Effects of two-stage microbial inoculation on organic carbon turnover and fungal community succession during co-composting of cattle manure and rice straw

The impact of microbial inoculants on large-scale composting of straw and manure under natural low-temperature conditions

Understanding large-scale composting under natural conditions is essential for improving waste management and promoting sustainable agriculture. In this study, corn straw (400 tons) and pig manure (200 tons) were composted with microbial inoculants. The thermophilic phase of composting lasted for fourteen weeks, resulting in an alkaline final product. Microbial systems with low-temperature initiation and high-temperature fermentation played a crucial role in enhancing lignocellulose degradation and humic substances (HS) formation. Adding microbes, including Rhodanobacter, Pseudomonas, and Planococcus, showed a positive correlation with degradation rates of cellulose, hemicellulose, and lignin. Bacillus, Planococcus, and Acinetobacter were positively correlated with HS formation. Microorganisms facilitated efficient hydrolysis of lignocelluloses, providing humic precursors to accelerate composting humification through phenolic protein and Maillard pathways. This study provides significant insights into large-scale composting under natural conditions, contributing to the advancement of waste management strategies and the promotion of sustainable agriculture.

Integrating bioprocess and metagenomics studies to enhance humic acid production from rice straw

Rice straw burning annually (millions of tons) leads to greenhouse gas emissions, and an alternative solution is producing humic acid with high added-value. This study aimed to examine the influence of a microbial consortium and other additives (chicken manure, urea, olive mill waste, zeolite, and biochar) on the composting process of rice straw and the subsequent production of humic acid. Results showed that among the fungal species, Thermoascus aurantiacus exhibited the most prominent impact in expediting maturation and improving compost quality, and Bacillus subtilis was the most abundant bacterial species based on metagenomics analysis. The highest temperature, C/N ratio reduction, and amount of humic acid production (Respectively in lab 61 °C, 54.67%, 298 g kg-1 and in pilot level 65 °C, 72.11%, 310 g kg-1) were related to treatments containing these microorganisms and other additives except urea. Consequently, T. aurantiacus and B. subtilis can be employed on an industrial scale as compost additives to further elevate quality. Functional analysis showed that the bacterial enzymes in the treatments had the highest metabolic activities, including carbohydrate and amino acid metabolism compared to the control. The maximum enzymatic activities were in the thermophilic phase in treatments which were significantly higher than that in the control. The research emphasizes the importance of identifying and incorporating enzymatically active strains that are suitable for temperature conditions, alongside the native strains in decomposing materials. This strategy significantly improves the composting process and yields high-quality humic acid during the thermophilic phase.

Effect of nitrogen retention composite additives Ca(H2PO4)2 and MgSO4 on the degradation of lignocellulose, compost maturation, and fungal communities in compost

This study investigated the effects of the nitrogen retention composite additives Ca(H2PO4)2 and MgSO4 on lignocellulose degradation, maturation, and fungal communities in composts. The study included control (C, without Ca(H2PO4)2 and MgSO4), 1% Ca(H2PO4)2 + 2% MgSO4 (CaPM1), 1.5% Ca(H2PO4)2 + 3% MgSO4 (CaPM2). The results showed that Ca(H2PO4)2 and MgSO4 enhanced the degradation of total organic carbon (TOC) and promoted the degradation of lignocellulose in compost, with CaPM2 showing the highest TOC and lignocellulose degradation. Changes in the three-dimensional excitation-emission matrix fluorescence spectroscopy (3D-EEM) of dissolved organic matter (DOM) components in compost indicated that the treatment group with the addition of Ca(H2PO4)2 and MgSO4 promoted the production of humic acids (HAs) and increased the degree of compost decomposition, with CaPM2 demonstrating the highest degree of decomposition. The addition of Ca(H2PO4)2 and MgSO4 modified the composition of the fungal community. Ca(H2PO4)2 and MgSO4 increased the relative abundance of Ascomycota, decreased unclassified_Fungi, and Glomeromycota, and activated the fungal genera Thermomyces and Aspergillus, which can degrade lignin and cellulose during the thermophilic stage of composting. Ca(H2PO4)2 and MgSO4 also increased the abundance of Saprotroph, particularly undefined Saprotroph. In conclusion, the addition of Ca(H2PO4)2 and MgSO4 in composting activated fungal communities involved in lignocellulose degradation, promoted the degradation of lignocellulose, and enhanced the maturation degree of compost.

Impact of Aspergillus fumigatus inoculation on the composting of wood shaving bedding for horses

Equine farming generates a significant amount of waste, prompting the need for effective management. Composting enhanced by filamentous fungi holds promise for this purpose. This study focused on inoculating Aspergillus fumigatus isolates in composting horse bedding made with wood shavings (Pinus elliottii). The experiment lasted 90 days, with two treatment groups, control and inoculated, analyzing temperature, pH, electrical conductivity, total organic carbon and nitrogen content, and cellulose, hemicellulose, and lignin contents. Both treatments entered the thermophilic phase by the fourth day, reaching temperatures above 55°C and mesophilic maturation at 35 days (41 ± 0.2°C). The inoculated treatment exhibited higher electrical conductivity after 30 days and a more pronounced reduction in the total carbon content (42.85% vs. 38.29%) compared to the control. While there was no significant nitrogen difference, the inoculated treatment had a sharper reduction in carbon/nitrogen ratio, and cellulose and hemicellulose contents. Both treatments showed low coliform counts, no Salmonella sp., and reduced Strongyloides sp. larvae. Inoculating A. fumigatus in saturated horse bedding made from wood shavings improved compost quality, providing a possibility for sustainable equine farming waste treatment.

A review of the definition, influencing factors, and mechanisms of rapid composting of organic waste

Composting is a traditional method of treating organic waste. A growing number of studies have been focusing on accelerating the process to achieve "rapid composting." However, the specific definition and influencing factors of rapid composting remain unclear. Therefore, we aimed to gather more insight into the features of rapid composting by reviewing the literature concerning organic waste composting published in the Web of Science database in the past 5 years. We selected 1615 sample studies with "composting" as the subject word and analyzed the effective composting time stated in each study. We defined rapid composting within 15 days using the median test and quartile method. Based on this definition, we summarized the influencing factors of "rapid composting," namely materials, reactors, temperature, and microorganisms. Finally, we summarized two mechanisms related to humus formation during organic waste rapid composting: high temperature-promoting maturation and microbial driving mechanisms. This literature review compiled useful references to help promote the development of rapid composting technology and related equipment.

Effect of inoculating thermophilic bacterial consortia on compost efficiency and quality

The objective of this study was to investigate the potential effects of thermophilic bacterial consortia on compost efficiency and quality. The application of bacterial consortia resulted in an earlier onset of the thermophilic period (THP), an increased upper temperature limit, and an extended duration of the THP by 3-5 days compared to the control group (CK). Microbial inoculation significantly improved the efficiency of organic matter degradation, as well as the content of water-soluble nitrogen (WSN) and humic acid-carbon (HAC). In the case of consortium Ⅱ inoculation (T2), the activities of cellobiohydrolase, β-glucosidase, and protease were increased by 81.81 %, 70.13 %, and 74.09 % at the THP respectively compared to CK. During the maturation stage, T2 also exhibited the highest PV, n/PIII, n value (1.33) and HAC content (39.53 mg·g-1), indicating that inoculation of consortium Ⅱ effectively promoted substrate maturity and product quality. Moreover, this inoculation effectively optimized the bacterial communities, particularly the growth of Planococcus, Chelatococcus, and Chelativorans during the composting, which were involved in carbon and nitrogen conversion or HAC synthesis. Carbohydrate and amino acid metabolism, and membrane transport were predominant in the consortia-inoculated samples, with an increased gene abundance, suggesting that inoculation contributed to promoting the biodegradation of lignocellulose and the exchange of favorable factors. In conclusion, this study demonstrates that inoculating thermophilic bacterial consortia has a positive impact on enhancing the resource utilization efficiency of agricultural waste and improving the quality of compost products.

Differences in microbial community structure and metabolic activity among tea plantation soils under different management strategies

Introduction

Microorganisms play an important role in the multifunctionality of soil ecosystems. Soil microbial diversity and functions have a great impact on plant growth and development. The interactions between tea trees and soil microbiota can be linked with planting patterns and management strategies, whose effects on soil microbial community structure and metabolites are still unclear.

Methods

Here we used amplicon sequencing and metabolomic analysis to investigate the differences in soil microbial composition and metabolites among three tea production systems: organic, non-organic, and intercropping.

Results

We detected significant differences among the three systems and found that Firmicutes, Proteobacteria, Acidobacteriota, Actinobacteriota and Chloroflexi were the main bacteria in the three soil groups, although they varied in relative abundance. Acidobacteria bacterium increased significantly in the organic and intercropping groups. For fungi, Ascomycota and Basidiomycota were the main differential fungal phyla. Fungi alpha-diversity in the non-organic group was significantly higher than that in the other two groups, and was correlated with multiple soil physical and chemical factors. Moreover, network analysis showed that bacteria and fungi were strongly correlated. The changes in soil microorganisms caused by management and planting patterns may affect soil quality through corresponding changes in metabolites. Metabolomic analysis showed differences in metabolite composition among different groups. It was also found that the arachidonic acid metabolic pathway was affected by changes in soil microorganisms, and may further affect soil quality in an essential manner.

Discussion

Planting patterns and management strategies may significantly affect soil microorganisms and therefore metabolites. Changes in soil microorganisms, especially in fungi, may alter soil quality by affecting soil physicochemical properties and metabolites. This study will provide new insights into soil quality monitoring from a microbiological perspective.

Shifts in bacterial diversity characteristics during the primary and secondary fermentation stages of bio-compost inoculated with effective microorganisms agent

Microbial inoculation was an effective way to improve product quality of composting and solve traditional composting shortage. However, the effect mechanism of microbial inoculation on compost microorganisms remains unclear. Here, Shifts in bacterial community, metabolic function and co-occurrence network during the primary and secondary fermentation stages of bio-compost inoculated with effective microorganisms (EM) agent were analyzed by high-throughput sequencing and network analysis. Microbial inoculation promoted organic carbon transformation in early stage of secondary fermentation (days 27 to 31). The beneficial biocontrol bacteria were main dominant genera at the second fermentation stage. Microbial inoculation can be good for the survival of beneficial bacteria. Inoculation with microbes promoted amino acid, carbohydrate and lipid metabolism, and inhibited energy metabolism and citrate cycle (TCA cycle). Microbial inoculation could enhance complexity of bacterial network and enhance mutual cooperation among bacteria during composting.

Combined use of biochar and microbial agent can promote lignocellulose degradation and humic acid formation during sewage sludge-reed straw composting

This study investigated the effects of corn straw biochar (CSB) and effective microorganisms (EM) added individually or combinedly on lignocellulose degradation, compost humification, and microbial communities during sewage sludge-reed straw composting process. All the additive practices were found to significantly elevate the humification degree of compost products. The degradation rates of cellulose, hemicellulose, and lignin in different additive treatments were 20.8-31.2 %, 36.2-44.8 %, and 19.9-25.7 %, respectively, which were greatly higher than those of the control. Compared with the single uses of CSB or EM, the combined use of CSB and EM generated greater promotions in lignin and hemicellulose degradations and increase in humic acid content. By comparing the differences in microbial communities among different treatments, the CSB-EM demonstrated greater increases in activity and diversity of lignocellulose degradation-related microbes, especially for fungus. Lastly, the combined use of CSB and EM was highly recommended as a high-efficient improvement strategy for organic compost production.

Food waste digestate composting enhancement by sodium polyacrylate addition: Effects on nitrogen transformation processes and bacterial community dynamics

The influences of sodium polyacrylate (PAAS) at the ratios of 0% (CK), 0.5% (F1), 1.0% (F2), 1.5% (F3), 2.0% (F4) and 2.5% (F5) on nitrogen transformation and bacterial community composition were investigated in the composting of food waste digestate (FWD) and corn straw (CS). PAAS addition increased the thermophilic temperature but had no significant effect on pH values. PAAS exerted significantly effects on the concentration of total nitrogen (TN), ammonia nitrogen (NH₄⁺-N), nitrite-nitrogen (NO₂^--N) and nitrate-nitrogen (NO₃^--N). The compost product in 1.0% PAAS treatment was more active in absorbing nutrients. Firmicutes (9.40-83.54%), Actinobacteriota (9.98-51.50%), Proteobacteria (0.20-27.87%) and Bacteroidota (0.11-34.69%) were the dominant phyla in FWD composting. Moreover, relative to CK, PAAS promoted the propagation of dominant bacterial phyla Firmicutes with increment of 30.05-102.06% in the thermophilic phase. Kroppenstedtia, Thermobifida and Saccharomonospora were observed to be dominant at the maturing phase and correlated with NH₄⁺-N, NO₂^--N, TN and NO₃^--N. Therefore, they might be regarded as probable biomarkers symbolic for the maturing phase during FWD composting. The compost product had the highest maturity degree in 1.0% PAAS treatment. These results indicated that PAAS addition improved the maturity and nutrient contents of the compost product as well as altered compost bacterial community dynamics.

Humification improvement by optimizing particle size of bulking agent and relevant mechanisms during swine manure composting

For purpose of clarifying the impact on particle size of bulking agents on humification and relevant mechanisms, different length (<2 cm, 2 cm, 5 cm, 10 cm) of branch and straw were blended with swine manure individually for 100 days aerobic composting. Results demonstrated that, 2 cm and 5 cm of branch and straw promoted the highest degradation of DOC by 41.49 % and 58.42 %, and increased the humic substances by 23.81 % and 55.82 % in maturity stage, respectively, compared with other treatments. As shown in microbial consequence, the maximum relative abundance of humus funguses increased by 99.55 % and 99.92 % at phylum, and 98.95 % and 99.24 % at genus in 2 cm and 5 cm of branch and straw treatment, thus verifying the result in variation of humus content. In a word, particle size could result in obvious impact on humification, and the optimized size were about 2 cm and 5 cm of branch and straw.

Changes of bacterial and fungal communities and relationship between keystone taxon and physicochemical factors during dairy manure ectopic fermentation

BACKGROUND

Due to interactions with variety of environmental and physicochemical factors, the composition and diversity of bacteria and fungi in manure ectopic fermentation are constantly changing. The purpose of this study was to investigated bacterial and fungal changes in dairy manure ectopic fermentation, as well as the relationships between keystone species and physicochemical characteristics.

METHODS

Ectopic fermentation was carried out for 93 days using mattress materials, which was combined with rice husk and rice chaff (6:4, v/v), and dairy waste mixed with manure and sewage. Physicochemical characteristics (moisture content, pH, NH4+-N (NN), total organic carbon (TO), total nitrogen (TN) and the C/N ratio) of ectopic fermentation samples were measured, as well as enzymatic activity (cellulose, urease, dehydrogenase and alkaline phosphatase). Furthermore, the bacterial and fungal communities were studied using 16S rRNA and 18S rRNA gene sequencing, as well as network properties and keystone species were analyzed.

RESULTS

During the ectopic fermentation, the main pathogenic bacteria reduced while fecal coliform increased. The C/N ratio gradually decreased, whereas cellulase and dehydrogenase remained at lower levels beyond day 65, indicating fermentation maturity and stability. During fermentation, the dominant phyla were Chloroflexi, Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria of bacteria, and Ascomycota of fungi, while bacterial and fungal community diversity changed dramatically and inversely. The association between physicochemical characteristics and community keystone taxon was examined, and C/N ratio was negative associated to keystone genus.

CONCLUSION

These data indicated that microbial composition and diversity interacted with fermentation environment and parameters, while regulation of keystone species management of physicochemical factors might lead to improved maturation rate and quality during dairy manure ectopic fermentation. These findings provide a reference to enhance the quality and efficiency of waste management on dairy farm.

Two novel phosphorus/potassium-degradation bacteria: Bacillus aerophilus SD-1/Bacillus altitudinis SD-3 and their application in two-stage composting of corncob residue

For effective utilization of corncob residue to realize green circular production, using composting to obtain a high-quality and low-cost biomass fertilizer has become a very important transformation avenue. In this paper, two novel phosphorus/potassium-degradation bacterial strains were isolated from tobacco straw and identified as Bacillus aerophilus SD-1/Bacillus altitudinis SD-3 (abbreviated as SD-1/SD-3). These identified two novel bacteria SD-1/SD-3 show that the soluble phosphorus content of SD-1/SD-3 reached 360.89 mg L^-1/403.56 mg L^-1 in the shake flask test, and the mass concentration of soluble potassium is 136.56 mg L^-1/139.89 mg L^-1. In addition, the Laccase (Lac), Lignin peroxidase (LiP), and Manganese peroxidase (MnP) activities of SD-1 and SD-3 are 54.45 U L^-1/394.84 U L^-1/222.79 U L^-1 and 46.27 U L^-1/395.26 U L^-1/203.98 U L^-1 respectively, with the carboxy-methyl cellulase (CMCase) of 72.07 U mL^-1 and 52.69 U mL^-1. Meanwhile, the effects of three different combinations of cultures, i.e., no inoculation (K1), inoculation of SD-1/SD-3 on day 21 (K2) and on day 0 (G) are investigated to understand the influence on the degradation degree of corncob residue compost. The results of K2 compost treatment showed that the effective P/K content increased nearly 3.1/2.4 times, the degradation of cellulose/lignin was 49.1/68.0%, and the germination rate was 110.23%, which were higher than other experiment groups K1/G. In conclusion, knowledge of this paper will be very useful for the industrial sector for the treatment of complex corncob residue.

Deciphering the effect of exogenous lignocellulases addition on the composting efficiency and microbial communities

This study aimed to reveal the potential effects of exogenous lignocellulases addition on the composting efficiency and microbial communities. The lignocellulases addition at the mesophilic phase (MEP) greatly expedited the substrate conversion and the rise of temperature at the initial stage, driving the early arrival of thermophilic phase (THP), caused by the positive effects of Sphingobacterium and Brevundimonas. When being added at the THP, the potential functions and interactions of microbial communities were stimulated, especially for Thermobispora and Mycothermus, which prolonged the duration of the THP and expedited the humic acid formation. Simultaneous addition (MEP and THP) significantly altered the microbial community succession and activated the microbes that contributed to the lignocellulases secretion, exhibiting the highest cellobiohydrolase (36.19 ± 3.25 U· g^-1 dw) and xylanase (47.51 ± 3.32 U·g^-1 dw) activity at the THP. These findings provide new strategies that can be effectively utilized to improve the efficiency and quality of composting.

Metagenomic analysis of the soil microbial composition and salt tolerance mechanism in Yuncheng Salt Lake, Shanxi Province

The soil in Yuncheng Salt Lake has serious salinization and the biogeographic environment affects the composition and distribution of special halophilic and salt-tolerant microbial communities in this area. Therefore, this study collected soils at distances of 15, 30, and 45 m from the Salt Lake and used non-saline soil (60 m) as a control to explore the microbial composition and salt tolerance mechanisms using metagenomics technology. The results showed that the dominant species and abundance of salt-tolerant microorganisms changed gradually with distance from Salt Lake. The salt-tolerant microorganisms can increase the expression of the Na⁺/H⁺ antiporter by upregulating the Na⁺/H⁺ antiporter subunit mnhA-G to respond to salt stress, simultaneously upregulating the genes in the betaine/proline transport system to promote the conversion of choline into betaine, while also upregulating the trehalose/maltose transport system encode genes to promote the synthesis of trehalose to resist a high salt environment.

Effect of attapulgite on heavy metals passivation and microbial community during co-composting of river sediment with agricultural wastes

This paper investigated the effects of attapulgite addition on the physicochemical processes, heavy metal transformation, and microbial community during the composting of agricultural wastes and sediment. In addition, the correlation between environmental factors, heavy metals (HMs), and microbial community was also assessed by redundancy analysis (RDA). The results showed that pile B with attapulgite addition entered the thermophilic phase earlier and lasted longer than pile A as the control group. The reduction in the bioavailability of HMs (Cr, Cd, and Zn) was also greater in pile B, and the passivation of HMs was ranked as Cd > Zn > Cr. The relative abundance of phylum Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria was the highest throughout the composting process. Furthermore, the RDA showed that the bacterial community composition was significantly correlated with temperature and C/N ratio in pile A, while significantly correlated with organic matter and pH in pile B. And the addition of attapulgite facilitated the conversion of HMs into more stable fractions by Pseudomonas. The study would provide a reference for the application of attapulgite to remediate the river sediment polluted by HMs.

The functions of potential intermediates and fungal communities involved in the humus formation of different materials at the thermophilic phase

Humus is the final product of humus precursors (HPS) during the humification process, while the associated mechanisms of humus formation have not been clarified. Here, the HPS degradation intermediate and core fungal function for wheat straw and chicken manure compost (SCM), cow dung compost (CD), Chinese traditional medicine residue compost (CTM) and mushroom dreg and chicken manure compost (MCM) was investigated during the thermophilic phase. The results showed SCM and MCM were rich in proteins, lipids, cellulose, low-molecular-weight organic acids, while CD and CTM contained abundant carbohydrates, aliphatic compounds, easily biodegradable aromatic structures, and intermediates from the lignocellulose degradation. In particular, the HPS degrading intermediates including O-alkyl-C and aromatic C compounds were the critical factors, and Scedosporium, Hypsizygus and Remersonia were the core fungal genera for the humification. Furthermore, the potential fungal functional genes involved in carbohydrate and lignin degradation might be the key factors to drive the humification process.

Pretreatment of rice straw by newly isolated fungal consortium enhanced lignocellulose degradation and humification during composting

The slow decomposition rate of the reluctant structure of lignocellulose in agricultural waste is the great limitation of composting processes, which can be averted by pretreatment-strategies. This study focused on the impacts of pretreating rice straw using a consortium of newly isolated fungal species on lignocellulose degradation and humic substances during composting. Fungal pretreatment had a significant impact on lignocellulose degradation (84%) of rice straw by producing higher lignocellulytic enzymes than chemical pretreatments (79%) or the control (61%). The compost with fungal pretreated rice straw (FPT) showed significantly high composting temperature in the late mesophilic stage, which enhanced the degradation of lignocellulose. The fluorescence excitation emission spectroscopy revealed that significantly more humic acid-like compounds were formed in FPT. These findings suggest that fungal pretreatment is a feasible method to accelerate straw degradation and humification.

Insights into the effect of iron-carbon particle amendment on food waste composting: Physicochemical properties and the microbial community

The effects of iron-carbon (Fe-C) particle amendment on organic matter degradation, product quality and functional microbial community in food waste composting were investigated. Fe-C particles (10%) were added to the material and composted for 32 days in a lab-scale composting system. The results suggested that Fe-C particle enhanced organic matter degradation by 12.3%, particularly lignocellulose, leading to a greater humification process (increased by 15.5%). In addition, NO₃^--N generation was enhanced (15.9%) by nitrification with more active ammonia monooxygenase and nitrite oxidoreductase activities in the cooling and maturity periods. Fe-C particles not only significantly increased the relative abundances of Bacillus and Aspergillus for organic matter decomposition, but also decreased the relative abundances of acid-producing bacteria. RDA analysis demonstrated that the bacterial community was significantly influenced by dissolved organic matter, C/N, NO₃^--N, humic acid, volatile fatty acids and pH, while electrical conductivity was the key factor affecting the fungal community.

Effects of burning rice straw residue on-field on soil organic carbon pools: Environment-friendly approach from a conventional rice paddy in central Viet Nam

Rice straw residue management is still facing many problems worldwide. This study used two environmentally friendly methods to investigate the effects of rice straw burning activity on water-extracted carbohydrate content in long-term paddy soil. Soil samples were collected at a depth within 0-15 cm at the paddy field before and after burning rice straw (pre-burning and post-burning), then extracted by distilled water at the ratio of 1:10 (soil: water) for measuring hot water (at 80 °C) and water extracted carbohydrate (at 25 °C) (HECH and WECH). The results showed that burning rice straw did not alter soil organic carbon (SOC); however, soil pH increased approximately 8.3%. Meanwhile, WECH and HECH ranged from 233 to 630 mg kg^-1, with the highest HECH in Pre-burning treatment, while the lowest amount addressed WECH of Post-burning treatment. Extracted carbohydrate decreased after burning rice straw compared to Pre-burning soil. On the other hand, hot water increased 39-58% of carbohydrates compared to water extraction. We conclude that burning rice straw did not affect SOC but tends to reduce their labile carbon pools, and the heating process likely degrade part of SOC when extracted at high temperatures.

Inoculation of Prickly Pear Litter with Microbial Agents Promotes the Efficiency in Aerobic Composting

Prickly pear (Rosa roxburghii Tratt), a shrub mainly distributed in South China, is an economically essential plant for helping the local people out of poverty. To efficiently provide sufficient nutrients to the plant in the soil for the ecological cultivation of prickly pear, we studied the aerobic composting of a prickly pear litter with three agents, including AC (Bacillus natto, Bacillus sp., Actinomycetes sp., Saccharomyces sp., Trichoderma sp., Azotobacter sp., and Lactobacillus sp.), BC (Bacillus subtilis, Lactobacillaceae sp., Bacillus licheniformis, Saccharomyces sp., and Enterococcus faecalis), and CC (Bacillus sp., Actinomycetes sp., Lactobacillaceae sp., Saccharomyces sp., and Trichoderma sp.) and a control without microbial agents. The results show that the physicochemical and microbial traits of three resultant prickly pear composts were different after the inoculation with AC, BC, or CC. The pH values of three composts ranged from 8.0 to 8.5, and their conductivity values were between 1.6 and 1.9 mS/cm. The seed germination index of all three composts exceeded 70%. The contents of volatile solids and organic matter of the three composts both decreased significantly. The BC maximally increased the total N (18%) of the compost, whereas the CC maximally increased the total P (48%) and total K (38%) contents. Contents of available P and available K of the three composts increased significantly, and the available N content in compost after BC inoculation increased by 16%. The physicochemical features showed that three composts were non-hazardous to plants, and the microbial agents improved nutrient availability. The richness, Chao1, and Shannon index in the bacterial communities of three composts increased significantly. At the phylum level, Proteobacteria, Bacteroidetes, and Firmicutes bacterium became dominant in the three composts, whereas at the family level, Microscillaceae and A4b (phylum Chloroflexi) became the dominant groups. Abundant cellulose-degrading bacteria existed at the dominant phylum level, which promoted fiber degradation in composts. Organic matter and the available N content regulated the composting bacterium. The inoculants enhanced the efficiency of composting: agents B and C were more suitable exogenous inoculants for the composting of a prickly pear litter.