1 and WWTP2, respectively. To the best of our knowledge, this is the first study to investigate the vermiremediation of such a large group of micropollutants in real SS samples and provide a thorough evaluation of the effect of SS on earthworms at tissue and cellular level.

Earthworms drastically change fungal and bacterial communities during vermicomposting of sewage sludge

Wastewater treatment plants produce hundreds of million tons of sewage sludge every year all over the world. Vermicomposting is well established worldwide and has been successful at processing sewage sludge, which can contribute to alleviate the severe environmental problems caused by its disposal. Here, we utilized 16S and ITS rRNA high-throughput sequencing to characterize bacterial and fungal community composition and structure during the gut- and cast-associated processes (GAP and CAP, respectively) of vermicomposting of sewage sludge. Bacterial and fungal communities of earthworm casts were mainly composed of microbial taxa not found in the sewage sludge; thus most of the bacterial (96%) and fungal (91%) taxa in the sewage sludge were eliminated during vermicomposting, mainly through the GAP. Upon completion of GAP and during CAP, modified microbial communities undergo a succession process leading to more diverse microbiotas than those found in sewage sludge. Consequently, bacterial and fungal community composition changed significantly during vermicomposting. Vermicomposting of sewage resulted in a stable and rich microbial community with potential biostimulant properties that may aid plant growth. Our results support the use of vermicompost derived from sewage sludge for sustainable agricultural practices, if heavy metals or other pollutants are under legislation limits or adequately treated.

Cleaner production of agriculturally valuable benignant materials from industry generated bio-wastes: A review

Bio-wastes from different agro-based industries are increasing at a rapid rate with the growing human population's demand for the products. The industries procure raw materials largely from agriculture, finish it with the required major product, and produce huge bio-wastes which are mostly disposed unscientifically. This creates serious environmental problems and loss of resources and nutrients. Traditional bio-wastes disposal possess several demerits which again return with negative impact over the eco-system. Anaerobic digestion, composting, co-composting, and vermicomposting are now-a-days given importance due to the improved and modified methods with enhanced transformation of bio-wastes into suitable soil amendments. The advanced and modified methods like biochar assisted composting and vermicomposting is highlighted with the updated knowledge in the field. Hence, the present study has been carried to compile the effective and efficient methods of utilizing industry generated bio-wastes for circularity between agriculture - industrial sectors to promote sustainability.

Changes in layers of laboratory vermicomposting using spent mushroom substrate of Agaricus subrufescens P

World mushroom production in 2018 was approximately 8.99 million tonnes. The most commonly cultivated species in the Czech Republic are Agaricus spp., which are sold fresh or canned. In 2017, 2018 mushroom production in the Czech Republic was approximately 540 tonnes. Vermicomposting is an easy and less ecologically harmful way to process the spent mushroom substrate. Earthworms, which are referred to as the engine of the process of vermicomposting, and microorganisms, help convert organic waste into fertilizer. This study is concerned with laboratory vermicomposting in a system of continuous feeding of earthworms Eisenia andrei. It compares the differences between variants with and without earthworms. The dry matter percentage was approximately 20% or more in both variants. The variant with earthworms showed a significant decrease in electrical conductivity. The C/N ratio was very low in both variants. The highest total P was recorded in the variant with earthworms, but the highest values of K and Mg were found in the control. Both variants recorded higher content of bacteria than fungi. All values of microorganism contents were higher in the vermicomposter without earthworms, but the bacterial/fungal ratio was higher in the variant with earthworms. The highest content in both variants shows the bacteria especially G-bacteria, on the other side, the lowest content shows the actinobacteria. The highest activity of β-D-glucosidase and acid phosphatase was measured in the vermicomposter with earthworms, but the activity of other enzymes was higher in the control. In both vermicomposters laccase activity was below the detection limit. The method of classical vermicomposting can be used for processing the spent mushroom substrate. However, in terms of higher content of total and available nutrients, there seems to be a better method of processing the substrate without earthworms.

Mutual interactions of E. andrei earthworm and pathogens during the process of vermicomposting

Vermicomposting is a process by which earthworms together with microorganisms degrade organic wastes into a humus-like material called vermicompost. This process does not include a thermophilic stage, and therefore, the possible presence of pathogens represents a potential health hazard. To elucidate the effect of earthworms in the selective reduction of pathogens, grape marc substrate was artificially inoculated with Escherichia coli, Enterococcus spp., thermotolerant coliform bacteria (TCB), and Salmonella spp., and their reduction during vermicomposting was monitored. Various defense mechanisms eliminating microorganisms in the earthworm gut were assumed to be involved in the process of pathogen reduction. Therefore, we followed the expression of three pattern recognition receptors (coelomic cytolytic factor (CCF), lipopolysaccharide-binding protein (LBP), and Toll-like receptor (v-TLR)), two antimicrobial molecules (fetidin/lysenins and lysozyme), and heat shock protein HSP70. We detected the significant decrease of some defense molecules (fetidin/lysenins and LBP) in all pathogen-inoculated substrates, and the increase of CCF and LBP in the Salmonella spp.-inoculated substrate. At the same time, the reduction of pathogens during vermicomposting was assessed. We observed the accelerated reduction of E. coli, Enterococcus spp., and TCB in pathogen-inoculated substrates with earthworms compared to that without earthworms. Moreover, the differences between the microbiome of grape marc substrate and earthworm intestines were determined by high throughput sequencing. This analysis revealed that the bacterial composition of grape marc substrate differed from the composition of the content of earthworm intestines, suggesting the elimination of specific bacterial species during food passage through the gut.

Change of the parameters of layers in a large-scale grape marc vermicomposting system with continuous feeding

The main by-product of wine-making is grape marc. With proper treatment, grape marc may return to the vineyard as a fertiliser. This study deals with the vermicomposting of grape marc in a continuous feeding system in outdoor conditions for more than 12 months. The N-NH₄⁺, dissolved organic carbon (DOC), and N-NH₄⁺/N-NO₃^- contents were greater in the top layers. The pH value was about 8 in all the layers. The electrical conductivity was the greatest in the bottom layer. The ion-exchange capacity did not modify significantly during vermicomposting. The microbial biomass was the greatest in the upper layer, as well as the number and the biomass of the earthworms. The process of vermicomposting seems to be an ideal way of processing residues from the winemaking industry. This vermicompost has very good properties for use as a fertiliser, and for returning the nutrients and organic matter to the soil, for example, in a vineyard.

Bioconversion of Scotch broom into a high-quality organic fertiliser: Vermicomposting as a sustainable option

Wild Scotch broom ( Cytisus scoparius (L.) Link) shrubs are widely distributed throughout the world and, in some countries, are considered to be a threat to other plant species. The use of plant biomass from Scotch broom as a fertiliser seems to be the optimum solution for its disposal because it contains considerable amounts of macronutrients. However, its direct application to soils may cause phytotoxicity due to the release of polyphenols, which could negatively affect crop growth. This study evaluated the efficiency of vermicomposting in processing this leguminous plant on an industrial scale. Vermicomposting substantially reduced the biomass of Scotch broom (by 84%), mainly as a result of the loss of volatile solids. Simultaneously, the initial population of earthworms ( Eisenia andrei) increased remarkably throughout the process, offering the possibility of obtaining earthworm protein for animal feed. A nutrient-rich and stabilised peat-like material without polyphenol-associated phytotoxicity was obtained after 42 days of vermicomposting. Lower values of microbial biomass and activity, indicative of stabilised materials, were recorded at the end of the trial. These findings suggest that vermicomposting is an environmentally sound management system for Scotch broom and could easily be scaled up for industrial application.

Contribution of Eisenia andrei earthworms in pathogen reduction during vermicomposting

Vermicomposting is a process of degradation of biowaste which involves complex interactions between earthworms and microorganisms. This process lacks a thermophilic stage and thus, the possible presence of pathogens poses a potential health hazard. To assess the contribution of earthworms during the selective reduction of various pathogens, apple pomace substrate was artificially inoculated with Escherichia coli, Salmonella spp., thermotolerant coliform bacteria, and Enterococci. The artificial bacterial load did not influence the weight, reproduction, or intestinal enzymatic activity of the earthworms, but it caused reversible histological changes to the epithelial layer and chloragogen tissue of their intestines. The reduction of pathogenic Enterococci and E. coli from the substrate was accelerated by earthworms (63-fold, 77-fold, and 840-fold for Enterococci and 6-fold, 36-fold, and 7-fold for E. coli inoculated substrates after 2, 4, and 6 weeks, respectively). Moreover, the rapid elimination of Salmonella spp. was supported by the upregulated expression of two pattern recognition receptors which bind lipopolysaccharide, coelomic cytolytic factor, and lipopolysaccharide-binding protein. Further, the microbiomes of the intestine and the composting substrate differed significantly. Graphical abstract.

Preliminary evaluation of pathogenic bacteria loading on organic Municipal Solid Waste compost and vermicompost

The use of composts or vermicomposts derived from organic fraction of Municipal Solid Waste (OFMSW) brought about certain disagreement in terms of high level of bacterial pathogens, thereby surpassing the legal restrictions. This preliminary study was undertaken to compare the evolution of pathogenic bacteria on OFMSW compost against vermicompost (generated by Eudrilus eugeniae) with promises of achieving sanitation goals. Analysis to quality data showed that OFMSW vermicomposting caused a moderately higher reduction in total coliforms in contrast to composting. E. coli in OFMSW composts was found to be in the range of 4.72-4.96 log₁₀ CFU g^-1 whilst on a clear contrary, E. coli was undetectable in the final vermicomposts (6.01-6.14 logs of reduction) which might be explained by the involvement of the digestive processes in worms' guts. Both OFMSW composts and vermicomposts generated Salmonella-free products which were acceptable for agricultural usage and soil improvement. In comparison to compost, the analysis of this research indicated that earthworm activity can effectively destroy bacterial pathogenic load in OFMSW vermicomposts. But still, this study necessitates extra research in order to comprehend the factors that direct pathogenic bacteria in vermicomposting and earthworm-free decomposition systems.

A Comprehensive Review of the Fate of Pathogens during Vermicomposting of Organic Wastes

Management of both municipal and industrial organic wastes remains a major threat to biota and the environment due to the presence of pathogens in abundance. Vermicomposting employing earthworms is increasingly gaining attention as a sustainable and ecofriendly technique to transform and sanitize a variety of organic wastes into nutrient-rich biofertilizer. Although considerable research has been undertaken to show that vermicomposting can significantly reduce pathogenic contents, there is little effort to summarize the various mechanisms responsible for it. With the aim to assess the fate of pathogens during vermicomposting of various organic wastes, this article provides a comprehensive summary on the occurrence of pathogens in a variety of wastes vis-à-vis pathogens standards, the efficacy of the process for pathogen reduction, and current knowledge of the plausible mechanisms involved. It is evident from the present study that earthworms and endosymbiotic microbes during vermicomposting tend to eliminate pathogens by enhancing enzymatic activities in both gut- and cast-associated processes. Pathogen reduction during vermicomposting can be plausibly attributed to direct actions like microbial inhibition due to intestinal enzymatic action, and secretion of coelomic fluids with antibacterial properties, as well as indirect actions like stimulation of endemic microbes leading to competition and antagonism, and aeration by burrowing activity. Further, the pathogen reduction during vermicomposting is largely selective, and earthworms exert a differential effect according to the earthworm species and whether the pathogen considered is Gram-positive or -negative, owing to its cell wall composition. However, further research is necessary to understand the exact mechanisms involved for pathogen reduction during vermistabilization of municipal and industrial organic wastes.

Inactivation of bacterial pathogenic load in compost against vermicompost of organic solid waste aiming to achieve sanitation goals: A review

Waste management strategies for organic residues, such as composting and vermicomposting, have been implemented in some developed and developing countries to solve the problem of organic solid waste (OSW). Yet, these biological treatment technologies do not always result in good quality compost or vermicompost with regards to sanitation capacity owing to the presence of bacterial pathogenic substances in objectionable concentrations. The presence of pathogens in soil conditioners poses a potential health hazard and their occurrence is of particular significance in composts and/or vermicomposts produced from organic materials. Past and present researches demonstrated a high-degree of agreement that various pathogens survive after the composting of certain OSW but whether similar changes in bacterial pathogenic loads arise during vermitechnology has not been thoroughly elucidated. This review garners information regarding the status of various pathogenic bacteria which survived or diffused after the composting process compared to the status of these pathogens after the vermicomposting of OSW with the aim of achieving sanitation goals. This work is also indispensable for the specification of compost quality guidelines concerning pathogen loads which would be specific to treatment technology. It was hypothesized that vermicomposting process for OSW can be efficacious in sustaining the existence of pathogenic organisms most specifically; human pathogens under safety levels. In summary, earthworms can be regarded as a way of obliterating pathogenic bacteria from OSW in a manner equivalent to earthworm gut transit mechanism which classifies vermicomposting as a promising sanitation technique in comparison to composting processes.

A metagenomic analysis displays the diverse microbial community of a vermicomposting system in Uganda

Background

Vermicomposting is a mesophilic process using earthworms to efficiently and at low cost process large volumes of organic waste. It has been suggested to not only increase soil fertility but also increase biomass of beneficial bacteria while reducing harmful bacteria. The aim of this study was to set up a strategy to investigate and characterise the viral as well as the bacterial composition of a vermicomposting system.

Material and methods

The vermicomposting unit used in this study was placed at the Makerere University Agricultural Research Institute Kabanyolo on the outskirts of Kampala, Uganda, and was fed with 80% cattle manure and 20% food waste. On Day 172, the compost was terminated and compost samples were collected from three layers of the unit: the top, the middle and the bottom layer. A metagenomic approach was then applied to characterise the viral and bacterial composition of the vermicomposting system.

Results and discussion

A high abundance and diversity of bacteria were identified. Proteobacteria was the largest phyla in the compost (mainly Alpha-, Gamma- and Betaproteobacteria), constituting almost 65% of the bacterial reads in the data sets. DNA samples from several possible pathogenic bacteria, such as Salmonella spp., Escherichia coli, Enterobacter spp., Enterococcus spp. and Clostridium spp, were detected in the vermicompost, suggesting that there might still be harmful bacteria in the vermicast. Phages constituted the main viral group; apart from phages, mainly insect viruses were identified. The only animal or human virus identified was kobuvirus. In summary, metagenomic analysis was shown to be an efficient technology to characterise the microbial composition of vermicast. The data from this study contribute to a better understanding of the microbes present in this kind of composting system and can help determine measures necessary for safe manure handling.

Assessing the changes in E. coli levels and nutrient dynamics during vermicomposting of food waste under lab and field scale conditions

Vermicomposting (VC) has proven to be a promising method for treating garden, household, and municipal wastes. Although the VC has been used extensively for converting wastes into fertilizers, pathogens such as Escherichia coli (E. coli) survival during this process is not well documented. In this study, both lab and field scale experiments were conducted assessing the impacts of earthworms in reducing E. coli concentration during VC of food waste. In addition, other pertinent parameters such as temperature, carbon and nitrogen content, moisture content, pH, volatile solids, micronutrients (P, K, Ca, Mg, and S), and heavy metals (Zn, Mn, Fe, and Cu) were monitored during the study. The lab and field scale experiments were conducted for 107 and 103 days, respectively. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study. Results showed that VC was not significantly effective in reducing E. coli levels in food waste under both lab and field scale settings. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study.

An Overview of the Control of Bacterial Pathogens in Cattle Manure

Cattle manure harbors microbial constituents that make it a potential source of pollution in the environment and infections in humans. Knowledge of, and microbial assessment of, manure is crucial in a bid to prevent public health and environmental hazards through the development of better management practices and policies that should govern manure handling. Physical, chemical and biological methods to reduce pathogen population in manure do exist, but are faced with challenges such as cost, odor pollution, green house gas emission, etc. Consequently, anaerobic digestion of animal manure is currently one of the most widely used treatment method that can help to salvage the above-mentioned adverse effects and in addition, produces biogas that can serve as an alternative/complementary source of energy. However, this method has to be monitored closely as it could be fraught with challenges during operation, caused by the inherent characteristics of the manure. In addition, to further reduce bacterial pathogens to a significant level, anaerobic digestion can be combined with other methods such as thermal, aerobic and physical methods. In this paper, we review the bacterial composition of cattle manure as well as methods engaged in the control of pathogenic microbes present in manure and recommendations that need to be respected and implemented in order to prevent microbial contamination of the environment, animals and humans.

Cow Manure Composting by Microbial Treatment for Using as Potting Material: An Overview

Dairy industry is flourishing in Saudi Arabia for the last two decades producing milk and milk products to meet the population needs. Simultaneously, it is also producing large amount of dairy waste (animal manure) posing a serious environmental issues. Vermicomposting (conversion of animal manure into compost by bacterial treatments) is considered as one of the safest means for efficient management and to mitigate environmental pollution issues resulting from land disposal of raw dairy wastes. The main objective of this studywas to summarize different processes of vermicomposting and identified the most important bacteria species suitable for vermicomposting using animal manure especially the cowdung. The review showed that among the different bacteria species, Eisenia fetida is the most efficient and commonly used bacteria for vermicomposting to develop compost using cow dung (dairy manure). Overall,this review has highlighted the various vermicomposting technologies, various bacteria species involved in vermicomposting, effect on soil and plant growth as well as the benefits of using compost prepared by way of vermicomposting. The study showed a lot of potential for the production of compost by vermicomposting technology using appropriate bacteria species which is safe, friendly and is associated with minimum environmental issues for safe land disposal of dairy waste (animal manure) with minimum possible environmental issues for the adjacent population.

Effects of digestate on soil chemical and microbiological properties: A comparative study with compost and vermicompost

Anaerobic digestion has become increasingly popular as an alternative for recycling wastes from different origins. Consequently, biogas residues, most of them with unknown chemical and biological composition, accrue in large quantities and their application into soil has become a widespread agricultural practise. The aim of this study was to evaluate the effects of digestate application on the chemical and microbiological properties of an arable soil in comparison with untreated manure, compost and vermicompost. Once in the soil matrix either the addition of compost or digestate led to an increased nitrification rate, relative to unamended and manure-treated soil, after 15 and 60 days of incubation. Faecal coliform and E. coli colony forming units (CFUs) were not detected in any of the amended soils after 60 days. The highest number of Clostridium perfringens CFUs was recorded in manure-amended soil at the beginning of the experiment and after 15 days; whilst after 60 days the lowest CFU number was registered in digestate-treated soil. Denaturing gradient gel electrophoresis patterns also showed that besides the treatment the date of sampling could have contributed to modifications in the soil ammonia-oxidising bacteria community, thereby indicating that the soil itself may influence the community diversity more strongly than the treatments.

Vermicomposting as manure management strategy for urban small-holder animal farms - Kampala case study

Inadequate organic waste management can contribute to the spread of diseases and have negative impacts on the environment. Vermicomposting organic waste could have dual beneficial effects by generating an economically viable animal feed protein in the form of worm biomass, while alleviating the negative effects of poor organic waste management. In this study, a low-maintenance vermicomposting system was evaluated as manure and food waste management system for small-holder farmers. A vermicomposting system using the earthworm species Eudrilus eugeniae and treating cow manure and food waste was set up in Kampala, Uganda, and monitored for 172days. The material degradation and protein production rates were evaluated after 63days and at the end of the experiment. The material reduction was 45.9% and the waste-to-biomass conversion rate was 3.5% in the vermicomposting process on a total solids basis. A possible increase in the conversion rate could be achieved by increasing the frequency of worm harvesting. Vermicomposting was found to be a viable manure management method in small-scale urban animal agriculture; the return of investment was calculated to be 280% for treating the manure of a 450kg cow. The vermicompost was not sanitised, although hygiene quality could be improved by introducing a post-stabilisation step in which no fresh material is added. The value of the animal feed protein generated in the process can act as an incentive to improve current manure management strategies.

Changes in the bacterial community structure in stored wormbed leachate

Organic wastes, such as cow manure, are often composted with earthworms (vermicomposting) while excess water is drained and collected. This wormbed leachate is nutrient-rich and it has been extensively used to fertilize plants. However, it is derived partially from a not yet finished compost process and could exhibit phytotoxicity or contain potentially hazardous microorganisms. The bacterial community in wormbed leachate derived from vermicomposting of cow manure was studied by pyrosequencing the 16S rRNA gene. The fresh wormbed leachate was rich in Mollicutes, particularly the genus Acholeplasma which contain phytopathogen species. The abundance of the Mollicutes decreased when the leachate was stored, while that of the Rhizobiales and the genus Pseudomonas increased. The bacterial communities changed rapidly in the leachate during storage. The changes in ammonium, nitrate and inorganic carbon content of the wormbed leachate when stored were correlated to changes in the bacterial community structure. It was found that storage of the wormbed leachate might be required before it can be applied to crops as large proportions of potentially plant pathogens were found in the fresh leachate.

The influence of earthworms on nutrient dynamics during the process of vermicomposting

In the present study the potential of the earthworm Eisenia andrei to modify chemical and microbiological properties, with a special focus on the nutrient content of fresh organic matter, was evaluated during 16 weeks of vermicomposting of cattle manure and sewage sludge. Samples were periodically collected in order to determine the changes in inorganic nitrogen (N), in total microbial biomass and activity, as well as in the total and available content of macro- and micronutrients. An optimal moisture level, ranging from 75% to 88%, was maintained throughout the process. The content of organic matter decreased over time, but no changes were found in this parameter as a result of earthworm activity. The carbon/N ratio rapidly decreased, but only in the manure, reflecting rapid decomposition and mineralisation of the organic matter by the earthworms. An increase in N mineralisation was also attributable to the presence of earthworms, although in the manure this effect was hardly detectable before the eighth week of vermicomposting. Earthworm activity also enhanced the total content of potassium, calcium and iron together with an increase in the availability of phosphorus and zinc. We did not detect a significant earthworm effect on microbial respiration, but their activity increased greatly microbial biomass nitrogen in sewage sludge.

Microbial diversity of vermicompost bacteria that exhibit useful agricultural traits and waste management potential

Vermicomposting is a non-thermophilic, boioxidative process that involves earthworms and associated microbes. This biological organic waste decomposition process yields the biofertilizer namely the vermicompost. Vermicompost is a finely divided, peat like material with high porosity, good aeration, drainage, water holding capacity, microbial activity, excellent nutrient status and buffering capacity thereby resulting the required physiochemical characters congenial for soil fertility and plant growth. Vermicompost enhances soil biodiversity by promoting the beneficial microbes which inturn enhances plant growth directly by production of plant growth-regulating hormones and enzymes and indirectly by controlling plant pathogens, nematodes and other pests, thereby enhancing plant health and minimizing the yield loss. Due to its innate biological, biochemical and physiochemical properties, vermicompost may be used to promote sustainable agriculture and also for the safe management of agricultural, industrial, domestic and hospital wastes which may otherwise pose serious threat to life and environment.