An evaluation of aerobic and anaerobic composting of banana peels treated with different inoculums for soil nutrient replenishment.

PubMed

Kalemelawa, Frank; Nishihara, Eiji; Endo, Tsuneyoshi; Ahmad, Zahoor; Yeasmin, Rumana; Tenywa, Moses M; Yamamoto, Sadahiro

2012-12-01

This study sought to evaluate the efficacy of aerobic and anaerobic composting of inoculated banana peels, and assess the agronomic value of banana peel-based compost. Changes in the chemical composition under aerobic and anaerobic conditions were examined for four formulations of banana peel-based wastes over a period of 12 weeks. The formulations i.e. plain banana peel (B), and a mixture with either cow dung (BC), poultry litter (BP) or earthworm (BE) were separately composted under aerobic and anaerobic conditions under laboratory conditions. Inoculation with either cow dung or poultry litter significantly facilitated mineralization in the order: BP>BC>B. The rate of decomposition was significantly faster under aerobic than in anaerobic composting conditions. The final composts contained high K (>100 g kg(-1)) and TN (>2%), indicating high potential as a source of K and N fertilizer. Copyright © 2012 Elsevier Ltd. All rights reserved.

In-Vessel Co-Composting of Food Waste Employing Enriched Bacterial Consortium

PubMed Central

2018-01-01

Summary The aim of the present study is to develop a good initial composting mix using a bacterial consortium and 2% lime for effective co-composting of food waste in a 60-litre in-vessel composter. In the experiment that lasted for 42 days, the food waste was first mixed with sawdust and 2% lime (by dry mass), then one of the reactors was inoculated with an enriched bacterial consortium, while the other served as control. The results show that inoculation of the enriched natural bacterial consortium effectively overcame the oil-laden co-composting mass in the composter and increased the rate of mineralization. In addition, CO2 evolution rate of (0.81±0.2) g/(kg·day), seed germination index of (105±3) %, extractable ammonium mass fraction of 305.78 mg/kg, C/N ratio of 16.18, pH=7.6 and electrical conductivity of 3.12 mS/cm clearly indicate that the compost was well matured and met the composting standard requirements. In contrast, control treatment exhibited a delayed thermophilic phase and did not mature after 42 days, as evidenced by the maturity parameters. Therefore, a good composting mix and potential bacterial inoculum to degrade the oil are essential for food waste co-composting systems. PMID:29796000

In-Vessel Co-Composting of Food Waste Employing Enriched Bacterial Consortium.

PubMed

Awasthi, Mukesh Kumar; Wang, Quan; Wang, Meijing; Chen, Hongyu; Ren, Xiuna; Zhao, Junchao; Zhang, Zengqiang

2018-03-01

The aim of the present study is to develop a good initial composting mix using a bacterial consortium and 2% lime for effective co-composting of food waste in a 60-litre in-vessel composter. In the experiment that lasted for 42 days, the food waste was first mixed with sawdust and 2% lime (by dry mass), then one of the reactors was inoculated with an enriched bacterial consortium, while the other served as control. The results show that inoculation of the enriched natural bacterial consortium effectively overcame the oil-laden co-composting mass in the composter and increased the rate of mineralization. In addition, CO 2 evolution rate of (0.81±0.2) g/(kg·day), seed germination index of (105±3) %, extractable ammonium mass fraction of 305.78 mg/kg, C/N ratio of 16.18, pH=7.6 and electrical conductivity of 3.12 mS/cm clearly indicate that the compost was well matured and met the composting standard requirements. In contrast, control treatment exhibited a delayed thermophilic phase and did not mature after 42 days, as evidenced by the maturity parameters. Therefore, a good composting mix and potential bacterial inoculum to degrade the oil are essential for food waste co-composting systems.

Composting of bio-waste, aerobic and anaerobic sludges--effect of feedstock on the process and quality of compost.

PubMed

Himanen, Marina; Hänninen, Kari

2011-02-01

In-vessel composting of three stocks with originally different degree of organic matter degradation was conducted for: (1) kitchen source-separated bio-waste (BW), (2) aerobic (AS) as well as (3) anaerobic sludges (AnS) from municipal wastewater treatment plant. Composting experiment lasted over a year. The highest activity of the process was in the BW compost. It was implied by the highest temperature, CO(2) release, ammonification and nitrification, intensive accumulation and removal of low-weight carboxylic acids (water- and NaOH-extractable). Between the sludges higher mineralization and CO2 release was in AnS, while ammonification and nitrification were higher in AS compost; no significant difference between sludge composts was noticed for dynamics of pH, conductivity, concentrations of LWCA, and some nutrient compounds and heavy metals. Nitrogen content of the final compost increased in BW, but decreased in AS and AnS. Phytotoxicity of Lepidium sativum was eliminated faster in sludge composts compared to BW compost. Copyright © 2010 Elsevier Ltd. All rights reserved.

Application of aerobic composting system for space agriculture

NASA Astrophysics Data System (ADS)

Oshima, Tairo; Yoshii, Takahiro; Moriya, Toshiyuki; Yamashita, Masamichi

Composting is a classical technique to decompose organic wastes such as animal bodies, straw, paper, raw sludge, and so on. Compared with burning of wastes, the composting method has many advantages. It is an inexpensive and safer method because of its self-heating without spending extra energy resources. It does not emit toxic pollutants such as dioxin, NOx , and SOx . The composting products can be used as organic fertilizers for agricultural production. Composting is a promising way for digesting organic wastes safely on spaceships or manned exploration on extraterrestrial planets. We have developed a small scale high-temperature composter in order to examine its feasobility to operate food waste disposing facility and fertilizer production in space. This composter has a heated reaction vessel containing compost soil (seed bacteria) provided by a compost factory. To determine the optimal condition for its operation, we analyzed the effect of temperature on metabolic activity (CO2 production rate), and water content. The dynamics of microbial community was studied by polymerase chain reaction - denaturing gradient gel electrophoresis (PCR-DGGE). Water content was maintained to a range between 27% and 40% by continuously adding water. The highest CO2 emission was observed at around 70° C. PCR-DGGE analysis shows that the bacterial community of the compost soil is dramatically changed by changing reaction temperature. We will discuss the application of the composter in space in order to establish the closed recycling loop of bio-elements in space agriculture.

[Degradation of oxytetracycline in chicken feces aerobic-composting and its effects on their related parameters].

PubMed

Wang, Gui-Zhen; Li, Zhao-Jun; Zhang, Shu-Qing; Ma, Xiao-Tong; Liang, Yong-Chao

2013-02-01

In order to illustrate the degradation of tetracyclines (TCs) and their influences on process parameters during the period of chicken feces aerobic-composting, the degradation of oxytetracycline (OTC), a kind of TCs and its effects on parameters during the period of chick feces aerobic-composting including temperature, pH, and germination index were investigated using the method of aerobic-composting. The contents of OTC decreased gradually with composting time. The degradation rate was high before 10 d, and then decreased gradually. The differences in OTC degradation among the OTC treatments were also found. The degradation rate of OTC was higher at the level of 25 mg.kg-1, than that of other levels. The degradation curve of OTC could be described by the first-order kinetic model, and the correlation coefficients ranged from 0. 911 1 to 0. 9913. The impacts of OTC on chick feces composting were found. OTC could decrease the rising rate of composting temperature and make the high temperature (> or =50 degrees C) period shorter than that of the control. The values of pH, TN, WSC, and the content of NH: -N of composting were 4.58%, 12.62%, 49.06%, and 35.30% higher than those of the control. The impacts of OTC on maturity of chicken feces composting was not found when the OTC addition contents were lower than 50 mg.kg-1. However, the strong impacts of OTC on maturity of chicken feces composting were found when the OTC addition contents were higher than 50 mg.kg-1. The rates of NH+4 -N to NO-3 -N, and GI were much higher than 0. 5 and lower than 80% , respectively. Theses results suggest that OTC have strong impacts on chicken feces composting when the contents of TOC was higher than 50 mg.kg-1, although OTC have the short half-life period ranged from 1.79-4.88 d.

Chlorophenols in leachates originating from different landfills and aerobic composting plants.

PubMed

Ozkaya, Bestamin

2005-09-30

Both type and concentration of organic contaminants in landfill leachates show great variation depending on many factors, such as type of wastes, rate of water application, moisture content, landfill design and operation age. In this paper, highly toxic chlorophenol derivatives, poorly biodegradable, carcinogenic existence and recalcitrant properties are determined by solid phase microextraction (SPME)-GC/FID in different leachates from landfill and composting plant in Istanbul. Leachates originated from acidogenic, methanogenic phases of Odayeri sanitary landfill (OSL) and from an aerobic composting plant are considered for different chlorophenol types. It is observed that acidogenic leachate from Odayeri landfill includes 2,4-dichlorophenol, 2,6-dichlorophenol, 2,3,4-trichlorophenol, 2,3,4,5-tetrachlorophenol and 2,3,4,6-tetrachlorophenol at concentration ranges, 15-130, 18-65, 8-40, 5-20 and 10-25 microg/l, respectively. Whereas, only 2,4-dichlorophenol at a concentration range 8-40 microg/l is determined in the methanogenic leachate of the landfill, which can be considered as an indication of reductive dechlorination. There is no chlorophenol derivative in aerobic composting leachate. It is determined that acidogenic leachate from Odayeri landfill includes more species of chlorinated phenols at higher concentration.

Bacterial population dynamics in recycled mushroom compost leachate.

PubMed

Safianowicz, Katarzyna; Bell, Tina L; Kertesz, Michael A

2018-06-01

Mushrooms are an important food crop throughout the world. The most important edible mushroom is the button mushroom (Agaricus bisporus), which comprises about 30% of the global mushroom market. This species is cultivated commercially on a selective compost that is produced predominantly from wheat straw/stable bedding and chicken manure, at a moisture content of around 70% (w/w) and temperatures of up to 80 °C. Large volumes of water are required to achieve this moisture content, and many producers therefore collect leachate from the composting windrows and bunkers (known in the industry as "goody water") and reuse it to wet the raw ingredients. This has the benefit of recycling and saving water and has the potential to enrich beneficial microorganisms that stimulate composting, but also the risk of enhancing pathogen populations that could reduce productivity. Here, we show by 16S rRNA gene sequencing that mushroom compost leachate contains a high diversity of unknown microbes, with most of the species found affiliated with the phyla Firmicutes and Proteobacteria. However, by far the most abundant species was the thermophile Thermus thermophilus, which made up approximately 50% of the bacterial population present. Although the leachate was routinely collected and stored in an aerated central storage tank, many of the bacterial species found in leachate were facultative anaerobes. However, there was no evidence for sulfide production, and no sulfate-reducing bacterial species were detected. Because T. thermophilus is important in the high temperature phase of composting, the use of recycled leachate as an inoculum for the raw materials is likely to be beneficial for the composting process.

Removal of trichloroethylene (TCE) contaminated soil using a two-stage anaerobic-aerobic composting technique.

PubMed

Ponza, Supat; Parkpian, Preeda; Polprasert, Chongrak; Shrestha, Rajendra P; Jugsujinda, Aroon

2010-01-01

The effect of organic carbon addition on remediation of trichloroethylene (TCE) contaminated clay soil was investigated using a two stage anaerobic-aerobic composting system. TCE removal rate and processes involved were determined. Uncontaminated clay soil was treated with composting materials (dried cow manure, rice husk and cane molasses) to represent carbon based treatments (5%, 10% and 20% OC). All treatments were spiked with TCE at 1,000 mg TCE/kg DW and incubated under anaerobic and mesophillic condition (35 degrees C) for 8 weeks followed by continuous aerobic condition for another 6 weeks. TCE dissipation, its metabolites and biogas composition were measured throughout the experimental period. Results show that TCE degradation depended upon the amount of organic carbon (OC) contained within the composting treatments/matrices. The highest TCE removal percentage (97%) and rate (75.06 micro Mole/kg DW/day) were obtained from a treatment of 10% OC composting matrices as compared to 87% and 27.75 micro Mole/kg DW/day for 20% OC, and 83% and 38.08 micro Mole/kg DW/day for soil control treatment. TCE removal rate was first order reaction kinetics. Highest degradation rate constant (k(1) = 0.035 day(- 1)) was also obtained from the 10% OC treatment, followed by 20% OC (k(1) = 0.026 day(- 1)) and 5% OC or soil control treatment (k(1) = 0.023 day(- 1)). The half-life was 20, 27 and 30 days, respectively. The overall results suggest that sequential two stages anaerobic-aerobic composting technique has potential for remediation of TCE in heavy texture soil, providing that easily biodegradable source of organic carbon is present.

Process Improvements: Aerobic Food Waste Composting at ISF Academy

NASA Astrophysics Data System (ADS)

Lau, Y. K.

2015-12-01

ISF Academy, a school with 1500 students in Hong Kong, installed an aerobic food waste composting system in November of 2013. The system has been operational for over seven months; we will be making improvements to the system to ensure the continued operational viability and quality of the compost. As a school we are committed to reducing our carbon footprint and the amount of waste we send to the local landfill. Over an academic year we produce approximately 27 metric tons of food waste. Our system processes the food waste to compost in 14 days and the compost is used by our primary school students in a organic farming project.There are two areas of improvement: a) if the composting system becomes anaerobic, there is an odor problem that is noticed by the school community; we will be testing the use of a bio-filter to eliminate the odor problem and, b) we will be working with an equipment vendor from Australia to install an improved grease trap system. The grease and oil that is collected will be sold to a local company here in Hong Kong that processes used cooking oil for making biofuels. This system will include a two stage filtration system and a heated vessel for separating the oil from the waste water.The third project will be to evaluate biodegradable cutlery for the compositing in the system. Currently, we use a significant quantity of non-biodegradable cutlery that is then thrown away after one use. Several local HK companies are selling biodegradable cutlery, but we need to evaluate the different products to determine which ones will work with our composting system. The food waste composting project at ISF Academy demonstrates the commitment of the school community to a greener environment for HK, the above listed projects will improve the operation of the system.

Composting: Fast 2.

ERIC Educational Resources Information Center

Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

Composting is a way of using organic wastes from yards and kitchens to help plants grow. This book discusses how composting happens in nature, the classification of composting methods, and their characteristics. Examples of containers for aerobic/anaerobic decomposition are introduced along with sample activities. The process of aerobic/anaerobic…

Effects of sulphur and Thiobacillus thioparus on cow manure aerobic composting.

PubMed

Gu, Wenjie; Zhang, Fabao; Xu, Peizhi; Tang, Shuanhu; Xie, Kaizhi; Huang, Xu; Huang, Qiaoyi

2011-06-01

A simulated aerobic composting experiment was used to explore the effects of sulphur and Thiobacillus thioparus during six manure composting treatments. The addition of sulphur led to a decrease of the pH level within the range 6-6.3, which was lower than the control treatment (CK). The concentration of ammonium nitrogen in T1 (0.25% sulphur), T2 (0.5% sulphur), T3 (0.25% sulphur + T. thioparus) and T4 (0.5% sulphur + T. thioparus) were much higher than the ammonium N in CK. The results indicated that addition of sulphur could increase the concentration of ammonium N and reduce loss of nitrogen. However, excess sulphur had a negative effect on temperature and GI. Addition of T. thioparus could increase concentration of available S, alleviate these negative influences and reduce compost biological toxicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nutrient transformation during aerobic composting of pig manure with biochar prepared at different temperatures.

PubMed

Li, Ronghua; Wang, Quan; Zhang, Zengqiang; Zhang, Guangjie; Li, Zhonghong; Wang, Li; Zheng, Jianzhong

2015-01-01

The effects of the corn stalk charred biomass (CB) prepared at different pyrolysis temperatures as additives on nutrient transformation during aerobic composting of pig manure were investigated. The results showed that the addition of CB carbonized at different temperatures to pig manure compost significantly influenced the compost temperature, moisture, pH, electrical conductivity, organic matter degradation, total nitrogen, [Formula: see text] and NH3 variations during composting. Compared with control and adding CB charred at lower temperature treatments, the addition of CB prepared over 700°C resulted in higher pH (over 9.2) and NH3 emission and lower potherb mustard seed germination index value during the thermophilic phase. Peak temperatures of composts appeared at 7 days for control and 11 days for CB added treatments. During 90 days composting, the organic matter degradation could be increased over 14.8-29.6% after adding of CB in the compost mixture. The introduction of CB in pig manure could prolong the thermophilic phase, inhibit moisture reduce, facilitate the organic matter decomposition, reduce diethylene triamine pentaacetic acid (DTPA) extractable Zn and Cu contents in pig manure composts and increase ryegrass growth. The study indicated that the corn stalk CB prepared around 500°C was a suitable additive in pig manure composting.

Relationship between bacterial diversity and environmental parameters during composting of different raw materials.

PubMed

Wang, Xueqin; Cui, Hongyang; Shi, Jianhong; Zhao, Xinyu; Zhao, Yue; Wei, Zimin

2015-12-01

The aim of this study was to compare the bacterial structure of seven different composts. The primary environmental factors affecting bacterial species were identified, and a strategy to enhance the abundance of uncultured bacteria through controlling relevant environmental parameters was proposed. The results showed that the physical-chemical parameters of each different pile changed in its own manner during composting, which affected the structure and succession of bacteria in different ways. DGGE profiles showed that there were 10 prominent species during composting. Among them, four species existed in all compost types, two species existed in several piles and four species were detected in a single material. Redundancy analysis results showed that bacterial species compositions were significantly influenced by C/N and moisture (p<0.05). The optimal range of C/N was 14-27. Based on these results, the primary environmental factors affecting a certain species were further identified as a potential control of bacterial diversity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diversity of bacterial isolates from commercial and homemade composts.

PubMed

Vaz-Moreira, Ivone; Silva, Maria E; Manaia, Célia M; Nunes, Olga C

2008-05-01

The diversity of heterotrophic bacterial isolates of three commercial and two homemade composts was studied. The commercial composts were produced from poultry litter (PC), sewage sludge (SC), municipal solid waste (MC), and homemade composts (thermal compost [DC] and vermicompost [VC]) from food wastes. The taxonomic and physiological diversity of the heterotrophic culturable bacteria was assessed using phenotypic and genotypic characterization and the analysis of the partial 16S rRNA gene sequence. Composts DC and SC presented the higher genotypic diversity, as could be inferred from the number of distinct genotypic patterns observed, 28 and 21, respectively. Gram-positive bacteria, mainly Firmicutes, were predominant in all the composts. Some organisms related with taxa rarely reported in composts, as Rhodanobacter spathiphylli, Moraxella osloensis, Lysobacter, Corynebacterium, Pigmentiphaga kullae, and new taxa were also isolated. The highest relative proportion of isolates able to degrade starch was found in compost SC (> 70%), to degrade gelatine in compost DC (> 70%), to degrade Tween 80 in compost PC (> 90%), and to degrade poly-epsilon-caprolactones in compost DC (> 80%). Compost MC presented the lowest relative proportions of isolates able to degrade starch (< 25%), gelatine (< 20%), and poly-epsilon-caprolactone (< 40%). When compared with the others, the homemade composts presented higher relative proportions of Gram-positive isolates able to inhibit the target organisms Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, or Pseudomonas aeruginosa. In compost MC, none of the Gram-positive isolates was able to inhibit those targets.

Evaluation of biochar powder on oxygen supply efficiency and global warming potential during mainstream large-scale aerobic composting.

PubMed

He, Xueqin; Chen, Longjian; Han, Lujia; Liu, Ning; Cui, Ruxiu; Yin, Hongjie; Huang, Guangqun

2017-12-01

This study investigated the effects of biochar powder on oxygen supply efficiency and global warming potential (GWP) in the large-scale aerobic composting pattern which includes cyclical forced-turning with aeration at the bottom of composting tanks in China. A 55-day large-scale aerobic composting experiment was conducted in two different groups without and with 10% biochar powder addition (by weight). The results show that biochar powder improves the holding ability of oxygen, and the duration time (O 2 >5%) is around 80%. The composting process with above pattern significantly reduce CH 4 and N 2 O emissions compared to the static or turning-only styles. Considering the average GWP of the BC group was 19.82% lower than that of the CK group, it suggests that rational addition of biochar powder has the potential to reduce the energy consumption of turning, improve effectiveness of the oxygen supply, and reduce comprehensive greenhouse effects. Copyright © 2017. Published by Elsevier Ltd.

Unique hyper-thermal composting process in Kagoshima City forms distinct bacterial community structures.

PubMed

Tashiro, Yukihiro; Tabata, Hanae; Itahara, Asuka; Shimizu, Natsuki; Tashiro, Kosuke; Sakai, Kenji

2016-11-01

A unique compost, Satsuma soil, is produced from three types of wastewater sludge using hyper-thermal processes at temperatures much higher than that of general thermophilic processes in Kagoshima City, Japan. We analyzed the bacterial community structures of this hyper-thermal compost sample and other sludges and composts by a high-throughput barcoded pyrosequencing method targeting the 16S rRNA gene. In total, 621,076 reads were derived from 17 samples and filtered. Artificial sequences were deleted and the reads were clustered based on the operational taxonomic units (OTUs) at 97% similarity. Phylum-level analysis of the hyper-thermal compost revealed drastic changes of the sludge structures (each relative abundance) from Firmicutes (average 47.8%), Proteobacteria (average 22.3%), and Bacteroidetes (average 10.1%) to two main phyla including Firmicutes (73.6%) and Actinobacteria (25.0%) with less Proteobacteria (∼0.3%) and Bacteroidetes (∼0.1%). Furthermore, we determined the predominant species (each relative abundance) of the hyper-thermal compost including Firmicutes related to Staphylococcus cohnii (13.8%), Jeotgalicoccus coquinae (8.01%), and Staphylococcus lentus (5.96%), and Actinobacteria related to Corynebacterium stationis (6.41%), and found that these species were not predominant in wastewater sludge. In contrast, we did not observe any common structures among eight other composts produced, using the hyper-thermal composts as the inoculums, under thermophilic conditions from different materials. Principle coordinate analysis of the hyper-thermal compost indicated a large difference in bacterial community structures from material sludge and other composts. These results suggested that a distinct bacterial community structure was formed by hyper-thermal composting. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Effect of phosphate-solubilizing bacteria on phosphorus dynamics and the bacterial community during composting of sugarcane industry waste.

PubMed

Estrada-Bonilla, German A; Lopes, Cintia M; Durrer, Ademir; Alves, Paulo R L; Passaglia, Nicolle; Cardoso, Elke J B N

2017-07-01

Sugarcane processing generates a large quantity of residues, such as filter cake and ashes, which are sometimes composted prior to their amendment in soil. However, important issues still have to be addressed on this subject, such as the description of bacterial succession that occurs throughout the composting process and the possibilities of using phosphate-solubilizing bacteria (PSB) during the process to improve phosphorus (P) availability in the compost end product. Consequently, this study evaluated the bacterial diversity and P dynamics during the composting process when inoculated with Pseudomonas aeruginosa PSBR12 and Bacillus sp. BACBR01. To characterize the bacterial community structure during composting, and to compare PSB-inoculated compost with non-inoculated compost, partial sequencing of the bacterial 16S rRNA gene and sequential P fractionation were used. The data indicated that members of the order Lactobacillales prevailed in the early stages of composting for up to 30 days, mostly due to initial changes in pH and the C/N ratio. This dominant bacterial group was then slowly replaced by Bacillales during a composting process of up to 60 days. In addition, inoculation of PSB reduced the levels of Ca-bound P by 21% and increased the labile organic P fraction. In PSB-inoculated compost, Ca-P compound solubilization occurred concomitantly with an increase of the genus Bacillus. The bacterial succession and the final community is described in compost from sugarcane residues and the possible use of these inoculants to improve P availability in the final compost is validated. Copyright © 2017 Elsevier GmbH. All rights reserved.

Critical evaluation of post-consumption food waste composting employing thermophilic bacterial consortium.

PubMed

Awasthi, Mukesh Kumar; Selvam, Ammaiyappan; Lai, Ka Man; Wong, Jonathan W C

2017-12-01

Effect of single-function (oil degrading) and multi-functional bacterial consortium with zeolite as additive for post-consumption food waste (PCFW) composting was investigated through assessing the oil content reduction in a computer controlled 20-L composter. Three treatments of PCFWs combined with 10% zeolite were developed: Treatment-2 and Treatment-3 were inoculated with multi-functional (BC-1) and oil degrading bacterial consortium (BC-2), respectively, while T-1 was without bacterial inoculation and served as control. Results revealed that BC-2 inoculated treatment (T-3) was superior to control treatment and marginally better than T-2 in terms of oil degradation. The reduction of oil content was >97.8% in T-3 and 92.27% in T-2, while total organic matter degradation was marginally higher in T-2 (42.95%) than T-3 (41.67%). Other parameters of compost maturity including germination test indicated that T-2 was marginally better than T-3 and significantly enhanced the oily PCFW decomposition and shortened the composting period by 20days. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling for reactor-style aerobic composting based on coupling theory of mass-heat-momentum transport and Contois equation.

PubMed

He, Xueqin; Han, Lujia; Ge, Jinyi; Huang, Guangqun

2018-04-01

This study establishes an optimal mathematical modelling to rationally describe the dynamic changes and spatial distribution of temperature and oxygen concentration in the aerobic composting process using coupling mass-heat-momentum transfer based on the microbial mechanism. Two different conditional composting experiments, namely continuous aeration and intermittent aeration, were performed to verify the proposed model. The results show that the model accurately predicted the dynamic changes in temperature (case I: R 2  = 0.93, RMSE = 1.95 K; case II: R 2  = 0.86, RMSE = 4.69 K) and oxygen concentration (case I: R 2  = 0.90, RMSE = 1.26%; case II: R 2  = 0.75, RMSE = 2.93%) in the central point of compost substrates. It also systematically simulated fluctuations in oxygen concentration caused by boundary conditions and the spatial distribution of the actual temperature and oxygen concentration. The proposed model exhibits good applicability in simulating the actual working conditions of aerobic composting process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Functional characteristics and influence factors of microbial community in sewage sludge composting with inorganic bulking agent.

PubMed

Wang, Ke; Mao, Hailong; Li, Xiangkun

2018-02-01

The metabolic function of microbial community dominated organics and nutrients transformation in aerobic composting process. In this study, the metabolic characteristics of bacterial and fungal communities were evaluated in 60 days composting of sludge and pumice by using FUNGuild and PICRUSt, respectively. The results showed that microbial community structure and metabolic characteristics were distinctively different at four composting periods. Bacterial genes related to carbohydrate metabolisms decreased during the first 30 days, but bacterial sequences associated with oxidative phosphorylation and fatty acids synthesis were enhanced in curing phase. Most of fungal animal pathogen and plant pathogen disappeared after treatment, and the abundance of saprotroph fungi increased from 44.3% to 97.8%. Oxidation reduction potential (ORP) significantly increased from -28 to 175 mV through incubation. RDA analysis showed that ORP was a crucial factor on the succession of both bacterial and fungal communities in sludge composting system. Copyright © 2017. Published by Elsevier Ltd.

N-15 NMR study of the immobilization of 2,4- and 2,6-dinitrotoluene in aerobic compost

USGS Publications Warehouse

Thorn, K.A.; Pennington, J.C.; Kennedy, K.R.; Cox, L.G.; Hayes, C.A.; Porter, B.E.

2008-01-01

Large-scale aerobic windrow composting has been used to bioremediate washout lagoon soils contaminated with the explosives TNT (2,4,6- trinitrotoluene) and RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) at several sites within the United States. We previously used 15N NMR to investigate the reduction and binding of T15NT in aerobic bench -scale reactors simulating the conditions of windrow composting. These studies have been extended to 2,4-dinitrotoluene (2,4DNT) and 2,6-dinitrotoluene (2,6DNT), which, as impurities in TNT, are usually present wherever soils have been contaminated with TNT. Liquid-state 15N NMR analyses of laboratory reactions between 4-methyl-3-nitroaniline-15N, the major monoamine reduction product of 2,4DNT, and the Elliot soil humic acid, both in the presence and absence of horseradish peroxidase, indicated that the amine underwent covalent binding with quinone and other carbonyl groups in the soil humic acid to form both heterocyclic and non-heterocyclic condensation products. Liquid-state 15N NMR analyses of the methanol extracts of 20 day aerobic bench-scale composts of 2,4-di-15N-nitrotoluene and 2,6-di-15N-nitrotoluene revealed the presence of nitrite and monoamine, but not diamine, reduction products, indicating the occurrence of both dioxygenase enzyme and reductive degradation pathways. Solid-state CP/MAS 15N NMR analyses of the whole composts, however, suggested that reduction to monoamines followed by covalent binding of the amines to organic matter was the predominant pathway. ?? 2008 American Chemical Society.

Emission of greenhouse gases from home aerobic composting, anaerobic digestion and vermicomposting of household wastes in Brisbane (Australia).

PubMed

Chan, Yiu C; Sinha, Rajiv K; Weijin Wang

2011-05-01

This study investigated greenhouse gas (GHG) emissions from three different home waste treatment methods in Brisbane, Australia. Gas samples were taken monthly from 34 backyard composting bins from January to April 2009. Averaged over the study period, the aerobic composting bins released lower amounts of CH(4) (2.2 mg m(- 2) h(-1)) than the anaerobic digestion bins (9.5 mg m(-2) h(-1)) and the vermicomposting bins (4.8 mg m(-2) h( -1)). The vermicomposting bins had lower N(2)O emission rates (1.2 mg m(-2) h(- 1)) than the others (1.5-1.6 mg m(-2) h( -1)). Total GHG emissions including both N(2)O and CH(4) were 463, 504 and 694 mg CO(2)-e m(- 2) h(-1) for vermicomposting, aerobic composting and anaerobic digestion, respectively, with N(2)O contributing >80% in the total budget. The GHG emissions varied substantially with time and were regulated by temperature, moisture content and the waste properties, indicating the potential to mitigate GHG emission through proper management of the composting systems. In comparison with other mainstream municipal waste management options including centralized composting and anaerobic digestion facilities, landfilling and incineration, home composting has the potential to reduce GHG emissions through both lower on-site emissions and the minimal need for transportation and processing. On account of the lower cost, the present results suggest that home composting provides an effective and feasible supplementary waste management method to a centralized facility in particular for cities with lower population density such as the Australian cities.

Bacterial and fungal communities and contribution of physicochemical factors during cattle farm waste composting.

PubMed

Huhe; Jiang, Chao; Wu, Yanpei; Cheng, Yunxiang

2017-12-01

During composting, the composition of microbial communities is subject to constant change owing to interactions with fluctuating physicochemical parameters. This study explored the changes in bacterial and fungal communities during cattle farm waste composting and aimed to identify and prioritize the contributing physicochemical factors. Microbial community compositions were determined by high-throughput sequencing. While the predominant phyla in the bacterial and fungal communities were largely consistent during the composting, differences in relative abundances were observed. Bacterial and fungal community diversity and relative abundance varied significantly, and inversely, over time. Relationships between physicochemical factors and microbial community compositions were evaluated by redundancy analysis. The variation in bacterial community composition was significantly related to water-soluble organic carbon (WSOC), and pile temperature and moisture (p < .05), while the largest portions of variation in fungal community composition were explained by pile temperature, WSOC, and C/N (p < .05). These findings indicated that those parameters are the most likely ones to influence, or be influenced by the bacterial and fungal communities. Variation partitioning analyses indicated that WSOC and pile temperature had predominant effects on bacterial and fungal community composition, respectively. Our findings will be useful for improving the quality of cattle farm waste composts. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Evaluation of microbial dynamics during post-consumption food waste composting.

PubMed

Awasthi, Sanjeev Kumar; Wong, Jonathan W C; Li, Jiao; Wang, Quan; Zhang, Zengqiang; Kumar, Sunil; Awasthi, Mukesh Kumar

2018-03-01

The objective of present study was to evaluate the efficacy of bacterial consortium to boost the microbial population and enzyme activities during post-consumption food waste (PCFWs) composting. Three treatments of PCFWs mixed with saw dust and 10% zeolite (dry weight basis) was design, where treatments T-2 and T-3 were applied with two distinctive bacterial consortium, respectively, while T-1 was served as control. The results showed that total aerobic proteolytic, amylolytic, cellulolytic, oil degrading and total aerobic bacteria populations were significantly higher in treatment T2 and T3 than T1. Consequently, the selected hydrolytic enzymes were also higher in T2 and T3 than T1, whose apparently gave the interesting information about rate of decomposition and end product stability. Furthermore, T2 and T3 showed significant correlations between the enzymatic activities and microbial population with other physico-chemical parameters. Based on germination assays and CO 2 -C evolution rate, T2 and T3 were considered phytotoxic free and highly stable final compost on day 56. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fungal and bacterial successions in the process of co-composting of organic wastes as revealed by 454 pyrosequencing.

PubMed

Galitskaya, Polina; Biktasheva, Liliya; Saveliev, Anatoly; Grigoryeva, Tatiana; Boulygina, Eugenia; Selivanovskaya, Svetlana

2017-01-01

Composting is viewed as one of the primary methods to treat organic wastes. Co-composting may improve the efficiency of this treatment by establishing the most suitable conditions for decomposers than those present in the individual wastes. Given that bacteria and fungi are the driving agents of composting, information about the composition of their communities and dynamics during composting may improve reproducibility, performance and quality of the final compost as well as help to evaluate the potential human health risk and the choice of the most appropriate application procedure. In this study, the co-composting of mixtures containing two similar components (organic fraction of municipal solid waste and sawdust polluted by oil) and one discriminate component (sewage sludges of different origin) were investigated. Bacterial and fungal community successions in the two mixtures were analyzed during the composting process by determining the change in their structural dynamics using qPCR and 454 pyrosequencing methods in a lab experiment for a period of 270 days. During the initial composting stage, the number of 16S bacterial copies was (3.0±0.2) x 106 and (0.4±0.0) x 107 g-1, and the Rhodospiralles and Lactobacialles orders dominated. Fungal communities had (2.9±0.0) x105 and (6.1±0.2) x105 ITS copies g-1, and the Saccharomycetales order dominated. At the end of the thermophilic stage on the 30th day of composting, bacterial and fungal communities underwent significant changes: dominants changed and their relative abundance decreased. Typical compost residents included Flavobacteriales, Chitinophagaceae and Bacterioidetes for bacteria and Microascaceae, Dothideomycetes, Eurotiomycetes, Sordariomycetes, and Agaricomycetes for fungi. During the later composting stages, the dominating taxa of both bacterial and fungal communities remained, while their relative abundance decreased. In accordance with the change in the dominating OTUs, it was concluded that the

Fungal and bacterial successions in the process of co-composting of organic wastes as revealed by 454 pyrosequencing

PubMed Central

Galitskaya, Polina; Saveliev, Anatoly; Grigoryeva, Tatiana; Boulygina, Eugenia; Selivanovskaya, Svetlana

2017-01-01

Composting is viewed as one of the primary methods to treat organic wastes. Co-composting may improve the efficiency of this treatment by establishing the most suitable conditions for decomposers than those present in the individual wastes. Given that bacteria and fungi are the driving agents of composting, information about the composition of their communities and dynamics during composting may improve reproducibility, performance and quality of the final compost as well as help to evaluate the potential human health risk and the choice of the most appropriate application procedure. In this study, the co-composting of mixtures containing two similar components (organic fraction of municipal solid waste and sawdust polluted by oil) and one discriminate component (sewage sludges of different origin) were investigated. Bacterial and fungal community successions in the two mixtures were analyzed during the composting process by determining the change in their structural dynamics using qPCR and 454 pyrosequencing methods in a lab experiment for a period of 270 days. During the initial composting stage, the number of 16S bacterial copies was (3.0±0.2) x 106 and (0.4±0.0) x 107 g-1, and the Rhodospiralles and Lactobacialles orders dominated. Fungal communities had (2.9±0.0) x105 and (6.1±0.2) x105 ITS copies g-1, and the Saccharomycetales order dominated. At the end of the thermophilic stage on the 30th day of composting, bacterial and fungal communities underwent significant changes: dominants changed and their relative abundance decreased. Typical compost residents included Flavobacteriales, Chitinophagaceae and Bacterioidetes for bacteria and Microascaceae, Dothideomycetes, Eurotiomycetes, Sordariomycetes, and Agaricomycetes for fungi. During the later composting stages, the dominating taxa of both bacterial and fungal communities remained, while their relative abundance decreased. In accordance with the change in the dominating OTUs, it was concluded that the

Pharmaceutically active compounds in sludge stabilization treatments: anaerobic and aerobic digestion, wastewater stabilization ponds and composting.

PubMed

Martín, Julia; Santos, Juan Luis; Aparicio, Irene; Alonso, Esteban

2015-01-15

Sewage sludge disposal onto lands has been stabilized previously but still many pollutants are not efficiently removed. Special interest has been focused on pharmaceutical compounds due to their potential ecotoxicological effects. Nowadays, there is scarce information about their occurrence in different sludge stabilization treatments. In this work, the occurrence of twenty-two pharmaceutically active compounds has been studied in sludge from four sludge stabilization treatments: anaerobic digestion, aerobic digestion, composting and lagooning. The types of sludge evaluated were primary, secondary, anaerobically-digested and dehydrated, composted, mixed, aerobically-digested and dehydrated and lagoon sludge. Nineteen of the twenty-two pharmaceutically active compounds monitored were detected in sewage sludge. The most contaminated samples were primary sludge, secondary sludge and mixed sludge (the average concentrations of studied compounds in these sludges were 179, 310 and 142 μg/kg dm, respectively) while the mean concentrations found in the other types of sewage sludge were 70 μg/kg dm (aerobically-digested sludge), 63 μg/kg dm (lagoon sludge), 12 μg/kg dm (composted sludge) and 8 μg/kg dm (anaerobically-digested sludge). The antibiotics ciprofloxacin and norfloxacin were found at the highest concentration levels in most of the analyzed sludge samples (up to 2660 and 4328 μg/kg dm, respectively). Anaerobic-digestion treatment reduced more considerably the concentration of most of the studied compounds than aerobic-digestion (especially in the case of bezafibrate and fluoroquinolones) and more than anaerobic stabilization ponds (in the case of acetaminophen, atenolol, bezafibrate, carbamazepine, 17α-ethinylestradiol, naproxen and salicylic acid). Ecotoxicological risk assessment, of sludge application onto soils, has also been evaluated. Risk quotients, expressed as the ratio between the predicted environmental concentration and the predicted non

Fate of tetracycline, sulfonamide and fluoroquinolone resistance genes and the changes in bacterial diversity during composting of swine manure.

PubMed

Selvam, Ammaiyappan; Xu, Delin; Zhao, Zhenyong; Wong, Jonathan W C

2012-12-01

This study monitored the abundance of antibiotic resistant genes (ARGs) and the bacterial diversity during composting of swine manure spiked with chlortetracycline, sulfadiazine and ciprofloxacin at two different levels and a control without antibiotics. Resistance genes of tetracycline (tetQ, tetW, tetC, tetG, tetZ and tetY), sulfonamide (sul1, sul2, dfrA1 and dfrA7) and fluoroquinolone (gyrA and parC) represented 0.02-1.91%, 0.67-10.28% and 0.00005-0.0002%, respectively, of the total 16S rDNA copies in the initial composting mass. After 28-42 days of composting, these ARGs, except parC, were undetectable in the composting mass indicating that composting is a potential method of manure management. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis of bacterial 16S rDNA of the composting mass indicated that the addition of antibiotics up to 100, 20 and 20mg/kg of chlortetracycline, sulfadiazine and ciprofloxacin, respectively, elicited only a transient perturbation and the bacterial diversity was restored in due course of composting. Copyright © 2012 Elsevier Ltd. All rights reserved.

Experimenting with Different Bulking Agents in an Aerobic Food Waste Composter

NASA Astrophysics Data System (ADS)

Chann, S.

2016-12-01

With one third of Hong Kong's solid wastage being food scraps, reducing food waste has become crucial. The ISF Academy, a Hong Kong private school, had an A900 Rocket Food Composter installed in 2013, hoping to reduce its carbon footprint. The 27 metric tons of food wastage produced annually by the school is put through an aerobic process and the wastage is converted into humus. The composter has a capacity of 1750 litres of food and it produces humus every 14 days. The base of the humus consists of a bulking agent and food waste (2:1). A bulking agent is a carbon based material used to absorb moisture and odors, add structure and air and eliminate bugs from humus. This study contains comparative data on a few of the listed bulking agents: Hemp, Kenaf, rapeseed oil straw, miscanthus and shredded cardboard. The aim of this study is to determine an alternative reliable, affordable and suitable bulking agent to wood shavings: the current agent used. The humus produced must pass regulations for "general agricultural use" as it is used for experiential learning and gardening with primary school students. Over 500 children are participating in the school's plantation project, producing legumes for the school cafeteria. ISF pioneers and sets an example for other Hong Kong schools, showing that a composting and plantation scheme, not only proves to have environmental benefits but also educational uses.

Metaproteomics reveals major microbial players and their biodegradation functions in a large-scale aerobic composting plant

PubMed Central

Liu, Dongming; Li, Mingxiao; Xi, Beidou; Zhao, Yue; Wei, Zimin; Song, Caihong; Zhu, Chaowei

2015-01-01

Composting is an appropriate management alternative for municipal solid waste; however, our knowledge about the microbial regulation of this process is still scare. We employed metaproteomics to elucidate the main biodegradation pathways in municipal solid waste composting system across the main phases in a large-scale composting plant. The investigation of microbial succession revealed that Bacillales, Actinobacteria and Saccharomyces increased significantly with respect to abundance in composting process. The key microbiologic population for cellulose degradation in different composting stages was different. Fungi were found to be the main producers of cellulase in earlier phase. However, the cellulolytic fungal communities were gradually replaced by a purely bacterial one in active phase, which did not support the concept that the thermophilic fungi are active through the thermophilic phase. The effective decomposition of cellulose required the synergy between bacteria and fungi in the curing phase. PMID:25989417

The influence of temperature and moisture contents regimes on the aerobic microbial activity of a biosolids composting blend.

PubMed

Liang, C; Das, K C; McClendon, R W

2003-01-01

To understand the relationships between temperature, moisture content, and microbial activity during the composting of biosolids (municipal wastewater treatment sludge), well-controlled incubation experiments were conducted using a 2-factor factorial design with six temperatures (22, 29, 36, 43, 50, and 57 degrees C) and five moisture contents (30, 40, 50, 60, and 70%). The microbial activity was measured as O2 uptake rate (mg g(-1) h(-1)) using a computer controlled respirometer. In this study, moisture content proved to be a dominant factor impacting aerobic microbial activity of the composting blend. Fifty percent moisture content appeared to be the minimal requirement for obtaining activities greater than 1.0 mg g(-1) h(-1). Temperature was also documented to be an important factor for biosolids composting. However, its effect was less influential than moisture content. Particularly, the enhancement of composting activities induced by temperature increment could be realized by increasing moisture content alone.

Use of additive and pretreatment to control odors in municipal kitchen waste during aerobic composting.

PubMed

Yuan, Jing; Yang, Qingyuan; Zhang, Zhiye; Li, Guoxue; Luo, Wenhai; Zhang, Difang

2015-11-01

The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used 20-L reactors and each test lasted 28days. The objective was to decrease NH3 and H2S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15% (wet weight) bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride (FeCl3). Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H2S to be emitted, but had little impact on the amount of NH3 emitted. The FeCl3 was found to act as an effective chemical flocculant, and its presence significantly decreased the amounts of NH3 and H2S emitted. Kitchen waste mixed with cornstalks and treated with FeCl3 emitted 42% less NH3 and 76% less H2S during composting than did pure kitchen waste. Copyright © 2015. Published by Elsevier B.V.

Comparison of bacterial community structure and dynamics during the thermophilic composting of different types of solid wastes: anaerobic digestion residue, pig manure and chicken manure.

PubMed

Song, Caihong; Li, Mingxiao; Jia, Xuan; Wei, Zimin; Zhao, Yue; Xi, Beidou; Zhu, Chaowei; Liu, Dongming

2014-09-01

This study investigated the impact of composting substrate types on the bacterial community structure and dynamics during composting processes. To this end, pig manure (PM), chicken manure (CM), a mixture of PM and CM (PM + CM), and a mixture of PM, CM and anaerobic digestion residue (ADR) (PM + CM + ADR) were selected for thermophilic composting. The bacterial community structure and dynamics during the composting process were detected and analysed by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) coupled with a statistic analysis. The physical-chemical analyses indicated that compared to single-material composting (PM, CM), co-composting (PM + CM, PM + CM + ADR) could promote the degradation of organic matter and strengthen the ability of conserving nitrogen. A DGGE profile and statistical analysis demonstrated that co-composting, especially PM + CM + ADR, could improve the bacterial community structure and functional diversity, even in the thermophilic stage. Therefore, co-composting could weaken the screening effect of high temperature on bacterial communities. Dominant sequencing analyses indicated a dramatic shift in the dominant bacterial communities from single-material composting to co-composting. Notably, compared with PM, PM + CM increased the quantity of xylan-degrading bacteria and reduced the quantity of human pathogens. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Comparison of bacterial community structure and dynamics during the thermophilic composting of different types of solid wastes: anaerobic digestion residue, pig manure and chicken manure

PubMed Central

Song, Caihong; Li, Mingxiao; Jia, Xuan; Wei, Zimin; Zhao, Yue; Xi, Beidou; Zhu, Chaowei; Liu, Dongming

2014-01-01

This study investigated the impact of composting substrate types on the bacterial community structure and dynamics during composting processes. To this end, pig manure (PM), chicken manure (CM), a mixture of PM and CM (PM + CM), and a mixture of PM, CM and anaerobic digestion residue (ADR) (PM + CM + ADR) were selected for thermophilic composting. The bacterial community structure and dynamics during the composting process were detected and analysed by polymerase chain reaction–denaturing gradient gel electrophoresis (DGGE) coupled with a statistic analysis. The physical-chemical analyses indicated that compared to single-material composting (PM, CM), co-composting (PM + CM, PM + CM + ADR) could promote the degradation of organic matter and strengthen the ability of conserving nitrogen. A DGGE profile and statistical analysis demonstrated that co-composting, especially PM + CM + ADR, could improve the bacterial community structure and functional diversity, even in the thermophilic stage. Therefore, co-composting could weaken the screening effect of high temperature on bacterial communities. Dominant sequencing analyses indicated a dramatic shift in the dominant bacterial communities from single-material composting to co-composting. Notably, compared with PM, PM + CM increased the quantity of xylan-degrading bacteria and reduced the quantity of human pathogens. PMID:24963997

Genome-Centric Analysis of a Thermophilic and Cellulolytic Bacterial Consortium Derived from Composting

PubMed Central

Lemos, Leandro N.; Pereira, Roberta V.; Quaggio, Ronaldo B.; Martins, Layla F.; Moura, Livia M. S.; da Silva, Amanda R.; Antunes, Luciana P.; da Silva, Aline M.; Setubal, João C.

2017-01-01

Microbial consortia selected from complex lignocellulolytic microbial communities are promising alternatives to deconstruct plant waste, since synergistic action of different enzymes is required for full degradation of plant biomass in biorefining applications. Culture enrichment also facilitates the study of interactions among consortium members, and can be a good source of novel microbial species. Here, we used a sample from a plant waste composting operation in the São Paulo Zoo (Brazil) as inoculum to obtain a thermophilic aerobic consortium enriched through multiple passages at 60°C in carboxymethylcellulose as sole carbon source. The microbial community composition of this consortium was investigated by shotgun metagenomics and genome-centric analysis. Six near-complete (over 90%) genomes were reconstructed. Similarity and phylogenetic analyses show that four of these six genomes are novel, with the following hypothesized identifications: a new Thermobacillus species; the first Bacillus thermozeamaize genome (for which currently only 16S sequences are available) or else the first representative of a new family in the Bacillales order; the first representative of a new genus in the Paenibacillaceae family; and the first representative of a new deep-branching family in the Clostridia class. The reconstructed genomes from known species were identified as Geobacillus thermoglucosidasius and Caldibacillus debilis. The metabolic potential of these recovered genomes based on COG and CAZy analyses show that these genomes encode several glycoside hydrolases (GHs) as well as other genes related to lignocellulose breakdown. The new Thermobacillus species stands out for being the richest in diversity and abundance of GHs, possessing the greatest potential for biomass degradation among the six recovered genomes. We also investigated the presence and activity of the organisms corresponding to these genomes in the composting operation from which the consortium was built

Pyrosequencing reveals bacterial community differences in composting and vermicomposting on the stabilization of mixed sewage sludge and cattle dung.

PubMed

Lv, Baoyi; Xing, Meiyan; Yang, Jian; Zhang, Liangbo

2015-12-01

This study aimed to compare the microbial community structures and compositions in composting and vermicomposting processes. We applied 454 high-throughput pyrosequencing to analyze the 16S rRNA gene of bacteria obtained from bio-stabilization of sewage sludge and cattle dung. Results demonstrated that vermicomposting process presented higher operational taxonomic units and bacterial diversity than the composting. Analysis using weighted UniFrac indicated that composting exhibited higher effects on shaping microbial community structure than the vermicomposting. The succession of dominant bacteria was also detected during composting. Firmicutes was the dominant bacteria in the thermophilic phase of composting and shifted to Actinomycetes in the maturing stage. By contrast, Proteobacteria accounted for the highest proportions in the whole process of the vermicomposting. Furthermore, vermicomposting contained more uncultured and unidentified bacteria at the taxonomy level of genus than the composting. In summary, the bacterial community during composting significantly differed from that during vermicomposting. These two techniques played different roles in changing the diversity and composition of microbial communities.

15N NMR investigation of the reduction and binding of TNT in an aerobic bench scale reactor simulating windrow composting

USGS Publications Warehouse

Thorn, K.A.; Pennington, J.C.; Hayes, C.A.

2002-01-01

T15NT was added to a soil of low organic carbon content and composted for 20 days in an aerobic bench scale reactor. The finished whole compost and fulvic acid, humic acid, humin, and lignocellulose fractions extracted from the compost were analyzed by solid-state CP/MAS and DP/MAS 15N NMR. 15N NMR spectra provided direct spectroscopic evidence for reduction of TNT followed by covalent binding of the reduced metabolites to organic matter of the composted soil, with the majority of metabolite found in the lignocellulose fraction, by mass also the major fraction of the compost. In general, the types of bonds formed between soil organic matter and reduced TNT amines in controlled laboratory reactions were observed in the spectra of the whole compost and fractions, confirming that during composting TNT is reduced to amines that form covalent bonds with organic matter through aminohydroquinone, aminoquinone, heterocyclic, and imine linkages, among others. Concentrations of imine nitrogens in the compost spectra suggestthat covalent binding bythe diamines 2,4DANT and 2,6DANT is a significant process in the transformation of TNT into bound residues. Liquid-phase 15N NMR spectra of the fulvic acid and humin fractions provided possible evidence for involvement of phenoloxidase enzymes in covalent bond formation.

Evaluation and Analysis of Cotton Bedding as a Bulking Agent in an Aerobic Food Waste Composting System

NASA Astrophysics Data System (ADS)

Chan, A. S. L.

2017-12-01

Food wastage is a prominent issue in Hong Kong that should be addressed. Here at The Independent Schools Foundation Academy, we are continuously looking for ways to improve, including that of food waste. In 2013 the school installed an A900 Rocket Food Composter, in hopes of reducing carbon footprint. Since the installation, the school has tested various elements of the food composter to further improve upon it to make it increasingly more sustainable and effective. These improvements vary from the revamping of the odour control system, increasing the nitrogen content and the installation of an improved grease trap. The school composts the food waste through combining a variety of substances together: coffee, compost, food waste, and a bulking agent - which will be tested in this study. Recently, the school has changed the compost bulking agent from wood shavings and cardboard to cotton bedding - a side product of the production of UK passports. In this study, I will evaluate the effectiveness of cotton bedding as a bulking agent in an aerobic composting system, focusing primarily on three points: a) microbial activity - the identification of cellulose digesting bacteria and the associated kinetics, b) the soil gas composition - the data shall be collected through the use of the Gasmet DX 4015, and c) the chemical analysis of the compost - specifically the amount of aluminum in the compost and whether or not it is significant enough to discredit cotton bedding as an effective bulking agent. The the analysis of cotton bedding using these three specifications will allow ISF Academy to evaluate the overall effectiveness of cotton bedding as a bulking agent.

Effect of semi-permeable cover system on the bacterial diversity during sewage sludge composting.

PubMed

Robledo-Mahón, Tatiana; Aranda, Elisabet; Pesciaroli, Chiara; Rodríguez-Calvo, Alfonso; Silva-Castro, Gloria Andrea; González-López, Jesús; Calvo, Concepción

2018-06-01

Sewage sludge composting is a profitable process economically viable and environmentally friendly. In despite of there are several kind of composting types, the use of combined system of semipermeable cover film and aeration air-floor is widely developed at industrial scale. However, the knowledge of the linkages between microbial communities structure, enzyme activities and physico-chemical factors under these conditions it has been poorly explored. Thus, the aim of this study was to investigate the bacterial dynamic and community structure using next generation sequencing coupled to analyses of microbial enzymatic activity and culturable dependent techniques in a full-scale real composting plant. Sewage sludge composting process was conducted using a semi-permeable Gore-tex cover, in combination with an air-insufflation system. The highest values of enzymatic activities such as dehydrogenase, protease and arylsulphatase were detected in the first 5 days of composting; suggesting that during this period of time a greater degrading activity of organic matter took place. Culturable bacteria identified were in agreement with the bacteria found by massive sequencing technologies. The greatest bacterial diversity was detected between days 15 and 30, with Actinomycetales and Bacillales being the predominant orders at the beginning and end of the process. Bacillus was the most representative genus during all the process. A strong correlation between abiotic factors as total organic content and organic matter and enzymatic activities such as dehydrogenase, alkaline phosphatase, and ß-glucosidase activity was found. Bacterial diversity was strongly influenced by the stage of the process, community-structure change was concomitant with a temperature rise, rendering favorable conditions to stimulate microbial activity and facilitate the change in the microbial community linked to the degradation process. Moreover, results obtained confirmed that the use of semipermeable

Changes in bacterial community of anthracene bioremediation in municipal solid waste composting soil*

PubMed Central

Zhang, Shu-ying; Wang, Qing-feng; Wan, Rui; Xie, Shu-guang

2011-01-01

Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in a municipal solid waste (MSW) composting site. Knowledge of changes in microbial structure is useful to identify particular PAH degraders. However, the microbial community in the MSW composting soil and its change associated with prolonged exposure to PAHs and subsequent biodegradation remain largely unknown. In this study, anthracene was selected as a model compound. The bacterial community structure was investigated using terminal restriction fragment length polymorphism (TRFLP) and 16S rRNA gene clone library analysis. The two bimolecular tools revealed a large shift of bacterial community structure after anthracene amendment and subsequent biodegradation. Genera Methylophilus, Mesorhizobium, and Terrimonas had potential links to anthracene biodegradation, suggesting a consortium playing an active role. PMID:21887852

Influence of aeration on volatile sulfur compounds (VSCs) and NH3 emissions during aerobic composting of kitchen waste.

PubMed

Zhang, Hongyu; Li, Guoxue; Gu, Jun; Wang, Guiqin; Li, Yangyang; Zhang, Difang

2016-12-01

This study investigates the influence of aeration on volatile sulfur compounds (VSCs) and ammonia (NH 3 ) emissions during kitchen waste composting. Aerobic composting of kitchen waste and cornstalks was conducted at a ratio of 85:15 (wet weight basis) in 60L reactors for 30days. The gas emissions were analyzed with force aeration at rates of 0.1 (A1), 0.2 (A2) and 0.3 (A3) L (kgDMmin) -1 , respectively. Results showed that VSCs emission at the low aeration rate (A1) was more significant than that at other two rates (i.e., A2 and A3 treatment), where no considerable emission difference was observed. On the other hand, NH 3 emission reduced as the aeration rate decreased. It is noteworthy that the aeration rate did not significantly affect the compost quality. These results suggest that the aeration rate of 0.2L (kgDMmin) -1 may be applied to control VSCs and NH 3 emissions during kitchen waste composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced bioremediation of 4-nonylphenol and cadmium co-contaminated sediment by composting with Phanerochaete chrysosporium inocula.

PubMed

Xu, Piao; Lai, Cui; Zeng, Guangming; Huang, Danlian; Chen, Ming; Song, Biao; Peng, Xin; Wan, Jia; Hu, Liang; Duan, Abing; Tang, Wangwang

2018-02-01

Composting is identified as an effective approach for solid waste disposal. The bioremediation of 4-nonylphenol (4NP) and cadmium (Cd) co-contaminated sediment was investigated by composting with Phanerochaete chrysosporium (P. chrysosporium) inocula. P. chrysosporium inocula and proper C/N ratios (25.51) accelerated the composting process accompanied with faster total organic carbon loss, 4NP degradation and Cd passivation. Microbiological analysis demonstrated that elevated activities of lignocellulolytic enzymes and sediment enzymes was conducive to organic chemical transformation. Bacterial community diversity results illustrated that Firmicutes and Proteobacteria were predominant species during the whole composting process. Aerobic cellulolytic bacteria and organic degrading species played significant roles. Toxicity characteristic leaching procedure (TCLP) extraction and germination indices results indicated the efficient detoxification of 4NP and Cd co-contaminated sediment after 120 days of composting. Overall, results demonstrated that P. chrysosporium enhanced composting was available for the bioremediation of 4NP and Cd co-contaminated sediment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Importance of Soil Amendments: Survival of Bacterial Pathogens in Manure and Compost Used as Organic Fertilizers.

PubMed

Sharma, Manan; Reynnells, Russell

2016-08-01

Biological soil amendments (BSAs) such as manure and compost are frequently used as organic fertilizers to improve the physical and chemical properties of soils. However, BSAs have been known to be a reservoir for enteric bacterial pathogens such as enterohemorrhagic Escherichia coli (EHEC), Salmonella spp., and Listeria spp. There are numerous mechanisms by which manure may transfer pathogens to growing fruits and vegetables, and several outbreaks of infections have been linked to manure-related contamination of leafy greens. In the United States several commodity-specific guidelines and current and proposed federal rules exist to provide guidance on the application of BSAs as fertilizers to soils, some of which require an interval between the application of manure to soils and the harvest of fruits and vegetables. This review examines the survival, persistence, and regrowth/resuscitation of bacterial pathogens in manure, biosolids, and composts. Moisture, along with climate and the physicochemical properties of soil, manure, or compost, plays a significant role in the ability of pathogens to persist and resuscitate in amended soils. Adaptation of enteric bacterial pathogens to the nonhost environment of soils may also extend their persistence in manure- or compost-amended soils. The presence of antibiotic-resistance genes in soils may also be increased by manure application. Overall, BSAs applied as fertilizers to soils can support the survival and regrowth of pathogens. BSAs should be handled and applied in a manner that reduces the prevalence of pathogens in soils and the likelihood of transfer of food-borne pathogens to fruits and vegetables. This review will focus on two BSAs-raw manure and composted manure (and other feedstocks)-and predominantly on the survival of enteric bacterial pathogens in BSAs as applied to soils as organic fertilizers.

Survival of Human Pathogens in Composted Sewage

PubMed Central

Wiley, B. Beauford; Westerberg, Stephen C.

1969-01-01

Studies were conducted to assess the effectiveness of an aerobic composter in destroying pathogens that may possibly be present in raw sewage sludge. Experiments conducted in this study were designed to determine whether or not selected indicator organisms (i.e., Salmonella newport, poliovirus type 1, Ascaris lumbricoides ova, and Candida albicans) could survive the composting process. The results of the assay showed that after 43 hr of composting, no viable indicator organisms could be detected. The poliovirus type I was the most sensitive, being inactivated within the first hour, whereas C. albicans was the most resistant, requiring more than 28 hr of composting for its inactivation. The data from this study indicated that aerobic composting of sewage sludge would destroy the indicator pathogens when a temperature of 60 to 70 C is maintained for a period of 3 days. PMID:4313209

Method of making compost and spawned compost, mushroom spawn and generating methane gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoller, B.B.

1981-04-28

Newly designed ribbon-type mixers provide an improved method for making composts, aerating composts, growing mushroom spawn, generating methane gas, and filling conveyors in the mushroom-growing industry. The mixers may be the double-ribbon type for purely mixing operations or the single-ribbon type for moving the material from one place to another. Both types can operate under pressure. In preparing compost for mushroom growing, operators can first use the airtight mixers for a preliminary anaerobic fermentation to produce methane, then by changing the atmosphere to an oxidizing one, complete the compost preparation under the necessary aerobic conditions.

Bacterial community shift for monitoring the co-composting of oil palm empty fruit bunch and palm oil mill effluent anaerobic sludge.

PubMed

Zainudin, Mohd Huzairi Mohd; Ramli, Norhayati; Hassan, Mohd Ali; Shirai, Yoshihito; Tashiro, Kosuke; Sakai, Kenji; Tashiro, Yukihiro

2017-06-01

A recently developed rapid co-composting of oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) anaerobic sludge is beginning to attract attention from the palm oil industry in managing the disposal of these wastes. However, a deeper understanding of microbial diversity is required for the sustainable practice of the co-compositing process. In this study, an in-depth assessment of bacterial community succession at different stages of the pilot scale co-composting of OPEFB-POME anaerobic sludge was performed using 454-pyrosequencing, which was then correlated with the changes of physicochemical properties including temperature, oxygen level and moisture content. Approximately 58,122 of 16S rRNA gene amplicons with more than 500 operational taxonomy units (OTUs) were obtained. Alpha diversity and principal component analysis (PCoA) indicated that bacterial diversity and distributions were most influenced by the physicochemical properties of the co-composting stages, which showed remarkable shifts of dominant species throughout the process. Species related to Devosia yakushimensis and Desemzia incerta are shown to emerge as dominant bacteria in the thermophilic stage, while Planococcus rifietoensis correlated best with the later stage of co-composting. This study proved the bacterial community shifts in the co-composting stages corresponded with the changes of the physicochemical properties, and may, therefore, be useful in monitoring the progress of co-composting and compost maturity.

Effects of composting process on the dissipation of extractable sulfonamides in swine manure.

PubMed

Liu, Bei; Li, Yanxia; Zhang, Xuelian; Feng, Chenghong; Gao, Min; Shen, Qiu

2015-01-01

Effects of composting on the fate of sulfonamides (SAs) in the manure-straw mixture were explored through a simulation of aerobic composting process. Additionally, factors of temperature and coexistence of heavy metal Cu that might influence the removal efficiency were particularly investigated. As shown in the results, the extractable SAs dissipated rapidly during the composting process. The coexistence of Cu in the composting process might have delayed the decline of SAs, but the drugs could still be completely removed by the end of the composting. In contrast to the thermophilic aerobic composting, extractable SAs in air-temperature-placed mixture dissipated much slower and 1.12-1.56mg/kg could be detected after 35days of incubation. The results confirmed that temperature could influence the dissipation of SAs, which was identified as a more important factor than Cu-coexistence. Hence, thermophilic aerobic composting is an effective process to eliminate VAs before manure land application. Copyright © 2014 Elsevier Ltd. All rights reserved.

An Exploration into the Bacterial Community under Different Pasteurization Conditions during Substrate Preparation (Composting-Phase II) for Agaricus bisporus Cultivation.

PubMed

Vieira, Fabricio Rocha; Pecchia, John Andrew

2018-02-01

Substrate preparation (i.e., composting) for Agaricus bisporus cultivation is the most critical point of mushroom production. Among many factors involved in the composting process, the microbial ecology of the system is the underlying drive of composting and can be influenced by composting management techniques. Pasteurization temperature at the beginning of phase II, in theory, may influence the bacterial community and subsequently the "selectivity" and nutrition of the final substrate. Therefore, this hypothesis was tested by simulation in bioreactors under different pasteurization conditions (57 °C/6 h, 60 °C/2 h, and 68 °C/2 h), simulating conditions adopted by many producers. Bacterial diversity, based on 16S ribosomal RNA obtained by high-throughput sequencing and classified in operational taxonomic units (OTUs), was greater than previously reported using culture-dependent methods. Alpha diversity estimators show a lower diversity of OTUs under a high-temperature pasteurization condition. Bacillales order shows a relatively higher OTU abundance under a high-pasteurization temperature, which also was related to high ammonia emission measurements. On the other hand, beta diversity analysis showed no significantly changes in the bacterial community structure under different conditions. Agaricus bisporus mycelium growth during a standard spawn run period was significantly slower in the compost pasteurized at high temperature. Since the bacterial community structure was not greatly affected by different pasteurization conditions but by-products left (e.g., ammonia) at the end of compost conditioning varied, further studies need to be conducted to determine the functional role of the microbial communities found during substrate preparation for Agaricus bisporus cultivation.

Definition of a type of abnormal vaginal flora that is distinct from bacterial vaginosis: aerobic vaginitis.

PubMed

Donders, Gilbert G G; Vereecken, Annie; Bosmans, Eugene; Dekeersmaecker, Alfons; Salembier, Geert; Spitz, Bernard

2002-01-01

To define an entity of abnormal vaginal flora: aerobic vaginitis. Observational study. University Hospital Gasthuisberg, Leuven, Belgium. 631 women attending for routine prenatal care or attending vaginitis clinic. Samples were taken for fresh wet mount microscopy of vaginal fluid, vaginal cultures and measurement of lactate, succinate and cytokine levels in vaginal fluid. Smears deficient in lactobacilli and positive for clue cells were considered to indicate a diagnosis of bacterial vaginosis. Aerobic vaginitis was diagnosed if smears were deficient in lactobacilli, positive for cocci or coarse bacilli, positive for parabasal epithelial cells, and/or positive for vaginal leucocytes (plus their granular aspect). Genital complaints include red inflammation, yellow discharge, vaginal dyspareunia. Group B streptococci, escherichia coli, staphylococcus aureus and trichomonas vaginalis are frequently cultured. Vaginal lactate concentration is severely depressed in women with aerobic vaginitis, as in bacterial vaginosis, but vaginal succinate is not produced. Also in contrast to bacterial vaginosis, aerobic vaginitis produces a host immune response that leads to high production of interleukin-6, interleukin-1-beta and leukaemia inhibitory factor in the vaginal fluid. Aerobic vaginitis is associated with aerobic micro-organisms, mainly group B streptococci and E. coli. Its characteristics are different from those of bacterial vaginosis and elicit an important host response. The most severe form of aerobic vaginitis equals desquamative inflammatory vaginitis. In theory, aerobic vaginitis may be a better candidate than bacterial vaginosis as the cause of pregnancy complications, such as ascending chorioamnionitis, preterm rupture of the membranes and preterm delivery.

Aerobic composting of distilled grain waste eluted from a Chinese spirit-making process: The effects of initial pH adjustment.

PubMed

Wang, Shi-Peng; Zhong, Xiao-Zhong; Wang, Ting-Ting; Sun, Zhao-Yong; Tang, Yue-Qin; Kida, Kenji

2017-12-01

Aerobic composting of distilled grain waste (DGW) at different initial pH values adjusted by CaO addition was investigated. Three pH-adjusted treatments with initial pH values of 4 (R1), 5 (R2) and 6 (R3) and a control treatment (R0) with a pH value of 3.5 were conducted simultaneously. The results showed that R0 had an unsuccessful start-up of composting. However, the pH-adjusted treatments produced remarkable results, with a relatively high initial pH being beneficial for the start-up. Within 65days of composting, the degradation of volatile solids (VS) and the physicochemical properties of R2 and R3 displayed similar tendencies, and both produced a mature end-product, while R1 exhibited a lower VS degradation rate, and some of its physicochemical properties indicated the end-product was immature. Quantitative PCR analysis of ammonia oxidizers indicated that the occurrence of nitrification during the composting of DGW could be attributed to the activity of ammonia-oxidizing bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Copper Addition on Copper Resistance, Antibiotic Resistance Genes, and intl1 during Swine Manure Composting

PubMed Central

Yin, Yanan; Gu, Jie; Wang, Xiaojuan; Song, Wen; Zhang, Kaiyu; Sun, Wei; Zhang, Xin; Zhang, Yajun; Li, Haichao

2017-01-01

Copper is one of the most abundant heavy metals present in swine manure. In this study, a laboratory-scale aerobic composting system was amended with Cu at three levels (0, 200, and 2000 mg kg-1, i.e., control, Cu200, and Cu2000 treatments, respectively) to determine its effect on the fate of copper resistance genes [copper resistance genes (CRGs): pcoA, cusA, copA, and tcrB], antibiotic resistance genes [antibiotic resistance genes (ARGs): erm(A) and erm(B)], and intl1. The results showed that the absolute abundances of pcoA, tcrB, erm(A), erm(B), and intl1 were reduced, whereas those of copA and cusA increased after swine manure composting. Redundancy analysis showed that temperature significantly affected the variations in CRGs, ARGs, and intl1. The decreases in CRGs, ARGs, and intI1 were positively correlated with the exchangeable Cu levels. The bacterial community could be grouped according to the composting time under different treatments, where the high concentration of copper had a more persistent effect on the bacterial community. Network analysis determined that the co-occurrence of CRGs, ARGs, and intI1, and the bacterial community were the main contributors to the changes in CRGs, ARG, and intl1. Thus, temperature, copper, and changes in the bacterial community composition had important effects on the variations in CRGs, ARGs, and intl1 during manure composting in the presence of added copper. PMID:28316595

Cultivation of a bacterial consortium with the potential to degrade total petroleum hydrocarbon using waste activated sludge.

PubMed

Sivakumar, S; Song, Y C; Kim, S H; Jang, S H

2015-11-01

Waste activated sludge was aerobically treated to demonstrate multiple uses such as cultivating an oil degrading bacterial consortium; studying the influence of a bulking agent (peat moss) and total petroleum hydrocarbon concentration on bacterial growth and producing a soil conditioner using waste activated sludge. After 30 days of incubation, the concentration of oil-degrading bacteria was 4.3 x 10(8) CFU g(-1) and 4.5 x 10(8) CFU g(-1) for 5 and 10 g of total petroleum hydrocarbon, respectively, in a mixture of waste activated sludge (1 kg) and peat moss (0.1 kg). This accounts for approximately 88.4 and 91.1%, respectively, of the total heterotrophic bacteria (total-HB). The addition of bulking agent enhanced total-HB population and total petroleum hydrocarbon-degrading bacterial population. Over 90% of total petroleum hydrocarbon degradation was achieved by the mixture of waste activated sludge, bulking agent and total petroleum hydrocarbon. The results of physico-chemical parameters of the compost (waste activated sludge with and without added peat moss compost) and a substantial reduction in E. coli showed that the use of this final product did not exhibit risk when used as soil conditioner. Finally, the present study demonstrated that cultivation of total petroleum hydrocarbon-degrading bacterial consortium and production of compost from waste activated sludge by aerobic treatment was feasible.

Effects of aerobic and anaerobic biological processes on leaching of heavy metals from soil amended with sewage sludge compost.

PubMed

Fang, Wen; Wei, Yonghong; Liu, Jianguo; Kosson, David S; van der Sloot, Hans A; Zhang, Peng

2016-12-01

The risk from leaching of heavy metals is a major factor hindering land application of sewage sludge compost (SSC). Understanding the change in heavy metal leaching resulting from soil biological processes provides important information for assessing long-term behavior of heavy metals in the compost amended soil. In this paper, 180days aerobic incubation and 240days anaerobic incubation were conducted to investigate the effects of the aerobic and anaerobic biological processes on heavy metal leaching from soil amended with SSC, combined with chemical speciation modeling. Results showed that leaching concentrations of heavy metals at natural pH were similar before and after biological process. However, the major processes controlling heavy metals were influenced by the decrease of DOC with organic matter mineralization during biological processes. Mineralization of organic matter lowered the contribution of DOC-complexation to Ni and Zn leaching. Besides, the reducing condition produced by biological processes, particularly by the anaerobic biological process, resulted in the loss of sorption sites for As on Fe hydroxide, which increased the potential risk of As release at alkaline pH. Copyright © 2016 Elsevier Ltd. All rights reserved.

The influences of inoculants from municipal sludge and solid waste on compost stability, maturity and enzyme activities during chicken manure composting.

PubMed

Li, Shuyan; Li, Jijin; Yuan, Jing; Li, Guoxue; Zang, Bing; Li, Yangyang

2017-07-01

The aim of this study was to investigate the influence of inoculants on compost stability, maturity and enzyme activities during composting of chicken manure and cornstalk. Two microbial inoculants (originated from aerobic municipal sludge and municipal solid waste, respectively) were used in composting at the rate of 0.3% of initial raw materials (wet weight). No microbial inoculums were added to the control. The experiment was conducted under aerobic conditions for 53 days. The results show that enzyme activity is an important index to comprehensively evaluate the composting stability and maturity. Microbes originated from sludge works best in terms of composting stability and maturity (C:N ratio decreased from 15.5 to 10, and germination index increased to 109%). Microbial inoculums originated from sludge and municipal solid waste extended the time of thermophilic phase for 11 and 7 days, respectively. Microbial inoculums originated from sludge and MSW significantly increased the average of catalase activity (by 15.0% and 12.1%, respectively), urease activity (by 21.5% and 12.2%, respectively) and cellulase activity (by 32.1% and 26.1%, respectively) during composting.

Yolo County's Accelerated Anaerobic and Aerobic Composting (Full-Scale Controlled Landfill Bioreactor) Project

NASA Astrophysics Data System (ADS)

Yazdani, R.; Kieffer, J.; Akau, H.; Augenstein, D.

2002-12-01

Sanitary landfilling is the dominant method of solid waste disposal in the United States, accounting for about 217 million tons of waste annually (U.S. EPA, 1997) and has more than doubled since 1960. In spite of increasing rates of reuse and recycling, population and economic growth will continue to render landfilling as an important and necessary component of solid waste management. Yolo County Department of Planning and Public Works, Division of Integrated Waste Management is demonstrating a new landfill technology called Bioreactor Landfill to better manage solid waste. In a Bioreactor Landfill, controlled quantities of liquid (leachate, groundwater, gray-water, etc.) are added and recirculated to increase the moisture content of the waste and improve waste decomposition. As demonstrated in a small-scale demonstration project at the Yolo County Central Landfill in 1995, this process significantly increases the biodegradation rate of waste and thus decreases the waste stabilization and composting time (5 to 10 years) relative to what would occur within a conventional landfill (30 to 50 years or more). When waste decomposes anaerobically (in absence of oxygen), it produces landfill gas (biogas). Biogas is primarily a mixture of methane, a potent greenhouse gas, carbon dioxide, and small amounts of Volatile Organic Compounds (VOC's) which can be recovered for electricity or other uses. Other benefits of a bioreactor landfill composting operation include increased landfill waste settlement which increases in landfill capacity and life, improved leachate chemistry, possible reduction of landfill post-closure management time, opportunity to explore decomposed waste for landfill mining, and abatement of greenhouse gases through highly efficient methane capture over a much shorter period of time than is typical of waste management through conventional landfilling. This project also investigates the aerobic decomposition of waste of 13,000 tons of waste (2.5 acre) for

Turning refuse into resource: a study on aerobic composting.

PubMed

Janakiram, T; Sridevi, K

2012-07-01

The management of solid waste disposal had been a perennial problem every where in our country. In order to overcome this problem one possible solution is to compost the solid waste in the presence of air, so that it may be converted into an useful manure. With this intention, solid wastes like coir waste and water hyacinth had been collected and composted with the addition of cow dung. The composted material had been examined for the physical and chemical parameters. The content of macronutrients was found to be higher as the period of composting increased. There were gradual variations in the case of other parameters. A comparative account of the two types of solid waste is also given.

Microbial enhancement of compost extracts based on cattle rumen content compost - characterisation of a system.

PubMed

Shrestha, Karuna; Shrestha, Pramod; Walsh, Kerry B; Harrower, Keith M; Midmore, David J

2011-09-01

Microbially enhanced compost extracts ('compost tea') are being used in commercial agriculture as a source of nutrients and for their perceived benefit to soil microbiology, including plant disease suppression. Rumen content material is a waste of cattle abattoirs, which can be value-added by conversion to compost and 'compost tea'. A system for compost extraction and microbial enhancement was characterised. Molasses amendment increased bacterial count 10-fold, while amendment based on molasses and 'fish and kelp hydrolysate' increased fungal count 10-fold. Compost extract incubated at 1:10 (w/v) dilution showed the highest microbial load, activity and humic/fulvic acid content compared to other dilutions. Aeration increased the extraction efficiency of soluble metabolites, and microbial growth rate, as did extraction of compost without the use of a constraining bag. A protocol of 1:10 dilution and aerated incubation with kelp and molasses amendments is recommended to optimise microbial load and fungal-to-bacterial ratio for this inoculum source. Copyright © 2011 Elsevier Ltd. All rights reserved.

A Combination of Biochar–Mineral Complexes and Compost Improves Soil Bacterial Processes, Soil Quality, and Plant Properties

PubMed Central

Ye, Jun; Zhang, Rui; Nielsen, Shaun; Joseph, Stephen D.; Huang, Danfeng; Thomas, Torsten

2016-01-01

Organic farming avoids the use of synthetic fertilizers and promises food production with minimal environmental impact, however this farming practice does not often result in the same productivity as conventional farming. In recent years, biochar has received increasing attention as an agricultural amendment and by coating it with minerals to form biochar–mineral complex (BMC) carbon retention and nutrient availability can be improved. However, little is known about the potential of BMC in improving organic farming. We therefore investigated here how soil, bacterial and plant properties respond to a combined treatment of BMC and an organic fertilizer, i.e., a compost based on poultry manure. In a pakchoi pot trial, BMC and compost showed synergistic effects on soil properties, and specifically by increasing nitrate content. Soil nitrate has been previously observed to increase leaf size and we correspondingly saw an increase in the surface area of pakchoi leaves under the combined treatment of BMC and composted chicken manure. The increase in soil nitrate was also correlated with an enrichment of bacterial nitrifiers due to BMC. Additionally, we observed that the bacteria present in the compost treatment had a high turnover, which likely facilitated organic matter degradation and a reduction of potential pathogens derived from the manure. Overall our results demonstrate that a combination of BMC and compost can stimulate microbial process in organic farming that result in better vegetable production and improved soil properties for sustainable farming. PMID:27092104

A Combination of Biochar-Mineral Complexes and Compost Improves Soil Bacterial Processes, Soil Quality, and Plant Properties.

PubMed

Ye, Jun; Zhang, Rui; Nielsen, Shaun; Joseph, Stephen D; Huang, Danfeng; Thomas, Torsten

2016-01-01

Organic farming avoids the use of synthetic fertilizers and promises food production with minimal environmental impact, however this farming practice does not often result in the same productivity as conventional farming. In recent years, biochar has received increasing attention as an agricultural amendment and by coating it with minerals to form biochar-mineral complex (BMC) carbon retention and nutrient availability can be improved. However, little is known about the potential of BMC in improving organic farming. We therefore investigated here how soil, bacterial and plant properties respond to a combined treatment of BMC and an organic fertilizer, i.e., a compost based on poultry manure. In a pakchoi pot trial, BMC and compost showed synergistic effects on soil properties, and specifically by increasing nitrate content. Soil nitrate has been previously observed to increase leaf size and we correspondingly saw an increase in the surface area of pakchoi leaves under the combined treatment of BMC and composted chicken manure. The increase in soil nitrate was also correlated with an enrichment of bacterial nitrifiers due to BMC. Additionally, we observed that the bacteria present in the compost treatment had a high turnover, which likely facilitated organic matter degradation and a reduction of potential pathogens derived from the manure. Overall our results demonstrate that a combination of BMC and compost can stimulate microbial process in organic farming that result in better vegetable production and improved soil properties for sustainable farming.

Microbial succession in a compost-packed biofilter treating benzene-contaminated air.

PubMed

Borin, Sara; Marzorati, Massimo; Brusetti, Lorenzo; Zilli, Mario; Cherif, Hanene; Hassen, Abdennaceur; Converti, Attilio; Sorlini, Claudia; Daffonchio, Daniele

2006-03-01

Air artificially contaminated with increasing concentrations of benzene was treated in a laboratory scale compost-packed biofilter for 240 days with a removal efficiency of 81-100%. The bacterial community in the packing material (PM) at different heights of the biofilter was analysed every 60 days. Bacterial plate counts and ribosomal intergenic spacer analysis (RISA) of the isolated strains showed that the number of cultivable aerobic heterotrophic bacteria and the species diversity increased with benzene availability. Identification of the isolated species and the main bands in denaturing gradient gel electrophoresis (DGGE) profiles from total compost DNA during the treatment revealed that, at a relatively low volumetric benzene load (1.2< or =VBL< or =6.4 g m(-3) (PM) h(-1)), besides low G+C Gram positive bacteria, originally present in the packing compost, bacteroidetes and beta- and gamma-proteobacteria became detectable in the colonising population. At the VBL value (24.8 g m(-3) (PM) h(-1)) ensuring the maximum elimination capacity of the biofilter (20.1 g m(-3) (PM) h(-1)), strains affiliated to the genus Rhodococcus dominated the microflora, followed by beta-proteobacteria comprising the genera Bordetella and Neisseria. Under these conditions, more than 35% of the isolated strains were able to grow on benzene as the sole carbon source. Comparison of DGGE and automated RISA profiles of the total community and isolated strains showed that a complex bacterial succession occurred in the reactor in response to the increasing concentrations of the pollutant and that cultivable bacteria played a major role in benzene degradation under the adopted conditions.

Compost supplementation with nutrients and microorganisms in composting process.

PubMed

Sánchez, Óscar J; Ospina, Diego A; Montoya, Sandra

2017-11-01

The composting is an aerobic, microorganism-mediated, solid-state fermentation process by which different organic materials are transformed into more stable compounds. The product obtained is the compost, which contributes to the improvement of physical, chemical and microbiological properties of the soil. However, the compost usage in agriculture is constrained because of its long-time action and reduced supply of nutrients to the crops. To enhance the content of nutrients assimilable by the plants in the compost, its supplementation with nutrients and inoculation with microorganisms have been proposed. The objective of this work was to review the state of the art on compost supplementation with nutrients and the role played by the microorganisms involved (or added) in their transformation during the composting process. The phases of composting are briefly compiled and different strategies for supplementation are analyzed. The utilization of nitrogenous materials and addition of microorganisms fixing nitrogen from the atmosphere or oxidizing ammonia into more assimilable for plants nitrogenous forms are analyzed. Several strategies for nitrogen conservation during composting are presented as well. The supplementation with phosphorus and utilization of microorganisms solubilizing phosphorus and potassium are also discussed. Main groups of microorganisms relevant during the composting process are described as well as most important strategies to identify them. In general, the development of this type of nutrient-enriched bio-inputs requires research and development not only in the supplementation of compost itself, but also in the isolation and identification of microorganisms and genes allowing the degradation and conversion of nitrogenous substances and materials containing potassium and phosphorus present in the feedstocks undergoing the composting process. In this sense, most important research trends and strategies to increase nutrient content in the compost

Nitrogen conservation in simulated food waste aerobic composting process with different Mg and P salt mixtures.

PubMed

Li, Yu; Su, Bensheng; Liu, Jianlin; Du, Xianyuan; Huang, Guohe

2011-07-01

To assess the effects of three types of Mg and P salt mixtures (potassium phosphate [K3PO4]/magnesium sulfate [MgSO4], potassium dihydrogen phosphate [K2HPO4]/MgSO4, KH2PO4/MgSO4) on the conservation of N and the biodegradation of organic materials in an aerobic food waste composting process, batch experiments were undertaken in four reactors (each with an effective volume of 30 L). The synthetic food waste was composted of potatoes, rice, carrots, leaves, meat, soybeans, and seed soil, and the ratio of C and N was 17:1. Runs R1-R3 were conducted with the addition of K3PO4/ MgSO4, K2HPO4/MgSO4, and KH2PO4/MgSO4 mixtures, respectively; run R0 was a blank performed without the addition of Mg and P salts. After composting for 25 days, the degrees of degradation of the organic materials in runs R0-R3 were 53.87, 62.58, 59.14, and 49.13%, respectively. X-ray diffraction indicated that struvite crystals were formed in runs R1-R3 but not in run R0; the gaseous ammonia nitrogen (NH3-N) losses in runs R0-R3 were 21.2, 32.8, 12.6, and 3.5% of the initial total N, respectively. Of the tested Mg/P salt mixtures, the K2HPO4/ MgSO4 system provided the best combination of conservation of N and biodegradation of organic materials in this food waste composting process.

Enhancement of aerobic biodegradability potential of municipal waste activated sludge by ultrasonic aided bacterial disintegration.

PubMed

Kavitha, S; Jessin Brindha, G M; Sally Gloriana, A; Rajashankar, K; Yeom, Ick Tae; Rajesh Banu, J

2016-01-01

An investigation was performed to study the influence of ultrasonic aided bacterial disintegration on the aerobic degradability of sludge. In first phase of the study, effective floc disruption was achieved at an ultrasonic specific energy input of 2.45kJ/kg TS with 44.5mg/L of Extracellular Polymeric Substance (EPS) release including 0.035U/mL and 0.025U/mL protease and amylase activity respectively. In second phase, experimental outcomes revealed bacterial disintegration of floc disrupted-sludge showing a maximum solubilization of about 23% and was observed to be superior to bacterially disintegrated (11%) and control (6%), respectively. The result of aerobic biodegradability of ultrasonic aided bacterially pretreated sludge showed volatile solids (VS) degradation of about 40.2%. The kinetic study of aerobic biodegradability through non linear regression modelling reveals that floc disrupted sludge showed better biodegradability with decay constant of about 0.19d(-1) relatively higher than the control (0.14d(-1)) and bacterially disintegrated (0.17d(-1)) sludges. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed

Soobhany, Nuhaa; Mohee, Romeela; Garg, Vinod Kumar

2017-06-01

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. Copyright © 2017 Elsevier Ltd. All rights reserved.

The composting option for human waste disposal in the backcountry

Treesearch

S. C. Fay; R. H. Walke

1977-01-01

The disposal of human waste by composting at backcountry recreation areas is a possible alternative to methods that are considered unsafe. The literature indicates that aerobic, thermophilic composting is a reliable disposal method that can be low in cost and in maintenance. A bark-sewage mixture can be composted to produce a pathogen-free substance that might be used...

A quasi-universal medium to break the aerobic/anaerobic bacterial culture dichotomy in clinical microbiology.

PubMed

Dione, N; Khelaifia, S; La Scola, B; Lagier, J C; Raoult, D

2016-01-01

In the mid-19th century, the dichotomy between aerobic and anaerobic bacteria was introduced. Nevertheless, the aerobic growth of strictly anaerobic bacterial species such as Ruminococcus gnavus and Fusobacterium necrophorum, in a culture medium containing antioxidants, was recently demonstrated. We tested aerobically the culture of 623 bacterial strains from 276 bacterial species including 82 strictly anaerobic, 154 facultative anaerobic, 31 aerobic and nine microaerophilic bacterial species as well as ten fungi. The basic culture medium was based on Schaedler agar supplemented with 1 g/L ascorbic acid and 0.1 g/L glutathione (R-medium). We successively optimized this media, adding 0.4 g/L uric acid, using separate autoclaving of the component, or adding haemin 0.1 g/L or α-ketoglutarate 2 g/L. In the basic medium, 237 bacterial species and ten fungal species grew but with no growth of 36 bacterial species, including 22 strict anaerobes. Adding uric acid allowed the growth of 14 further species including eight strict anaerobes, while separate autoclaving allowed the growth of all tested bacterial strains. To extend its potential use for fastidious bacteria, we added haemin for Haemophilus influenzae, Haemophilus parainfluenzae and Eikenella corrodens and α-ketoglutarate for Legionella pneumophila. This medium allowed the growth of all tested strains with the exception of Mycobacterium tuberculosis and Mycobacterium bovis. Testing primoculture and more fastidious species will constitute the main work to be done, but R-medium coupled with a rapid identification method (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) will facilitate the anaerobic culture in clinical microbiology laboratories. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Time series analysis of aerobic bacterial flora during Miso fermentation.

PubMed

Onda, T; Yanagida, F; Tsuji, M; Shinohara, T; Yokotsuka, K

2003-01-01

This article reports a microbiological study of aerobic mesophilic bacteria that are present during the fermentation process of Miso. Aerobic bacteria were enumerated and isolated from Miso during fermentation and divided into nine groups using traditional phenotypic tests. The strains were identified by biochemical analysis and 16S rRNA sequence analysis. They were identified as Bacillus subtilis, B. amyloliquefaciens, Kocuria kristinae, Staphylococcus gallinarum and S. kloosii. All strains were sensitive to the bacteriocins produced by the lactic acid bacteria isolated from Miso. The dominant species among the undesirable species throughout the fermentation process were B. subtilis and B. amyloliquefaciens. It is suggested that bacteriocin-producing lactic acid bacteria are effective in the growth prevention of aerobic bacteria in Miso. This study has provided useful information for controlling of bacterial flora during Miso fermentation.

Physico-chemical and biological characteristics of compost from decentralised composting programmes.

PubMed

Vázquez, M A; Sen, R; Soto, M

2015-12-01

Composts that originated from small-scale composting programmes including home, community and canteen waste composters were studied. Heavy metals concentration indicated compliance with current regulations for conventional and organic agriculture. Compost from canteen waste showed high organic matter content (74% VS), while community (44 ± 20% VS) and home composts (31 ± 16% VS) had moderate levels. N content increased from home compost (1.3 ± 0.9% dm) to community (2.0 ± 0.9%) and canteen compost (2.5-3.0%) while P content ranged from 0.4% to 0.6% dm. C/N, absorbance E4/E6 and N-NH4(+)/N-NO3(-) ratios as well as respiration index indicated well-stabilized final products. Culturable bacterial and fungal cfu linkage to composting dynamics were identified and higher diversity of invertebrates was found in the smaller scale static systems. With similar process evolution indicators to industrial systems, overall results support the sustainability of these small-scale, self-managed composting systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Aerobic bacterial flora of addled raptor eggs in Saskatchewan.

PubMed

Houston, C S; Saunders, J R; Crawford, R D

1997-04-01

In south-central Saskatchewan, Canada, in 1986, 1987 and 1989, the aerobic bacterial flora was evaluated from 75 unhatched raptor eggs of three species: 42 of the Swainson's hawk (Buteo Swainsoni), 21 of the ferruginous hawk (Buteo regalis), and 12 of the great horned owl (Bubo virginianus). In addled Swainson's hawk eggs, the most common bacterial genera were Enterobacter (18 eggs), Escherichia (12), and Streptococcus (10). Seven great horned owl eggs and six ferruginous hawk eggs also contained Escherichia coli. Salmonella spp. were not isolated. These bacteria were interpreted as secondary contaminants and not the primary cause of reproductive failure.

Bacterial and fungal core microbiomes associated with small grain silages during ensiling and aerobic spoilage.

PubMed

Duniere, Lysiane; Xu, Shanwei; Long, Jin; Elekwachi, Chijioke; Wang, Yuxi; Turkington, Kelly; Forster, Robert; McAllister, Tim A

2017-03-03

Describing the microbial populations present in small grain silage and understanding their changes during ensiling is of interest for improving the nutrient value of these important forage crops. Barley, oat and triticale forages as well as an intercropped mixture of the 3 crops were harvested and ensiled in mini silos for a period of 90 days, followed by 14 days of aerobic exposure. Changes in fermentation characteristics and nutritive value were assessed in terminal silages and bacterial and fungal communities during ensiling and aerobic exposure were described using 16S and 18S rDNA sequencing, respectively. All small grain silages exhibited chemical traits that were associated with well ensiled forages, such as low pH value (4.09 ± 0.28) and high levels of lactic acid (59.8 ± 14.59 mg/g DM). The number of microbial core genome operational taxonomic units (OTUs) decreased with time of ensiling. Taxonomic bacterial community profiles were dominated by the Lactobacillales after fermentation, with a notable increase in Bacillales as a result of aerobic exposure. Diversity of the fungal core microbiome was shown to also be reduced during ensiling. Operational taxonomic units assigned to filamentous fungi were found in the core microbiome at ensiling and after aerobic exposure, whereas the Saccharomycetales were the dominate yeast population after 90 days of ensiling and aerobic exposure. Bacterial and fungal orders typically associated with silage spoilage were identified in the core microbiome after aerobic exposure. Next Generation Sequencing was successfully used to describe bacterial communities and the first record of fungal communities throughout the process of ensiling and utilization. Adequately describing the microbial ecology of silages could lead to improved ensiling practices and the selection of silage inoculants that act synergistically with the natural forage microbiome.

Importance of soil amendments: survival of bacterial pathogens in manure and compost used as organic fertizliers

USDA-ARS?s Scientific Manuscript database

Biological soil amendments (BSA’s) like manure and compost are frequently used as organic fertilizers to soils to improve its physical and chemical properties. However, BSAs have been known to be a reservoir for enteric bacterial pathogens like enterohemorrhagic E. coli, Salmonella spp, and Listeri...

Condensed tannins affect bacterial and fungal microbiomes and mycotoxin production during ensiling and upon aerobic exposure.

PubMed

Peng, Kai; Jin, Long; Niu, Yan D; Huang, Qianqian; McAllister, Tim A; Yang, Hee Eun; Denise, Hubert; Xu, Zhongjun; Acharya, Surya; Wang, Shunxi; Wang, Yuxi

2017-12-15

Purple prairie clover (PPC; Dalea purpurea Vent.) containing 84.5 g/kg DM of condensed tannin (CT) was ensiled without (Control) or with polyethylene glycol (PEG) for 76 days, followed by 14 days of aerobic exposure. Changes in fermentation characteristics were determined and bacterial and fungal communities were assessed using metagenomic sequencing. Addition of PEG that deactivated CT at ensiling increased ( P < 0.05∼0.001) soluble N, non-protein N, lactic acid, total volatile fatty acids, ammonia N, deoxynivalenol (DON) and ochratoxin A (OTA), but decreased ( P < 0.001) pH and water soluble carbohydrates. Concentration of DON and OTA increased ( P < 0.001) for both silages with the extent of increase being greater for Control than for PEG treated silage during aerobic exposure. The PEG treated silage exhibited higher ( P < 0.01∼0.001) copy numbers of total bacteria, Lactobacillus , yeasts and fungi than Control. Addition of PEG decreased ( P < 0.01) bacterial diversity during both ensiling and aerobic exposure, whereas it increased ( P < 0.05) fungal diversity during aerobic exposure. Addition of PEG at ensiling increased ( P < 0.05) abundances of Lactobacillus and Pediococcus , but decreased ( P < 0.01) abundances of Lactococcus and Leuconostoc Filamentous fungi were found in the microbiome at ensiling and after aerobic exposure, whereas the Bacillus were the dominate bacteria after aerobic exposure. In conclusion, CT decreased protein degradation and improved aerobic stability of silage. These desirable outcomes likely reflect the ability of PPC CT to inhibit those microorganisms involved in lowering silage quality and in the production of mycotoxins. IMPORTANCE The present study reports the effects of condensed tannins on the complex microbial communities involved in ensiling and aerobic exposure of purple prairie clover. This study documents the ability of condensed tannins to lower mycotoxin production and associated microbiome. Taxonomic bacterial

A compost bin for handling privy wastes: its fabrication and use

Treesearch

R.E. Leonard; S.C. Fay

1978-01-01

A 24-ft3 (6.8-m3) fiberglass bin was constructed and tested for its effectiveness in composting privy wastes. A mixture of ground hardwood bark and raw sewage was used for composting. Temperatures in excess of 60°C for 36 hours were produced in the bin by aerobic, thermophilic composting. This temperature is...

Impact of compost process conditions on organic micro pollutant degradation during full scale composting.

PubMed

Sadef, Yumna; Poulsen, Tjalfe Gorm; Bester, Kai

2015-06-01

Knowledge about the effects of oxygen concentration, nutrient availability and moisture content on removal of organic micro-pollutants during aerobic composting is at present very limited. Impact of oxygen concentration, readily available nitrogen content (NH4(+), NO3(-)), and moisture content on biological transformation of 15 key organic micro-pollutants during composting, was therefore investigated using bench-scale degradation experiments based on non-sterile compost samples, collected at full-scale composting facilities. In addition, the adequacy of bench-scale composting experiments for representing full-scale composting conditions, was investigated using micro-pollutant concentration measurements from both bench- and full-scale composting experiments. Results showed that lack of oxygen generally prevented transformation of organic micro-pollutants. Increasing readily available nitrogen content from about 50 mg N per 100 g compost to about 140 mg N per 100 g compost actually reduced micro-pollutant transformation, while changes in compost moisture content from 50% to 20% by weight, only had minor influence on micro-pollutant transformation. First-order micro-pollutant degradation rates for 13 organic micro-pollutants were calculated using data from both full- and bench-scale experiments. First-order degradation coefficients for both types of experiments were similar and ranged from 0.02 to 0.03 d(-1) on average, indicating that if a proper sampling strategy is employed, bench-scale experiments can be used to represent full-scale composting conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of organic acids production and bacterial community on the possible mechanism of phosphorus solubilization during composting with enriched phosphate-solubilizing bacteria inoculation.

PubMed

Wei, Yuquan; Zhao, Yue; Shi, Mingzi; Cao, Zhenyu; Lu, Qian; Yang, Tianxue; Fan, Yuying; Wei, Zimin

2018-01-01

Enriched phosphate-solubilizing bacteria (PSB) agent were acquired by domesticated cultivation, and inoculated into kitchen waste composting in different stages. The effect of different treatments on organic acids production, tricalcium phosphate (TCP) solubilization and their relationship with bacterial community were investigated during composting. Our results pointed out that inoculation affected pH, total acidity and the production of oxalic, lactic, citric, succinic, acetic and formic acids. We also found a strong advantage in the solubilization of TCP and phosphorus (P) availability for PSB inoculation especially in the cooling stage. Redundancy analysis and structural equation models demonstrated inoculation by different methods changed the correlation of the bacterial community composition with P fractions as well as organic acids, and strengthened the cooperative function related to P transformation among species during composting. Finally, we proposed a possible mechanism of P solubilization with enriched PSB inoculation, which was induced by bacterial community and organic acids production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of microbially enhanced compost extracts produced from composted cattle rumen content material and from commercially available inocula.

PubMed

Shrestha, Karuna; Adetutu, Eric M; Shrestha, Pramod; Walsh, Kerry B; Harrower, Keith M; Ball, Andrew S; Midmore, David J

2011-09-01

A comparative study was performed on compost extracts prepared from cattle rumen content composted for three and nine months, nine month old compost inoculated with a Nutri-Life 4/20™ inoculum, and two commercial preparations (LivingSoil™ and Nutri-Life 4/20™), all incubated for 48h. Nutri-Life 4/20™ had the highest concentrations of NO(3)(-)-N and K(+)-K, while rumen compost extract had higher humic and fulvic acids concentration. The bacterial and fungal community level functional diversity of three month old compost extract and of LivingSoil™, assessed with Biolog™, were higher than that of nine month old rumen compost extract, with or without Nutri-Life 4/20™ inoculum, or Nutri-Life 4/20™. No difference in fungal diversity was observed between treatments, as indicated by Denaturing Gradient Gel Electrophoresis (DGGE) analysis, however, bacterial diversity was higher in all compost extracts and LivingSoil™ compared to the Nutri-Life 4/20™. Criteria for judging the quality of a microbially enhanced extract are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Co-composting high moisture vegetable waste and flower waste in a sequential fed operation].

PubMed

Zhang, Xiangfeng; Wang, Hongtao; Nie, Yongfeng

2003-11-01

Co-composting of high moisture vegetable wastes (celery and cabbage) and flower wastes (carnation) were studied in a sequential fed bed. The preliminary materials of composting were celery and carnation wastes. The sequential fed materials of composting were cabbage wastes and were fed every 4 days. Moisture content of mixture materials was between 60% and 70%. Composting was done in an aerobic static bed of composting based temperature feedback and control via aeration rate regulation. Aeration was ended when temperature of the pile was about 40 degrees C. Changes of composting of temperature, aeration rate, water content, organic matter, ash, pH, volume, NH4(+)-N, and NO3(-)-N were studied. Results show that co-composting of high moisture vegetable wastes and flower wastes, in a sequential fed aerobic static bed based temperature feedback and control via aeration rate regulation, can stabilize organic matter and removal water rapidly. The sequential fed operation are effective to overcome the difficult which traditional composting cannot applied successfully where high moisture vegetable wastes in more excess of flower wastes, such as Dianchi coastal.

In-vessel composting of household wastes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iyengar, Srinath R.; Bhave, Prashant P.

The process of composting has been studied using five different types of reactors, each simulating a different condition for the formation of compost; one of which was designed as a dynamic complete-mix type household compost reactor. A lab-scale study was conducted first using the compost accelerators culture (Trichoderma viridae, Trichoderma harzianum, Trichorus spirallis, Aspergillus sp., Paecilomyces fusisporus, Chaetomium globosum) grown on jowar (Sorghum vulgare) grains as the inoculum mixed with cow-dung slurry, and then by using the mulch/compost formed in the respective reactors as the inoculum. The reactors were loaded with raw as well as cooked vegetable waste for amore » period of 4 weeks and then the mulch formed was allowed to maturate. The mulch was analysed at various stages for the compost and other environmental parameters. The compost from the designed aerobic reactor provides good humus to build up a poor physical soil and some basic plant nutrients. This proves to be an efficient, eco-friendly, cost-effective, and nuisance-free solution for the management of household solid wastes.« less

The disease complex of the gypsy moth. II. Aerobic bacterial pathogens

Treesearch

J.D. Podgwaite; R.W. Campbell

1972-01-01

Eighty-six pathogenic aerobic bacterial isolates from diseased gypsy moth larvae collected in both sparse and dense populations were characterized and identified as members of the families Bacillaceae, Enterobacteriaceae, Lactobacillaceae, Pseudomonadaceae, and Achromobacteraceae. The commonest pathogens were Streptococcus faecalis, Bacillus cereus, Bacillus...

Changes in physical, chemical, and microbiological properties during the two-stage co-composting of green waste with spent mushroom compost and biochar.

PubMed

Zhang, Lu; Sun, Xiangyang

2014-11-01

This research determined whether the two-stage co-composting can be used to convert green waste (GW) into a useful compost. The GW was co-composted with spent mushroom compost (SMC) (at 0%, 35%, and 55%) and biochar (BC) (at 0%, 20%, and 30%). The combined addition of SMC and BC greatly increased the nutrient contents of the compost product and also improved the compost quality in terms of composting temperature, particle-size distribution, free air space, cation exchange capacity, nitrogen transformation, organic matter degradation, humification, element contents, abundance of aerobic heterotrophs, dehydrogenase activity, and toxicity to germinating seeds. The addition of 35% SMC and 20% BC to GW (dry weight % of initial GW) and the two-stage co-composting technology resulted in the production of the highest quality compost product in only 24 days rather than the 90-270 days required with traditional composting. Copyright © 2014 Elsevier Ltd. All rights reserved.

Changes in structure and function of fungal community in cow manure composting.

PubMed

Wang, Ke; Yin, Xiangbo; Mao, Hailong; Chu, Chu; Tian, Yu

2018-05-01

In this study, dynamic changes in fungal communities, trophic modes and effect factors in 60 days composting of cow manure were analyzed by using high throughput sequencing, FUNGuild and Biolog FF MicroPlate, respectively. Orpinomyces (relative abundance >10.85%) predominated in feedstock, and Mycothermus became the dominating genus (relative abundance >75%) during the active phase. Aerobic composting treatment had a significant effect on fungal trophic modes with pathogenic fungi fading away and wood saprotrophs increasing over composting time. Fungal communities had the higher carbon sources utilization capabilities at the thermophilic phase and mature phase than those in the other periods. Oxidation reduction potential (ORP) significantly increased from -180 to 180 mV during the treatment. Redundancy analysis showed that the succession of fungal community during composting had a significant association with ORP (p < .05). This indicated that aerobic composting treatment not only influenced fungal community structure, but also changed fungal trophic modes and metabolic characteristics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Molecular Phylogenetic Diversity and Spatial Distribution of Bacterial Communities in Cooling Stage during Swine Manure Composting

PubMed Central

Guo, Yan; Zhang, Jinliang; Yan, Yongfeng; Wu, Jian; Zhu, Nengwu; Deng, Changyan

2015-01-01

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and subsequent sub-cloning and sequencing were used in this study to analyze the molecular phylogenetic diversity and spatial distribution of bacterial communities in different spatial locations during the cooling stage of composted swine manure. Total microbial DNA was extracted, and bacterial near full-length 16S rRNA genes were subsequently amplified, cloned, RFLP-screened, and sequenced. A total of 420 positive clones were classified by RFLP and near-full-length 16S rDNA sequences. Approximately 48 operational taxonomic units (OTUs) were found among 139 positive clones from the superstratum sample; 26 among 149 were from the middle-level sample and 35 among 132 were from the substrate sample. Thermobifida fusca was common in the superstratum layer of the pile. Some Bacillus spp. were remarkable in the middle-level layer, and Clostridium sp. was dominant in the substrate layer. Among 109 OTUs, 99 displayed homology with those in the GenBank database. Ten OTUs were not closely related to any known species. The superstratum sample had the highest microbial diversity, and different and distinct bacterial communities were detected in the three different layers. This study demonstrated the spatial characteristics of the microbial community distribution in the cooling stage of swine manure compost. PMID:25925066

Predominance of single bacterial cells in composting bioaerosols

NASA Astrophysics Data System (ADS)

Galès, Amandine; Bru-Adan, Valérie; Godon, Jean-Jacques; Delabre, Karine; Catala, Philippe; Ponthieux, Arnaud; Chevallier, Michel; Birot, Emmanuel; Steyer, Jean-Philippe; Wéry, Nathalie

2015-04-01

Bioaerosols emitted from composting plants have become an issue because of their potential harmful impact on public or workers' health. Accurate knowledge of the particle-size distribution in bioaerosols emitted from open-air composting facilities during operational activity is a requirement for improved modeling of air dispersal. In order to investigate the aerodynamic diameter of bacteria in composting bioaerosols this study used an Electrical Low Pressure Impactor for sampling and quantitative real-time PCR for quantification. Quantitative PCR results show that the size of bacteria peaked between 0.95 μm and 2.4 μm and that the geometric mean diameter of the bacteria was 1.3 μm. In addition, total microbial cells were counted by flow cytometry and revealed that these qPCR results corresponded to single whole bacteria. Finally, the enumeration of cultivable thermophilic microorganisms allowed us to set the upper size limit for fragments at an aerodynamic diameter of ∼0.3 μm. Particle-size distributions of microbial groups previously used to monitor composting bioaerosols were also investigated. In collected the bioaerosols, the aerodynamic diameter of the actinomycetes Saccharopolyspora rectivirgula-and-relatives and also of the fungus Aspergillus fumigatus, appeared to be consistent with a majority of individual cells. Together, this study provides the first culture-independent data on particle-size distribution of composting bioaerosols and reveals that airborne single bacteria were emitted predominantly from open-air composting facilities.

Influence of zeolite and superphosphate as additives on antibiotic resistance genes and bacterial communities during factory-scale chicken manure composting.

PubMed

Peng, Shuang; Li, Huijie; Song, Dan; Lin, Xiangui; Wang, Yiming

2018-04-30

Factory-scale chicken manure composting added with zeolite (F), superphosphate (G), or zeolite and ferrous sulfate (FL) simultaneously, were evaluate for their effects on the behaviors of antibiotic resistance genes (ARGs) and bacterial communities. After composting, ARGs in manure decreased by 67.3% in the control, whereas the reductions were 86.5%, 68.6% and 72.2% in F, G and FL, respectively. ARGs encoding ribosomal protection proteins (tetO, tetB(P), and tetM) were reduced to a greater extent than tetG, tetL, sul1 and sul2. Bacteria pathogens were also effectively removed by composting. Network analysis showed that Firmicutes were the important potential host bacteria for ARGs. The bacterial communities and environmental factors, as well as the intI gene, contributed significantly to the variation of ARGs. The ARGs and integrons were reduced more when zeolite was added than when superphosphate was added; thus, it may be useful for reducing the risks of ARGs in chicken manure. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparison of U.S. Environmental Protection Agency and U.S. Composting Council... Escherichia coli O157:H7 in finished compost

USDA-ARS?s Scientific Manuscript database

Composting management or conditions that result in inadequate exposure of the compostable materials to destructive time-temperature regimens can result in survival of enteric human pathogens. Bacterial pathogens, such as Escherichia coli O157:H7 and Salmonella spp., can regrow in finished compost. ...

Effect of enzyme secreting bacterial pretreatment on enhancement of aerobic digestion potential of waste activated sludge interceded through EDTA.

PubMed

Kavitha, S; Adish Kumar, S; Yogalakshmi, K N; Kaliappan, S; Rajesh Banu, J

2013-12-01

In this study, the effect of Ethylene diamine tetra acetic acid (EDTA) on Extracellular polymeric substance (EPS) removal tailed with bacterial enzymatic pretreatment on aerobic digestion of activated sludge was studied. In order to enhance the accessibility of sludge to the enzyme secreting bacteria; the extracellular polymeric substances were removed using EDTA. EDTA efficiently removed the EPS with limited cell lysis and enhanced the sludge enzyme activity at its lower concentration of 0.2 g/g SS. The sludge was then subjected to bacterial pretreatment to enhance the aerobic digestion. In aerobic digestion the best results in terms of Suspended solids (SS) reduction (48.5%) and COD (Chemical oxygen demand) solubilization (47.3%) was obtained in experimental reactor than in control. These results imply that aerobic digestion can be enhanced efficiently through bacterial pretreatment of EPS removed sludge. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bacterial community dynamics in long-term operation of a pilot plant using aerobic granular sludge to treat pig slurry.

PubMed

Fra-Vázquez, A; Morales, N; Figueroa, M; Val Del Río, A; Regueiro, L; Campos, J L; Mosquera-Corral, A

2016-09-01

Aerobic granular sludge represents an interesting approach for simultaneous organic matter and nitrogen removal in wastewater treatment plants. However, the information about microbial communities in aerobic granular systems dealing with industrial wastewater like pig slurry is limited. Herein, bacterial diversity and dynamics were assessed in a pilot scale plant using aerobic granular sludge for organic matter and nitrogen elimination from swine slurry during more than 300 days. Results indicated that bacterial composition evolved throughout the operational period from flocculent activated sludge, used as inoculum, to mature aerobic granules. Bacterial diversity increased at the beginning of the granulation process and then declined due to the application of transient organic matter and nitrogen loads. The operational conditions of the pilot plant and the degree of granulation determined the microbial community of the aerobic granules. Brachymonas, Zoogloea and Thauera were attributed with structural function as they are able to produce extracellular polymeric substances to maintain the granular structure. Nitrogen removal was justified by partial nitrification (Nitrosomonas) and denitrification (Thauera and Zoogloea), while Comamonas was identified as the main organic matter oxidizing bacteria. Overall, clear links between bacterial dynamics and composition with process performance were found and will help to predict their biological functions in wastewater ecosystems improving the future control of the process. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1212-1221, 2016. © 2016 American Institute of Chemical Engineers.

Determination of reaction rates and activation energy in aerobic composting processes for yard waste.

PubMed

Uma, R N; Manjula, G; Meenambal, T

2007-04-01

The reaction rates and activation energy in aerobic composting processes for yard waste were determined using specifically designed reactors. Different mixture ratios were fixed before the commencement of the process. The C/N ratio was found to be optimum for a mixture ratio of 1:6 containing one part of coir pith to six parts of other waste which included yard waste, yeast sludge, poultry yard waste and decomposing culture (Pleurotosis). The path of stabilization of the wastes was continuously monitored by observing various parameters such as temperature, pH, Electrical Conductivity, C.O.D, VS at regular time intervals. Kinetic analysis was done to determine the reaction rates and activation energy for the optimum mixture ratio under forced aeration condition. The results of the analysis clearly indicated that the temperature dependence of the reaction rates followed the Arrhenius equation. The temperature coefficients were also determined. The degradation of the organic fraction of the yard waste could be predicted using first order reaction model.

Influence of aeration on CH4, N2O and NH3 emissions during aerobic composting of a chicken manure and high C/N waste mixture.

PubMed

Shen, Yujun; Ren, Limei; Li, Guoxue; Chen, Tongbin; Guo, Rui

2011-01-01

Co-composting of chicken manure, straw and dry grasses was investigated in a forced aeration system to estimate the effect of aeration rates on NH(3), CH(4) and N(2)O emissions and compost quality. Continuous measurements of gas emissions were carried out and detailed gas emission patterns were obtained using an intermittent-aeration of 30 min on/30 min off at rates of 0.01 (A1), 0.1 (A2) and 0.2 (A3) m(3)min(-1)m(-3). Concentrations of CH(4) and N(2)O at the low aeration rate (A1) were significantly greater than those at the other two rates, but there was no significant difference between the A2 and A3 treatments. CH(4) and N(2)O emissions for this mixture could be controlled when the composting process was aerobic and ammonia emissions were reduced at a lower aeration rate. Comparison of CH(4), N(2)O, NH(3) emissions and compost quality showed that the aeration rate of the A2 treatment was superior to the other two aeration rates. Copyright © 2010 Elsevier Ltd. All rights reserved.

Devitalization of bacterial and parasitic germs in sewage sludge during aerobic digestion under laboratory conditions.

PubMed

Juris, P; Plachý, P; Lauková, A

1995-05-01

The survival of 8 bacterial species (Pseudomonas sp., Salmonella sp., Enterobacteriae, Streptococcus sp., Escherichia coli) was detected in municipal sewage sludge up to 37 hours of mesophilic aerobic digestion under laboratory conditions. The model strain Enterococcus faecium CCM 4231 survived almost twice as long as the above-mentioned isolates. Similar findings, regarding the viability of the microorganisms studied, were also determined during thermophilic aerobic digestion of municipal sewage sludges. The final reduction in the total count of bacteria was not directly dependent on the temperature during aerobic digestion. It may be supposed that E. faecium CCM 4231 strain as a bacteriocin-producing strain with a broad antimicrobial spectrum, inoculated into the sludges, could inhibit the growth of microorganisms in the sludges by the way of its bacteriocin activity. Studying the effect of aerobic digestion on the viability of helminth eggs, the observed negative effect of higher temperatures was more expressive in comparison with bacterial strains. During thermophilic digestion process all helminth eggs (Ascaris suum, Toxocara canis) were devitalized. All eggs of T. canis were killed in experiments under mesophilic temperature. However, 32% of nonembryonated A. suum eggs remained viable.

Characterisation of source-separated household waste intended for composting

PubMed Central

Sundberg, Cecilia; Franke-Whittle, Ingrid H.; Kauppi, Sari; Yu, Dan; Romantschuk, Martin; Insam, Heribert; Jönsson, Håkan

2011-01-01

Large-scale composting of source-separated household waste has expanded in recent years in the Nordic countries. One problem can be low pH at the start of the process. Incoming biowaste at four composting plants was characterised chemically, physically and microbiologically. The pH of food waste ranged from 4.7 to 6.1 and organic acid concentration from 24 to 81 mmol kg−1. The bacterial diversity in the waste samples was high, with all samples dominated by Gammaproteobacteria, particularly Pseudomonas and Enterobacteria (Escherichia coli, Klebsiella, Enterobacter). Lactic acid bacteria were also numerically important and are known to negatively affect the composting process because the lactic acid they produce lowers the pH, inhibiting other bacteria. The bacterial groups needed for efficient composting, i.e. Bacillales and Actinobacteria, were present in appreciable amounts. The results indicated that start-up problems in the composting process can be prevented by recycling bulk material and compost. PMID:21075618

Characterisation of source-separated household waste intended for composting.

PubMed

Sundberg, Cecilia; Franke-Whittle, Ingrid H; Kauppi, Sari; Yu, Dan; Romantschuk, Martin; Insam, Heribert; Jönsson, Håkan

2011-02-01

Large-scale composting of source-separated household waste has expanded in recent years in the Nordic countries. One problem can be low pH at the start of the process. Incoming biowaste at four composting plants was characterised chemically, physically and microbiologically. The pH of food waste ranged from 4.7 to 6.1 and organic acid concentration from 24 to 81 mmol kg(-1). The bacterial diversity in the waste samples was high, with all samples dominated by Gammaproteobacteria, particularly Pseudomonas and Enterobacteria (Escherichia coli, Klebsiella, Enterobacter). Lactic acid bacteria were also numerically important and are known to negatively affect the composting process because the lactic acid they produce lowers the pH, inhibiting other bacteria. The bacterial groups needed for efficient composting, i.e. Bacillales and Actinobacteria, were present in appreciable amounts. The results indicated that start-up problems in the composting process can be prevented by recycling bulk material and compost. Copyright © 2010 Elsevier Ltd. All rights reserved.

Evaluation of an aerobic composting process for the management of Specified Risk Materials (SRM).

PubMed

Zeng, J; Price, G W; Arnold, P

2012-06-15

In Nova Scotia (NS), approximately 2700 tonnes of Specified Risk Materials (SRM) are produced annually. SRM disposal is a serious concern for abattoirs and the beef industry. Composting offers a low risk and simple means to transform raw SRM into a more stable and easily managed material. In this project, wheat straw and sawdust were used to compost with SRM on a pilot scale. The study evaluated changes over time in total carbon, total nitrogen, pH, temperature, moisture content and electrical conductivity. Compost temperatures in all treatments met the Canadian Council of Ministers of the Environment (CCME) guidelines for pathogen kill. The compost maturity tests showed that the evolution of CO(2)-C in all the final compost products was less than 1 mg g(-1) organic matter day(-1). Wheat straw performed well as a composting feedstock for raw SRM as sawdust. While the wheat straw has advantages including greater availability, lower cost and easily decomposable carbon compounds more management is required to maintain adequate compost temperatures. The influences of seasonal variations due to temperate climatic conditions on SRM composting were also studied with wheat straw. The results suggest no significant differences in composting effectiveness between the two seasons. Copyright © 2012 Elsevier B.V. All rights reserved.

Autoheated thermophilic aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deeny, K.; Hahn, H.; Leonhard, D.

1991-10-01

Autothermal thermophilic aerobic digestion (ATAD) is first and foremost a digestion process, the primary purpose of which is to decompose a portion of the waste organic solids generated from wastewater treatment. As a result of the high operating temperature, digestion is expected to occur within a short time period (6 days) and accomplish a high degree of pathogen reduction. ATAD systems are two-stage aerobic digestion processes that operate under thermophilic temperature conditions (40 to 80C) without supplemental heat. Like composting, the systems rely on the conservation of heat released during digestion itself to attain and sustain the desired operating temperature.more » Typical ATAD systems operate at 55C and may reach temperatures of 60 to 65C in the second-stage reactor. Perhaps because of the high operating temperature, this process has been referred to as Liquid Composting.' Major advantages associated with thermophilic operation include high biological reaction rates and a substantial degree of pathogen reduction.« less

Effect of spent mushroom substrate as a bulking agent on gaseous emissions and compost quality during pig manure composting.

PubMed

Li, Shuyan; Li, Danyang; Li, Jijin; Li, Yangyang; Li, Guoxue; Zang, Bing; Li, Yun

2018-05-01

The aim of this study was to investigate the gaseous emissions (CH 4 , N 2 O, and NH 3 ) and compost quality during the pig manure composting by adding spent mushroom substrate (SMS) as a bulking agent. The control treatment was also studied using corn stalk (CS) as a bulking agent. The experiment was conducted in a pilot scale composting reactor under aerobic condition with the initial C/N ratio of 20. Results showed that bulking agents significantly affected gaseous emissions and compost quality. Using SMS as a bulking agent improved composting efficiency by shortening the time for maturity. SMS increased germination index and humic acid of the final compost (by 13.44 and 41.94%, respectively) compared with CS. Furthermore, composting with SMS as a bulking agent could reduce nitrogen loss, NH 3 , and N 2 O emissions (by 13.57, 35.56, and 46.48%, respectively) compared with the control. SMS slightly increased CH 4 emission about 1.1 times of the CS. However, a 33.95% decrease in the global warming potential of CH 4 and N 2 O was obtained by adding SMS treatment. These results indicate that SMS is a favorable bulking agent for reducing gaseous emissions and increasing compost quality.

Effects of phosphogypsum and superphosphate on compost maturity and gaseous emissions during kitchen waste composting.

PubMed

Yang, Fan; Li, Guoxue; Shi, Hong; Wang, Yiming

2015-02-01

This study investigated the effects of phosphogypsum and superphosphate on the maturity and gaseous emissions of composting kitchen waste. Two amended compost treatments were conducted using phosphogypsum and superphosphate as additives with the addition of 10% of initial raw materials (dry weight). A control treatment was also studied. The treatments were conducted under aerobic conditions in 60-L reactors for 35 days. Maturity indexes were determined, and continuous measurements of CH4, N2O, and NH3 were taken. Phosphogypsum and superphosphate had no negative effects on compost maturity, although superphosphate inhibited the temperature rise in the first few days. The addition of phosphogypsum and superphosphate drastically reduced CH4 emissions (by 85.8% and 80.5%, respectively) and decreased NH3 emissions (by 23.5% and 18.9%, respectively). However, a slight increase in N2O emissions (by 3.2% and 14.8%, respectively) was observed. Composting with phosphogypsum and superphosphate reduced total greenhouse gas emissions by 17.4% and 7.3% respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Relationships between stability, maturity, water-extractable organic matter of municipal sewage sludge composts and soil functionality.

PubMed

Sciubba, Luigi; Cavani, Luciano; Grigatti, Marco; Ciavatta, Claudio; Marzadori, Claudio

2015-09-01

Compost capability of restoring or enhancing soil quality depends on several parameters, such as soil characteristics, compost carbon, nitrogen and other nutrient content, heavy metal occurrence, stability and maturity. This study investigated the possibility of relating compost stability and maturity to water-extractable organic matter (WEOM) properties and amendment effect on soil quality. Three composts from municipal sewage sludge and rice husk (AN, from anaerobic wastewater treatment plants; AE, from aerobic ones; MIX, from both anaerobic and aerobic ones) have been analysed and compared to a traditional green waste compost (GM, from green manure, solid waste and urban sewage sludge). To this aim, WEOMs were characterized through chemical analysis; furthermore, compost stability was evaluated through oxygen uptake rate calculation and maturity was estimated through germination index determination, whereas compost impact on soil fertility was studied, in a lab-scale experiment, through indicators as inorganic nitrogen release, soil microbial biomass carbon, basal respiration rate and fluorescein di-acetate hydrolysis. The obtained results indicated that WEOM characterization could be useful to investigate compost stability (which is related to protein and phenol concentrations) and maturity (related to nitrate/ammonium ratio and degree of aromaticity) and then compost impact on soil functionality. Indeed, compost stability resulted inversely related to soil microbial biomass, basal respiration rate and fluorescein di-acetate hydrolysis when the products were applied to the soil.

Assessment of compost maturity by using an electronic nose.

PubMed

López, Rafael; Giráldez, Inmaculada; Palma, Alberto; Jesús Díaz, M

2016-02-01

The composting process produces and emits hundreds of different gases. Volatile organic compounds (VOCs) can provide information about progress of composting process. This paper is focused on the qualitative and quantitative relationships between compost age, as sign of compost maturity, electronic-nose (e-nose) patterns and composition of compost and composting gas at an industrial scale plant. Gas and compost samples were taken at different depths from composting windrows of different ages. Temperature, classical chemical parameters, O2, CO, combustible gases, VOCs and e-nose profiles were determined and related using principal component analysis (PCA). Factor analysis carried out to a data set including compost physical-chemical properties, pile pore gas composition and composting time led to few factors, each one grouping together standard composting parameters in an easy to understand way. PCA obtained from e-nose profiles allowed the classifying of piles, their aerobic-anaerobic condition, and a rough estimation of the composting time. That would allow for immediate and in-situ assessment of compost quality and maturity by using an on-line e-nose. The e-nose patterns required only 3-4 sensor signals to account for a great percentage (97-98%) of data variance. The achieved patterns both from compost (chemical analysis) and gas (e-nose analysis) samples are robust despite the high variability in feedstock characteristics (3 different materials), composting conditions and long composting time. GC-MS chromatograms supported the patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effects of apple pomace, bentonite and calcium superphosphate on swine manure aerobic composting.

PubMed

Jiang, Jishao; Huang, Yimei; Liu, Xueling; Huang, Hua

2014-09-01

The effects of additives such as apple pomace, bentonite and calcium superphosphate on swine manure composting were investigated in a self-built aerated static box (90 L) by assessing their influences on the transformation of nitrogen, carbon, phosphorous and compost maturity. The results showed that additives all prolonged the thermophilic stage in composting compared to control. Nitrogen losses amounted to 34-58% of the initial nitrogen, in which ammonia volatilization accounted for 0.3-4.6%. Calcium superphosphate was helpful in facilitating composting process as it significantly reduced the ammonia volatilization during thermophilic stage and increased the contents of total nitrogen and phosphorous in compost, but bentonite increased the ammonia volatilization and reduced the total nitrogen concentration. It suggested that calcium superphosphate is an effective additive for keeping nitrogen during swine manure composting. Copyright © 2014 Elsevier Ltd. All rights reserved.

New evidence for Cu-decorated binary-oxides mediating bacterial inactivation/mineralization in aerobic media.

PubMed

Rtimi, S; Pulgarin, C; Bensimon, M; Kiwi, J

2016-08-01

Binary oxide semiconductors TiO2-ZrO2 and Cu-decorated TiO2-ZrO2 (TiO2-ZrO2-Cu) uniform films were sputtered on polyester (PES). These films were irradiated under low intensity solar simulated light and led to bacterial inactivation in aerobic and anaerobic media as evaluated by CFU-plate counting. But bacterial mineralization was only induced by TiO2-ZrO2-Cu in aerobic media. The highly oxidative radicals generated on the films surface under light were identified by the use of appropriate scavengers. The hole generated on the TiO2-ZrO2 films is shown to be the main specie leading to bacterial inactivation. TiO2-ZrO2 and Cu-decorated TiO2-ZrO2 films release Zr and Ti <1ppb and Cu 4.6ppb/cm(2) as determined by inductively coupled plasma mass spectrometry (ICP-MS) This level is far below the citotoxicity permitted level allowed for mammalian cells suggesting that bacterial disinfection proceeds through an oligodynamic effect. By Fourier transform attenuated infrared spectroscopy (ATR-FTIR) the systematic shift of the predominating νs(CH2) vibrational-rotational peak making up most of the bacterial cell-wall content in C was monitored. Based on this evidence a mechanism suggested leading to CH bond stretching followed by cell lysis and cell death. Bacterial inactivation cycling was observed on TiO2-ZrO2-Cu showing the stability of these films leading to bacterial inactivation. Copyright © 2016 Elsevier B.V. All rights reserved.

Emission of bacterial bioaerosols from a composting facility in Maharashtra, India.

PubMed

Pahari, Arnab Kumar; Dasgupta, Debdeep; Patil, Rashmi S; Mukherji, Suparna

2016-07-01

This study was undertaken to quantify and characterize size-segregated bacterial bioaerosols both on-site and off-site of a waste treatment facility (WTF) in Maharashtra employing windrow composting. Viable bacterial bioaerosols on nutrient agar (NA) and actinomycetes isolation agar (AIA) were quantified after sampling using Anderson-six stage impactor. Viable bacterial bioaerosols were identified based on 16S rDNA sequencing. Approximately, 16-34% of the total viable bacteria collected at the WTF were in the size range 0.65-2.1μm that can penetrate deep into the respiratory tract and also represents bacteria present in free form. Thus, 66-84% of bacterial bioaerosols were associated with coarse airborne particles greater than 2.1μm. A total of 24 bacterial species were isolated and characterized through gram staining. Among these 25% were gram negative and 75% were gram positive. The predominant bacterial genera were Bacillus, Streptococcus, Staphylococcus, Acinetobacter and Kocuria. The mean on-site concentration of total viable bacteria on NA and AIA and airborne particles (PM2.5 and PM10) were higher than the corresponding off-site values. The mean on-site concentration of viable bacteria on NA and AIA were in the range of 3.8×10(3) to 5.4×10(4)CFU/m(3) and 9.8×10(3) to 1.2×10(5)CFU/m(3), respectively, during activity period. Good correlation (R(2)=0.999) was observed between total bioaerosols and aerosols (PM10) collected using Anderson impactor and High volume sampler, respectively. Sampling size segregated aerosols using the Siotus personal cascade impactor indicated higher association of bacteria with the coarse fraction (greater than 2.5μm). Copyright © 2016 Elsevier Ltd. All rights reserved.

Succession and diversity of microorganisms and their association with physicochemical properties during green waste thermophilic composting.

PubMed

Liu, Ling; Wang, Shuqi; Guo, Xiaoping; Zhao, Tingning; Zhang, Bolin

2018-03-01

A comprehensive characterization of the bacterial diversity associated to thermophilic stages of green waste composting was achieved. In this study, eight different treatments (T1-T8) and three replicated lab-scale green waste composting were carried out to compare the effect of the cellulase (i.e. 0, 2%), microbial inoculum (i.e. 0, 2 and 4%) and particle size (i.e. 2 and 5 mm) on bacterial community structure. Physicochemical properties and bacterial communities of T1-T8 composts were observed, and the bacterial structure and diversity were examined by high-throughput sequencing via a MiSeq platform. The results showed that the most abundant phyla among the treatments were the Firmicutes, Chloroflexi and Proteobacteria. The shannon index and non-metric multidimensional scaling (NMDS) showed higher bacterial abundance and diversity at the metaphase of composting. Comparing with 5-mm treatments, particle size of 2-mm had a richer diversity of bacterial communities. The addition of cellulase and a microbial inoculum could promote the fermentation temperature, reduce the compost pH and C/N ratio and result in higher GI index. The humic substance (HS) and humic acid (HA) contents for 2-mm particle size treatments were higher than those of 5-mm treatments. Canonical correspondence analysis suggested that differences in bacterial abundance and diversity significantly correlated with HA, E 4 /E 6 and temperature, and the relationship between bacterial diversity and environmental parameters was affected by composting stages. Based on these results, the application of cellulase to promote green waste composting was feasible, and particle size was identified as a potential control of composting physicochemical properties and bacterial diversity. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of composting on the persistence of four ionophores in dairy manure and poultry litter

USDA-ARS?s Scientific Manuscript database

Manure composting is a well-described approach for stabilization of nutrients and reduction of pathogens and odors. Although composting studies have shown that thermophilic temperatures and aerobic conditions can increase removal rates of selected antibiotics, comparable information is lacking for ...

Vaginal Microbiomes Associated With Aerobic Vaginitis and Bacterial Vaginosis.

PubMed

Kaambo, Evelyn; Africa, Charlene; Chambuso, Ramadhani; Passmore, Jo-Ann Shelley

2018-01-01

A healthy vaginal microbiota is considered to be significant for maintaining vaginal health and preventing infections. However, certain vaginal bacterial commensal species serve an important first line of defense of the body. Any disruption of this microbial barrier might result in a number of urogenital conditions including aerobic vaginitis (AV) and bacterial vaginosis (BV). The health of the vagina is closely associated with inhabitant microbiota. Furthermore, these microbes maintain a low vaginal pH, prevent the acquisition of pathogens, stimulate or moderate the local innate immune system, and further protect against complications during pregnancies. Therefore, this review will focus on vaginal microbial "health" in the lower reproductive tract of women and on the physiological characteristics that determine the well-being of reproductive health. In addition, we explore the distinct versus shared characteristics of BV and AV, which are commonly associated with increased risk for preterm delivery.

Vaginal Microbiomes Associated With Aerobic Vaginitis and Bacterial Vaginosis

PubMed Central

Kaambo, Evelyn; Africa, Charlene; Chambuso, Ramadhani; Passmore, Jo-Ann Shelley

2018-01-01

A healthy vaginal microbiota is considered to be significant for maintaining vaginal health and preventing infections. However, certain vaginal bacterial commensal species serve an important first line of defense of the body. Any disruption of this microbial barrier might result in a number of urogenital conditions including aerobic vaginitis (AV) and bacterial vaginosis (BV). The health of the vagina is closely associated with inhabitant microbiota. Furthermore, these microbes maintain a low vaginal pH, prevent the acquisition of pathogens, stimulate or moderate the local innate immune system, and further protect against complications during pregnancies. Therefore, this review will focus on vaginal microbial “health” in the lower reproductive tract of women and on the physiological characteristics that determine the well-being of reproductive health. In addition, we explore the distinct versus shared characteristics of BV and AV, which are commonly associated with increased risk for preterm delivery. PMID:29632854

Effect of Co-Composting Cattle Manure with Construction and Demolition Waste on the Archaeal, Bacterial, and Fungal Microbiota, and on Antimicrobial Resistance Determinants

PubMed Central

Holman, Devin B.; Hao, Xiying; Topp, Edward; Yang, Hee Eun; Alexander, Trevor W.

2016-01-01

Agricultural operations generate large quantities of manure which must be eliminated in a manner that is consistent with public health guidelines. Meanwhile, construction and demolition waste makes up about 25% of total solid municipal waste. Co-composting of manure with construction and demolition waste offers a potential means to make manure safe for soil amendment and also divert construction and demolition waste from municipal landfills. Therefore, the archaeal, bacterial, and fungal microbiota of two different types of composted cattle manure and one co-composted with construction and demolition waste, were assessed over a 99-day composting period. The microbiota of the three compost mixtures did not differ, but significant changes over time and by sampling depth were observed. Bacillus and Halocella, however, were more relatively abundant in composted manure from cattle fed dried distillers’ grains and solubles. Proteobacteria and Bacteroidetes were enriched at day 0 and Firmicutes at day 99. The fungal genus Kernia was the most relatively abundant overall and was enriched at day 0. The concentration of 12 antimicrobial resistance determinants in the compost mixtures was also determined, and 10 of these determinants decreased significantly from days 0 to 99. The addition of construction and demolition waste did not affect the persistence of antimicrobial resistance genes or community structure of the compost microbiota and therefore co-composting construction and demolition waste with cattle manure offers a safe, viable way to divert this waste from landfills. PMID:27300323

Effect of Co-Composting Cattle Manure with Construction and Demolition Waste on the Archaeal, Bacterial, and Fungal Microbiota, and on Antimicrobial Resistance Determinants.

PubMed

Holman, Devin B; Hao, Xiying; Topp, Edward; Yang, Hee Eun; Alexander, Trevor W

2016-01-01

Agricultural operations generate large quantities of manure which must be eliminated in a manner that is consistent with public health guidelines. Meanwhile, construction and demolition waste makes up about 25% of total solid municipal waste. Co-composting of manure with construction and demolition waste offers a potential means to make manure safe for soil amendment and also divert construction and demolition waste from municipal landfills. Therefore, the archaeal, bacterial, and fungal microbiota of two different types of composted cattle manure and one co-composted with construction and demolition waste, were assessed over a 99-day composting period. The microbiota of the three compost mixtures did not differ, but significant changes over time and by sampling depth were observed. Bacillus and Halocella, however, were more relatively abundant in composted manure from cattle fed dried distillers' grains and solubles. Proteobacteria and Bacteroidetes were enriched at day 0 and Firmicutes at day 99. The fungal genus Kernia was the most relatively abundant overall and was enriched at day 0. The concentration of 12 antimicrobial resistance determinants in the compost mixtures was also determined, and 10 of these determinants decreased significantly from days 0 to 99. The addition of construction and demolition waste did not affect the persistence of antimicrobial resistance genes or community structure of the compost microbiota and therefore co-composting construction and demolition waste with cattle manure offers a safe, viable way to divert this waste from landfills.

Identification of thermophilic bacterial strains producing thermotolerant hydrolytic enzymes from manure compost.

PubMed

Charbonneau, David M; Meddeb-Mouelhi, Fatma; Boissinot, Maurice; Sirois, Marc; Beauregard, Marc

2012-03-01

Ten thermophilic bacterial strains were isolated from manure compost. Phylogenetic analysis based on 16S rRNA genes and biochemical characterization allowed identification of four different species belonging to four genera: Geobacillus thermodenitrificans, Bacillus smithii, Ureibacillus suwonensis and Aneurinibacillus thermoaerophilus. PCR-RFLP profiles of the 16S-ITS-23S rRNA region allowed us to distinguish two subgroups among the G. thermodenitrificans isolates. Isolates were screened for thermotolerant hydrolytic activities (60-65°C). Thermotolerant lipolytic activities were detected for G. thermodenitrificans, A. thermoaerophilus and B. smithii. Thermotolerant protease, α-amylase and xylanase activities were also observed in the G. thermodenitrificans group. These species represent a source of potential novel thermostable enzymes for industrial applications.

The distribution of active β-glucosidase-producing microbial communities in composting.

PubMed

Zang, Xiangyun; Liu, Meiting; Wang, Han; Fan, Yihong; Zhang, Haichang; Liu, Jiawen; Xing, Enlu; Xu, Xiuhong; Li, Hongtao

2017-12-01

The composting ecosystem is a suitable source for the discovery of novel microorganisms and secondary metabolites. Cellulose degradation is an important part of the global carbon cycle, and β-glucosidases complete the final step of cellulose hydrolysis by converting cellobiose to glucose. This work analyzes the succession of β-glucosidase-producing microbial communities that persist throughout cattle manure - rice straw composting, and evaluates their metabolic activities and community advantage during the various phases of composting. Fungal and bacterial β-glucosidase genes belonging to glycoside hydrolase families 1 and 3 (GH1 and GH3) amplified from DNA were classified and gene abundance levels were analyzed. The major reservoirs of β-glucosidase genes were the fungal phylum Ascomycota and the bacterial phyla Firmicutes, Actinobacteria, Proteobacteria, and Deinococcus-Thermus. This indicates that a diverse microbial community utilizes cellobiose. The succession of dominant bacteria was also detected during composting. Firmicutes was the dominant bacteria in the thermophilic phase of composting; there was a shift to Actinomycetes in the maturing stage. Proteobacteria accounted for the highest proportions during the heating and thermophilic phases of composting. By contrast, the fungal phylum Ascomycota was a minor microbial community constituent in thermophilic phase of composting. Combined with the analysis of the temperature, cellulose degradation rate and the carboxymethyl cellulase and β-glucosidase activities showed that the bacterial GH1 family β-glucosidase genes make greater contribution in cellulose degradation at the later thermophilic stage of composting. In summary, even GH1 bacteria families β-glucosidase genes showing low abundance in DNA may be functionally important in the later thermophilic phase of composting. The results indicate that a complex community of bacteria and fungi expresses β-glucosidases in compost. Several �

Effects of superabsorbent polymers on the abundances of antibiotic resistance genes, mobile genetic elements, and the bacterial community during swine manure composting.

PubMed

Guo, Aiyun; Gu, Jie; Wang, Xiaojuan; Zhang, Ranran; Yin, Yanan; Sun, Wei; Tuo, Xiaxia; Zhang, Li

2017-11-01

Superabsorbent polymers (SAPs) are considered suitable amendments for reducing the selection pressure due to heavy metals and the abundances of antibiotic resistance genes (ARGs) during composting. In this study, three SAP (sodium polyacrylate) levels (0, 5, and 15mgkg -1 of compost) were applied and their effects on the abundances of ARGs, mobile genetic elements (MGEs), and the bacterial community were investigated. After composting, the abundances of ARGs and MGEs decreased to different extent, where the removal efficiencies for tetW, dfrA7, ermX, aac(6')-ib-cr and MGEs exceeded 90%. The high SAP concentration significantly reduced the abundances of ARGs and MGEs, and changed the microbial community. Redundancy analysis indicated that the moisture content mainly explained the changes in ARGs and MGEs. Network analysis determined the potential hosts of ARGs and MGEs, and their co-occurrence. The results suggested that applying 15mgkg -1 SAP is appropriate for reducing ARGs in compost. Copyright © 2017. Published by Elsevier Ltd.

Comparison of NOx Removal Efficiencies in Compost Based Biofilters Using Four Different Compost Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacey, Jeffrey Alan; Lee, Brady Douglas; Apel, William Arnold

2001-06-01

In 1998, 3.6 trillion kilowatt-hours of electricity were generated in the United States. Over half of this was from coal-fired power plants, resulting in more than 8.3 million tons of nitrogen oxide (NOx) compounds being released into the environment. Over 95% of the NOx compounds produced during coal combustion are in the form of nitric oxide (NO). NOx emission regulations are becoming increasingly stringent, leading to the need for new, cost effective NOx treatment technologies. Biofiltration is such a technology. NO removal efficiencies were compared in compost based biofilters using four different composts. In previous experiments, removal efficiencies were typicallymore » highest at the beginning of the experiment, and decreased as the experiments proceeded. This work tested different types of compost in an effort to find a compost that could maintain NO removal efficiencies comparable to those seen early in the previous experiments. One of the composts was wood based with manure, two were wood based with high nitrogen content sludge, and one was dairy compost. The wood based with manure and one of the wood based with sludge composts were taken directly from an active compost pile while the other two composts were received in retail packaging which had been out of active piles for an indeterminate amount of time. A high temperature (55-60°C) off-gas stream was treated in biofilters operated under denitrifying conditions. Biofilters were operated at an empty bed residence time of 13 seconds with target inlet NO concentrations of 500 ppmv. Lactate was the carbon and energy source. Compost was sampled at 10-day intervals to determine aerobic and anaerobic microbial densities. Compost was mixed at a 1:1 ratio with lava rock and calcite was added at 100g/kg of compost. In each compost tested, the highest removal efficiencies occurred within the first 10 days of the experiment. The wood based with manure peaked at day 3 (77.14%), the dairy compost at day 1 (80

Effects of phosphogypsum and superphosphate on compost maturity and gaseous emissions during kitchen waste composting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Fan; Beijing Municipal Research Institute of Environmental Protection, Beijing 100037; Li, Guoxue, E-mail: yangfan19870117@126.com

2015-02-15

Highlights: • Effect of phosphogypsum and superphosphate on composting gas emissions was studied. • The reduction mechanisms of composting gas were clarified in this study. • No negative effect was caused on maturity with phosphogypsum and superphosphate. • CH{sub 4} and NH{sub 3} emission was decreased with phosphogypsum and superphosphate addition. • GHG decreased by 17.4% and 7.3% with phosphogypsum and superphosphate addition. - Abstract: This study investigated the effects of phosphogypsum and superphosphate on the maturity and gaseous emissions of composting kitchen waste. Two amended compost treatments were conducted using phosphogypsum and superphosphate as additives with the addition ofmore » 10% of initial raw materials (dry weight). A control treatment was also studied. The treatments were conducted under aerobic conditions in 60-L reactors for 35 days. Maturity indexes were determined, and continuous measurements of CH{sub 4}, N{sub 2}O, and NH{sub 3} were taken. Phosphogypsum and superphosphate had no negative effects on compost maturity, although superphosphate inhibited the temperature rise in the first few days. The addition of phosphogypsum and superphosphate drastically reduced CH{sub 4} emissions (by 85.8% and 80.5%, respectively) and decreased NH{sub 3} emissions (by 23.5% and 18.9%, respectively). However, a slight increase in N{sub 2}O emissions (by 3.2% and 14.8%, respectively) was observed. Composting with phosphogypsum and superphosphate reduced total greenhouse gas emissions by 17.4% and 7.3% respectively.« less

Escherichia coli removal in biochar-augmented biofilter: effect of infiltration rate, initial bacterial concentration, biochar particle size, and presence of compost.

PubMed

Mohanty, Sanjay K; Boehm, Alexandria B

2014-10-07

Bioretention systems and biofilters are used in low impact development to passively treat urban stormwater. However, these engineered natural systems are not efficient at removing fecal indicator bacteria, the contaminants responsible for a majority of surface water impairments. The present study investigates the efficacy of biochar-augmented model sand biofilters for Escherichia coli removal under a variety of stormwater bacterial concentrations and infiltration rates. Additionally, we test the role of biochar particle size and "presence of compost on model" biofilter performance. Our results show that E. coli removal in a biochar-augmented sand biofilter is ∼ 96% and is not greatly affected by increases in stormwater infiltration rates and influent bacterial concentrations, particularly within the ranges expected in field. Removal of fine (<125 μm) biochar particles from the biochar-sand biofilter decreased the removal capacity from 95% to 62%, indicating biochar size is important. Addition of compost to biochar-sand biofilters not only lowered E. coli removal capacity but also increased the mobilization of deposited bacteria during intermittent infiltration. This result is attributed to exhaustion of attachment sites on biochar by the dissolved organic carbon leached from compost. Overall, our study indicates that biochar has potential to remove bacteria from stormwater under a wide range of field conditions, but for biochar to be effective, the size should be small and biochar should be applied without compost. Although the results aid in the optimization of biofilter design, further studies are needed to examine biochar potential in the field over an entire rainy season.

Effects of biochar amendment on bacterial and fungal diversity for co-composting of gelatin industry sludge mixed with organic fraction of municipal solid waste.

PubMed

Awasthi, Mukesh Kumar; Li, Jiao; Kumar, Sunil; Awasthi, Sanjeev Kumar; Wang, Quan; Chen, Hongyu; Wang, Meijing; Ren, Xiuna; Zhang, Zengqiang

2017-12-01

The aim of the study was to evaluate the bacterial and fungal diversities of 18contrastivecomposts applied with 17 different sources mad biochars applied treatments using 16S rRNA and 18S rDNA technology, while T-1 used as a control. The results showed that bacterial species of the phyla Actinobacteria, Proteobacteria and Chloroflexi, and fungi of the phylum Ascomycota and Basidiomycota were pre-dominant among the all treatments. The bacterial genus Subgroup_6_norank, Nocardioides, Pseudonocardia, Sphingomonas, Solirubrobacter and RB41_norank are first time identified in composting ecosystem. In addition, the fungal genus Ascomycota_unclassified, Aspergillus, Penicillium, Pleosporales_unclassified and Herpotrichlellacease_unclassified ubiquitous among the all compost. The Shannon and refraction-curve biodiversity indices showed a clear heterogeneity among all the treatments, which could be due to isolation of new genera in this system. Finally, the principal component analysis of the relative number of sequences also confirmed that bacterial and fungal population indiscriminate in different sources mad biochar applied treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerobic composting of digested residue eluted from dry methane fermentation to develop a zero-emission process.

PubMed

Huang, Yu-Lian; Sun, Zhao-Yong; Zhong, Xiao-Zhong; Wang, Ting-Ting; Tan, Li; Tang, Yue-Qin; Kida, Kenji

2017-03-01

Digested residue remained at the end of a process for the production of fuel ethanol and methane from kitchen garbage. To develop a zero-emission process, the compostability of the digested residue was assessed to obtain an added-value fertilizer. Composting of the digested residue by adding matured compost and a bulking agent was performed using a lab-scale composting reactor. The composting process showed that volatile total solid (VTS) degradation mainly occurred during the first 13days, and the highest VTS degradation efficiency was about 27% at the end. The raw material was not suitable as a fertilizer due to its high NH 4 + and volatile fatty acids (VFAs) concentration. However, the composting process produced remarkable results; the physicochemical properties indicated that highly matured compost was obtained within 62days of the composting process, and the final N concentration, NO 3 - concentration, and the germination index (GI) at the end of the composting process was 16.4gkg -1 -TS, 9.7gkg -1 -TS, and 151%, respectively. Real-time quantitative PCR (qPCR) analysis of ammonia oxidizers indicated that the occurrence of nitrification during the composting of digested residue was attributed to the activity of ammonia-oxidizing bacteria (AOB). Copyright © 2017 Elsevier Ltd. All rights reserved.

Bacterial survival and association with sludge flocs during aerobic and anaerobic digestion of wastewater sludge under laboratory conditions.

PubMed Central

Farrah, S R; Bitton, G

1983-01-01

The fate of indicator bacteria, a bacterial pathogen, and total aerobic bacteria during aerobic and anaerobic digestion of wastewater sludge under laboratory conditions was determined. Correlation coefficients were calculated between physical and chemical parameters (temperature, dissolved oxygen, pH, total solids, and volatile solids) and either the daily change in bacterial numbers or the percentage of bacteria in the supernatant. The major factor influencing survival of Salmonella typhimurium and indicator bacteria during aerobic digestion was the temperature of sludge digestion. At 28 degrees C with greater than 4 mg of dissolved oxygen per liter, the daily change in numbers of these bacteria was approximately -1.0 log10/ml. At 6 degrees C, the daily change was less than -0.3 log10/ml. Most of the bacteria were associated with the sludge flocs during aerobic digestion of sludge at 28 degrees C with greater than 2.4 mg of dissolved oxygen per liter. Lowering the temperature or the amount of dissolved oxygen decreased the fraction of bacteria associated with the flocs and increased the fraction found in the supernatant. PMID:6401978

Association between aerobic vaginitis, bacterial vaginosis and squamous intraepithelial lesion of low grade.

PubMed

Jahic, Mahira; Mulavdic, Mirsada; Hadzimehmedovic, Azra; Jahic, Elmir

2013-01-01

To determine frequency of HPV infection, aerobic vaginitis and bacterial vaginosis in respondents with squamous intraepithelial lesion of lower grade comparing to respondents with normal PAP test results. Prospective research of 100 respondents has been conducted at University-Clinic Center Tuzla and Gynecology and Obstetrics Department at Primary Health Care Center Tuzla in period from May 2011 untill January 2012. Examination program included: anamnesis, clinical gynecological examination, HPV typization, microbiological examination of vaginal and cervical smear and PAP test. High risk HPV group has been found more frequently among the respondents with LG SIL 46% (23) than in those with normal PAP result 14% (7) p < 0.05. Aerobic vaginitis has been found in the respondents with LG SIL in 28% (14) and there is statistically significant difference of this vaginitis comparing to the respondents with normal PAP result (p < 0.05). Bacterial vaginosis has been found in 12% (6) of the respondents with LG SIL and in 4% (2) of those with normal PAP result which is not statistically significant. In women with LG SIL and aerobic vaginitis in 9 cases E. coli has been isolated, in 4 E. faecalis and in 1 Staphylococcus aureus, while in women with normal PAP test results 3 cases of E.coli have been isolated. Examining changes in pH value of vaginal environment, higher measured values have been found in the respondents with LG SIL- 5.26 while in the respondents with normal PAP test result was 4.94 (p < 0.05). There is also statistically significant increase in the number of leukocytes in the respondents with LG SIL in relation to those with normal result. In women with LG SIL aerobic vaginitis is very common but is not an indicator of HPV infection. An adequate treatment of aerobic vaginitis would decrease the frequency of LG SIL and number of precancerous lesions which may

Accelerated In-vessel Composting for Household Waste

NASA Astrophysics Data System (ADS)

Bhave, Prashant P.; Joshi, Yadnyeshwar S.

2017-12-01

Composting at household level will serve as a viable solution in managing and treating the waste efficiently. The aim of study was to design and study household composting reactors which would treat the waste at source itself. Keeping this aim in mind, two complete mix type aerobic reactors were fabricated. A comparative study between manually operated and mechanically operated reactor was conducted which is the value addition aspect of present study as it gives an effective option of treatment saving the time and manpower. Reactors were loaded with raw vegetable waste and cooked food waste i.e. kitchen waste for a period of 30 days after which mulch was allowed to mature for 10 days. Mulch was analyzed for its C/N ratio, nitrate, phosphorous, potassium and other parameters to determine compost quality, every week during its period of operation. The results showed that compost obtained from both the reactors satisfied almost all compost quality criteria as per CPHEEO manual on municipal solid waste management and thus can be used as soil amendment to increase the fertility of soil.In terms of knowledge contribution, this study puts forth an effective way of decentralized treatment.

Composting oily sludges: Characterizing microflora using randomly amplified polymorphic DNA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Persson, A.; Quednau, M.; Ahrne, S.

1995-12-31

Laboratory-scale composts in which oily sludge was composted under mesophilic conditions with amendments such as peat, bark, and fresh or decomposed horse manure, were studied with respect to basic parameters such as oil degradation, respirometry, and bacterial numbers. Further, an attempt was made to characterize a part of the bacterial flora using randomly amplified polymorphic DNA (RAPD). The compost based on decomposed horse manure showed the greatest reduction of oil (85%). Comparison with a killed control indicated that microbial degradation actually had occurred. However, a substantial part of the oil was stabilized rather than totally broken down. Volatiles, on themore » contrary, accounted for a rather small percentage (5%) of the observed reduction. RAPD indicated that a selection had taken place and that the dominating microbial flora during the active degradation of oil were not the same as the ones dominating the different basic materials. The stabilized compost, on the other hand, had bacterial flora with similarities to the ones found in peat and bark.« less

Performance evaluation of an anaerobic/aerobic landfill-based digester using yard waste for energy and compost production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yazdani, Ramin, E-mail: ryazdani@sbcglobal.net; Civil and Environmental Engineering, University of California, One Shields Avenue, Ghausi Hall, Davis, CA 95616; Barlaz, Morton A., E-mail: barlaz@eos.ncsu.edu

2012-05-15

Highlights: Black-Right-Pointing-Pointer Biochemical methane potential decreased by 83% during the two-stage operation. Black-Right-Pointing-Pointer Net energy produced was 84.3 MWh or 46 kWh per million metric tons (Mg). Black-Right-Pointing-Pointer The average removal efficiency of volatile organic compounds (VOCs) was 96-99%. Black-Right-Pointing-Pointer The average removal efficiency of non-methane organic compounds (NMOCs) was 68-99%. Black-Right-Pointing-Pointer The two-stage batch digester proved to be simple to operate and cost-effective. - Abstract: The objective of this study was to evaluate a new alternative for yard waste management by constructing, operating and monitoring a landfill-based two-stage batch digester (anaerobic/aerobic) with the recovery of energy and compost. Themore » system was initially operated under anaerobic conditions for 366 days, after which the yard waste was aerated for an additional 191 days. Off gas generated from the aerobic stage was treated by biofilters. Net energy recovery was 84.3 MWh, or 46 kWh per million metric tons of wet waste (as received), and the biochemical methane potential of the treated waste decreased by 83% during the two-stage operation. The average removal efficiencies of volatile organic compounds and non-methane organic compounds in the biofilters were 96-99% and 68-99%, respectively.« less

Changes in carbon fractions during composting and maturation of organic wastes

NASA Astrophysics Data System (ADS)

Garcia, Carlos; Hernandez, Teresa; Costa, Francisco

1991-05-01

Seven mixtures from four organic residues—an aerobic sewage sludge, a city refuse, a peat residue, and a grape debris—were composted, and the changes undergone by their different carbon fractions during their composting and maturation were studied. In most cases a decrease in carbon fractions during the composting and maturation processes was observed. The extractable carbon, however, increased during maturation. Organic matter mineralization was greater in the composts with city refuse than in those with sewage sludge. The samples with peat residue showed the lowest decreases in carbon fractions. During maturation, an increase of humiclike fraction was observed, which was reflected by a decrease in the soluble carbon-precipitated carbon ratio at pH 2. Water-soluble carbon was the carbon fraction most easily degradable by microorganisms, and its amount correlated significantly with composting time in all the samples.

7 CFR 3201.56 - Mulch and compost materials.

Code of Federal Regulations, 2013 CFR

2013-01-01

... protective covering placed over the soil, primarily to keep down weeds and to improve the appearance of landscaping. Compost is the aerobically decomposed remnants of organic materials used in gardening and agriculture as a soil amendment, and commercially by the landscaping and container nursery industries. (b...

7 CFR 3201.56 - Mulch and compost materials.

Code of Federal Regulations, 2012 CFR

2012-01-01

... protective covering placed over the soil, primarily to keep down weeds and to improve the appearance of landscaping. Compost is the aerobically decomposed remnants of organic materials used in gardening and agriculture as a soil amendment, and commercially by the landscaping and container nursery industries. (b...

7 CFR 2902.56 - Mulch and compost materials.

Code of Federal Regulations, 2011 CFR

2011-01-01

... covering placed over the soil, primarily to keep down weeds and to improve the appearance of landscaping. Compost is the aerobically decomposed remnants of organic materials used in gardening and agriculture as a soil amendment, and commercially by the landscaping and container nursery industries. (b) Minimum...

7 CFR 3201.56 - Mulch and compost materials.

Code of Federal Regulations, 2014 CFR

2014-01-01

... protective covering placed over the soil, primarily to keep down weeds and to improve the appearance of landscaping. Compost is the aerobically decomposed remnants of organic materials used in gardening and agriculture as a soil amendment, and commercially by the landscaping and container nursery industries. (b...

Effect of temperature on bacterial species diversity in thermophilic solid-waste composting.

PubMed Central

Strom, P F

1985-01-01

Continuously thermophilic composting was examined with a 4.5-liter reactor placed in an incubator maintained at representative temperatures. Feed was a mixture of dried table scraps and shredded newspaper wetted to 55% moisture. One run at 49 degrees C (run A) employed a 1:4 feed-to-compost ratio, while the other runs used a 10:1 ratio and were incubated at 50, 55, 60, or 65 degrees C. Due to self-heating, internal temperatures of the composting mass were 0 to 7 degrees C hotter than the incubator. Two full-scale composting plants (at Altoona, Pa., and Leicester, England) were also examined. Plate counts per gram (dry weight) on Trypticase soy broth (BBL Microbiology Systems) with 2% agar ranged from 0.7 X 10(9) to 5.3 X 10(9) for laboratory composting and 0.02 X 10(9) to 7.4 X 10(9) for field composting. Fifteen taxa were isolated, including 10 of genus Bacillus, which dominated all samples except that from run A. Species diversity decreased markedly in laboratory composting at 60 degrees C and above, but was similar for the three runs incubated at 49, 50, and 55 degrees C. The maximum desirable composting temperature based on species diversity is thus 60 degrees C, the same as that previously recommended based on measures of the rate of decomposition. PMID:4083885

Utilization of solar energy in sewage sludge composting: Fertilizer effect and application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yiqun; Yu, Fang; Liang, Shengwen

2014-11-15

Highlights: • Solar energy technologies were utilized in aerobic sewage sludge composting. • Greenhouse and solar reactors were constructed to compare impacts on the composting. • Impatiens balsamina was planted in pot experiments to evaluate fertilizer effect. - Abstract: Three reactors, ordinary, greenhouse, and solar, were constructed and tested to compare their impacts on the composting of municipal sewage sludge. Greenhouse and solar reactors were designed to evaluate the use of solar energy in sludge composting, including their effects on temperature and compost quality. After 40 days of composting, it was found that the solar reactor could provide more stablemore » heat for the composting process. The average temperature of the solar reactor was higher than that of the other two systems, and only the solar reactor could maintain the temperature above 55 °C for more than 3 days. Composting with the solar reactor resulted in 31.3% decrease in the total organic carbon, increased the germination index to 91%, decreased the total nitrogen loss, and produced a good effect on pot experiments.« less

Compost biodegradation of recalcitrant hoof keratin by bacteria and fungi.

PubMed

Reuter, T; Gilroyed, B H; Xu, W; McAllister, T A; Stanford, K

2015-08-01

Compost activities efficiently break down a wide range of organic substances over time. In this study, bovine hoof was used as recalcitrant protein model to gain so far cryptic information on biodegradation during livestock mortalities composting. Bovine hooves (black and white), containing different amounts of melanin, placed into nylon bags were monitored during composting of cattle mortalities for up to 230 days. Besides physiochemical analysis, bacterial 16S and fungal 18S DNA fragments were amplified by PCR and profiles were separated by DGGE. Sequence analysis of separated fragments revealed various bacterial and fungal identities during composting. The microbial diversity was affected by a time-temperature interaction and by the hoof colour. Our molecular data, supported by electron microscopy, suggest hoof colonization by shifting bacteria and fungi communities. During composting, microbial communities work collaboratively in the degradation of recalcitrant organic matter such as keratin over time. A number of biomolecules including recalcitrant proteins may persist in environmental reservoirs, but breakdown can occur during composting. A combination of bioactivity and physiochemical conditions appear to be decisive for the fate of persistent biomolecules. © 2015 The Society for Applied Microbiology.

Comparison of aerobic and anaerobic [3H]leucine incorporation assays for determining pollution-induced bacterial community tolerance in copper-polluted, irrigated soils.

PubMed

Aaen, Karoline Nolsø; Holm, Peter E; Priemé, Anders; Hung, Ngoc Ngo; Brandt, Kristian Koefoed

2011-03-01

Pollution-induced community tolerance (PICT) constitutes a sensitive and ecologically relevant impact parameter in ecotoxicology. We report the development and application of a novel anaerobic [(3) H]leucine incorporation assay and its comparison with the conventional aerobic [(3) H]leucine incorporation assay for PICT detection in soil bacterial communities. Selection of bacterial communities was performed over 42 d in bulk soil microcosms (no plants) and in rice (Oryza sativa) rhizosphere soil mesocosms. The following experimental treatments were imposed using a full factorial design: two soil types, two soil water regimes, and four Cu application rates (0, 30, 120, or 280 µg g(-1)). Bacterial communities in bulk soil microcosms exhibited similar Cu tolerance patterns when assessed by aerobic and anaerobic PICT assays, whereas aerobic microorganisms tended to be more strongly selected for Cu tolerance than anaerobic microorganisms in rhizosphere soil. Despite similar levels of water-extractable Cu, bacterial Cu tolerance was significantly higher in acid sulfate soil than in alluvial soil. Copper amendment selected for significant PICT development in soils subjected to alternate wetting and drying, but not in continuously flooded soils. Our results demonstrate that soil bacterial communities subjected to alternate wetting and drying may be more affected by Cu than bacterial communities subjected to continuous flooding. We conclude that the parallel use of anaerobic and aerobic [(3) H]leucine PICT assays constitutes a valuable improvement over existing procedures for PICT detection in irrigated soils and other redox gradient environments such as sediments and wetlands. Copyright © 2010 SETAC.

Carbon Sequestration and Nitrogen Mineralization in Soil Cooperated with Organic Composts and Bio-char During Corn (Zea mays) Cultivation

NASA Astrophysics Data System (ADS)

Shin, Joung-Du; Lee, Sun-Ill; Park, Wu-Gyun; Choi, Yong-Su; Hong, Seong-Gil; Park, Sang-Won

2014-05-01

Objectives of this study were to estimate the carbon sequestration and to evaluate nitrogen mineralization and nitrification in soils cooperated with organic composts and bio-char during corn cultivation. For the experiment, the soil used in this study was clay loam types, and application rates of chemical fertilizer and bio-char were recommended amount after soil test and 2 % to soil weight, respectively. The soil samples were periodically taken at every 15 day intervals during the experimental periods. The treatments were consisted of non-application, cow manure compost, pig manure compost, swine digestate from aerobic digestion system, their bio-char cooperation. For the experimental results, residual amount of inorganic carbon was ranged from 51 to 208kg 10a-1 in soil only cooperated with different organic composts. However it was estimated to be highest at 208kg 10a-1 in the application plot of pig manure compost. In addition to bio-char application, it was ranged from 187.8 to 286kg 10a-1, but was greatest accumulated at 160.3kg 10a-1 in the application plot of cow manure compost. For nitrogen mineralization and nitrification rates, it was shown that there were generally low in the soil cooperated with bio-char compared to the only application plots of different organic composts except for 71 days after sowing. Also, they were observed to be highest in the application plot of swine digestate from aerobic digestion system. For the loss of total inorganic carbon (TIC) by run-off water, it was ranged from 0.18 to 0.36 kg 10a-1 in the different treatment plots. Also, with application of bio-char, total nitrogen was estimated to be reduced at 0.42(15.1%) and 0.38(11.8%) kg 10a-1 in application plots of the pig manure compost and aerobic digestate, respectively.

Sewage sludge drying by energy recovery from OFMSW composting: preliminary feasibility evaluation.

PubMed

Rada, Elena Cristina; Ragazzi, Marco; Villotti, Stefano; Torretta, Vincenzo

2014-05-01

In this paper an original energy recovery method from composting is analyzed. The integrated system exploits the heat available from the aerobic biochemical process in order to support the drying of sewage sludge, using a specific solar greenhouse. The aim is to tackle the problem of organic waste treatment, with specific regard to food waste. This is done by optimizing the energy consumption of the aerobic process of composting, using the heat produced to solve a second important waste management problem such as the sewage waste treatment. Energy and mass balances are presented in a preliminary feasibility study. Referring to a composting plant with a capacity of 15,000 t/y of food waste, the estimation of the power from recovered heat for the entire plant resulted about 42 kW. The results demonstrated that the energy recoverable can cover part of the heat necessary for the treatment of sludge generated by the population served by the composting plant (in terms of food waste and green waste collection). The addition of a renewable source such as solar energy could cover the residual energy demand. The approach is presented in detail in order for it to be replicated in other case studies or at full scale applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial communities and greenhouse gas emissions associated with the biodegradation of specified risk material in compost

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Shanwei; Agriculture and Agri-Food Canada, Lethbridge Research Centre, P.O. Box 3000, Lethbridge, Alberta, Canada T1J 4B1; Reuter, Tim

Highlights: ► Addition of feathers altered bacterial and fungal communities in compost. ► Microbial communities degrading SRM and compost matrix were distinct. ► Addition of feathers may enrich for microbial communities that degrade SRM. ► Inclusion of feather in compost increased both CH{sub 4} and N{sub 2}O emissions from compost. ► Density of methanogens and methanotrophs were weakly associated with CH{sub 4} emissions. - Abstract: Provided that infectious prions (PrP{sup Sc}) are inactivated, composting of specified risk material (SRM) may be a viable alternative to rendering and landfilling. In this study, bacterial and fungal communities as well as greenhouse gasmore » emissions associated with the degradation of SRM were examined in laboratory composters over two 14 day composting cycles. Chicken feathers were mixed into compost to enrich for microbial communities involved in the degradation of keratin and other recalcitrant proteins such as prions. Feathers altered the composition of bacterial and fungal communities primarily during the first cycle. The bacterial genera Saccharomonospora, Thermobifida, Thermoactinomycetaceae, Thiohalospira, Pseudomonas, Actinomadura, and Enterobacter, and the fungal genera Dothideomycetes, Cladosporium, Chaetomium, and Trichaptum were identified as candidates involved in SRM degradation. Feathers increased (P < 0.05) headspace concentrations of CH{sub 4} primarily during the early stages of the first cycle and N{sub 2}O during the second. Although inclusion of feathers in compost increases greenhouse gas emissions, it may promote the establishment of microbial communities that are more adept at degrading SRM and recalcitrant proteins such as keratin and PrP{sup Sc}.« less

Sewage sludge drying by energy recovery from OFMSW composting: Preliminary feasibility evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rada, Elena Cristina; Ragazzi, Marco; Villotti, Stefano

2014-05-01

Highlights: • The aim is to support the drying of sewage sludge, using a solar greenhouse. • The system allows the exploitation of heat available from OFMSW aerobic process. • Another aim is to face the problem of OFMSW treatment, in particular food waste. • Energy and mass balances are presented for a case study. - Abstract: In this paper an original energy recovery method from composting is analyzed. The integrated system exploits the heat available from the aerobic biochemical process in order to support the drying of sewage sludge, using a specific solar greenhouse. The aim is to tacklemore » the problem of organic waste treatment, with specific regard to food waste. This is done by optimizing the energy consumption of the aerobic process of composting, using the heat produced to solve a second important waste management problem such as the sewage waste treatment. Energy and mass balances are presented in a preliminary feasibility study. Referring to a composting plant with a capacity of 15,000 t/y of food waste, the estimation of the power from recovered heat for the entire plant resulted about 42 kW. The results demonstrated that the energy recoverable can cover part of the heat necessary for the treatment of sludge generated by the population served by the composting plant (in terms of food waste and green waste collection). The addition of a renewable source such as solar energy could cover the residual energy demand. The approach is presented in detail in order for it to be replicated in other case studies or at full scale applications.« less

Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater

PubMed Central

Kandasamy, Sujatha; Dananjeyan, Balachandar; Krishnamurthy, Kumar; Benckiser, Gero

2015-01-01

Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide concentrations of up to 5 mM. Increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. The rate of cyanide removal by the strains depends on the initial cyanide and glucose concentrations. When initial cyanide and glucose concentrations were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by Bacillus pumilus and Pseudomonas putida. Metabolic products such as ammonia and formate were detected in culture supernatants, suggesting a direct hydrolytic pathway without an intermediate formamide. The study clearly demonstrates the potential of aerobic treatment with cyanide degrading bacteria for cyanide removal in cassava factory wastewaters. PMID:26413045

Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater.

PubMed

Kandasamy, Sujatha; Dananjeyan, Balachandar; Krishnamurthy, Kumar; Benckiser, Gero

2015-01-01

Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide concentrations of up to 5 mM. Increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. The rate of cyanide removal by the strains depends on the initial cyanide and glucose concentrations. When initial cyanide and glucose concentrations were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by Bacillus pumilus and Pseudomonas putida. Metabolic products such as ammonia and formate were detected in culture supernatants, suggesting a direct hydrolytic pathway without an intermediate formamide. The study clearly demonstrates the potential of aerobic treatment with cyanide degrading bacteria for cyanide removal in cassava factory wastewaters.

The effect of composting on the persistence of four ionophores in dairy manure and poultry litter.

PubMed

Arikan, Osman A; Mulbry, Walter; Rice, Clifford

2016-08-01

Manure composting is a well-described approach for stabilization of nutrients and reduction of pathogens and odors. Although composting studies have shown that thermophilic temperatures and aerobic conditions can increase removal rates of selected antibiotics, comparable information is lacking for many other compounds in untreated or composted manure. The objective of this study was to determine the relative effectiveness of composting conditions to reduce concentrations of four widely used ionophore feed supplements in dairy manure and poultry litter. Replicate aliquots of fresh poultry litter and dairy manure were amended with monensin, lasalocid, salinomycin, or amprolium to 10mgkg(-1)DW. Non-amended and amended dairy manure and poultry litter aliquots were incubated at 22, 45, 55, or 65°C under moist, aerobic conditions. Residue concentrations were determined from aliquots removed after 1, 2, 4, 6, 8, and 12weeks. Results suggest that the effectiveness of composting for contaminant reduction is compound and matrix specific. Composting temperatures were not any more effective than ambient temperature in increasing the rate or extent of monensin removal in either poultry litter or dairy manure. Composting was effective for lasalocid removal in poultry litter, but is likely to be too slow to be useful in practice (8-12weeks at 65°C for >90% residue removal). Composting was effective for amprolium removal from poultry litter and salinomycin in dairy manure but both required 4-6weeks for >90% removal. However, composting did not increase the removal rates or salinomycin in poultry litter or the removal rates of lasalocid or amprolium in dairy manure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inactivation of pathogens during aerobic composting of fresh and aged dairy manure and different carbon amendments.

PubMed

Erickson, Marilyn C; Liao, Jean; Jiang, Xiuping; Doyle, Michael P

2014-11-01

Two separate studies were conducted to address the condition and the type of feedstocks used during composting of dairy manure. In each study, physical (temperature), chemical (ammonia, volatile acids, and pH), and biological (Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7) parameters were monitored during composting in bioreactors to assess the degree to which they were affected by the experimental variables and, ultimately, the ability of the chemical and physical parameters to predict the fate of pathogens during composting. Compost mixtures that contained either aged dairy manure or pine needles had reduced heat generation; therefore, pathogen reduction took longer than if fresh manure or carbon amendments of wheat straw or peanut hulls were used. Based on regression models derived from these results, ammonia concentration, in addition to heat, were the primary factors affecting the degree of pathogen inactivation in compost mixtures formulated to an initial carbon-nitrogen (C:N) ratio of 40:1, whereas, the pH of the compost mixture along with the amount of heat exposure were most influential in compost mixtures formulated to an initial C:N ratio of 30:1. Further studies are needed to validate these models so that additional criteria in addition to time and temperature can be used to evaluate the microbiological safety of composted manures.

[Co-composting of high-moisture vegetable waste and flower waste in a batch operation].

PubMed

Zhang, Xiangfeng; Wang, Hongtao; Nie, Yongfeng

2003-09-01

Co-composting of different mixture made of vegetable waste and flower waste were studied. The first stage of composting was aerobic static bed based temperature feedback in a batch operation and control via aeration rate regulation. The second stage was window composting. The total composting period was 45 days. About the station of half of celery and half of carnation, the pile was insulated and temperatures of at least 55 degrees C were maintained for about 11 days. The highest temperature was up to 65 degrees C. This is enough to kill pathogens. Moisture of pile decreased from 64.2% to 46.3% and organic matter was degraded from 74.7% to 55.6% during composting. The value of pH was had stable at 7. Analysis of maturity and nutrition of compost show that end-products of composting were bio-stable and had abundant nutrition. This shows that co-composting of vegetable waste and flower waste can get high quality compost by optimizing composting process during 45 days. Composting can decrease non-point resource of organic solid waste by recycling nutrition to soil and improve fertility of soil.

[Co-composting of high moisture vegetable waste, flower waste and chicken litter in pilot scale].

PubMed

Zhang, Xiangfeng; Wang, Hongtao; Nie, Yongfeng; Qiu, Xiangyang

2003-03-01

Co-composting of different mixture made of vegetable waste, flower waste and chicken litter were studied. The first stage of composting was aerobic static bed based temperature feedback and control via aeration rate regulation. The second stage was window composting. At first stage, the pile was insulated and temperatures of at least 55 degrees C were maintained for a minimum of 3 days. The highest temperature was up to 73.3 degrees C. This is enough to kill pathogens. Moisture of pile decreased from 75% to 56% and organic matter was degraded from 65% to 50% during composting. The value of pH was stable at 8. Analysis of maturity and nutrition of compost showed that end-products of composting ware bio-stable and had abundant nutrition. This shows that co-composting of vegetable waste, flower waste and chicken litter can get high quality compost by optimizing composting process during 45 days. Composting can decrease nonpoint resource of organic solid waste by recycling nutrition to soil and improve fertility of soil.

Short communication: Environmental mastitis pathogen counts in freestalls bedded with composted and fresh recycled manure solids.

PubMed

Cole, K J; Hogan, J S

2016-02-01

An experiment was conducted to compare bacterial counts of environmental mastitis pathogens in composted recycled manure solids bedding with those in fresh recycled manure solids. Eighteen Holstein cows were housed in 1 pen with 18 stalls. One row of 9 freestalls included mattresses and was bedded weekly with composted recycled manure solids. The second row of 9 freestalls included mattresses and was bedded weekly with fresh recycled manure solids. The back one-third of stalls toward the alleyway was covered in 25 to 50 mm of bedding. Samples were taken from the back one-third of 4 stalls for both treatments on d 0, 1, 2, and 6 of each week. After 3 wk, bedding treatments were switched between rows, making the total duration 6 wk. Mean total gram-negative bacterial counts were approximately 0.5 log10 cfu/g of dry matter lower in the composted recycled manure solids on d 0 compared with fresh recycled manure solids. Klebsiella species, coliform, and Streptococcus species counts were at least 1.0 log10 cfu/g of dry matter lower in composted compared with fresh recycled manure solids on d 0. Only gram-negative bacterial counts on d 1 were reduced in composted recycled manure solids compared with fresh recycled manure solids. Differences were not observed between treatments in gram-negative bacterial, coliform, Klebsiella species, or Streptococcus species counts on d 2 and 6. Ash content was higher in composted recycled manure solids compared with fresh recycled manure solids on d 0, 1, 2, and 6. Despite the increase in ash after composting, bacterial counts of mastitis pathogens in composted recycled manure solids were comparable with those in fresh recycled manure when used as freestall bedding. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of alkyl polyglycoside (APG) on composting of agricultural wastes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Fabao; Gu Wenjie, E-mail: guwenjie1982@yahoo.cn; Xu Peizhi

2011-06-15

Composting is the biological degradation and transformation of organic materials under controlled conditions to promote aerobic decomposition. To find effective ways to accelerate composting and improve compost quality, numerous methods including additive addition, inoculation of microorganisms, and the use of biosurfactants have been explored. Studies have shown that biosurfactant addition provides more favorable conditions for microorganism growth, thereby accelerating the composting process. However, biosurfactants have limited applications because they are expensive and their use in composting and microbial fertilizers is prohibited. Meanwhile, alkyl polyglycoside (APG) is considered a 'green' surfactant. This study aims to determine whether APG addition into amore » compost reaction vessel during 28-day composting can enhance the organic matter degradation and composting process of dairy manure. Samples were periodically taken from different reactor depths at 0, 3, 5, 7, 14, 21, and 28 days. pH levels, electrical conductivity (EC), ammonium and nitrate nitrogen, seed germination indices, and microbial population were determined. Organic matter and total nitrogen were also measured. Compared with the untreated control, the sample with APG exhibited slightly increased microbial populations, such as bacteria, fungi, and actinomycetes. APG addition increased temperatures without substantially affecting compost pH and EC throughout the process. After 28 days, APG addition increased nitrate nitrogen concentrations, promoted matter degradation, and increased seed germination indices. The results of this study suggest that the addition of APG provides more favorable conditions for microorganism growth, slightly enhancing organic matter decomposition and accelerating the composting process, improving the compost quality to a certain extent.« less

Effects of alkyl polyglycoside (APG) on composting of agricultural wastes.

PubMed

Zhang, Fabao; Gu, Wenjie; Xu, Peizhi; Tang, Shuanhu; Xie, Kaizhi; Huang, Xu; Huang, Qiaoyi

2011-06-01

Composting is the biological degradation and transformation of organic materials under controlled conditions to promote aerobic decomposition. To find effective ways to accelerate composting and improve compost quality, numerous methods including additive addition, inoculation of microorganisms, and the use of biosurfactants have been explored. Studies have shown that biosurfactant addition provides more favorable conditions for microorganism growth, thereby accelerating the composting process. However, biosurfactants have limited applications because they are expensive and their use in composting and microbial fertilizers is prohibited. Meanwhile, alkyl polyglycoside (APG) is considered a "green" surfactant. This study aims to determine whether APG addition into a compost reaction vessel during 28-day composting can enhance the organic matter degradation and composting process of dairy manure. Samples were periodically taken from different reactor depths at 0, 3, 5, 7, 14, 21, and 28 days. pH levels, electrical conductivity (EC), ammonium and nitrate nitrogen, seed germination indices, and microbial population were determined. Organic matter and total nitrogen were also measured. Compared with the untreated control, the sample with APG exhibited slightly increased microbial populations, such as bacteria, fungi, and actinomycetes. APG addition increased temperatures without substantially affecting compost pH and EC throughout the process. After 28 days, APG addition increased nitrate nitrogen concentrations, promoted matter degradation, and increased seed germination indices. The results of this study suggest that the addition of APG provides more favorable conditions for microorganism growth, slightly enhancing organic matter decomposition and accelerating the composting process, improving the compost quality to a certain extent. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterisation of the aerobic bacterial flora of boid snakes: application of MALDI-TOF mass spectrometry.

PubMed

Plenz, Bastian; Schmidt, Volker; Grosse-Herrenthey, Anke; Krüger, Monika; Pees, Michael

2015-03-14

The aim of this study was to identify aerobic bacterial isolates from the respiratory tract of boids with matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry (MALDI-TOF MS). From 47 boid snakes, swabs from the oral cavity, tracheal wash samples and, in cases in which postmortem examination was performed, pulmonary tissue samples were taken. Each snake was classified as having inflammation of the respiratory tract and/or oral cavity, or without evidence of inflammation based on combination of clinical, cytological and histopathological findings. Samples collected from the respiratory tract and oral cavity were inoculated onto routine media and bacteria were cultured aerobically. All morphologically distinct individual colonies obtained were analysed using MALDI-TOF MS. Unidentified isolates detected in more than three snakes were selected for further 16S rDNA PCR and sequencing. Among all examined isolates (n=243), 49 per cent (n=119) could be sufficiently speciated using MALDI-TOF MS. Molecular biology revealed several bacterial species that have not been previously described in reptiles. With an average of 6.3 different isolates from the respiratory tract and/or oral cavity, boids with inflammatory disease harboured significantly more bacterial species than boids without inflammatory disease (average 2.8 isolates). British Veterinary Association.

Spatial nitrifications of microbial processes during composting of swine, cow and chicken manure

PubMed Central

Wang, Ke; Li, Weiguang; Li, Xiangkun; Ren, Nanqi

2015-01-01

Composting is a widely-used method to recycle the nutrients in livestock manure for agriculture. The spatial stratifications of microbial processes inside the manure particle that determine organic and nitrogen transformation are virtually unclear. Here, we show the evolution of the interior microenvironment of swine, cow and chicken manure by using microelectrodes during forced-aeration composting. Composting has generally been regarded as an aerobic bioprocess, however, the long-existing of a large anoxic zone inside these manures was confirmed during the active phase in this study. The profile of the oxidation–reduction potential dramatically decreased first and then gradually increased. The spatial difference in the ammonia concentration was not significant, but nitrate concentration continuously decreased with depth. The anoxic condition within the manure particle was demonstrated to be a primary cause of the severe ammonia emission and the long composting period. These founding provided a new insight toward “aerobic” composting process and a sound foundation for the development of efficient composting technology. PMID:26442637

Spatial nitrifications of microbial processes during composting of swine, cow and chicken manure

NASA Astrophysics Data System (ADS)

Wang, Ke; Li, Weiguang; Li, Xiangkun; Ren, Nanqi

2015-10-01

Composting is a widely-used method to recycle the nutrients in livestock manure for agriculture. The spatial stratifications of microbial processes inside the manure particle that determine organic and nitrogen transformation are virtually unclear. Here, we show the evolution of the interior microenvironment of swine, cow and chicken manure by using microelectrodes during forced-aeration composting. Composting has generally been regarded as an aerobic bioprocess, however, the long-existing of a large anoxic zone inside these manures was confirmed during the active phase in this study. The profile of the oxidation-reduction potential dramatically decreased first and then gradually increased. The spatial difference in the ammonia concentration was not significant, but nitrate concentration continuously decreased with depth. The anoxic condition within the manure particle was demonstrated to be a primary cause of the severe ammonia emission and the long composting period. These founding provided a new insight toward “aerobic” composting process and a sound foundation for the development of efficient composting technology.

Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement

PubMed Central

Kim, Eunjong; Lee, Dong-Hyun; Won, Seunggun; Ahn, Heekwon

2016-01-01

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg O2/g VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS’s optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust’s coarse particle size and bulking effect. PMID:26954138

Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement.

PubMed

Kim, Eunjong; Lee, Dong-Hyun; Won, Seunggun; Ahn, Heekwon

2016-05-01

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg O2/g VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.

Comparison of aerobic conjunctival bacterial flora in pregnant, reproductive-aged and postmenopausal women

PubMed Central

Balikoglu-Yilmaz, Melike; Sen, Emine; Sevket, Osman; Polat, Yusuf; Karabulut, Aysun; Uysal, Omer

2012-01-01

AIM To evaluate the effect of hormonal status on aerobic conjunctival flora in women. METHODS One hundred fifty-eight women [reproductive-aged (n=55), pregnant (n=51), and postmenopausal (n=52)] who admitted to outpatient clinic of Obstetrics and Gynecology Department of Denizli State Hospital were enrolled. Age, body-mass index (BMI), obstetric history, cigarette smoking, drug usage, presence of systemic disease, and intraocular pressure (IOP) were recorded for each patient. The samples were taken from the lower fornix with two culture swabs and directly incubated in culture containing 5% sheep blood, eosin-methylene blue and chocolate agar. The other swab specimen was Gram stained. All growths and microscopic results were analyzed. RESULTS The coagulase-negative Staphylococcus was the predominant organism isolated in the conjunctival samples in both three groups. The aerobic microorganism growth rate for all isolated aerobic organisms revealed no significant change in the three groups (P >0.05). The conjunctival culture positivity rates were similar in the three groups (49% in reproductive-aged, 57% in pregnant and 58% in postmenopausal women) (P >0.05). Age, IOP, BMI, gravidity, parity, cigarette smoking, drug usage, and presence of systemic diseases did not have an effect on culture positivity in three groups. CONCLUSION Results of this study showed that conjunctival aerobic flora and bacterial colonization did not differ between reproductive-aged, pregnant and postmenopausal women. PMID:23275909

Microbiological study on bioremediation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) contaminated soil by agricultural waste composting.

PubMed

Chen, Yaoning; Ma, Shuang; Li, Yuanping; Yan, Ming; Zeng, Guangming; Zhang, Jiachao; Zhang, Jie; Tan, Xuebin

2016-11-01

This paper studied the degradation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in contaminated soil under composting and natural conditions, respectively. BDE-47 residue in agricultural waste-composting pile was determined during 45-day composting. The microbial communities were determined by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and the relationships between the DGGE results and physico-chemical parameters were evaluated by redundancy analysis (RDA) and heatmap-clustering analysis. The results showed that the degradation rate of BDE-47 was significantly higher in agricultural waste-composting pile compared with control group, which was enhanced up to almost 15 % at the end of composting. There were different environmental factors which affected the distribution of composting bacterial and fungal communities. The bacterial community composition was more significantly affected by the addition of BDE-47 compared with other physico-chemical parameters, and BDE-47 had stronger influences on bacterial community than fungal community during the composting. Meanwhile, the most variation in distribution of fungal community was explained by pile temperature.

Effect of multi-stage inoculation on the bacterial and fungal community structure during organic municipal solid wastes composting.

PubMed

Xi, Beidou; He, Xiaosong; Dang, Qiuling; Yang, Tianxue; Li, Mingxiao; Wang, Xiaowei; Li, Dan; Tang, Jun

2015-11-01

In this study, PCR-DGGE method was applied to investigate the impact of multi-stage inoculation treatment on the community composition of bacterial and fungal during municipal solid wastes (MSW) composting process. The results showed that the high temperature period was extended by the multi-stage inoculation treatment, 1day longer than initial-stage inoculation treatment, and 5days longer than non-inoculation treatment. The temperature of the secondary fermentation increased to 51°C with multi-stage inoculation treatment. The multi-stage inoculation method improved the community diversity of bacteria and fungi that the diversity indexes reached the maximum on the 17days and 20days respectively, avoided the competition between inoculations and indigenous microbes, and enhanced the growth of dominant microorganisms. The DNA sequence indicated that various kinds of uncultured microorganisms with determined ratios were detected, which were dominant microbes during the whole fermentation process. These findings call for further researches of compost microbial cultivation technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Home composting versus industrial composting: influence of composting system on compost quality with focus on compost stability.

PubMed

Barrena, Raquel; Font, Xavier; Gabarrell, Xavier; Sánchez, Antoni

2014-07-01

Stability is one of the most important properties of compost obtained from the organic fraction of municipal solid wastes. This property is essential for the application of compost to land to avoid further field degradation and emissions of odors, among others. In this study, a massive characterization of compost samples from both home producers and industrial facilities is presented. Results are analyzed in terms of chemical and respiration characterizations, the latter representing the stability of the compost. Results are also analyzed in terms of statistical validation. The main conclusion from this work is that home composting, when properly conducted, can achieve excellent levels of stability, whereas industrial compost produced in the studied facilities can also present a high stability, although an important dispersion is found in these composts. The study also highlights the importance of respiration techniques to have a reliable characterization of compost quality, while the chemical characterization does not provide enough information to have a complete picture of a compost sample. Copyright © 2014 Elsevier Ltd. All rights reserved.

Management of aerobic vaginitis.

PubMed

Tempera, Gianna; Furneri, Pio Maria

2010-01-01

Aerobic vaginitis is a new nonclassifiable pathology that is neither specific vaginitis nor bacterial vaginosis. The diversity of this microbiological peculiarity could also explain several therapeutic failures when patients were treated for infections identified as bacterial vaginosis. The diagnosis 'aerobic vaginitis' is essentially based on microscopic examinations using a phase-contrast microscope (at ×400 magnification). The therapeutic choice for 'aerobic vaginitis' should take into consideration an antibiotic characterized by an intrinsic activity against the majority of bacteria of fecal origin, bactericidal effect and poor/absent interference with the vaginal microbiota. Regarding the therapy for aerobic vaginitis when antimicrobial agents are prescribed, not only the antimicrobial spectrum but also the presumed ecological disturbance on the anaerobic and aerobic vaginal and rectal microbiota should be taken into a consideration. Because of their very low impact on the vaginal microbiota, kanamycin or quinolones are to be considered a good choice for therapy. Copyright © 2010 S. Karger AG, Basel.

Hyperthermophilic Composting Accelerates the Removal of Antibiotic Resistance Genes and Mobile Genetic Elements in Sewage Sludge.

PubMed

Liao, Hanpeng; Lu, Xiaomei; Rensing, Christopher; Friman, Ville Petri; Geisen, Stefan; Chen, Zhi; Yu, Zhen; Wei, Zhong; Zhou, Shungui; Zhu, Yongguan

2018-01-02

Composting is an efficient way to convert organic waste into fertilizers. However, waste materials often contain large amounts of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) that can reduce the efficacy of antibiotic treatments when transmitted to humans. Because conventional composting often fails to remove these compounds, we evaluated if hyperthermophilic composting with elevated temperature is more efficient at removing ARGs and MGEs and explored the underlying mechanisms of ARG removal of the two composting methods. We found that hyperthermophilic composting removed ARGs and MGEs more efficiently than conventional composting (89% and 49%, respectively). Furthermore, the half-lives of ARGs and MGEs were lower in hyperthermophilic compositing compared to conventional composting (67% and 58%, respectively). More-efficient removal of ARGs and MGEs was associated with a higher reduction in bacterial abundance and diversity of potential ARG hosts. Partial least-squares path modeling suggested that reduction of MGEs played a key role in ARG removal in hyperthermophilic composting, while ARG reduction was mainly driven by changes in bacterial community composition under conventional composting. Together these results suggest that hyperthermophilic composting can significantly enhance the removal of ARGs and MGEs and that the mechanisms of ARG and MGE removal can depend on composting temperature.

Optimum moisture levels for biodegradation of mortality composting envelope materials.

PubMed

Ahn, H K; Richard, T L; Glanville, T D

2008-01-01

Moisture affects the physical and biological properties of compost and other solid-state fermentation matrices. Aerobic microbial systems experience different respiration rates (oxygen uptake and CO2 evolution) as a function of moisture content and material type. In this study the microbial respiration rates of 12 mortality composting envelope materials were measured by a pressure sensor method at six different moisture levels. A wide range of respiration (1.6-94.2mg O2/g VS-day) rates were observed for different materials, with alfalfa hay, silage, oat straw, and turkey litter having the highest values. These four envelope materials may be particularly suitable for improving internal temperature and pathogen destruction rates for disease-related mortality composting. Optimum moisture content was determined based on measurements across a range that spans the maximum respiration rate. The optimum moisture content of each material was observed near water holding capacity, which ranged from near 60% to over 80% on a wet basis for all materials except a highly stabilized soil compost blend (optimum around 25% w.b.). The implications of the results for moisture management and process control strategies during mortality composting are discussed.

Detection of hepatitis E virus (HEV) through the different stages of pig manure composting plants

PubMed Central

García, M; Fernández-Barredo, S; Pérez-Gracia, M T

2014-01-01

Hepatitis E virus (HEV) is an increasing cause of acute hepatitis in industrialized countries. The aim of this study was to evaluate the presence of HEV in pig manure composting plants located in Spain. For this purpose, a total of 594 samples were taken in 54 sampling sessions from the different stages of composting treatment in these plants as follows: slurry reception ponds, anaerobic ponds, aerobic ponds, fermentation zone and composting final products. HEV was detected by reverse transcription polymerase chain reaction (RT-nested PCR) in four (80%) of five plants studied, mainly in the first stages of the process. HEV was not detected in any final product (compost) sample, destined to be commercialized as a soil fertilizer, suggesting that composting is a suitable method to eliminate HEV and thus, to reduce the transmission of HEV from pigs to humans. PMID:24206540

Pelleted organo-mineral fertilisers from composted pig slurry solids, animal wastes and spent mushroom compost for amenity grasslands.

PubMed

Rao, Juluri R; Watabe, Miyuki; Stewart, T Andrew; Millar, B Cherie; Moore, John E

2007-01-01

In Ireland, conversion of biodegradable farm wastes such as pig manure spent mushroom compost and poultry litter wastes to pelletised fertilisers is a desirable option for farmers. In this paper, results obtained from the composting of pig waste solids (20% w/w) blended with other locally available biodegradable wastes comprising poultry litter (26% w/w), spent mushroom compost (26% w/w), cocoa husks (18% w/w) and moistened shredded paper (10% w/w) are presented. The resulting 6-mo old 'mature' composts had a nutrient content of 2.3% total N, 1.6% P and 3.1% K, too 'low' for direct use as an agricultural fertiliser. Formulations incorporating dried blood or feather meal amendments enriched the organic N-content, reduced the moisture in mature compost mixtures and aided the granulation process. Inclusion of mineral supplements viz., sulphate of ammonia, rock phosphate and sulphate of potash, yielded slow release fertilisers with nutrient N:P:K ratios of 10:3:6 and 3:5:10 that were suited for amenity grasslands such as golf courses for spring or summer application and autumn dressing, respectively. Rigorous microbiological tests carried out throughout the composting, processing and pelletising phases indicated that the formulated organo-mineral fertilisers were free of vegetative bacterial pathogens.

[Effects of grape seed addition in swine manure-wheat straw composting on the compost microbial community and carbon and nitrogen contents].

PubMed

Huang, Yi-Mei; Liu, Xue-Ling; Jiang, Ji-Shao; Huang, Hua; Liu, Dong

2012-08-01

Taking substrates swine manure and wheat straw (fresh mass ratio 10.5:1) as the control (PMW), a composting experiment was conducted in a self-made aerated static composting bin to study the effects of adding 8% grape seed (treatment PMW + G) on the succession of microbial community and the transformation of carbon and nitrogen in the substrates during the composting. Seven samples were collected from each treatment, according to the temperature of the compost during the 30 d composting period. The microbial population and physiological groups were determined, and the NH4(+)-N, NO3(-)-N, organic N, and organic C concentrations in the compost were measured. Grape seed addition induced a slight increase of bacterial count and a significant increase of actinomycetes count, but decreased the fungal count significantly. Grape seed addition also decreased the ratio of bacteria to actinomycetes and the counts of ammonifiers and denitrifiers, but increased the counts of nitrifiers, N-fixing bacteria, and cellulose-decomposing microorganisms. The contents of NH4(+)-N and organic C decreased, while that of NO3(-)-N increased obviously. The NO3(-)-N content in the compost was positively correlated with the actinomycetes count. During composting, the compost temperature in treatment PMW + G increased more rapidly, and remained steady in thermophilic phase, while the water content changed little, which provided a stable and higher population of actinomycetes and nitrifiers in thermophilic phase, being beneficial to the increase of compost nitrate N.

Characterization and open windrow composting of MSW in Jodhpur City, Rajasthan, India.

PubMed

Ambade, Bhushan; Sharma, Sunil; Sharma, Yukti; Sharma, Yagya

2013-07-01

Solid waste is sometimes not suitable for direct land application. Processing solid waste through composting converts it to a humus-containing organic material advantageous for agriculture/horticulture use. Major advantages of composting are stabilization of the wastes; substantially reduced C/N ratio and gas formation, and virtually elimination of odors and pathogens. Composting is accomplished under aerobic conditions developing temperatures of 55 degrees C or above. The windrow technique is simple and accomplished easily with standard equipments. The open windrow composting of municipal solid waste (MSW) in windrows was analyzed in this study for six weeks. The raw MSW was introduced to active composting without any source segregations. The moisture content of the MSW dropped from 58.88% to 48.06% and windrow attained a thermophillic temperature for about two weeks. It was observed that the pH, C/N ratio and temperature variations were comparable to that of traditional windrow composting. The peak temperature recorded was 68 degrees C and temperature remained above 60 degrees C for more than three weeks. The volume reduction was obtained by using one-cu.m. cage. The results indicate that the bulk composting could reduce by about 29% the total mass of the waste.

Comparison of characterization and microbial communities in rice straw- and wheat straw-based compost for Agaricus bisporus production.

PubMed

Wang, Lin; Mao, Jiugeng; Zhao, Hejuan; Li, Min; Wei, Qishun; Zhou, Ying; Shao, Heping

2016-09-01

Rice straw (RS) is an important raw material for the preparation of Agaricus bisporus compost in China. In this study, the characterization of composting process from RS and wheat straw (WS) was compared for mushroom production. The results showed that the temperature in RS compost increased rapidly compared with WS compost, and the carbon (C)/nitrogen (N) ratio decreased quickly. The microbial changes during the Phase I and Phase II composting process were monitored using denaturing gradient gel electrophoresis (DGGE) and phospholipid fatty acid (PLFA) analysis. Bacteria were the dominant species during the process of composting and the bacterial community structure dramatically changed during heap composting according to the DGGE results. The bacterial community diversity of RS compost was abundant compared with WS compost at stages 4-5, but no distinct difference was observed after the controlled tunnel Phase II process. The total amount of PLFAs of RS compost, as an indicator of microbial biomass, was higher than that of WS. Clustering by DGGE and principal component analysis of the PLFA compositions revealed that there were differences in both the microbial population and community structure between RS- and WS-based composts. Our data indicated that composting of RS resulted in improved degradation and assimilation of breakdown products by A. bisporus, and suggested that the RS compost was effective for sustaining A. bisporus mushroom growth as well as conventional WS compost.

The abundance and diversity of antibiotic resistance genes in the atmospheric environment of composting plants.

PubMed

Gao, Min; Qiu, Tianlei; Sun, Yanmei; Wang, Xuming

2018-07-01

Composting is considered to reduce the introduction of antimicrobial resistance genes (ARGs) into the environment through land application of manure; however, the possible pollution of ARGs in the atmospheric environment of composting plants is unknown. In this study, 29 air samples including up- and downwind, composting, packaging, and office areas from 4 composting plants were collected. Dynamic concentrations of 22 subtypes of ARGs, class 1 integron (intl1), and 2 potential human pathogenic bacteria (HPB), and bacterial communities were investigated using droplet digital PCR and 16S rRNA gene sequencing, respectively. In this study, intl1 and 22 subtypes of ARGs (except tetQ) were detected in air of composting, packaging, office, and downwind areas. The highest concentration of 15 out of 22 subtypes of ARGs was detected in the packaging areas, and intl1 also had the maximum average concentration of 10 4  copies/m 3 , with up to (1.78 ± 0.49) × 10 -2 copies/16S rRNA copy. Non-metric multi-dimensional scaling of ARGs, potential HPBs, and bacterial components all indicated that the bioaerosol pollutant pattern in packaging areas was most similar to that in composting areas, followed by office, downwind, and upwind areas. The co-occurrence between ARGs and bacterial taxa assessed by Procrustes test, mantel test, and network analysis implied that aerosolized ARG fragments from composting and packaging areas contributed to the compositions of ARG aerosols in office and downwind areas. The results presented here show that atmoshperic environments of composting plants harbor abundant and diverse ARGs, which highlight the urgent need for comprehensive evaluation of potential human health and ecological risks of composts during both production as well as land application. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Interaction Between Sulfonamide Antibiotics Fates and Chicken Manure Composting].

PubMed

Lin, Hui; Wang, Jian-mei; Sun, Wan-chun; Fu, Jian-rong; Chen, Hong-jin; Ma, Jun-wei

2016-05-15

Based on aerobic manure composting with or without the addition of a mixture of sulfadimethoxine SM2 and sulfamonomethoxine SMM (1:1, m/m), changes in the physic-chemical properties of manure compost, the microbial community physiological profiles, the antibiotics concentration and the abundances of five antibiotic resistance genes (ARGs) during the composting were tracked. The results indicated that the introduction of sulfonamide antibiotics led to inhibition on the basal respiration of manure compost during the early composting period, delayed the formation of thermophilic temperature and reduced the conversion of nutrients such as organic matter, ammonia nitrogen and nitrate nitrogen. Meanwhile, the introduction of sulfonamide antibiotics dramatically affected the physiological profile of microbial community in manure in the middle stage of composting. HPLC-MS/MS results showed that both SMM and SM2 in manure were completely degraded within 14 days, while the degradation rate of SMM was faster than that of SM2. For both composting treatments with or without addition of exogenous antibiotics, the relative abundance of sull and sul2 showed an initial decline in the first 14 or 21 days and a slight increase thereafter. The addition of exogenous antibiotics showed insignificant enhancement on increasing the relative abundance of sul1 and IntI1 in manure, but resulted in an apparent increase in sul2 relative abundance. Although the fates of tetQ and tetW during composting were different from that of sulfonamide ARGs, the introduction of sulfonamide antibiotics into manure increased the relative abundance of tetracycline ARGs. Redundancy analysis indicated that composting temperature correlated negatively with sul1, sul2 and IntI1 relative abundance in manure but had no obvious relationship with tetQ and tetW relative abundance. All the ARGs detected in this work correlated negatively with C/N ratio and the nitrate nitrogen concentration of manure compost but

Effective biotransformation and detoxification of anthraquinone dye reactive blue 4 by using aerobic bacterial granules.

PubMed

Chaudhari, Ashvini U; Paul, Dhiraj; Dhotre, Dhiraj; Kodam, Kisan M

2017-10-01

Treatment of textile wastewater containing anthraquinone dye is quite a huge challenge due to its complex aromatic structure and toxicity. Present study deals with the degradation and detoxification of anthraquinone dye reactive blue 4 using aerobic bacterial granules. Bacterial granules effectively decolorized reactive blue 4 at wide range of pH (4.0-11.0) and temperature (20-55 °C) as well as decolorized and tolerated high concentration of reactive blue 4 dye upto 1000 mg l -1 with V max 6.16 ± 0.82 mg l -1 h -1 and K m 227 ± 41 mg l -1 . Metagenomics study evaluates important role of Clostridia, Actinobacteria, and Proteobacterial members in biotransformation and tolerance of high concentrations of reactive blue 4 dye. Up-regulation of xenobiotic degradation and environmental information processing pathways during dye exposure signifies their noteworthy role in dye degradation. Biotransformation of dye was confirmed by significant decrease in the values of total suspended solids, biological and chemical oxygen demand. The metabolites formed after biotransformation was characterized by FT-IR and GC-MS analysis. The reactive blue 4 dye was found to be phytotoxic, cytotoxic and genotoxic whereas its biotransformed product were non-toxic. This study comprehensively illustrates that, bacterial aerobic granules can be used for eco-friendly remediation and detoxification of wastewater containing high organic load of anthraquinone dye. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerobic bacterial microbiota isolated from the cloaca of the European pond turtle (Emys orbicularis) in Poland.

PubMed

Nowakiewicz, Aneta; Ziółkowska, Grażyna; Zięba, Przemysław; Dziedzic, Barbara Majer; Gnat, Sebastian; Wójcik, Mariusz; Dziedzic, Roman; Kostruba, Anna

2015-01-01

We conducted a comparative analysis of the aerobic cloacal bacteria of European pond turtles (Emys orbicularis) living in their natural environment and juvenile turtles reared under controlled conditions in a breeding center. We included 130 turtles in the study. The aerobic bacteria isolated from the cloaca of the juvenile turtles were less diverse and more prevalent than the bacteria isolated from free-living adults. We isolated 17 bacterial species from juvenile captive turtles, among which the dominant species were Cellulomonas flavigena (77/96), Enterococcus faecalis (96/96), Escherichia coli (58/96), and Proteus mirabilis (41/96). From the adult, free-living turtles, we isolated 36 bacterial species, some of which are a potential threat to public health (e.g., Salmonella enterica serovars Newport, Daytona, and Braenderup; Listeria monocytogenes; Yersinia enterocolitica; Yersinia ruckeri; Klebsiella pneumoniae; Vibrio fluvialis; and Serratia marcescens), and pathogens that are etiologic agents of diseases of ectothermic animals (e.g., Aeromonas sobria, Aeromonas caviae, Hafnia alvei, Edwardsiella tarda, and Citrobacter braakii; the last two species were isolated from both groups of animals). The cloacal bacterial biota of the European pond turtle was characterized by numerous species of bacteria, and its composition varied with turtle age and environmental conditions. The small number of isolated bacteria that are potential human pathogens may indicate that the European pond turtle is of relatively minor importance as a threat to public health.

The relative isotopic abundance (δ13C, δ15N) during composting of agricultural wastes in relation to compost quality and feedstock.

PubMed

Inácio, Caio T; Magalhães, Alberto M T; Souza, Paulo O; Chalk, Phillip M; Urquiaga, Segundo

2018-05-01

Variations in the relative isotopic abundance of C and N (δ 13 C and δ 15 N) were measured during the composting of different agricultural wastes using bench-scale bioreactors. Different mixtures of agricultural wastes (horse bedding manure + legume residues; dairy manure + jatropha mill cake; dairy manure + sugarcane residues; dairy manure alone) were used for aerobic-thermophilic composting. No significant differences were found between the δ 13 C values of the feedstock and the final compost, except for dairy manure + sugarcane residues (from initial ratio of -13.6 ± 0.2 ‰ to final ratio of -14.4 ± 0.2 ‰). δ 15 N values increased significantly in composts of horse bedding manure + legumes residues (from initial ratio of +5.9 ± 0.1 ‰ to final ratio of +8.2 ± 0.5 ‰) and dairy manure + jatropha mill cake (from initial ratio of +9.5 ± 0.2 ‰ to final ratio of +12.8 ± 0.7 ‰) and was related to the total N loss (mass balance). δ 13 C can be used to differentiate composts from different feedstock (e.g. C 3 or C 4 sources). The quantitative relationship between N loss and δ 15 N variation should be determined.

Effects of oxytetracycline on the abundance and community structure of nitrogen-fixing bacteria during cattle manure composting.

PubMed

Sun, Jiajun; Qian, Xun; Gu, Jie; Wang, Xiaojuan; Gao, Hua

2016-09-01

The effects of oxytetracycline (OTC) on nitrogen-fixing bacterial communities were investigated during cattle manure composting. The abundance and community structure of nitrogen-fixing bacteria were determined by qPCR and denaturing gradient gel electrophoresis (DGGE), respectively. The matrix was spiked with OTC at four levels: no OTC, 10mg/kg dry weight (DW) OTC (L), 60mg/kg DW OTC (M), and 200mg/kg DW OTC (H). The high temperature period of composting was shorter with M and H, and the decline in temperature during the cooling stage was accelerated by OTC. OTC had a concentration-dependent inhibitory effect on the nitrogenase activity during early composting, and the nifH gene abundance declined significantly during the later composting stage. The DGGE profile and statistical analysis showed that OTC changed the nitrogen-fixing bacterial community succession and reduced the community richness and dominance. The nitrogen-fixing bacterial community structure was affected greatly by the high level of OTC. Copyright © 2016. Published by Elsevier Ltd.

Waste utilization of red snapper (Lutjanus sp.) fish bone to improve phosphorus contents in compost

NASA Astrophysics Data System (ADS)

Ramadhani, S.; Iswanto, B.; Purwaningrum, P.

2018-01-01

The purpose of this research is to get the idea that bone waste will be the P content enhancer in compost so that the compost produced meets the standard P levels specified in SNI 19-7030-2004 which regulating compost quality standard. Nutrient levels were obtained in fish bone meal (FBM) are C (3.35%), N (0.48%), P (30.90%) and K (0.02%). Effects of fish bone meal to the rising levels of P in the compost has been known. P levels of compost B, C, D, and E increased at 428.57; 542.85; 657.14 and 914.28% against the compost A (blank). FBM ideal addition indicated in compost B, as much as 15 gr, with a P content of 0.37% and has been passed according standards (0.10% for P). C/N ratio decreased over the 21 days period of composting, with the greatest decline was compost E with a ratio of 16:1. Highest nitrogen (N) levels recorded respectively in compost B and C with value of 1.09% and the lowest of recorded N content was compost A, D and E (1.08%). N content in all samples of compost were eligible minimum N of 0.40%. Carbon (C) is the highest recorded in compost B; 20.20% and the lowest in the compost E; 17.34%. Highest and lowest C levels on the compost has met the minimum C of 9.80%. Composting is done in a bucket as an aerobic composter (with air holes), compost pile turnover for each sample is controlled as much as once/2 days. Mesophilic period (23-450C) occurs during the 21-day period of composting. Compost B has P content of 0.37%, so it has fulfilled the provisions of SNI 19-7030-2004 about the recommended compost standard.

Universal ligation-detection-reaction microarray applied for compost microbes

PubMed Central

Hultman, Jenni; Ritari, Jarmo; Romantschuk, Martin; Paulin, Lars; Auvinen, Petri

2008-01-01

Background Composting is one of the methods utilised in recycling organic communal waste. The composting process is dependent on aerobic microbial activity and proceeds through a succession of different phases each dominated by certain microorganisms. In this study, a ligation-detection-reaction (LDR) based microarray method was adapted for species-level detection of compost microbes characteristic of each stage of the composting process. LDR utilises the specificity of the ligase enzyme to covalently join two adjacently hybridised probes. A zip-oligo is attached to the 3'-end of one probe and fluorescent label to the 5'-end of the other probe. Upon ligation, the probes are combined in the same molecule and can be detected in a specific location on a universal microarray with complementary zip-oligos enabling equivalent hybridisation conditions for all probes. The method was applied to samples from Nordic composting facilities after testing and optimisation with fungal pure cultures and environmental clones. Results Probes targeted for fungi were able to detect 0.1 fmol of target ribosomal PCR product in an artificial reaction mixture containing 100 ng competing fungal ribosomal internal transcribed spacer (ITS) area or herring sperm DNA. The detection level was therefore approximately 0.04% of total DNA. Clone libraries were constructed from eight compost samples. The LDR microarray results were in concordance with the clone library sequencing results. In addition a control probe was used to monitor the per-spot hybridisation efficiency on the array. Conclusion This study demonstrates that the LDR microarray method is capable of sensitive and accurate species-level detection from a complex microbial community. The method can detect key species from compost samples, making it a basis for a tool for compost process monitoring in industrial facilities. PMID:19116002

Changes in microbial and nutrient composition associated with rumen content compost incubation.

PubMed

Shrestha, Karuna; Shrestha, Pramod; Adetutu, Eric M; Walsh, Kerry B; Harrower, Keith M; Ball, Andrew S; Midmore, David J

2011-02-01

Physico-chemical and microbiological investigations were carried out on rumen content material composted for nine months, fresh vermicasts (obtained after passing the same compost through the guts of a mixture of three species of earthworms: Eisenia fetida, Lumbricus rubellus and Perionyx excavates) and microbially enhanced extracts derived from rumen compost, vermicast and vermicast leachate incubated for up to 48 h. Compared to composted rumen contents, vermicast was only improved in terms of microbial biomass C, while vermicast leached extract was significantly higher in NH(4)(+)-N,PO(4)(-)-P, humic acid, bacterial counts and total microbial activity compared to rumen compost extract. Although no difference between treatments was observed in genetic diversity as indicated by DGGE analysis, community level functional diversity of vermicast leached extract (Biolog™) was higher than that of composted rumen contents, vermicast and rumen compost extract indicating an enhancement of microbial activity rather than diversity due to liquid incubation. Copyright © 2010 Elsevier Ltd. All rights reserved.

Liver abscesses in dromedary camels: Pathological characteristics and aerobic bacterial aetiology

PubMed Central

Aljameel, M.A.; Halima, M.O.; ElTigani-Asil, A.E.; Abdalla, A.S.; Abdellatif, M.M.

2014-01-01

The study was carried out at Nyala abattoirs, South Darfur State, Sudan during a period from 2009 to 2011. Slaughtered camels (822) were examined for pathological changes of liver abscesses and identification of the involved aerobic bacteria. Grossly, a total of 111 (13.5%) liver abscesses were recorded in different camel ages; 90 (81.1%) were less than seven years old and 21 (18.9%) were more than seven years old. Histopathology of sectioned tissues revealed necrotic abscesses with infiltration of inflammatory cells, hydropic degeneration with swelling of hepatocytes comprising the sinusoid and different size of vacuoles in the hepatic cells. Proliferation of bile ducts with fibrous tissue and infiltration of inflammatory cells was also recorded. Investigation of bacteria revealed 90 aerobic isolates; they were identified to 52 (57.8%) gram positive cocci, 20 (22.2%) gram positive rods and 18 (20.0%) gram negative rods. Staphylococcus spp. (41.1%), Corynebacterium spp. (17.9%) and Streptococcus spp. (13.3%) were the most frequently identified bacteria involved in liver abscesses of camels in the region. Further studies are required to assess the pathogenicity of bacterial isolates from camel livers. This is particularly important from a public health perspective, since some people of Sudan are known to consume raw camel liver. PMID:26623351

Effect of red mud addition on tetracycline and copper resistance genes and microbial community during the full scale swine manure composting.

PubMed

Wang, Rui; Zhang, Junya; Sui, Qianwen; Wan, Hefeng; Tong, Juan; Chen, Meixue; Wei, Yuansong; Wei, Dongbin

2016-09-01

Swine manure has been considered as the reservoir of antibiotic resistance genes (ARGs). Composting is one of the most suitable technologies for treating livestock manures, and red mud was proved to have a positive effect on nitrogen conservation during composting. This study investigated the abundance of eight tetracycline and three copper resistance genes, the bacterial community during the full scale swine manure composting with or without addition of red mud. The results showed that ARGs in swine manure could be effectively removed through composting (reduced by 2.4log copies/g TS), especially during the thermophilic phase (reduced by 1.5log copies/g TS), which the main contributor might be temperature. Additionally, evolution of bacterial community could also have a great influence on ARGs. Although addition of red mud could enhance nitrogen conservation, it obviously hindered removal of ARGs (reduced by 1.7log copies/g TS) and affected shaping of bacterial community during composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cultivable anaerobic and aerobic bacterial communities in the fermentation chambers of Holotrichia parallela (coleoptera: scarabaeidae) larvae.

PubMed

Zhang, Zhen-Yu; Yuan, Yimin; Ali, Muhammad Waqar; Peng, Tao; Peng, Wei; Raza, Muhammad Fahim; Zhao, Yongshun; Zhang, Hongyu

2018-01-01

As important pests, scarab beetle larvae survive on plant biomass and the microbiota of the fermentation chamber play an important role in the digestion of lignocellulose-rich diets. However, the cultivable microbes, especially the anaerobic cultivable microbes, are still largely unknown. Here, both cultivable anaerobic and aerobic bacterial communities associated with the fermentation chamber of Holotrichia parallela larvae were investigated. In total bacteria cells directly enumerated by the 4', 6-diamidino-2-phenylindole (DAPI) staining method, the viable plate counts of cultivable bacteria in the fermentation chamber accounted for 0.92% of proportion. These cultivable bacteria were prone to attach to the fermentation chamber wall (88.41%) compared to the chamber contents. Anaerobic bacteria were dominant in the cultivable bacteria attaching to the fermentation chamber wall (70.20%), while the quantities of anaerobes and aerobes were similar in the chamber contents. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), fingerprinting and sequence analysis of isolated colonies revealed that the cultivable bacteria are affiliated with class γ-Proteobacteria, Bacteroidia, Actinobacteria, Clostridia and β-Proteobacteria. γ-Proteobacteria was the major type of anaerobic cultivable bacteria and even the only one type of aerobic cultivable bacteria. Taken together, our results suggest, for the first time, that anaerobic microbiota are dominant in cultivable bacteria in the special anoxia niche of the fermentation chamber from H. parallela larvae. These bacterial isolates could be a treasure trove for screening lignocellulytic microbes which are essential for the plant biomass digestion of this scarab species.

Cultivable anaerobic and aerobic bacterial communities in the fermentation chambers of Holotrichia parallela (coleoptera: scarabaeidae) larvae

PubMed Central

Ali, Muhammad Waqar; Peng, Tao; Peng, Wei; Raza, Muhammad Fahim; Zhao, Yongshun; Zhang, Hongyu

2018-01-01

As important pests, scarab beetle larvae survive on plant biomass and the microbiota of the fermentation chamber play an important role in the digestion of lignocellulose-rich diets. However, the cultivable microbes, especially the anaerobic cultivable microbes, are still largely unknown. Here, both cultivable anaerobic and aerobic bacterial communities associated with the fermentation chamber of Holotrichia parallela larvae were investigated. In total bacteria cells directly enumerated by the 4’, 6-diamidino-2-phenylindole (DAPI) staining method, the viable plate counts of cultivable bacteria in the fermentation chamber accounted for 0.92% of proportion. These cultivable bacteria were prone to attach to the fermentation chamber wall (88.41%) compared to the chamber contents. Anaerobic bacteria were dominant in the cultivable bacteria attaching to the fermentation chamber wall (70.20%), while the quantities of anaerobes and aerobes were similar in the chamber contents. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), fingerprinting and sequence analysis of isolated colonies revealed that the cultivable bacteria are affiliated with class γ-Proteobacteria, Bacteroidia, Actinobacteria, Clostridia and β-Proteobacteria. γ-Proteobacteria was the major type of anaerobic cultivable bacteria and even the only one type of aerobic cultivable bacteria. Taken together, our results suggest, for the first time, that anaerobic microbiota are dominant in cultivable bacteria in the special anoxia niche of the fermentation chamber from H. parallela larvae. These bacterial isolates could be a treasure trove for screening lignocellulytic microbes which are essential for the plant biomass digestion of this scarab species. PMID:29304141

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

PubMed

Soobhany, Nuhaa

2018-01-15

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 log 10  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. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial Abundances Predict Methane and Nitrous Oxide Fluxes from a Windrow Composting System

PubMed Central

Li, Shuqing; Song, Lina; Gao, Xiang; Jin, Yaguo; Liu, Shuwei; Shen, Qirong; Zou, Jianwen

2017-01-01

Manure composting is a significant source of atmospheric methane (CH4) and nitrous oxide (N2O) that are two potent greenhouse gases. The CH4 and N2O fluxes are mediated by methanogens and methanotrophs, nitrifying and denitrifying bacteria in composting manure, respectively, while these specific bacterial functional groups may interplay in CH4 and N2O emissions during manure composting. To test the hypothesis that bacterial functional gene abundances regulate greenhouse gas fluxes in windrow composting systems, CH4 and N2O fluxes were simultaneously measured using the chamber method, and molecular techniques were used to quantify the abundances of CH4-related functional genes (mcrA and pmoA genes) and N2O-related functional genes (amoA, narG, nirK, nirS, norB, and nosZ genes). The results indicate that changes in interacting physicochemical parameters in the pile shaped the dynamics of bacterial functional gene abundances. The CH4 and N2O fluxes were correlated with abundances of specific compositional genes in bacterial community. The stepwise regression statistics selected pile temperature, mcrA and NH4+ together as the best predictors for CH4 fluxes, and the model integrating nirK, nosZ with pmoA gene abundances can almost fully explain the dynamics of N2O fluxes over windrow composting. The simulated models were tested against measurements in paddy rice cropping systems, indicating that the models can also be applicable to predicting the response of CH4 and N2O fluxes to elevated atmospheric CO2 concentration and rising temperature. Microbial abundances could be included as indicators in the current carbon and nitrogen biogeochemical models. PMID:28373862

Multicenter Evaluation of the Bruker MALDI Biotyper CA System for the Identification of Clinical Aerobic Gram-Negative Bacterial Isolates

PubMed Central

Faron, Matthew L.; Buchan, Blake W.; Hyke, Josh; Madisen, Neil; Lillie, Jennifer L.; Granato, Paul A.; Wilson, Deborah A.; Procop, Gary W.; Novak-Weekley, Susan; Marlowe, Elizabeth; Cumpio, Joven; Griego-Fullbright, Christen; Kindig, Sandra; Timm, Karen; Young, Stephen; Ledeboer, Nathan A.

2015-01-01

The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA) System (Bruker Daltonics Inc, Billerica, MA) for the identification of aerobic gram-negative bacteria as part of a 510(k) submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score) ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score) value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263) to genus and 98.2% (2,222/2,263) to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria. PMID:26529504

Multicenter Evaluation of the Bruker MALDI Biotyper CA System for the Identification of Clinical Aerobic Gram-Negative Bacterial Isolates.

PubMed

Faron, Matthew L; Buchan, Blake W; Hyke, Josh; Madisen, Neil; Lillie, Jennifer L; Granato, Paul A; Wilson, Deborah A; Procop, Gary W; Novak-Weekley, Susan; Marlowe, Elizabeth; Cumpio, Joven; Griego-Fullbright, Christen; Kindig, Sandra; Timm, Karen; Young, Stephen; Ledeboer, Nathan A

2015-01-01

The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA) System (Bruker Daltonics Inc, Billerica, MA) for the identification of aerobic gram-negative bacteria as part of a 510(k) submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score) ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score) value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263) to genus and 98.2% (2,222/2,263) to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria.

Diversity of pufM genes, involved in aerobic anoxygenic photosynthesis, in the bacterial communities associated with colonial ascidians.

PubMed

Martínez-García, Manuel; Díaz-Valdés, Marta; Antón, Josefa

2010-03-01

Ascidians are invertebrate filter feeders widely distributed in benthic marine environments. A total of 14 different ascidian species were collected from the Western Mediterranean and their bacterial communities were analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene. Results showed that ascidian tissues harbored Bacteria belonging to Gamma- and Alphaproteobacteria classes, some of them phylogenetically related to known aerobic anoxygenic phototrophs (AAPs), such as Roseobacter sp. In addition, hierarchical cluster analysis of DGGE patterns showed a large variability in the bacterial diversity among the different ascidians analyzed, which indicates that they would harbor different bacterial communities. Furthermore, pufM genes, involved in aerobic anoxygenic photosynthesis in marine and freshwater systems, were widely detected within the ascidians analyzed, because nine out of 14 species had pufM genes inside their tissues. The pufM gene was only detected in those specimens that inhabited shallow waters (<77 m of depth). Most pufM gene sequences were very closely related to that of uncultured marine bacteria. Thus, our results suggest that the association of ascidians with bacteria related to AAPs could be a general phenomenon and that ascidian-associated microbiota could use the light that penetrates through the tunic tissue as an energy source.

Effect of inoculation with Penicillium expansum on the microbial community and maturity of compost.

PubMed

Wang, Hong-yuan; Fan, Bing-quan; Hu, Qing-xiu; Yin, Zhong-wei

2011-12-01

Compost prepared from wheat straw and cattle/chicken mature was inoculated with the lignocellulolytic fungus, Penicillium expansum. Compared to uninoculated compost, the inoculated compost exhibited a 150% higher germination index, more than 1.2 g kg(-1)-dw of changes in NH(4)(+)-N concentrations, a ca. 12.0% higher humus content and a lignocellulose degradation that proceeded 57.5% faster. Culture-based determinations of microbial populations demonstrated that aerobic heterotrophic bacteria and fungi were about 1-2 orders of magnitude higher in inoculated than in uninoculated compost. The number of ammonifying, ammonium-oxidizing, nitrite-oxidizing, denitrifying bacteria and cellulose-decomposing bacteria was 6.1-9.0 log(10) CFU g(-1)-dw, 1.2-4.3 log(10) MPN g(-1)-dw, 3.5-6.8 log(10) MPN g(-1)-dw, 3.58-4.34 log(10) MPN g(-1)-dw, 1.4-3.8 log(10)MPN g(-1)-dw, and 4.2-8.8 log(10) CFU g(-1)-dw higher in the compost inoculated with P. expansum. Copyright © 2011 Elsevier Ltd. All rights reserved.

Influence of biochar on heavy metals and microbial community during composting of river sediment with agricultural wastes.

PubMed

Chen, Yaoning; Liu, Yao; Li, Yuanping; Wu, Yanxin; Chen, Yanrong; Zeng, Guangming; Zhang, Jiachao; Li, Hui

2017-11-01

Studies were performed to evaluate influence of biochar addition on physico-chemical process, heavy metals transformation and bacterial community diversity during composting of sediment with agricultural wastes. Simultaneously, the relationships between those parameters including heavy metals and bacterial community compositions were evaluated by redundancy analysis (RDA). The results show that the extraction efficiency of DTPA extractable heavy metals decreased in both piles, and reduced more in pile with biochar addition about 0.1-2.96%. Biochar addition dramatically influenced the bacterial community structure during the composting process. Moreover, the bacterial community composition was significantly correlated with C/N ratio, water soluble carbon (WSC), and organic matter (OM) (P<0.05) in pile with biochar addition; while significantly correlated with temperature, WSC, and C/N ratio in pile which was free of biochar. This study would provide some valuable information for improving the composting for disposal of river sediment with heavy metals contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of biocontrol bacterial strains isolated from a suppressiveness-induced soil after amendment with composted almond shells.

PubMed

Vida, Carmen; Cazorla, Francisco M; de Vicente, Antonio

The improvement in soil quality of avocado crops through organic amendments with composted almond shells has a positive effect on crop yield and plant health, and enhances soil suppressiveness against the phytopathogenic fungus Rosellinia necatrix. In previous studies, induced soil suppressiveness against this pathogen was related to stimulation of Gammaproteobacteria, especially some members of Pseudomonas spp. with biocontrol-related activities. In this work, we isolated bacteria from this suppressiveness-induced amended soil using a selective medium for Pseudomonas-like microorganisms. We characterized the obtained bacterial collection to aid in identification, including metabolic profiles, antagonistic responses, hybridization to biosynthetic genes of antifungal compounds, production of lytic exoenzymatic activities and plant growth-promotion-related traits, and sequenced and compared amplified 16S rDNA genes from representative bacteria. The final selection of representative strains mainly belonged to the genus Pseudomonas, but also included the genera Serratia and Stenotrophomonas. Their biocontrol-related activities were assayed using the experimental avocado model, and results showed that all selected strains protected the avocado roots against R. necatrix. This work confirmed the biocontrol activity of these Gammaproteobacteria-related members against R. necatrix following specific stimulation in a suppressiveness-induced soil after a composted almond shell application. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Dynamic bacterial community changes in the autothermal thermophilic aerobic digestion process with cell lysis activities, shaking and temperature increase.

PubMed

Cheng, Huijun; Asakura, Yuya; Kanda, Kosuke; Fukui, Ryo; Kawano, Yoshihisa; Okugawa, Yuki; Tashiro, Yukihiro; Sakai, Kenji

2018-04-12

Autothermal thermophilic aerobic digestion (ATAD) is conducted for stabilization of sludge waste and is driven by the action of various microorganisms under aerobic conditions. However, the mechanism controlling bacterial community changes during ATAD via three (initial, middle and final) phases is currently unclear. To investigate this mechanism, activity analysis and a microcosm assay with shaking were performed on a bacterial community during the initial, middle, and final phases of incubation. Cell lysis activities toward gram-negative bacteria, but not gram-positive bacteria, were detected in the ATAD samples in the middle and final phases. During shaking incubation in initial-phase samples at 30 °C, major operational taxonomic units (OTUs) related to Acinetobacter indicus and Arcobacter cibarius dramatically increased along with decreases in several major OTUs. In middle-phase samples at 45 °C, we observed a major alteration of OTUs related to Caldicellulosiruptor bescii and Aciditerrimonas ferrireducens, together with distinct decreases in several other OTUs. Final-phase samples maintained a stable bacterial community with major OTUs showing limited similarities to Heliorestis baculata, Caldicellulosiruptorbescii, and Ornatilinea apprima. In conclusion, the changes in the bacterial community observed during ATAD could be partially attributed to the cell lysis activity toward gram-negative bacteria in the middle and final phases. The microcosm assay suggested that certain physical factors, such as a high oxygen supply and shearing forces, also might contribute to bacterial community changes in the initial and middle phases, and to the stable bacterial community in the final phase of ATAD. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

PubMed Central

Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

2015-01-01

Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L-1 concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn’t show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic

Biofuel components change the ecology of bacterial volatile petroleum hydrocarbon degradation in aerobic sandy soil.

PubMed

Elazhari-Ali, Abdulmagid; Singh, Arvind K; Davenport, Russell J; Head, Ian M; Werner, David

2013-02-01

We tested the hypothesis that the biodegradation of volatile petroleum hydrocarbons (VPHs) in aerobic sandy soil is affected by the blending with 10 percent ethanol (E10) or 20 percent biodiesel (B20). When inorganic nutrients were scarce, competition between biofuel and VPH degraders temporarily slowed monoaromatic hydrocarbon degradation. Ethanol had a bigger impact than biodiesel, reflecting the relative ease of ethanol compared to methyl ester biodegradation. Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes revealed that each fuel mixture selected for a distinct bacterial community, each dominated by Pseudomonas spp. Despite lasting impacts on soil bacterial ecology, the overall effects on VHP biodegradation were minor, and average biomass yields were comparable between fuel types, ranging from 0.40 ± 0.16 to 0.51 ± 0.22 g of biomass carbon per gram of fuel carbon degraded. Inorganic nutrient availability had a greater impact on petroleum hydrocarbon biodegradation than fuel composition. Copyright © 2012 Elsevier Ltd. All rights reserved.

Isolation of Thermus strains from hot composts (60 to 80 degrees C).

PubMed Central

Beffa, T; Blanc, M; Lyon, P F; Vogt, G; Marchiani, M; Fischer, J L; Aragno, M

1996-01-01

High numbers (10(7) to 10(10) cells per g [dry weight]) of heterotrophic, gram-negative, rod-shaped, non-sporeforming, aerobic, thermophilic bacteria related to the genus Thermus were isolated from thermogenic composts at temperatures between 65 and 82 degrees C. These bacteria were present in different types of wastes (garden and kitchen wastes and sewage sludge) and in all the industrial composting systems studied (open-air windows, boxes with automated turning and aeration, and closed bioreactors with aeration). Isolates grew fast on a rich complex medium at temperatures between 40 and 80 degrees C, with optimum growth between 65 and 75 degrees C. Nutritional characteristics, total protein profiles, DNA-DNA hybridization (except strain JT4), and restriction fragment length polymorphism profiles of the DNAs coding for the 16S rRNAs (16S rDNAs) showed that Thermus strains isolated from hot composts were closely related to Thermus thermophilus HB8. These newly isolated T. thermophilus strains have probably adapted to the conditions in the hot-compost ecosystem. Heterotrophic, ovalspore-forming, thermophilic bacilli were also isolated from hot composts, but none of the isolates was able to grow at temperatures above 70 degrees C. This is the first report of hot composts as habitats for a high number of thermophilic bacteria related to the genus Thermus. Our study suggests that Thermus strains play an important role in organic-matter degradation during the thermogenic phase (65 to 80 degrees C) of the composting process. PMID:8633870

Spot test analysis of microbial contents during composting of kitchen- and garden biowaste: sampling procedures, bacterial reductions, time-temperature relationships, and their relevance for EU-regulations concerning animal by-products.

PubMed

Bijlsma, P B; de Wit, D H; Duindam, J W; Elsinga, G J; Elsinga, W

2013-01-30

This study was aimed to collect data and develop methodologies to determine if and how Dutch biowaste composting plants can meet the microbiological requirements set out in EU-Regulations (EC) 1774/2002 and (EC) 1069/2009, and to provide the European Food and Safety Authority (EFSA) with data and analysis for evaluation of these regulations. We examined twenty plant locations and four types of composting technologies, all with forced aeration and without an anaerobic digestion phase. Raw biowaste, material after sanitation and compost were sampled by spot test analysis according to a standard protocol, and according to an additional protocol with enhanced hygienic precautions. Samples were analyzed for Escherichia coli, Enterococcaceae and Salmonella content. The latter protocol resulted in improved bacterial reductions after sanitation, whereas in compost Enterococcus levels but not E. coli levels increased substantially with both protocols, due to more thermo-resistant regrowth. Salmonella presence in compost coincided with low temperatures and increased levels of E. coli and Enterococcus, absence of Salmonella was associated with absence of E. coli (74%), but not with absence of Enterococcus (17%). In compost, E. coli and Salmonella showed a comparable time-temperature inactivation pattern. A pilot study with co-composting of biowaste and poultry manure indicated a similar inactivation pattern for ESBL-containing bacteria. We conclude that the abundance of Enterococcus in compost is caused by regrowth and not by (re)contamination, and that E. coli is a more reliable indicator species for the absence/presence of Salmonella in compost. Compliance with current EU-regulations concerning biowaste composting can be shown by spot test analysis at all examined plants, provided that adequate hygienic precautions are taken during sampling. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microbial community structure and dynamics in thermophilic composting viewed through metagenomics and metatranscriptomics

PubMed Central

Antunes, Luciana Principal; Martins, Layla Farage; Pereira, Roberta Verciano; Thomas, Andrew Maltez; Barbosa, Deibs; Lemos, Leandro Nascimento; Silva, Gianluca Major Machado; Moura, Livia Maria Silva; Epamino, George Willian Condomitti; Digiampietri, Luciano Antonio; Lombardi, Karen Cristina; Ramos, Patricia Locosque; Quaggio, Ronaldo Bento; de Oliveira, Julio Cezar Franco; Pascon, Renata Castiglioni; Cruz, João Batista da; da Silva, Aline Maria; Setubal, João Carlos

2016-01-01

Composting is a promising source of new organisms and thermostable enzymes that may be helpful in environmental management and industrial processes. Here we present results of metagenomic- and metatranscriptomic-based analyses of a large composting operation in the São Paulo Zoo Park. This composting exhibits a sustained thermophilic profile (50 °C to 75 °C), which seems to preclude fungal activity. The main novelty of our study is the combination of time-series sampling with shotgun DNA, 16S rRNA gene amplicon, and metatranscriptome high-throughput sequencing, enabling an unprecedented detailed view of microbial community structure, dynamics, and function in this ecosystem. The time-series data showed that the turning procedure has a strong impact on the compost microbiota, restoring to a certain extent the population profile seen at the beginning of the process; and that lignocellulosic biomass deconstruction occurs synergistically and sequentially, with hemicellulose being degraded preferentially to cellulose and lignin. Moreover, our sequencing data allowed near-complete genome reconstruction of five bacterial species previously found in biomass-degrading environments and of a novel biodegrading bacterial species, likely a new genus in the order Bacillales. The data and analyses provided are a rich source for additional investigations of thermophilic composting microbiology. PMID:27941956

Microbial community structure and dynamics in thermophilic composting viewed through metagenomics and metatranscriptomics.

PubMed

Antunes, Luciana Principal; Martins, Layla Farage; Pereira, Roberta Verciano; Thomas, Andrew Maltez; Barbosa, Deibs; Lemos, Leandro Nascimento; Silva, Gianluca Major Machado; Moura, Livia Maria Silva; Epamino, George Willian Condomitti; Digiampietri, Luciano Antonio; Lombardi, Karen Cristina; Ramos, Patricia Locosque; Quaggio, Ronaldo Bento; de Oliveira, Julio Cezar Franco; Pascon, Renata Castiglioni; Cruz, João Batista da; da Silva, Aline Maria; Setubal, João Carlos

2016-12-12

Composting is a promising source of new organisms and thermostable enzymes that may be helpful in environmental management and industrial processes. Here we present results of metagenomic- and metatranscriptomic-based analyses of a large composting operation in the São Paulo Zoo Park. This composting exhibits a sustained thermophilic profile (50 °C to 75 °C), which seems to preclude fungal activity. The main novelty of our study is the combination of time-series sampling with shotgun DNA, 16S rRNA gene amplicon, and metatranscriptome high-throughput sequencing, enabling an unprecedented detailed view of microbial community structure, dynamics, and function in this ecosystem. The time-series data showed that the turning procedure has a strong impact on the compost microbiota, restoring to a certain extent the population profile seen at the beginning of the process; and that lignocellulosic biomass deconstruction occurs synergistically and sequentially, with hemicellulose being degraded preferentially to cellulose and lignin. Moreover, our sequencing data allowed near-complete genome reconstruction of five bacterial species previously found in biomass-degrading environments and of a novel biodegrading bacterial species, likely a new genus in the order Bacillales. The data and analyses provided are a rich source for additional investigations of thermophilic composting microbiology.

Bacterial community analysis of swine manure treated with autothermal thermophilic aerobic digestion.

PubMed

Han, Il; Congeevaram, Shankar; Ki, Dong-Won; Oh, Byoung-Taek; Park, Joonhong

2011-02-01

Due to the environmental problems associated with disposal of livestock sludge, many stabilization studies emphasizing on the sludge volume reduction were performed. However, little is known about the microbial risk present in sludge and its stabilized products. This study microbiologically explored the effects of anaerobic lagoon fermentation (ALF) and autothermal thermophilic aerobic digestion (ATAD) on pathogen-related risk of raw swine manure by using culture-independent 16S rDNA cloning and sequencing methods. In raw swine manure, clones closely related to pathogens such as Dialister pneumosintes, Erysipelothrix rhusiopathiae, Succinivibrioan dextrinosolvens, and Schineria sp. were detected. Meanwhile, in the mesophilic ALF-treated swine manure, bacterial community clones closely related to pathogens such as Schineria sp. and Succinivibrio dextrinosolvens were still detected. Interestingly, the ATAD treatment resulted in no detection of clones closely related to pathogens in the stabilized thermophilic bacterial community, with the predominance of novel Clostridia class populations. These findings support the superiority of ATAD in selectively reducing potential human and animal pathogens compared to ALF, which is a typical manure stabilization method used in livestock farms.

Removal of tetracyclines, sulfonamides, and quinolones by industrial-scale composting and anaerobic digestion processes.

PubMed

Liu, Hang; Pu, Chengjun; Yu, Xiaolu; Sun, Ying; Chen, Junhao

2018-02-15

This study evaluated and compared the removal of antibiotics by industrial-scale composting and anaerobic digestion at different seasons. Twenty compounds belonged to three classes of widely used veterinary antibiotics (i.e., tetracyclines, sulfonamides, and quinolones) were investigated. Results show that of the three groups of antibiotics, tetracyclines were dominant in swine feces and poorly removed by anaerobic digestion with significant accumulation in biosolids, particularly in winter. Compared to that in winter, a much more effective removal (> 97%) by anaerobic digestion was observed for sulfonamides in summer. By contrast, quinolones were the least abundant antibiotics in swine feces and exhibited a higher removal by anaerobic digestion in winter than in summer. The overall removal of antibiotics by aerobic composting could be more than 90% in either winter or summer. Nevertheless, compost products from livestock farms in Beijing contained much higher antibiotics than commercial organic fertilizers. Thus, industrial composting standards should be strictly applied to livestock farms to further remove antibiotics and produce high quality organic fertilizer.

Comparison of U.S. Environmental Protection Agency and U.S. Composting Council microbial detection methods in finished compost and regrowth potential of Salmonella spp. and Escherichia coli O157:H7 in finished compost.

PubMed

Reynnells, Russell; Ingram, David T; Roberts, Cheryl; Stonebraker, Richard; Handy, Eric T; Felton, Gary; Vinyard, Bryan T; Millner, Patricia D; Sharma, Manan

2014-07-01

Bacterial pathogens may survive and regrow in finished compost due to incomplete thermal inactivation during or recontamination after composting. Twenty-nine finished composts were obtained from 19 U.S. states and were separated into three broad feedstock categories: biosolids (n=10), manure (n=4), and yard waste (n=15). Three replicates of each compost were inoculated with ≈ 1-2 log CFU/g of nonpathogenic Escherichia coli, Salmonella spp., and E. coli O157:H7. The U.S. Environmental Protection Agency's (EPA) protocols and U.S. Composting Council's (USCC) Test Methods for the Examination of Composting and Compost (TMECC) were compared to determine which method recovered higher percentages of inoculated E. coli (representing fecal coliforms) and Salmonella spp. from 400-g samples of finished composts. Populations of Salmonella spp. and E. coli O157:H7 were determined over 3 days while stored at 25°C and compared to physicochemical parameters to predict their respective regrowth potentials. EPA Method 1680 recovered significantly (p=0.0003) more inoculated E. coli (68.7%) than TMECC 07.01 (48.1%) due to the EPA method using more compost in the initial homogenate, larger transfer dilutions, and a larger most probable number scheme compared to TMECC 07.01. The recoveries of inoculated Salmonella spp. by Environmental Protection Agency Method 1682 (89.1%) and TMECC 07.02 (72.4%) were not statistically significant (p=0.44). The statistically similar recovery percentages may be explained by the use of a nonselective pre-enrichment step used in both methods. No physicochemical parameter (C:N, moisture content, total organic carbon) was able to serve as a sole predictor of regrowth of Salmonella spp. or E. coli O157:H7 in finished compost. However, statistical analysis revealed that the C:N ratio, total organic carbon, and moisture content all contributed to pathogen regrowth potential in finished composts. It is recommended that the USCC modify TMECC protocols to test

Rapid production of organic fertilizer by dynamic high-temperature aerobic fermentation (DHAF) of food waste.

PubMed

Jiang, Yang; Ju, Meiting; Li, Weizun; Ren, Qingbin; Liu, Le; Chen, Yu; Yang, Qian; Hou, Qidong; Liu, Yiliang

2015-12-01

Keep composting matrix in continuous collision and friction under a relatively high-temperature can significantly accelerate the progress of composting. A bioreactor was designed according to the novel process. Using this technology, organic fertilizer could be produced within 96h. The electric conductivity (EC) and pH value reached to a stable value of 2.35mS/cm and 7.7 after 96h of fermentation. The total carbon/total nitrogen (TC/TN) and dissolved carbon/dissolved nitrogen (DC/DN) ratio was decrease from 27.3 and 36.2 to 17.4 and 7.6 respectively. In contrast, it needed 24days to achieve the similar result in traditional static composting (TSC). Compost particles with different size were analyzed to explore the rapid degradation mechanism of food waste. The evidence of anaerobic fermentation was firstly discovered in aerobic composting. Copyright © 2015 Elsevier Ltd. All rights reserved.

Succession of the functional microbial communities and the metabolic functions in maize straw composting process.

PubMed

Wei, Huawei; Wang, Liuhong; Hassan, Muhammad; Xie, Bing

2018-05-01

Illumina MiSeq sequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) were applied to study the dynamic changes and effects of microbial community structures as well as the metabolic function of bacterial community in maize straw composting process. Results showed that humic acid contents in loosely combined humus (HA1) and stably combined humus (HA2) increased after composting and Staphylococcus, Cellulosimicrobium and Ochrobactrum possibly participated in the transformation of the process. The bacterial communities differed in different stages of the composting. Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria were reported the dominant phyla throughout the process and the relative abundance of the dominant phyla varied significantly (p < 0.05) over time. Moreover, the total phosphorus (TP) had the greatest influence on the microbial community structure among C/N ratio, available phosphorus (AP) and humic substances. Metabolism, cellular processes and environmental information processing might be the primary functions of microbial community during the composting. Copyright © 2018 Elsevier Ltd. All rights reserved.

Feasibility study of recycling cephalosporin C fermentation dregs using co-composting process with activated sludge as co-substrate.

PubMed

Chen, Zhiqiang; Wang, Yao; Wen, Qinxue; Zhang, Shihua; Yang, Lian

2016-09-01

Composting is a potential alternative for cephalosporin C fermentation dregs (CCFDs) compared with incineration process or landfill because of its advantage of recovering nutrients. In this research, CCFDs and activated sludge (AS) were co-composted to analyze the feasibility of recycling the nutrients in CCFDs. A pilot-scale aerobic composting system with an auto-control system was used in this research, and the maturity and security of the compost product were evaluated. The temperature of the composting mixtures was maintained above 55°C for more than 3 days during the composting, indicating that co-composting of CCFDs and AS could reach the compost maturity standard, and the seeds germination index (GI) increased from 17.61% to 68.93% by the end of the composting process (28 days). However, the degradation rate of cephalosporin C (CPC) was only 6.58% during the composting process. Monitoring the quality of antibiotic resistance genes (ARGs) in the composts showed that the log copy of blaTEM in the composts increased from 2.15 in the initial phase to 6.37 after 28 days. Long-term investigation of CPC degradation and ARGs variation was conducted for the composts; CPC could still be detected after the maturity phases. A removal efficiency of 49.10% could be achieved in 110 days, while the log copy of ARGs increased to 7.93. Although a higher GI value (>80.00%) was observed, the risk of recycling the CCFDs compost product into land is still high.

Compost bacteria and fungi that influence growth and development of Agaricus bisporus and other commercial mushrooms.

PubMed

Kertesz, Michael A; Thai, Meghann

2018-02-01

Mushrooms are an important food crop for many millions of people worldwide. The most important edible mushroom is the button mushroom (Agaricus bisporus), an excellent example of sustainable food production which is cultivated on a selective compost produced from recycled agricultural waste products. A diverse population of bacteria and fungi are involved throughout the production of Agaricus. A range of successional taxa convert the wheat straw into compost in the thermophilic composting process. These initially break down readily accessible compounds and release ammonia, and then assimilate cellulose and hemicellulose into compost microbial biomass that forms the primary source of nutrition for the Agaricus mycelium. This key process in composting is performed by a microbial consortium consisting of the thermophilic fungus Mycothermus thermophilus (Scytalidium thermophilum) and a range of thermophilic proteobacteria and actinobacteria, many of which have only recently been identified. Certain bacterial taxa have been shown to promote elongation of the Agaricus hyphae, and bacterial activity is required to induce production of the mushroom fruiting bodies during cropping. Attempts to isolate mushroom growth-promoting bacteria for commercial mushroom production have not yet been successful. Compost bacteria and fungi also cause economically important losses in the cropping process, causing a range of destructive diseases of mushroom hyphae and fruiting bodies. Recent advances in our understanding of the key bacteria and fungi in mushroom compost provide the potential to improve productivity of mushroom compost and to reduce the impact of crop disease.

Composting

ERIC Educational Resources Information Center

Stanley, Andrew; Turner, Geraldine

2010-01-01

Composting can provide both a means of managing organic waste, and a vehicle to teach Science at all levels of schooling. In response to a local organic waste issue a process has been developed to compost waste from an olive oil press and analyse the resultant compost. In this article, the composting process is described in a manner that can be…

Relationship of microbial communities and suppressiveness of Trichoderma fortified composts for pepper seedlings infected by Phytophthora nicotianae.

PubMed

Ros, Margarita; Raut, Iulia; Santisima-Trinidad, Ana Belén; Pascual, Jose Antonio

2017-01-01

The understanding of the dynamic of soil-borne diseases is related to the microbial composition of the rhizosphere which is the key to progress in the field of biological control. Trichoderma spp. is commonly used as a biological control agent. The use of next generation sequencing approaches and quantitative PCR are two successful approaches to assess the effect of using compost as substrate fortified with two Trichoderma strains (Trichoderma harzianum or Trichoderma asperellum) on bacterial and fungal communities in pepper rhizosphere infected with Phytophthora nicotianae. The results showed changes in the bacterial rhizosphere community not attributed to the Trichoderma strain, but to the pathogen infection, while, fungi were not affected by pathogen infection and depended on the type of substrate. The Trichoderma asperellum fortified compost was the most effective combination against the pathogen. This could indicate that the effect of fortified composts is greater than compost itself and the biocontrol effect should be attributed to the Trichoderma strains rather than the compost microbiota, although some microorganisms could help with the biocontrol effect.

Relationship of microbial communities and suppressiveness of Trichoderma fortified composts for pepper seedlings infected by Phytophthora nicotianae

PubMed Central

Ros, Margarita; Raut, Iulia; Santisima-Trinidad, Ana Belén; Pascual, Jose Antonio

2017-01-01

The understanding of the dynamic of soil-borne diseases is related to the microbial composition of the rhizosphere which is the key to progress in the field of biological control. Trichoderma spp. is commonly used as a biological control agent. The use of next generation sequencing approaches and quantitative PCR are two successful approaches to assess the effect of using compost as substrate fortified with two Trichoderma strains (Trichoderma harzianum or Trichoderma asperellum) on bacterial and fungal communities in pepper rhizosphere infected with Phytophthora nicotianae. The results showed changes in the bacterial rhizosphere community not attributed to the Trichoderma strain, but to the pathogen infection, while, fungi were not affected by pathogen infection and depended on the type of substrate. The Trichoderma asperellum fortified compost was the most effective combination against the pathogen. This could indicate that the effect of fortified composts is greater than compost itself and the biocontrol effect should be attributed to the Trichoderma strains rather than the compost microbiota, although some microorganisms could help with the biocontrol effect. PMID:28346470

Effects of Manure Compost Application on Soil Microbial Community Diversity and Soil Microenvironments in a Temperate Cropland in China

PubMed Central

Zhen, Zhen; Liu, Haitao; Wang, Na; Guo, Liyue; Meng, Jie; Ding, Na; Wu, Guanglei; Jiang, Gaoming

2014-01-01

The long-term application of excessive chemical fertilizers has resulted in the degeneration of soil quality parameters such as soil microbial biomass, communities, and nutrient content, which in turn affects crop health, productivity, and soil sustainable productivity. The objective of this study was to develop a rapid and efficient solution for rehabilitating degraded cropland soils by precisely quantifying soil quality parameters through the application of manure compost and bacteria fertilizers or its combination during maize growth. We investigated dynamic impacts on soil microbial count, biomass, basal respiration, community structure diversity, and enzyme activity using six different treatments [no fertilizer (CK), N fertilizer (N), N fertilizer + bacterial fertilizer (NB), manure compost (M), manure compost + bacterial fertilizer (MB), and bacterial fertilizer (B)] in the plowed layer (0–20 cm) of potted soil during various maize growth stages in a temperate cropland of eastern China. Denaturing gradient electrophoresis (DGGE) fingerprinting analysis showed that the structure and composition of bacterial and fungi communities in the six fertilizer treatments varied at different levels. The Shannon index of bacterial and fungi communities displayed the highest value in the MB treatments and the lowest in the N treatment at the maize mature stage. Changes in soil microorganism community structure and diversity after different fertilizer treatments resulted in different microbial properties. Adding manure compost significantly increased the amount of cultivable microorganisms and microbial biomass, thus enhancing soil respiration and enzyme activities (p<0.01), whereas N treatment showed the opposite results (p<0.01). However, B and NB treatments minimally increased the amount of cultivable microorganisms and microbial biomass, with no obvious influence on community structure and soil enzymes. Our findings indicate that the application of manure compost plus

Treatment of Palm Oil Mill Effluent by a Microbial Consortium Developed from Compost Soils

PubMed Central

Nwuche, Charles O.; Ogbonna, James C.

2014-01-01

A method for the aerobic treatment of palm oil mill effluent (POME) was investigated in shake-flask experiments using a consortium developed from POME compost. POME was initially centrifuged at 4,000 g for 15 min and the supernatant was enriched with (NH4)2SO4 (0.5%) and yeast extract (0.25%) to boost its nitrogen content. At optimum pH (pH 4) and temperature (40°C) conditions, the chemical oxygen demand (COD) of the effluent decreased from 10,350 to 1,000 mg/L (90.3%) after 7 days. The total bacterial population determined by plate count enumeration was 2.4 × 106 CFU/mL, while the fungal count was 1.8 × 103 colonies/mL. Bacteria of the genera Pseudomonas, Flavobacterium, Micrococcus, and Bacillus were isolated, while the fungal genera included Aspergillus, Penicillium, Trichoderma, and Mucor. When the isolated species were each inoculated into separate batches of the raw effluent, both pH and COD were unchanged. However, at 75 and 50% POME dilutions, the COD dropped by 52 and 44%, respectively, while the pH increased from 4 to 7.53. POME treatment by aerobic method is sustainable and holds promising prospects for cushioning the environment from the problems associated with the use of anaerobic systems. PMID:27433536

The efficiency of home composting programmes and compost quality.

PubMed

Vázquez, M A; Soto, M

2017-06-01

The efficiency of home composting programmes and the quality of the produced compost was evaluated in eight rural areas carrying out home composting programmes (up to 880 composting bins) for all household biowaste including meat and fish leftovers. Efficiency was analysed in terms of reduction of organic waste collected by the municipal services. An efficiency of 77% on average was obtained, corresponding to a composting rate of 126kg/person·year of biowaste (or 380kg/composter·year). Compost quality was determined for a total of 90 composting bins. The operation of composting bins by users was successful, as indicated by a low C/N ratio (10-15), low inappropriate materials (or physical contaminant materials, mean of 0.27±0.44% dry matter), low heavy metal content (94% of samples met required standards for agricultural use) and high nutrient content (2.1% N, 0.6% P, 2.5% K, 0.7% Mg and 3.7% Ca on average, dry matter). The high moisture (above 70% in 48% of the samples) did not compromise the compost quality. Results of this study show that home composting of household organic waste including meat and fish leftovers is a feasible practice. Home composting helps individuals and families to reduce the amount of household waste at the same time gaining a fertiliser material (compost) of excellent quality for gardens or vegetable plots. Copyright © 2017 Elsevier Ltd. All rights reserved.

Co-composting of two-phase olive-mill pomace and poultry manure with tomato harvest stalks.

PubMed

Sülük, Kemal; Tosun, İsmail; Ekinci, Kamil

2017-04-01

In this study, two-phase olive-mill pomace with poultry manure and chopped tomato harvest stalks were composted at different initial carbon/nitrogen (C/N) ratios with fixed free air space of 35%. Composting experiment was carried out in the 15 aerobic reactors made of stainless steel and was monitored for 28 days. During the composting process, temperature, moisture content, organic matter (OM), pH, electrical conductivity, oxygen and carbon dioxide concentrations, total carbon, total nitrogen, ammonium nitrogen ([Formula: see text]), nitrate nitrogen ([Formula: see text]), and total phosphorus were monitored. Compost mass and volume changes were determined at the beginning, during remixings, and at the end of composting. While the stabilization period took less time for the mixtures containing a high amount of poultry manure, the mixtures having the high portion of two-phase olive-mill pomace took a longer time due to the structure of olive stone and its lignin content. Dry matter loss (range: 18.1-34.0%.) in the mixtures increased with an increase in the share of poultry manure and tomato stalks in the initial mixture. OM loss (range: 21.7-46.1%) for tomato stalks (measured separately) during composting increased due to an increase in the ratio of poultry manure in the initial mixtures.

Effect of covering composting piles with mature compost on ammonia emission and microbial community structure of composting process.

PubMed

Maeda, Koki; Morioka, Riki; Osada, Takashi

2009-01-01

To control ammonia (NH(3)) volatilization from the dairy cattle (Bos taurus) manure composting process, a compost pile was covered with mature compost and the gas emissions evaluated using the dynamic chamber system. The peak of NH(3) volatilization observed immediately after piling up of the compost was reduced from 196 to 62 mg/m(3) by covering the compost pile with mature compost. The accumulation of NH(4)-N to the covered mature compost was also observed. Covering and mixing the compost with mature compost had no effect on the microbial community structure. However, over time the microbial community structure changed because of a decrease in easily degradable organic compounds in the compost piles. The availability of volatile fatty acids (VFA) was considered to be important for microbial community structure in the compost. After the VFA had disappeared, the NO(3)-N concentration increased and the cellulose degrading bacteria such as Cytophaga increased in number.

Dynamics of oxygen supply and consumption during mainstream large-scale composting in China.

PubMed

Zeng, Jianfei; Shen, Xiuli; Han, Lujia; Huang, Guangqun

2016-11-01

This study characterized some physicochemical and biological parameters to systematically evaluate the dynamics of oxygen supply and consumption during large-scale trough composting in China. The results showed that long active phases, low maximum temperatures, low organic matter losses and high pore methane concentrations were observed in different composting layers. Pore oxygen concentrations in the top, middle and bottom layers maintained <5vol.% for 40, 42 and 45days, respectively, which accounted for more than 89% of the whole period. After each mechanical turning, oxygen was consumed at a stable respiration rate to a concentration of 5vol.% in no more than 99min and remained anaerobic in the subsequent static condition. The daily percentage of time under aerobic condition was no more than 14% of a single day. Therefore, improving FAS, adjusting aeration interval or combining turning with forced aeration was suggested to provide sufficient oxygen during composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sequential anaerobic-aerobic degradation of munitions waste.

PubMed

Ibeanusi, Victor; Jeilani, Yassin; Houston, Samantha; Doss, Danielle; Coley, Bianca

2009-01-01

A sequential anaerobic-aerobic biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was studied. The results demonstrated that: (i) a complete degradation of RDX was achieved within 20 days using a consortium of bacteria from a wastewater activated sludge, (ii) RDX degradation did not occur under aerobic conditions alone, (iii) RDX-degrading bacterial strain that was isolated from the activated sludge completely degraded RDX within 2 days, and (iv) RDX- induced protein expressions were observed in the RDX-degrading bacterial strain. Based on fatty acid composition and a confirmation with a 16S rRNA analysis, the RDX-degrading bacterial strain was identified as a Bacillus pumilus-GC subgroup B.

A comparative study of composting the solid fraction of dairy manure with or without bulking material: Performance and microbial community dynamics.

PubMed

Zhong, Xiao-Zhong; Ma, Shi-Chun; Wang, Shi-Peng; Wang, Ting-Ting; Sun, Zhao-Yong; Tang, Yue-Qin; Deng, Yu; Kida, Kenji

2018-01-01

The present study compared the development of various physicochemical properties and the composition of microbial communities involved in the composting process in the solid fraction of dairy manure (SFDM) with a sawdust-regulated SFDM (RDM). The changes in several primary physicochemical properties were similar in the two composting processes, and both resulted in mature end-products within 48days. The bacterial communities in both composting processes primarily comprised Proteobacteria and Bacteroidetes. Firmicutes were predominant in the thermophilic phase, whereas Chloroflexi, Planctomycetes, and Nitrospirae were more abundant in the final mature phase. Furthermore, the succession of bacteria in both groups proceeded in a similar pattern, suggesting that the effects of the bulking material on bacterial dynamics were minor. These results demonstrate the feasibility of composting using only the SFDM, reflected by the evolution of physicochemical properties and the microbial communities involved in the composting process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Frequency and antimicrobial susceptibility of aerobic bacterial vaginal isolates.

PubMed

Tariq, Nabia; Jaffery, Tara; Ayub, Rukhsana; Alam, Ali Yawar; Javid, Mahmud Haider; Shafique, Shamsa

2006-03-01

To determine the frequency and antimicrobial susceptibility of aerobic bacterial isolates from high vaginal swab cultures. Cross-sectional survey. Shifa International Hospital, Islamabad, from January 2003 to February 2004. The subjects included 136 symptomatic women attending Obstetrics and Gynecology Out-Patient Department. A proforma was filled to document the demographic details, presenting complaint and examination findings. High vaginal swabs were taken for gram staining, culture and antimicrobial sensitivity testing using standard microbiologic techniques. Normal flora was isolated in 30% of the cases, followed by Candida spp. (21.3%), Enterococcus spp. (14.7%), E.coli (10.2%), Beta hemolytic Streptococcus spp. (7.3%), Staphylococcus spp. (4.4%), Enterobacter spp. (4.4%), while Streptococcus pyogenes, Staphylococcus epidermidis and Klebsiella spp. were isolated 1.5% each. Enterococcus, Staphylococcus and Streptococcus were mostly sensitive to penicillin and amoxicillin while E.coli and Klebsiella were sensitive to (piperacillin-Tazobactum, Imipenem and vancomycin. Enterococci species showed significant resistance to aminoglycoside antibiotics (68.8% to 81.3%) resistance to vancomycin was 5%. Thirty percent of symptomatic patients had normal flora on culture. Candida spp was the most frequent pathogen isolated. Co-amoxiclav should be used as empiric therapy until culture-sensitivity report is available.

Feasibility of composting combinations of sewage sludge, olive mill waste and winery waste in a rotary drum reactor.

PubMed

Fernández, Francisco J; Sánchez-Arias, Virginia; Rodríguez, Lourdes; Villaseñor, José

2010-10-01

Representative samples of the following biowastes typically generated in Castilla La Mancha (Spain) were composted using a pilot-scale closed rotary drum composting reactor provided with adequate control systems: waste from the olive oil industry (olive mill waste; OMW), winery-distillery waste containing basically grape stalk and exhausted grape marc (WDW), and domestic sewage sludge. Composting these biowastes was only successful when using a bulking agent or if sufficient porosity was supported. OMW waste composting was not possible, probably because of its negligible porosity, which likely caused anaerobic conditions. WDW was successfully composted using a mixture of solid wastes generated from the same winery. SS was also successfully composted, although its higher heavy metal content was a limitation. Co-composting was an adequate strategy because the improved mixture characteristics helped to maintain optimal operating conditions. By co-composting, the duration of the thermophilic period increased, the final maturity level improved and OMW was successfully composted. Using the proposed reactor, composting could be accelerated compared to classical outdoor techniques, enabling easy control of the process. Moisture could be easily controlled by wet air feeding and leachate recirculation. Inline outlet gas analysis helped to control aerobic conditions without excessive aeration. The temperature reached high values in a few days, and sufficient thermal requirements for pathogen removal were met. The correct combination of biowastes along with appropriate reactor design would allow composting as a management option for such abundant biowastes in this part of Spain. (c) 2010 Elsevier Ltd. All rights reserved.

Anaerobically digested food waste in compost for Agaricus bisporus and Agaricus subrufescens and its effect on mushroom productivity.

PubMed

Stoknes, Ketil; Beyer, David M; Norgaard, Erik

2013-07-01

Source-separated food waste is increasingly being treated by means of hygienisation followed by anaerobic digestion. The fibrous digester residue (digestate) is a potential mushroom substrate, while heat from the biogas can provide steam for the cultivation process. Using bag experiments the present study explored digestate as a full substitute for chicken manure conventionally used in mushroom composts. After mixing, a rapid temperature development in the compost was stimulated by a small amount of chicken manure, as aerobic microbial seeding. Mechanical elimination of lumps was essential for full mycelial colonisation. Three straw digestate composts had Agaricus bisporus mushroom yields above 370 g kg⁻¹ substrate. The optimal compost water content was 600 g kg⁻¹ at inoculation, and high digestate content (up to 500 g kg⁻¹ by dry weight) did not affect yield for this species. High yields of A. subrufescens (200 g kg⁻¹) were related to drier composts of lower digestate content (more straw) and lower pH values at inoculation. Digestate successfully substituted chicken manure in straw composts without affecting mushroom yields for both species. There were no clear differences between straw digestate and control composts in terms of mushroom dry matter, size, nitrogen or ash content. © 2012 Society of Chemical Industry.

Nitrate capture and slow release in biochar amended compost and soil.

PubMed

Hagemann, Nikolas; Kammann, Claudia I; Schmidt, Hans-Peter; Kappler, Andreas; Behrens, Sebastian

2017-01-01

Slow release of nitrate by charred organic matter used as a soil amendment (i.e. biochar) was recently suggested as potential mechanism of nutrient delivery to plants which may explain some agronomic benefits of biochar. So far, isolated soil-aged and composted biochar particles were shown to release considerable amounts of nitrate only in extended (>1 h) extractions ("slow release"). In this study, we quantified nitrate and ammonium release by biochar-amended soil and compost during up to 167 h of repeated extractions in up to six consecutive steps to determine the effect of biochar on the overall mineral nitrogen retention. We used composts produced from mixed manures amended with three contrasting biochars prior to aerobic composting and a loamy soil that was amended with biochar three years prior to analysis and compared both to non-biochar amended controls. Composts were extracted with 2 M KCl at 22°C and 65°C, after sterilization, after treatment with H2O2, after removing biochar particles or without any modification. Soils were extracted with 2 M KCl at 22°C. Ammonium was continuously released during the extractions, independent of biochar amendment and is probably the result of abiotic ammonification. For the pure compost, nitrate extraction was complete after 1 h, while from biochar-amended composts, up to 30% of total nitrate extracted was only released during subsequent extraction steps. The loamy soil released 70% of its total nitrate amount in subsequent extractions, the biochar-amended soil 58%. However, biochar amendment doubled the amount of total extractable nitrate. Thus, biochar nitrate capture can be a relevant contribution to the overall nitrate retention in agroecosystems. Our results also indicate that the total nitrate amount in biochar amended soils and composts may frequently be underestimated. Furthermore, biochars could prevent nitrate loss from agroecosystems and may be developed into slow-release fertilizers to reduce global N

Nitrate capture and slow release in biochar amended compost and soil

PubMed Central

Kammann, Claudia I.; Schmidt, Hans-Peter; Kappler, Andreas; Behrens, Sebastian

2017-01-01

Slow release of nitrate by charred organic matter used as a soil amendment (i.e. biochar) was recently suggested as potential mechanism of nutrient delivery to plants which may explain some agronomic benefits of biochar. So far, isolated soil-aged and composted biochar particles were shown to release considerable amounts of nitrate only in extended (>1 h) extractions (“slow release”). In this study, we quantified nitrate and ammonium release by biochar-amended soil and compost during up to 167 h of repeated extractions in up to six consecutive steps to determine the effect of biochar on the overall mineral nitrogen retention. We used composts produced from mixed manures amended with three contrasting biochars prior to aerobic composting and a loamy soil that was amended with biochar three years prior to analysis and compared both to non-biochar amended controls. Composts were extracted with 2 M KCl at 22°C and 65°C, after sterilization, after treatment with H2O2, after removing biochar particles or without any modification. Soils were extracted with 2 M KCl at 22°C. Ammonium was continuously released during the extractions, independent of biochar amendment and is probably the result of abiotic ammonification. For the pure compost, nitrate extraction was complete after 1 h, while from biochar-amended composts, up to 30% of total nitrate extracted was only released during subsequent extraction steps. The loamy soil released 70% of its total nitrate amount in subsequent extractions, the biochar-amended soil 58%. However, biochar amendment doubled the amount of total extractable nitrate. Thus, biochar nitrate capture can be a relevant contribution to the overall nitrate retention in agroecosystems. Our results also indicate that the total nitrate amount in biochar amended soils and composts may frequently be underestimated. Furthermore, biochars could prevent nitrate loss from agroecosystems and may be developed into slow-release fertilizers to reduce global N

Effect of gamma irradiation on hyperthermal composting microorganisms for feasible application in space

NASA Astrophysics Data System (ADS)

Yoon, Minchul; Choi, Jong-il; Yamashita, Masamichi

2013-05-01

The composting system is the most efficient method for processing organic waste in space; however, the composting activity of microorganisms can be altered by cosmic rays. In this study, the effect of ionizing irradiation on composting bacteria was investigated. Sequence analyses of amplified 16S rRNA, 18S rRNA, and amoA genes were used to identify hyperthermal composting microorganisms. The viability of microorganisms in compost soil after gamma irradiation was directly determined using LIVE/DEAD BacLight viability kit. The dominant bacterial genera were Weissella cibaria and Leuconostoc sp., and the fungal genera were Metschnikowia bicuspidata and Pichia guilliermondii. Gamma irradiation up to a dose of 10 kGy did not significantly alter the microbial population. Furthermore, amylase and cellulase activities were maintained after high-dose gamma irradiation. Our results show that hyperthermal microorganisms can be used to recycle agricultural and fermented material in space stations and other human-inhabiting facilities on the Moon, Mars, and other planets.

Bacterial community and groundwater quality changes in an anaerobic aquifer during groundwater recharge with aerobic recycled water.

PubMed

Ginige, Maneesha P; Kaksonen, Anna H; Morris, Christina; Shackelton, Mark; Patterson, Bradley M

2013-09-01

Managed aquifer recharge offers the opportunity to manage groundwater resources by storing water in aquifers when in surplus and thus increase the amount of groundwater available for abstraction during high demand. The Water Corporation of Western Australia (WA) is undertaking a Groundwater Replenishment Trial to evaluate the effects of recharging aerobic recycled water (secondary treated wastewater subjected to ultrafiltration, reverse osmosis, and ultraviolet disinfection) into the anaerobic Leederville aquifer in Perth, WA. Using culture-independent methods, this study showed the presence of Actinobacteria, Alphaproteobacteria, Bacilli, Betaproteobacteria, Cytophaga, Flavobacteria, Gammaproteobacteria, and Sphingobacteria, and a decrease in microbial diversity with an increase in depth of aquifer. Assessment of physico-chemical and microbiological properties of groundwater before and after recharge revealed that recharging the aquifer with aerobic recycled water resulted in elevated redox potentials in the aquifer and increased bacterial numbers, but reduced microbial diversity. The increase in bacterial numbers and reduced microbial diversity in groundwater could be a reflection of an increased denitrifier and sulfur-oxidizing populations in the aquifer, as a result of the increased availability of nitrate, oxygen, and residual organic matter. This is consistent with the geochemical data that showed pyrite oxidation and denitrification within the aquifer after recycled water recharge commenced. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Assessment of bacterial and structural dynamics in aerobic granular biofilms

PubMed Central

Weissbrodt, David G.; Neu, Thomas R.; Kuhlicke, Ute; Rappaz, Yoan; Holliger, Christof

2013-01-01

Aerobic granular sludge (AGS) is based on self-granulated flocs forming mobile biofilms with a gel-like consistence. Bacterial and structural dynamics from flocs to granules were followed in anaerobic-aerobic sequencing batch reactors (SBR) fed with synthetic wastewater, namely a bubble column (BC-SBR) operated under wash-out conditions for fast granulation, and two stirred-tank enrichments of Accumulibacter (PAO-SBR) and Competibacter (GAO-SBR) operated at steady-state. In the BC-SBR, granules formed within 2 weeks by swelling of Zoogloea colonies around flocs, developing subsequently smooth zoogloeal biofilms. However, Zoogloea predominance (37–79%) led to deteriorated nutrient removal during the first months of reactor operation. Upon maturation, improved nitrification (80–100%), nitrogen removal (43–83%), and high but unstable dephosphatation (75–100%) were obtained. Proliferation of dense clusters of nitrifiers, Accumulibacter, and Competibacter from granule cores outwards resulted in heterogeneous bioaggregates, inside which only low abundance Zoogloea (<5%) were detected in biofilm interstices. The presence of different extracellular glycoconjugates detected by fluorescence lectin-binding analysis showed the complex nature of the intracellular matrix of these granules. In the PAO-SBR, granulation occurred within two months with abundant and active Accumulibacter populations (56 ± 10%) that were selected under full anaerobic uptake of volatile fatty acids and that aggregated as dense clusters within heterogeneous granules. Flocs self-granulated in the GAO-SBR after 480 days during a period of over-aeration caused by biofilm growth on the oxygen sensor. Granules were dominated by heterogeneous clusters of Competibacter (37 ± 11%). Zoogloea were never abundant in biomass of both PAO- and GAO-SBRs. This study showed that Zoogloea, Accumulibacter, and Competibacter affiliates can form granules, and that the granulation mechanisms rely on the dominant

Effects of drying pretreatment and particle size adjustment on the composting process of discarded flue-cured tobacco leaves.

PubMed

Zhao, Gui-Hong; Yu, Yan-Ling; Zhou, Xiang-Tong; Lu, Bin-Yu; Li, Zi-Mu; Feng, Yu-Jie

2017-05-01

The main characteristic of discarded flue-cured tobacco leaves is their high nicotine content. Aerobic composting is an effective method to decrease the nicotine level in tobacco leaves and stabilize tobacco wastes. However, high levels of nicotine in discarded flue-cured tobacco leaves complicate tobacco waste composting. This work proposes a drying pretreatment process to reduce the nicotine content in discarded flue-cured tobacco leaves and thus enhance its carbon-to-nitrogen ratio to a suitable level for composting. The effect of another pretreatment method, particle size adjustment, on composting efficiency was also tested in this work. The results indicated that the air-dried (nicotine content: 1.35%) and relatively long discarded flue-cured tobacco leaves (25 mm) had a higher composting efficiency than damp (nicotine content: 1.57%) and short discarded flue-cured tobacco leaves (15 mm). When dry/25 mm discarded flue-cured tobacco leaves mixed with tobacco stems in an 8:2 ratio was composted at a temperature above 55 °C for 9 days, the nicotine content dropped from 1.29% to 0.28%. Since the discarded flue-cured tobacco leaves was successfully composted to a fertile and harmless material, the germination index values increased to 85.2%. The drying pretreatment and particle size adjustment offered ideal physical and chemical conditions to support microbial growth and bioactivity during the composting process, resulting in efficient conversion of discarded flue-cured tobacco leaves into a high quality and mature compost.

Survival of pathogenic bacteria in compost with special reference to Escherichia coli.

PubMed

Gong, Chun-ming; Koichi, Inoue; Shunji, Inanaga; Takashi, Someya

2005-01-01

Application of compost in agricultural practice could potentially cause contamination of foodstuffs with pathogenic bacteria such as Escherichia coli O157:H7 (E. Coli O157). We investigated pathogenic bacteria in compost collected from the compost facilities, and evaluated the survival of E. coli K12 and O157 in laboratory experiments. Out of 19 compost product samples, coliform bacteria and salmonella were detected in 7 and 3 samples respectively. The number of coliform bacteria was 1.8 x 10(2) to 2.5 x 10(6) CFU/g dw and that of salmonella was 4.2 x 10(1) to 6.0 x 10(3) CFU/g dw. Moreover, coliform bacteria, fecal coliform, E. coli and salmonella were detected during composting at 54 degrees C to 67 degrees C. The results indicated that moisture content was a very important factor to the heat sensitivity of pathogenic bacteria in compost, E. coil in compost of high moisture content was more sensitive than that in compost of low moisture content, cells harvested in logarithmic phase was more sensitive than these in stationary phase, and E. coli K12 was more sensitive than E. coli O157. Based on the D values, the lethal time of E. coli K12 and O157 from l0(8) to 10(0) CFU/g dw were 16.3 and 28.8 min, respectively, at 60 degrees C in compost with 40% moisture content. However, some E. coil cells survived in composting process at 54 degrees C to 67 degrees C. Water potential (low moisture content) and physiological aspects of bacteria (stationary phase) could explain only in part of the prolonged survival of E. coil in compost, and there should be some other factors that are conducive to bacterial survival in compost.

Effects of mixing and covering with mature compost on gaseous emissions during composting.

PubMed

Luo, Wen Hai; Yuan, Jing; Luo, Yi Ming; Li, Guo Xue; Nghiem, Long D; Price, William E

2014-12-01

This study investigated effects of mature compost on gaseous emissions during composting using pig manure amended with corn stalks. Apart from a control treatment, three treatments were conducted with the addition of 5% (wet weight of raw materials) of mature compost: (a) mixing raw materials with mature compost at the beginning of composting; (b) covering raw materials with mature compost throughout the experimental period; and (c) covering raw materials with mature compost at the start of composting, but incorporating it into composting pile on day 6 of composting. Mature compost used for the last treatment was inoculated with 2% (wet weight) of raw materials of strain M5 (a methanotrophic bacterium) solution. During 30-d of composting, three treatments with the addition of mature compost could reduce CH4 emission by 53-64% and N2O emission by 43-71%. However, covering with mature compost throughout the experimental period increased cumulative NH3 emission by 61%, although it could reduce 34% NH3 emission in the first 3d. Inoculating strain M5 in mature compost covered on the top of composting pile within first 6d enhanced CH4 oxidation, but simultaneously increased N2O emission. In addition, mixing with mature compost could improve compost maturity. Given the operational convenience in practice, covering with mature compost and then incorporating it into composting pile is a suitable approach to mitigate gaseous emissions during composting. Copyright © 2014. Published by Elsevier Ltd.

Innovative dual-step management of semi-aerobic landfill in a tropical climate.

PubMed

Lavagnolo, Maria Cristina; Grossule, Valentina; Raga, Roberto

2018-04-01

Despite concerted efforts to innovate the solid waste management (SWM) system, land disposal continues to represent the most widely used technology in the treatment of urban solid waste worldwide. On the other hand, landfilling is an unavoidable step in closing the material cycle, since final residues, although minimized, need to be safely disposed of and confined. In recent years, the implementation of more sustainable landfilling aims to achieve the Final Storage Quality conditions as fast as possible. In particular, semi-aerobic landfill appears to represent an effective solution for use in the poorest economies due to lower management costs and shorter aftercare resulting from aerobic stabilisation of the waste. Nevertheless, the implementation of a semi-aerobic landfill in a tropical climate may affect the correct functioning of the plant: a lack of moisture during the dry season and heavy rainfalls during the wet season could negatively affect performance of both the degradation process, and of leachate and biogas management. This paper illustrates the results obtained through the experimentation of a potential dual-step management of semi-aerobic landfilling in a tropical climate in which composting process was reproduced during the dry season and subsequently flushing (high rainfall rate) during the wet period. Eight bioreactors specifically designed: four operated under anaerobic conditions and four under semi-aerobic conditions; half of the reactors were filled with high organic content waste, half with residual waste obtained following enhanced source segregation. The synergic effect of the subsequent phases (composting and flushing) in the semi-aerobic landfill was evaluated on the basis of both types of waste. Biogas production, leachate composition and waste stabilization were analysed during the trial and at the end of each step, and compared in view of the performance of anaerobic reactors. The results obtained underlined the effectiveness of the

Assessment of microbial contamination within working environments of different types of composting plants.

PubMed

Gutarowska, Beata; Skóra, Justyna; Stępień, Łukasz; Szponar, Bogumiła; Otlewska, Anna; Pielech-Przybylska, Katarzyna

2015-04-01

The objective of the study was to determine the degree of microbiological contamination, type of microflora, bioaerosol particle size distribution, and concentration of endotoxins in dust in different types of composting plants. In addition, this study provides a list of indicator microorganisms that pose a biological threat in composting facilities, based on their prevalence within the workplace, source of isolation, and health hazards. We undertook microbiological analysis of the air, work surfaces, and compost, and assessed the particle size distribution of bioaerosols using a six-stage Andersen sampler. Endotoxins were determined using gas chromatography-mass spectrometry (GC-MS). Microbial identification was undertaken both microscopically and using biochemical tests. The predominant bacterial and fungal species were identified using 16S rRNA and ITS1/2 analysis, respectively. The number of mesophilic microorganisms in composting plants amounted to 6.9×10(2)-2.5×10(4) CFU/m3 in the air, 2.9×10(2)-3.3×10(3) CFU/100 cm2 on surfaces, and 2.2×10(5)-2.4×10(7) CFU/g in compost. Qualitative analysis revealed 75 microbial strains in composting plants, with filamentous fungi being the largest group of microorganisms, accounting for as many as 38 isolates. The total amount of endotoxins was 0.0062-0.0140 nmol/mg of dust. The dust fraction with aerodynamic particle diameter of 0.65-1.1 μm accounted for 28-39% of bacterial aerosols and 4-13% of fungal aerosols. We propose the following strains as indicators of harmful biological agent contamination: Bacillus cereus, Aspergillus fumigatus, Cladosporium cladosporioides, C. herbarum, Mucor hiemalis, and Rhizopus oryzae for both types of composting plants, and Bacillus pumilus, Mucor fragilis, Penicillium svalbardense, and P. crustosum for green waste composting plants. The biological hazards posed within these plants are due to the presence of potentially pathogenic microorganisms and the inhalation of respirable

Sialidase activity in aerobic vaginitis is equal to levels during bacterial vaginosis.

PubMed

Marconi, C; Donders, G G G; Bellen, G; Brown, D R; Parada, C M G L; Silva, M G

2013-04-01

To evaluate levels of proinflammatory cytokines and sialidase activity in aerobic vaginitis (AV) in relation to normal vaginal flora and bacterial vaginosis (BV). In this cross-sectional study, a total of 682 consecutive non-pregnant women attending the gynecology service were assessed and 408 women were included. Vaginal rinsing samples were collected from 223 women with microscopic finding of BV (n=98), aerobic vaginitis (n=25) and normal flora (n=100). Samples were tested for interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, and sialidase activity. Compared to women with normal flora, vaginal levels of IL-1β were highly increased in both BV and AV (p<0.0001). Significantly higher vaginal IL-6 was detected in AV (p<0.0001) but not in BV, in relation to normal flora. Women with AV also presented increased IL-8 levels (p<0.001), while those with BV presented levels similar to normal flora. Sialidase was increased in BV and AV compared with the normal group (p<0.0001) but no difference in sialidase activity was observed between BV and AV. A more intense inflammatory host response occurs for AV than for BV when compared with normal flora. Furthermore, the increased sialidase activity in AV and BV indicates that both abnormal vaginal flora types can be harmful to the maintenance of a healthy vaginal environment. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effect of long-term different fertilization on bacterial community structures and diversity in citrus orchard soil of volcanic ash.

PubMed

Joa, Jae Ho; Weon, Hang Yeon; Hyun, Hae Nam; Jeun, Young Chull; Koh, Sang Wook

2014-12-01

This study was conducted to assess bacterial species richness, diversity and community distribution according to different fertilization regimes for 16 years in citrus orchard soil of volcanic ash. Soil samples were collected and analyzed from Compost (cattle manure, 2,000 kg/10a), 1/2 NPK+compost (14-20-14+2,000 kg/10a), NPK+compost (28-40-28+2,000 kg/10a), NPK (28-40-28 kg/10a), 3 NPK (84-120-84 kg/10a), and Control (no fertilization) plot which have been managed in the same manners with compost and different amount of chemical fertilization. The range of pyrosequencing reads and OTUs were 4,687-7,330 and 1,790-3,695, respectively. Species richness estimates such as Ace, Chao1, and Shannon index were higher in 1/2 NPK+compost than other treatments, which were 15,202, 9,112, 7.7, respectively. Dominant bacterial groups at level of phylum were Proteobacteria, Acidobacteria, and Actinobacteria. Those were occupied at 70.9% in 1/2 NPK+compost. Dominant bacterial groups at level of genus were Pseudolabrys, Bradyrhizobium, and Acidobacteria. Those were distributed at 14.4% of a total of bacteria in Compost. Soil pH displayed significantly closely related to bacterial species richness estimates such as Ace, Chao1 (p<0.05) and Shannon index (p<0.01). However, it showed the negative correlation with exchangeable aluminum contents (p<0.05). In conclusion, diversity of bacterial community in citrus orchard soil was affected by fertilization management, soil pH changes and characteristics of volcanic ash.

Orbital abscess bacterial isolates and in vitro antimicrobial susceptibility patterns in dogs and cats.

PubMed

Wang, Annie L; Ledbetter, Eric C; Kern, Thomas J

2009-01-01

To determine bacterial populations, in vitro antimicrobial susceptibility patterns, and sources of microorganisms for dogs and cats with orbital abscess. In total, 34 dogs and 7 cats with orbital abscess participated in the study. Medical records of dogs and cats with a clinical diagnosis of orbital abscess, confirmed by cytologic or histopathologic evaluation of orbital specimens, were reviewed from the years 1990 to 2007. Animal signalment, presumptive source of microorganisms and mechanism of orbital introduction, bacterial isolates, and aerobic bacterial in vitro antimicrobial susceptibility test results were recorded. Percentages of susceptible aerobic bacterial isolates were compared among antimicrobials. Twenty dogs and five cats had positive culture results. The most frequent bacterial genera isolated from dogs were Staphylococcus, Escherichia, Bacteroides, Clostridium and Pasteurella. The most frequent bacterial genera isolated from cats were Pasteurella and Bacteroides. Aerobic bacterial isolates from dogs had the highest percentage of susceptibility to amikacin, ceftiofur, gentamicin, imipenem, ticarcillin and trimethoprim-sulfamethoxazole. Aerobic bacterial isolates from dogs had the lowest percentage of susceptibility to ampicillin, clindamycin, erythromycin and penicillin. Antimicrobial resistance was uncommon among feline aerobic bacterial isolates. The most commonly identified routes of orbital bacteria introduction were extension from adjacent anatomical structures, penetrating exogenous trauma, and foreign bodies. Mixed aerobic and anaerobic bacterial infections of the orbit occur commonly in dogs and cats. On the basis of aerobic and anaerobic bacterial isolates and in vitro susceptibility testing of aerobic bacterial isolates, cephalosporins, extended-spectrum penicillins, potentiated-penicillins and carbapenems are recommended for initial antimicrobial therapy of orbital abscess in dogs and cats.

Co-composting of municipal solid waste mixed with matured sewage sludge: The relationship between N2O emissions and denitrifying gene abundance.

PubMed

Bian, Rongxing; Sun, Yingjie; Li, Weihua; Ma, Qiang; Chai, Xiaoli

2017-12-01

Aerobic composting is an alternative measure to the disposal of municipal solid waste (MSW). However, it produces nitrous oxide (N 2 O), a highly potent greenhouse via microbial nitrification and denitrification. In this study, the effects of matured sewage sludge (MSS) amendment on N 2 O emissions and the inter-relationships between N 2 O emissions and the abundance of denitrifying bacteria were investigated during aerobic composting of MSW. The results demonstrated that MSW composting with MSS amendments (C1, and C2, with a MSW to MSS ratio of 2:1 and 4:1, (v/v), respectively) significantly increased N 2 O emissions during the initial stage, yet contributed to the mitigation of N 2 O emissions during the cooling and maturation stage. MSS amended composting emitted a total of 18.4%-25.7% less N 2 O than the control treatment without MSS amendment (CK). Matured sewage sludge amendment also significantly altered the abundance of denitrifying bacteria. The quantification of denitrifying functional genes revealed that the N 2 O emission rate had a significant positive correlation with the abundance of the nirS, nirK genes in both treatments with MSS amendment. The nosZ/(nirS + nirK) ratio could be a good indicator for predicting N 2 O emissions. The higher N 2 O emission rate during the initial stage of composting mixed with MSS was characterized by lower nosZ/(nirS + nirK) ratios, compared to CK treatment. Higher ratios of nosZ/(nirS + nirK) were measured during the cooling and maturation stage in treatments with MSS which resulted in a reduction of the N 2 O emissions. These results demonstrated that MSS amendment could be a valid strategy for mitigating N 2 O emissions during MSW composting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Decline in extractable antibiotics in manure-based composts during composting.

PubMed

Kim, K-R; Owens, G; Ok, Y S; Park, W-K; Lee, D B; Kwon, S-I

2012-01-01

A wide variety of antibiotics have been detected in natural water samples and this is of potential concern because of the adverse environmental effects of such antibiotic residues. One of the main sources of antibiotics effluence to the surrounding environment is livestock manures which often contain elevated concentrations of veterinary antibiotics (VAs) which survive digestion in the animal stomach following application in animal husbandry practices. In Korea, livestock manures are normally used for compost production indicating that there is potential for antibiotic release to the environment through compost application to agricultural lands. Therefore, reduction of the amount of VAs in composts is crucial. The purpose of this study was to understand the influence of the composting process and the components of the compost on the levels of three common classes of antibiotics (tetracyclines, sulfonamides, and macrolides). Composted materials at different stages of composting were collected from compost manufacturing plants and the variation in antibiotic concentrations was determined. Three different antibiotics, chlortetracycline (CTC), sulfamethazine (SMZ), and tylosin (TYL) at three different concentrations (2, 10, and 20mgkg(-1)) were also applied to a mixture of pig manure and sawdust and the mixtures incubated using a laboratory scale composting apparatus to monitor the changes in antibiotic concentrations during composting together with the physicochemical properties of the composts. During composting, in both field and lab-scale investigations, the concentrations of all three different antibiotics declined below the relevant Korean guideline values (0.8mgkg(-1) for tetracyclines, 0.2mgkg(-1) for sulfonamides and 1.0mgkg(-1) for macrolides). The decline of tetracycline and sulfonamide concentrations was highly dependent on the presence of sawdust while there was no influence of sawdust on TYL decline. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparative study on treatment of kitchen wastewater using a mixed microalgal culture and an aerobic bacterial culture: kinetic evaluation and FAME analysis.

PubMed

Katam, Keerthi; Bhattacharyya, Debraj

2018-05-12

Microalgae-based treatment systems have been successfully used for the polishing of domestic wastewater. Research is underway in studying the suitability of using these systems as main treatment units. This study focuses on comparing the performances of a mixed microalgal culture and an aerobic bacterial culture, based on the kinetic evaluation, in removing organic carbon from a kitchen wastewater. The two systems were operated at six different solid retention times (SRTs)-2, 4, 6, 8, 10, and 12 days in continuous mode. The influent and effluent samples were analyzed for chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN), phosphates, and surfactants. Steady-state kinetics (k, K s , Y, and k d ) for organic carbon removal were obtained by fitting experimental data in linearized Michaelis-Menten and Monod equations. The mixed microalgal system showed similar or better performance in COD and TN removal (88 and 85%, respectively) when compared with the COD and TN removal by the aerobic bacterial system (89 and 48%). A maximum lipid yield of 40% (w/w of dry biomass) was observed in the microalgal system. Saturated fatty acids accounted for 50% of the total observed FAME species. The study indicates that the mixed microalgal culture is capable of treating kitchen wastewater and has the potential to replace aerobic bacteria in biological treatment systems in certain cases.

Changes induced by Trichoderma harzianum in suppressive compost controlling Fusarium wilt.

PubMed

Blaya, Josefa; López-Mondéjar, Rubén; Lloret, Eva; Pascual, Jose Antonio; Ros, Margarita

2013-09-01

The addition of species of Trichoderma to compost is a widespread technique used to control different plant diseases. The biological control activity of these species is mainly attributable to a combination of several mechanisms of action, which may affect the microbiota involved in the suppressiveness of compost. This study was therefore performed to determine the effect of inoculation of Trichoderma harzianum (T. harzianum) on compost, focusing on bacterial community structure (16S rRNA) and chitinase gene diversity. In addition, the ability of vineyard pruning waste compost, amended (GCTh) or not (GC) with T. harzianum, to suppress Fusarium wilt was evaluated. The addition of T. harzianum resulted in a high relative abundance of certain chitinolytic bacteria as well as in remarkable protection against Fusarium oxysporum comparable to that induced by compost GC. Moreover, variations in the abiotic characteristics of the media, such as pH, C, N and iron levels, were observed. Despite the lower diversity of chitinolytic bacteria found in GCTh, the high relative abundance of Streptomyces spp. may be involved in the suppressiveness of this growing media. The higher degree of compost suppressiveness achieved after the addition of T. harzianum may be due not only to its biocontrol ability, but also to changes promoted in both abiotic and biotic characteristics of the growing media. Copyright © 2013 Elsevier Inc. All rights reserved.

Suppressive composts from organic wastes as agents of biological control of fusariosis in Tatartan Republic (Russia)

NASA Astrophysics Data System (ADS)

Gumerova, Raushaniya; Galitskaya, Polina; Beru, Franchesca; Selivanovskaya, Svetlana

2015-04-01

Plant diseases are one of the seriously limiting factors of agriculture efficiency around the world. Diseases caused by fungi are the major threat to plants. Crop protection in modern agriculture heavily depends on chemical fungicides. Disadvantages of chemical pesticides soon became apparent as damage to the environment and a hazard to human health. In this regard use of biopesticides becomes an attractive alternative method of plant protection. For biological control of fungal plant diseases, separate bacterial or fungal strains as well as their communities can be used. Biopreparations must consist of microbes that are typical for local climate and soil conditions and therefore are able to survive in environments for a long time. Another option of plant pests' biological control is implementation of suppressive composts made of agricultural or other organic wastes. These composts can not only prevent the development of plant diseases, but also improve the soil fertility. The objective of this work was estimation of potential of composts and strains isolated from these composts as means for biological control of fusariosis that is one of the most widespread plant soil born disease. The composts were made up of the commonly produced agricultural wastes produced in Tatarstan Republic (Russia). Fusarium oxysporum f. sp. radicis-lycopersici was used as a model phytopathogen. Ten types of organic waste (Goat manure (GM), Chicken dung (CD), Chicken dung with straw addition (CS), Rabbit dung (RD), Cow manure (CM), Rerotting pork manure (RPM), Fresh pork manure (FPM), Pork manure with sawdust and straw (PMS), the remains of plants and leaves (PL), the vegetable waste (VW) were sampled in the big farms situated in Tatarstan Republic which is one of the main agricultural regions of Russia. The initial wastes were composted for 150 days. Further, the following characteristics of the composts were assessed: pH, electro conductivity, TOC, DOC, Ntot. On petri dishes with meat

Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco.

PubMed

Makan, Abdelhadi; Assobhei, Omar; Mountadar, Mohammed

2013-01-03

This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts.For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times.This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications.

Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco

PubMed Central

2013-01-01

This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts. For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times. This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications. PMID:23369502

Physical analyses of compost from composting plants in Brazil.

PubMed

Barreira, L P; Philippi Junior, A; Rodrigues, M S; Tenório, J A S

2008-01-01

Nowadays the composting process has shown itself to be an alternative in the treatment of municipal solid wastes by composting plants. However, although more than 50% of the waste generated by the Brazilian population is composed of matter susceptible to organic composting, this process is, still today, insufficiently developed in Brazil, due to low compost quality and lack of investments in the sector. The objective of this work was to use physical analyses to evaluate the quality of the compost produced at 14 operative composting plants in the Sao Paulo State in Brazil. For this purpose, size distribution and total inert content tests were done. The results were analyzed by grouping the plants according to their productive processes: plants with a rotating drum, plants with shredders or mills, and plants without treatment after the sorting conveyor belt. Compost quality was analyzed considering the limits imposed by the Brazilian Legislation and the European standards for inert contents. The size distribution tests showed the influence of the machinery after the sorting conveyer on the granule sizes as well as the inert content, which contributes to the presence of materials that reduce the quality of the final product.

Characterisation of volatile organic compounds (VOCs) released by the composting of different waste matrices.

PubMed

Schiavon, Marco; Martini, Luca Matteo; Corrà, Cesare; Scapinello, Marco; Coller, Graziano; Tosi, Paolo; Ragazzi, Marco

2017-12-01

The complaints arising from the problem of odorants released by composting plants may impede the construction of new composting facilities, preclude the proper activity of existing facilities or even lead to their closure, with negative implications for waste management and local economy. Improving the knowledge on VOC emissions from composting processes is of particular importance since different VOCs imply different odour impacts. To this purpose, three different organic matrices were studied in this work: dewatered sewage sludge (M1), digested organic fraction of municipal solid waste (M2) and untreated food waste (M3). The three matrices were aerobically biodegraded in a bench-scale bioreactor simulating composting conditions. A homemade device sampled the process air from each treatment at defined time intervals. The samples were analysed for VOC detection. The information on the concentrations of the detected VOCs was combined with the VOC-specific odour thresholds to estimate the relative weight of each biodegraded matrix in terms of odour impact. When the odour formation was at its maximum, the waste gas from the composting of M3 showed a total odour concentration about 60 and 15,000 times higher than those resulting from the composting of M1 and M2, respectively. Ethyl isovalerate showed the highest contribution to the total odour concentration (>99%). Terpenes (α-pinene, β-pinene, p-cymene and limonene) were abundantly present in M2 and M3, while sulphides (dimethyl sulphide and dimethyl disulphide) were the dominant components of M1. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Effects of nitrogen preserving agent on composting process and nitrogen loss of Eichhornia crassipes].

PubMed

Li, Sen; Luo, Xue Mei; Tu, Wei Guo; Fan, Hua; Gou, Xiao Lin; DU, Yu Long; Li, Ling; Wang, Qiong Yao

2017-04-18

To study the effects of nitrogen preserving agent (NPA) on composting process and nitrogen loss of Eichhornia crassipes, an aerobic composting was conducted for 35 days using four treatments. The NPA was prepared by mixing ferrous sulfate, humic acid sodium, and superphosphate (M:M:M=75:20:5). Four treatments were included with different mass ratios of NPA, including 0% (CK), 1% (PN1), 2% (PN2), and 3% (PN3). The physical and chemical properties, N fraction concentrations, ammonia volatilization, and N loss rates were measured and explored during composting process. The results showed that the pile temperature of NPA treatments were higher than that of CK in thermophillic period, however their water contents were significantly (P＜0.05) lower than that in CK in cooling period. At the end of composting, the concentrations of total nitrogen and organic nitrogen increased significantly in NPA treatments (P＜0.05), and their highest concentrations in the PN3 treatment were 16.3% and 13.2% higher than those in CK, respectively. The ammonia volatilization losses of PN1, PN2 and PN3 treatments were 25.9%, 31.5% and 42.4% lower than that of CK, respectively, however, their nitrogen fixation rates reached 31.3%, 40.7% and 72.2% respectively. Therefore, adding NPA could accelerate start-up speed, shorten composting time, and also could effectively reduce ammonia volatilizations and nitrogen loss in the composting process of E. crassipes. Therefore, PN3 showed the best effects of nitrogen preserving.

Composting and compost utilization: accounting of greenhouse gases and global warming contributions.

PubMed

Boldrin, Alessio; Andersen, Jacob K; Møller, Jacob; Christensen, Thomas H; Favoino, Enzo

2009-11-01

Greenhouse gas (GHG) emissions related to composting of organic waste and the use of compost were assessed from a waste management perspective. The GHG accounting for composting includes use of electricity and fuels, emissions of methane and nitrous oxide from the composting process, and savings obtained by the use of the compost. The GHG account depends on waste type and composition (kitchen organics, garden waste), technology type (open systems, closed systems, home composting), the efficiency of off-gas cleaning at enclosed composting systems, and the use of the compost. The latter is an important issue and is related to the long-term binding of carbon in the soil, to related effects in terms of soil improvement and to what the compost substitutes; this could be fertilizer and peat for soil improvement or for growth media production. The overall global warming factor (GWF) for composting therefore varies between significant savings (-900 kg CO(2)-equivalents tonne(-1) wet waste (ww)) and a net load (300 kg CO(2)-equivalents tonne( -1) ww). The major savings are obtained by use of compost as a substitute for peat in the production of growth media. However, it may be difficult for a specific composting plant to document how the compost is used and what it actually substitutes for. Two cases representing various technologies were assessed showing how GHG accounting can be done when specific information and data are available.

Aerobic treatment of swine manure to enhance anaerobic digestion and microalgal cultivation.

PubMed

Bekoe, Dominic; Wang, Lijun; Zhang, Bo; Scott Todd, Matthew; Shahbazi, Abolghasem

2018-02-01

Aerobic treatment of swine manure was coupled with anaerobic digestion and microalgal cultivation. A 14-day aerobic treatment reduced the total solid content of swine manure by >15%. Ammonia and carbon dioxide were stripped by the air supplied, and this off-gas was further used to aerate the culture of Chlorella vulgaris. The microalgal growth rates in Bristol medium and the wastewater with the off-gas increased from 0.08 to 0.22 g/L/d and from 0.15 to 0.24 g/L/d, respectively. Meanwhile, the aerobically treated swine manure showed a higher methane yield during anaerobic digestion. The experimental results were used to establish a demonstration unit consisting of a 100 L composter, a 200 L anaerobic digester, a 60 L tubular photobioreactor, and a 300 L micro-open raceway pond.

Biomass ash reutilisation as an additive in the composting process of organic fraction of municipal solid waste.

PubMed

Asquer, Carla; Cappai, Giovanna; De Gioannis, Giorgia; Muntoni, Aldo; Piredda, Martina; Spiga, Daniela

2017-11-01

In this work the effects of selected types of biomass ash on the composting process and final product quality were studied by conducting a 96-day long experiment where the source separated organic fraction of municipal waste, mixed with wood prunings that served as bulking agent, was added with 0%, 2%, 4% and 8% wt/wt of biomass ash. The evolution over time of the main process parameters was observed, and the final composts were characterised. On the basis of the results, both the composting process and the quality of the final product were improved by ash addition. Enhanced volatile solids reduction and biological stability (up to 32% and 52%, respectively, as compared to the unamended product) were attained when ash was added, since ash favored the aerobic degradation by acting asa physical conditioner. In the final products, higher humification of organic matter (expressed in terms of the humification index, that was 2.25 times higher in the most-enriched compost than in the unamended one) and total Ca, K, Mg and P content were observed when ash was used. The latter aspect may influence the composts marketability positively, particularly with regards to potassium and phosphorus. The heavy metals content, that is regarded as the main environmental disadvantage when using ash asa composting additive, did not negatively affect the final composts quality. However, some other controversial effects of ash, related to the moisture and temperature values attained during the process, pH (8.8-9.2 as compared to 8.2 of the unamended compost) and electrical conductivity levels (up to 53% higher as compared to the unamended compost) in the final composts, were also observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Two-phase olive mill waste composting: enhancement of the composting rate and compost quality by grape stalks addition.

PubMed

Cayuela, Maria Luz; Sánchez-Monedero, Miguel A; Roig, Asunción

2010-06-01

Two-phase olive mill waste (TPOMW) is a semisolid sludge generated by the olive oil industry. Its recycling as a soil amendment, either unprocessed or composted, is being promoted as a beneficial agricultural practice in the Mediterranean area. One of the major difficulties when composting TPOMW is the compaction of the material due to its dough-like texture, which leads to an inadequate aeration. For this reason, the addition of bulking agents is particularly important to attain a proper composting process. In this study we followed the evolution of two composting mixtures (A and B) prepared by mixing equal amounts of TPOMW and sheep litter (SL) (in a dry weight basis). In pile B grape stalks (GS) were added (10% dry weight) as bulking agent to study their effect on the development of the composting process and the final compost quality. The incorporation of grape stalks to the composting mixture changed the organic matter (OM) degradation dynamics and notably reduced the total amount of lixiviates. The evolution of several maturation indices (C/N, germination index, water soluble carbon, humification indices, C/N in the leachates) showed a faster and improved composting process when GS were added. Moreover, chemical (NH4+, NO3(-), cation exchange capacity, macro and micronutrients, heavy metals) and physical properties (bulk and real densities, air content, total water holding capacity, porosity) of the final composts were analysed and confirmed the superior quality of the compost where GS were added.

Citrus compost and its water extract for cultivation of melon plants in greenhouse nurseries. Evaluation of nutriactive and biocontrol effects.

PubMed

Bernal-Vicente, A; Ros, M; Tittarelli, F; Intrigliolo, F; Pascual, J A

2008-12-01

Two different types of citrus composts, and their water extracts, were tested with regard to their utilisations as partial substitutes for peat in growing media for melon seedlings in greenhouse nurseries. Both compost showed higher plant growth than peat. Compost composed by citrus waste and green residue (C2) showed greater plant growth than compost obtained from the same organic matrices mentioned above further the addition of sludge obtained from citrus industry (C1). Compost C2 showed a greater auxinic effect than C1 and it was the only one that showed cytokinic effect. Both composts also demonstrated a biocontrol effect against Fusarium oxysporum for melon plants: the effects were also higher in C2 than in C1. Higher number of isolated fungi was active against F. oxysporum in compost C2, than compost C1. No different bacterial biocontrol efficacy was observed between both composts. The water extracts of both composts gave lower plant yields than their solid matrices, their relative effects being similar to those of the solid composts (C2 extract gave higher plant yields than the extract from C1). The biocontrol effects of compost water extracts followed the same trend.

Novel multifunctional plant growth-promoting bacteria in co-compost of palm oil industry waste.

PubMed

Chin, Clament Fui Seung; Furuya, Yoshihide; Zainudin, Mohd Huzairi Mohd; Ramli, Norhayati; Hassan, Mohd Ali; Tashiro, Yukihiro; Sakai, Kenji

2017-11-01

Previously, a unique co-compost produced by composting empty fruit bunch with anaerobic sludge from palm oil mill effluent, which contributed to establishing a zero-emission industry in Malaysia. Little was known about the bacterial functions during the composting process and fertilization capacity of this co-compost. We isolated 100 strains from the co-compost on 7 types of enumeration media and screened 25 strains using in vitro tests for 12 traits, grouping them according to three functions: plant growth promoting (fixation of nitrogen; solubilization of phosphorus, potassium, and silicate; production of 3-indoleacetic acid, ammonia, and siderophore), biocontrolling (production of chitinase and anti-Ganoderma activity), and composting (degradation of lignin, xylan, and cellulose). Using 16S rRNA gene sequence analysis, 25 strains with strong or multi-functional traits were found belong to the genera Bacillus, Paenibacillus, Citrobacter, Enterobacter, and Kosakonia. Furthermore, several strains of Citrobacter sedlakii exhibited a plant growth-stimulation in vivo komatsuna plant cultivation test. In addition, we isolated several multifunctional strains; Bacillus tequilensis CE4 (biocontrolling and composting), Enterobacter cloacae subsp. dissolvens B3 (plant growth promoting and biocontrolling), and C. sedlakii CESi7 (plant growth promoting and composting). Some bacteria in the co-compost play significant roles during the composting process and plant cultivation after fertilization, and some multifunctional strains have potential for use in accelerating the biodegradation of lignocellulosic biomass, protecting against Ganoderma boninense infection, and increasing the yield of palm oil. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Genotoxicity of the extracts from the compost of the organic and the total municipal garbage using three plant bioassays.

PubMed

Cabrera, G L; Rodriguez, D M; Maruri, A B

1999-05-19

The production of compost is one of the alternatives for the disposal of non-hazardous solid wastes. Compost is used in agriculture and gardening as fertilizer. In the State of Queretaro, Mexico, there is a project to produce compost from the municipal garbage which could be used as a fertilizer. The presence of mutagenic compounds in the compost could be a major disadvantage for the selection of this alternative. For the above reason, this study was initiated as a pilot project to determine the potential mutagenic activity in the compost using three plant bioassays: Tradescantia-micronucleus (Trad-MCN), Tradescantia stamen hair mutations (Trad-SHM) and Allium root anaphase aberrations (AL-RAA). Compost was produced using both aerobic and anaerobic processes from either organic waste (from the residential area) or from the total components of the municipal garbage. Extractions from the compost were done using distilled water and organic solvents and shaking the sample for about 12 h under relatively low temperatures (15-20 degrees C). Plant cuttings of Tradescantia or the roots of Allium were treated by submerging them in the extracts. Three replicates of each sample were analyzed in each one of the three bioassays. As expected the samples of compost from the total garbage showed a higher genetoxicity than those from organic waste. In conclusion, there are some substances present in the compost capable of inducing genotoxicity in the plant assays and therefore there must be some restrictions for its use as a fertilizer. Copyright 1999 Elsevier Science B.V.

Aerobic Growth on Nitroglycerin as the Sole Carbon, Nitrogen, and Energy Source by a Mixed Bacterial Culture

PubMed Central

Accashian, John V.; Vinopal, Robert T.; Kim, Byung-Joon; Smets, Barth F.

1998-01-01

Nitroglycerin (glycerol trinitrate [GTN]), an explosive and vasodilatory compound, was metabolized by mixed microbial cultures from aeration tank sludge previously exposed to GTN. Aerobic enrichment cultures removed GTN rapidly in the absence of a supplemental carbon source. Complete denitration of GTN, provided as the sole C and N source, was observed in aerobic batch cultures and proceeded stepwise via the dinitrate and mononitrate isomers, with successive steps occurring at lower rates. The denitration of all glycerol nitrate esters was found to be concomitant, and 1,2-glycerol dinitrate (1,2-GDN) and 2-glycerol mononitrate (2-GMN) were the primary GDN and GMN isomers observed. Denitration of GTN resulted in release of primarily nitrite-N, indicating a reductive denitration mechanism. Biomass growth at the expense of GTN was verified by optical density and plate count measurements. The kinetics of GTN biotransformation were 10-fold faster than reported for complete GTN denitration under anaerobic conditions. A maximum specific growth rate of 0.048 ± 0.005 h−1 (mean ± standard deviation) was estimated for the mixed culture at 25°C. Evidence of GTN toxicity was observed at GTN concentrations above 0.3 mM. To our knowledge, this is the first report of complete denitration of GTN used as a primary growth substrate by a bacterial culture under aerobic conditions. PMID:9726874

Additives aided composting of green waste: effects on organic matter degradation, compost maturity, and quality of the finished compost.

PubMed

Gabhane, Jagdish; William, S P M Prince; Bidyadhar, Rajnikant; Bhilawe, Priya; Anand, Duraisamy; Vaidya, Atul N; Wate, Satish R

2012-06-01

The effect of various additives such as fly ash, phosphogypsum, jaggery, lime, and polyethylene glycol on green waste composting was investigated through assessing their influence on microbial growth, enzymatic activities, organic matter degradation, bulk density, quality of finished compost including gradation test, heavy metal analysis, etc. A perusal of results showed that addition of jaggery and polyethylene glycol were helpful to facilitate composting process as they significantly influenced the growth of microbes and cellulase activity. The quality of finished compost prepared from jaggery and polyethylene glycol added treatments were superior to other composts, wherein reduction in C/N ratio was more than 8% in jaggery treatment. All other parameters of compost quality including gradation test also favored jaggery and polyethylene glycol as the best additives for green waste composting. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of Thiobacillus thioparus 1904 and sulphur addition on odour emission during aerobic composting.

PubMed

Gu, Wenjie; Sun, Wen; Lu, Yusheng; Li, Xia; Xu, Peizhi; Xie, Kaizhi; Sun, Lili; Wu, Hangtao

2018-02-01

The effects of sulphur and Thiobacillus thioparus 1904 on odour emissions during composting were studied. Results indicated that the sulphur addition reduced the pH and decreased cumulative emission of ammonia and the nitrogen loss by 47.80% and 44.23%, respectively, but the amount of volatile sulphur compounds (VSCs) and the sulphur loss increased. The addition of T. thioparus 1904 effectively reduced the cumulative emissions of H 2 S, methyl sulphide, methanethiol, dimethyl disulphide and the sulphur loss by 33.24%, 81.24%, 32.70%, 54.22% and 54.24%, respectively. T. thioparus 1904 also limited the nitrogen loss. The combined application of sulphur and T. thioparus 1904 resulted in the greatest amount of nitrogen retention. The accumulation of ammonia emissions was reduced by 63.33%, and the nitrogen loss was reduced by 71.93%. The combined treatment did not increase the emission of VSCs. The application of sulphur and T. thioparus 1904 may help to control the odour of compost. Copyright © 2017. Published by Elsevier Ltd.

Activity of nadifloxacin (OPC-7251) and seven other antimicrobial agents against aerobic and anaerobic Gram-positive bacteria isolated from bacterial skin infections.

PubMed

Nenoff, P; Haustein, U-F; Hittel, N

2004-10-01

The in vitro activity of nadifloxacin (OPC-7251), a novel topical fluoroquinolone, was assessed and compared with those of ofloxacin, oxacillin, flucloxacillin, cefotiam, erythromycin, clindamycin, and gentamicin against 144 Gram-positive bacteria: 28 Staphylococcus aureus, 10 Streptococcus spp., 68 coagulase-negative staphylococci (CNS), 36 Propionibacterium acnes, and 2 Propionibacterium granulosum strains. All strains originated from bacterial-infected skin disease and were isolated from patients with impetigo, secondary infected wounds, folliculitis and sycosis vulgaris, and impetiginized dermatitis. In vitro susceptibility of all clinical isolates was tested by agar dilution procedure and minimum inhibitory concentrations (MICs) were determined. Nadifloxacin was active against all aerobic and anaerobic isolates. MIC(90) (MIC at which 90% of the isolates are inhibited) was 0.1 microg/ml for S. aureus, 0.78 microg/ml for both Streptococcus spp. and CNS, and 0.39 microg/ml for Propionibacterium spp. On the other hand, resistant strains with MICs exceeding 12.5 mug/ml were found in tests with the other antibiotics. For both CNS and Propionibacterium acnes, MIC(90) values > or =100 microg/ml were demonstrated for erythromycin. Ofloxacin, cefotiam, erythromycin, clindamycin and gentamicin exhibited MIC(90) values < or =1 microg/ml for some bacterial species tested. Both oxacillin and flucloxacillin were active against all investigated bacterial species with MIC(90) values < or =1 microg/ml. In summary, nadifloxacin, a topical fluoroquinolone, was found to be highly active against aerobic and anaerobic bacteria isolated from patients with infected skin disease, and seems to be a new alternative for topical antibiotic treatment in bacterial skin infections.

Pyrosequence analysis of bacterial communities in aerobic bioreactors treating polycyclic aromatic hydrocarbon-contaminated soil

PubMed Central

Richardson, Stephen D.; Aitken, Michael D.

2011-01-01

Two aerobic, lab-scale, slurry-phase bioreactors were used to examine the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil and the associated bacterial communities. The two bioreactors were operated under semi-continuous (draw-and-fill) conditions at a residence time of 35 days, but one was fed weekly and the other monthly. Most of the quantified PAHs, including high-molecular-weight compounds, were removed to a greater extent in the weekly-fed bioreactor, which achieved total PAH removal of 76%. Molecular analyses, including pyrosequencing of 16S rRNA genes, revealed significant shifts in the soil bacterial communities after introduction to the bioreactors and differences in the abundance and types of bacteria in each of the bioreactors. The weekly-fed bioreactor displayed a more stable bacterial community with gradual changes over time, whereas the monthly-fed bioreactor community was less consistent and may have been more strongly influenced by the influx of untreated soil during feeding. Phylogenetic groups containing known PAH-degrading bacteria previously identified through stable-isotope probing of the untreated soil were differentially affected by bioreactor conditions. Sequences from members of the Acidovorax and Sphingomonas genera, as well as the uncultivated ‘‘Pyrene Group 2’’ were abundant in the bioreactors. However, the relative abundances of sequences from the Pseudomonas, Sphingobium, and Pseudoxanthomonas genera, as well as from a group of unclassified anthracene degraders, were much lower in the bioreactors compared to the untreated soil. PMID:21369833

Coffee husk composting: An investigation of the process using molecular and non-molecular tools

PubMed Central

Shemekite, Fekadu; Gómez-Brandón, María; Franke-Whittle, Ingrid H.; Praehauser, Barbara; Insam, Heribert; Assefa, Fassil

2014-01-01

Various parameters were measured during a 90-day composting process of coffee husk with cow dung (Pile 1), with fruit/vegetable wastes (Pile 2) and coffee husk alone (Pile 3). Samples were collected on days 0, 32 and 90 for chemical and microbiological analyses. C/N ratios of Piles 1 and 2 decreased significantly over the 90 days. The highest bacterial counts at the start of the process and highest actinobacterial counts at the end of the process (Piles 1 and 2) indicated microbial succession with concomitant production of compost relevant enzymes. Denaturing gradient gel electrophoresis of rDNA and COMPOCHIP microarray analysis indicated distinctive community shifts during the composting process, with day 0 samples clustering separately from the 32 and 90-day samples. This study, using a multi-parameter approach, has revealed differences in quality and species diversity of the three composts. PMID:24369846

Study and assessment of segregated biowaste composting: The case study of Attica municipalities.

PubMed

Malamis, D; Bourka, A; Stamatopoulou, Ε; Moustakas, K; Skiadi, O; Loizidou, M

2017-12-01

This work aims to assess the operation of the first large scale segregated biowaste composting scheme in Greece to divert Household Food Waste (HFW) from landfill and produce a material which can be recovered and used as compost. The source separation and collection of HFW was deployed in selected areas in Attica Region serving about 3700 households. Sorted HFW is collected & transported to the Mechanical and Biological Treatment (MBT) plant in Attica Region that has been designed to produce Compost Like Output (CLO) from mixed MSW. The MBT facility has been adjusted in order to receive and treat aerobically HFW mixed with shredded green waste in a dedicated composting tunnel. The composting process was monitored against temperature, moisture and oxygen content indicating that the biological conditions are sufficiently developed. The product quality was examined and assessed against the quality specifications of EU End of Waste Criteria for biowaste subjected to composting aiming to specify whether the HFW that has undergone recovery ceases to be waste and can be classified as compost. More specifically, the heavy metals concentrations (Cr, Cu, Ni, Cd, Pb, Zn and Hg) are within the set limits and much lower compared to the CLO material that currently is being produced at the MBT plant. In regard to the hygienic requirements of the product it has been found that the process conditions result in a pathogen free material (i.e. E. Coli and Salmonella) which does not favor the growth of viable weeds and plant propagules, while it acquires sufficient organic matter content for soil fertilization. Noticeable physical impurities (mainly fractions of glass) have been detected exceeding the quality control threshold limit of 0.5% w/w (plastics, metals and glass). The latter is related to the missorted materials and to the limited pre-treatment configurations prior to composting. The above findings indicate that effective source separation of biowaste is prerequisite for

The use of fatty acid methyl esters as biomarkers to determine aerobic, facultatively aerobic and anaerobic communities in wastewater treatment systems.

PubMed

Quezada, Maribel; Buitrón, Germán; Moreno-Andrade, Iván; Moreno, Gloria; López-Marín, Luz M

2007-01-01

The use of fatty acid methyl esters (FAME) as biomarkers to identify groups of microorganisms was studied. A database was constructed using previously published results that identify FAME biomarkers for aerobic, anaerobic and facultatively aerobic bacteria. FAME profiles obtained from pure cultures were utilized to confirm the predicted presence of biomarkers. Principal component analysis demonstrated that the FAME profiles can be used to determine the incidence of these bacterial groups. The presence of aerobic, anaerobic and facultatively aerobic bacteria in the communities, in four bioreactors being used to treat different wastewaters, was investigated by applying FAME biomarkers.

Effects of co-composting of lincomycin mycelia dregs with furfural slag on lincomycin degradation, maturity and microbial communities.

PubMed

Ren, Shengtao; Guo, Xiali; Lu, Aqian; Guo, Xiaoying; Wang, Yan; Sun, Guoping; Guo, Weiwei; Ren, Chaobin; Wang, Lianzhong

2018-05-26

This paper investigated the effect of co-composting of lincomycin mycelia dregs (LMDs) with furfural slag on the degradation of lincomycin, maturity and microbial communities. Results showed that after 66 days composting, the concentration of lincomycin was removed above 99%. The final pH, C/N and germination index (GI) all met the national standards in maturity. Enumeration of total cultivable microbes showed the composting process was not inhibited by the addition of LMDs. Microbial diversity suggested that co-composting was beneficial to increase the abundance and diversity of bacterial communities for LMDs' treatment. Canonical correlation analysis (CCA) indicated the bacteria communities were strongly affected by residual lincomycin, with lincomycin reduced greatly, microbial communities of T and CK became similar at the end of composting. The potential bacteria to degrade lincomycin were Anaerococcus, Peptostreptococcus, and Lactobacillus. Based on these results, this research indicated that the co-composting was a feasible treatment for LMDs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Changes in antibiotic concentrations and antibiotic resistome during commercial composting of animal manures.

PubMed

Xie, Wan-Ying; Yang, Xin-Ping; Li, Qian; Wu, Long-Hua; Shen, Qi-Rong; Zhao, Fang-Jie

2016-12-01

The over-use of antibiotics in animal husbandry in China and the concomitant enhanced selection of antibiotic resistance genes (ARGs) in animal manures are of serious concern. Thermophilic composting is an effective way of reducing hazards in organic wastes. However, its effectiveness in antibiotic degradation and ARG reduction in commercial operations remains unclear. In the present study, we determined the concentrations of 15 common veterinary antibiotics and the abundances of 213 ARGs and 10 marker genes for mobile genetic elements (MGEs) in commercial composts made from cattle, poultry and swine manures in Eastern China. High concentrations of fluoroquinolones were found in the poultry and swine composts, suggesting insufficient removal of these antibiotics by commercial thermophilic composting. Total ARGs in the cattle and poultry manures were as high as 1.9 and 5.5 copies per bacterial cell, respectively. After thermophilic composting, the ARG abundance in the mature compost decreased to 9.6% and 31.7% of that in the cattle and poultry manure, respectively. However, some ARGs (e.g. aadA, aadA2, qacEΔ1, tetL) and MGE marker genes (e.g. cintI-1, intI-1 and tnpA-04) were persistent with high abundance in the composts. The antibiotics that were detected at high levels in the composts (e.g. norfloxacin and ofloxacin) might have posed a selection pressure on ARGs. MGE marker genes were found to correlate closely with ARGs at the levels of individual gene, resistance class and total abundance, suggesting that MGEs and ARGs are closely associated in their persistence in the composts under antibiotic selection. Our research shows potential disseminations of antibiotics and ARGs via compost utilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessing carbon and nitrogen removal in a novel anoxic-aerobic cyanobacterial-bacterial photobioreactor configuration with enhanced biomass sedimentation.

PubMed

de Godos, I; Vargas, V A; Guzmán, H O; Soto, R; García, B; García, P A; Muñoz, R

2014-09-15

The carbon and nitrogen removal potential of an innovative anoxic-aerobic photobioreactor configuration operated with both internal and external recyclings was evaluated under different cyanobacterial-bacterial sludge residence times (9-31 days) during the treatment of wastewaters with low C/N ratios. Under optimal operating conditions, the two-stage photobioreactor was capable of providing organic carbon and nitrogen removals over 95% and 90%, respectively. The continuous biomass recycling from the settler resulted in the enrichment and predominance of rapidly-settling cyanobacterial-bacterial flocs and effluent suspended solid concentrations lower than 35 mg VSS L(-1). These flocs exhibited sedimentation rates of 0.28-0.42 m h(-1) but sludge volumetric indexes of 333-430 ml/g. The decoupling between the hydraulic retention time and sludge retention time mediated by the external recycling also avoided the washout of nitrifying bacteria and supported process operation at biomass concentrations of 1000-1500 mg VSS L(-1). The addition of additional NaHCO3 to the process overcame the CO2 limitation resulting from the intense competition for inorganic carbon between cyanobacteria and nitrifying bacteria in the photobioreactor, which supported the successful implementation of a nitrification-denitrification process. Unexpectedly, this nitrification-denitrification process occurred both simultaneously in the photobioreactor alone (as a result of the negligible dissolved oxygen concentrations) and sequentially in the two-stage anoxic-aerobic configuration with internal NO3(-)/NO2(-) recycling. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of TiO2 nanoparticles on aerobic granulation of algal-bacterial symbiosis system and nutrients removal from synthetic wastewater.

PubMed

Li, Bing; Huang, Wenli; Zhang, Chao; Feng, Sisi; Zhang, Zhenya; Lei, Zhongfang; Sugiura, Norio

2015-01-01

The influence of TiO2 nanoparticles (TiO2-NPs) (10-50mg/L) on aerobic granulation of algal-bacterial symbiosis system was investigated by using two identical sequencing batch reactors (SBRs). Although little adverse effect was observed on their nitritation efficiency (98-100% in both reactors), algal-bacterial granules in the control SBR (Rc) gradually lost stability mainly brought about by algae growth. TiO2-NPs addition to RT was found to enhance the granulation process achieving stable and compact algal-bacterial granules with remarkably improved nitratation thus little nitrite accumulation in RT when influent TiO2-NPs⩾30mg/L. Despite almost similar organics and phosphorus removals obtained in both reactors, the stably high nitratation efficiency in addition to much stable granular structure in RT suggests that TiO2-NPs addition might be a promising remedy for the long-term operation of algal-bacterial granular system, most probably attributable to the stimulated excretion of extracellular polymeric substances and less filamentous TM7. Copyright © 2015 Elsevier Ltd. All rights reserved.

Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan

PubMed Central

Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

2014-01-01

Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

Metagenomic Analysis of a Tropical Composting Operation at the São Paulo Zoo Park Reveals Diversity of Biomass Degradation Functions and Organisms

PubMed Central

Pascon, Renata C.; de Oliveira, Julio Cezar Franco; Digiampietri, Luciano A.; Barbosa, Deibs; Peixoto, Bruno Malveira; Vallim, Marcelo A.; Viana-Niero, Cristina; Ostroski, Eric H.; Telles, Guilherme P.; Dias, Zanoni; da Cruz, João Batista; Juliano, Luiz; Verjovski-Almeida, Sergio; da Silva, Aline Maria; Setubal, João Carlos

2013-01-01

Composting operations are a rich source for prospection of biomass degradation enzymes. We have analyzed the microbiomes of two composting samples collected in a facility inside the São Paulo Zoo Park, in Brazil. All organic waste produced in the park is processed in this facility, at a rate of four tons/day. Total DNA was extracted and sequenced with Roche/454 technology, generating about 3 million reads per sample. To our knowledge this work is the first report of a composting whole-microbial community using high-throughput sequencing and analysis. The phylogenetic profiles of the two microbiomes analyzed are quite different, with a clear dominance of members of the Lactobacillus genus in one of them. We found a general agreement of the distribution of functional categories in the Zoo compost metagenomes compared with seven selected public metagenomes of biomass deconstruction environments, indicating the potential for different bacterial communities to provide alternative mechanisms for the same functional purposes. Our results indicate that biomass degradation in this composting process, including deconstruction of recalcitrant lignocellulose, is fully performed by bacterial enzymes, most likely by members of the Clostridiales and Actinomycetales orders. PMID:23637931

An optimized regulating method for composting phosphorus fractions transformation based on biochar addition and phosphate-solubilizing bacteria inoculation.

PubMed

Wei, Yuquan; Zhao, Yue; Wang, Huan; Lu, Qian; Cao, Zhenyu; Cui, Hongyang; Zhu, Longji; Wei, Zimin

2016-12-01

The study was conducted to investigate the influence of biochar and/or phosphate-solubilizing bacteria (PSB) inoculants on microbial biomass, bacterial community composition and phosphorus (P) fractions during kitchen waste composting amended with rock phosphate (RP). There were distinct differences in the physic-chemical parameters, the proportion of P fractions and bacterial diversity in different treatments. The contribution of available P fractions increased during composting especially in the treatment with the addition of PSB and biochar. Redundancy analysis showed that bacterial compositions were significantly influenced by P content, inoculation and biochar. Variance partitioning further showed that synergy of inoculated PSB and indigenous bacterial communities and the joint effect between biochar and bacteria explained the largest two proportion of the variation in P fractions. Therefore, the combined application of PSB and biochar to improve the inoculation effect and an optimized regulating method were suggested based on the distribution of P fractions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of composting strategies on the degradation of nonylphenol in sewage sludge.

PubMed

Zheng, Guodi; Chen, Tongbin; Yu, Jie; Gao, Ding; Shen, Yujun; Niu, Mingjie; Liu, Hongtao

2015-12-01

Nonylphenol can be present in sewage sludge, and this can limit the use of the sewage sludge to amend soil. Composting is one of the most efficient and economical methods of making sewage sludge stable and harmless. The nonylphenol degradation rates during composting with added bulking agents and with aeration applied were studied. Three organic bulking agents (sawdust, corn stalk, and mushroom residue) were added to sewage sludge, and the effects of the bulking agents used and the amount added on nonylphenol degradation were determined. The highest apparent nonylphenol degradation rate (71.6%) was found for sewage sludge containing 20% mushroom residue. The lowest apparent nonylphenol degradation rate (22.5%) was found for sewage sludge containing 20% sawdust. The temperature of the composting pile of sewage sludge containing 20% sawdust became too high for nonylphenol to be efficiently degraded, and the apparent nonylphenol degradation rate was lower than was found for sewage sludge containing 10% sawdust. Increasing the ventilating time from 5 to 15 min increased the apparent nonylphenol degradation rate from 19.7 to 41.6%. Using appropriate aerobic conditions facilitates the degradation of nonylphenol in sewage sludge, decreasing the risks posed by sewage sludge applied to land. Adding too much of a bulking agent can decrease the amount of the nonylphenol degraded. Increasing the ventilating time and the amount of air supplied can increase the amount of nonylphenol degraded even if doing so causes the composting pile temperature to remain low.

Coffee husk composting: an investigation of the process using molecular and non-molecular tools.

PubMed

Shemekite, Fekadu; Gómez-Brandón, María; Franke-Whittle, Ingrid H; Praehauser, Barbara; Insam, Heribert; Assefa, Fassil

2014-03-01

Various parameters were measured during a 90-day composting process of coffee husk with cow dung (Pile 1), with fruit/vegetable wastes (Pile 2) and coffee husk alone (Pile 3). Samples were collected on days 0, 32 and 90 for chemical and microbiological analyses. C/N ratios of Piles 1 and 2 decreased significantly over the 90 days. The highest bacterial counts at the start of the process and highest actinobacterial counts at the end of the process (Piles 1 and 2) indicated microbial succession with concomitant production of compost relevant enzymes. Denaturing gradient gel electrophoresis of rDNA and COMPOCHIP microarray analysis indicated distinctive community shifts during the composting process, with day 0 samples clustering separately from the 32 and 90-day samples. This study, using a multi-parameter approach, has revealed differences in quality and species diversity of the three composts. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effect of pig manure on the chemical composition and microbial diversity during co-composting with spent mushroom substrate and rice husks.

PubMed

Meng, Xingyao; Liu, Bin; Xi, Chen; Luo, Xiaosha; Yuan, Xufeng; Wang, Xiaofen; Zhu, Wanbin; Wang, Hongliang; Cui, Zongjun

2018-03-01

In this study, the impact of pig manure on the maturity of compost consisting of spent mushroom substrate and rice husks was accessed. The results showed that the addition of pig manure (SMS-PM) reached 50°C 5days earlier and lasted 15days longer than without pig manure (SMS). Furthermore, the addition of pig manure improved nutrition and germination index. High-throughput 16S rRNA pyrosequencing was used to evaluate the bacterial and fungal composition during the composting process of SMS-PM compared to SMS alone. The SMS treatment showed a relatively higher abundance of carbon-degrading microbes (Bacillaceae and Thermomyces) and plant pathogenic fungi (Sordariomycetes_unclassified) at the end of the compost. In contrast, the SMS-PM showed an increased bacterial diversity with anti-pathogen (Pseudomonas). The results indicated that the addition of pig manure improved the decomposition of refractory carbon from the spent mushroom substrate and promoted the maturity and nutritional content of the compost product. Copyright © 2017. Published by Elsevier Ltd.

A novel challenge test incorporating irradiation (60Co) of compost sub-samples to validate thermal lethality towards pathogenic bacteria.

PubMed

Moore, John E; Watabe, Miyuki; Stewart, Andrew; Cherie Millar, B; Rao, Juluri R

2009-01-01

Maturing compost heaps normally attaining temperatures ranging from 55 to 65 degrees C is generally regarded to conform to recommended biological risks and sanitation standards for composts stipulated by either EU or US-EPA. Composted products derived from animal sources are further required by EU biohazard safety regulatory legislation that such composts either attain 70 degrees C for over 3h during maturation or via treatment at 70 degrees C for 1h before being considered for dispensation on land. The setting of the upper limit of thermal lethality at 70 degrees C/1h for achieving biosecurity of the animal waste composted products (e.g. pelleted fertilizer formulations) is not properly substantiated by specific validation tests, comprising a 'wipe-out' step (usually via autoclaving) followed by inoculation of a prescribed bacterium, exposure to 70 degrees C/1h and the lethality determined. Pelleted formulations of composts are not amenable for wet methods (autoclaving) for wipe-out sterilization step as this is detrimental to the pellet and compromises sample integrity. This study describes a laboratory method involving the employment of ((60)Co) irradiation 'wipe-out' step to: (a) compost sub-samples drawn from compost formulation heaps and (b) pelleted products derived from composted animal products while determining the thermal lethality of a given time/temperature (70 degrees C/1h) treatment process and by challenging the irradiated sample (not just with one bacterium but), out with 10 potential food-poisoning organisms from the bacterial genera (Campylobacter, Escherichia, Listeria, Salmonella, Yersinia) frequently detected in pig and poultry farm wastes. This challenge test on compost sub-samples can be a useful intervention ploy for 'inspection and validation' technique for composters during the compost maturity process, whose attainment of temperatures of 55-65 degrees C is presumed sufficient for attainment of sanitation. Stringent measures are further

Effects of genetically modified cotton stalks on antibiotic resistance genes, intI1, and intI2 during pig manure composting.

PubMed

Duan, Manli; Gu, Jie; Wang, Xiaojuan; Li, Yang; Zhang, Sheqi; Yin, Yanan; Zhang, Ranran

2018-01-01

Genetically modified (GM) cotton production generates a large yield of stalks and their disposal is difficult. In order to study the feasibility of using GM cotton stalks for composting and the changes that occur in antibiotic resistance genes (ARGs) during composting, we supplemented pig manure with GM or non-GM cotton stalks during composting and we compared their effects on the absolute abundances (AA) of intI1, intI2, and ARGs under the two treatments. The compost was mature after processing based on the germination index and C/N ratio. After composting, the AAs of ARGs, intI1, and intI2 were reduced by 41.7% and 45.0% in the non-GM and GM treatments, respectively. The ARG profiles were affected significantly by temperature and ammonia nitrogen. In addition, excluding tetC, GM cotton stalks had no significant effects on ARGs, intI1, and intI2 compared with the non-GM treatment (p < 0.05). Thus, similar to non-GM cotton stalks, GM cotton stalks can be used for aerobic composting with livestock manure, and the AAs of ARGs can be reduced. Furthermore, the results of this study provide a theoretical basis for the harmless utilization of GM cotton stalks. Copyright © 2017 Elsevier Inc. All rights reserved.

Composting of animal manures and chemical criteria for compost maturity assessment. A review.

PubMed

Bernal, M P; Alburquerque, J A; Moral, R

2009-11-01

New livestock production systems, based on intensification in large farms, produce huge amount of manures and slurries without enough agricultural land for their direct application as fertilisers. Composting is increasingly considered a good way for recycling the surplus of manure as a stabilised and sanitised end-product for agriculture, and much research work has been carried out in the last decade. However, high quality compost should be produced to overcome the cost of composting. In order to provide and review the information found in the literature about manure composting, the first part of this paper explains the basic concepts of the composting process and how manure characteristics can influence its performance. Then, a summary of those factors such as nitrogen losses (which directly reduce the nutrient content), organic matter humification and compost maturity which affect the quality of composts produced by manure composting is presented. Special attention has been paid to the relevance of using an adequate bulking agent for reducing N-losses and the necessity of standardising the maturity indices due to their great importance amongst compost quality criteria.

Bacterial diversity in the rhizosphere of cucumbers grown in soils covering a wide range of cucumber cropping histories and environmental conditions.

PubMed

Tian, Yongqiang; Gao, Lihong

2014-11-01

Rhizosphere microorganisms in soils are important for plant growth. However, the importance of rhizosphere microorganisms is still underestimated since many microorganisms associated with plant roots cannot be cultured and since the microbial diversity in the rhizosphere can be influenced by several factors, such as the cropping history, biogeography, and agricultural practice. Here, we characterized the rhizosphere bacterial diversity of cucumber plants grown in soils covering a wide range of cucumber cropping histories and environmental conditions by using pyrosequencing of bacterial 16S rRNA genes. We also tested the effects of compost addition and/or bacterial inoculation on the bacterial diversity in the rhizosphere. We identified an average of approximately 8,883 reads per sample, corresponding to around 4,993 molecular operational taxonomic units per sample. The Proteobacteria was the most abundant phylum in almost all soils. The abundances of the phyla Bacteroidetes, Actinobacteria, Firmicutes, Acidobacteria, and Verrucomicrobia varied among the samples, and together with Proteobacteria, these phyla were the six most abundant phyla in almost all analyzed samples. Analyzing all the sample libraries together, the predominant genera found were Flavobacterium, Ohtaekwangia, Opitutus, Gp6, Steroidobacter, and Acidovorax. Overall, compost and microbial amendments increased shoot biomass when compared to untreated soils. However, compost addition decreased the bacterial α-diversity in most soils (but for three soils compost increased diversity), and no statistical effect of microbial amendment on the bacterial α-diversity was found. Moreover, soil amendments did not significantly influence the bacterial β-diversity. Soil organic content appeared more important than compost and microbial amendments in shaping the structure of bacterial communities in the rhizosphere of cucumber.

Effective pine bark composting with the Dome Aeration Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trois, Cristina; Polster, Andreas

2007-07-01

In South Africa garden refuse is primarily disposed of in domestic landfills. Due to the large quantities generated, any form of treatment would be beneficial for volume reduction, waste stabilization and resource recovery. Dome Aeration Technology (DAT) is an advanced process for aerobic biological degradation of garden refuse and general waste [Paar, S., Brummack, J., Gemende, B., 1999a. Advantages of dome aeration in mechanical-biological waste treatment. In: Proceedings of the 7th International Waste Management and Landfill Symposium, Cagliari, 4-8 October 1999; Paar, S., Brummack, J., Gemende, B., 1999b. Mechanical-biological waste stabilization by the dome aeration method. Environment Protection Engineering 25more » (3/99). Mollekopf, N., Brummack, J., Paar, S., Vorster, K., 2002. Use of the Dome Aeration Technology for biochemical stabilization of waste prior to landfilling. In: Proceedings of the Wastecon 2002, Waste Congress and Exhibition, Durban, South Africa.]. It is a non-reactor open windrow composting process, with the main advantage being that the input material needs no periodic turning. A rotting time of only 3-4 months indicates the high efficiency. Additionally, the low capital/operational costs, low energy inputs and limited plant requirements provide potential for use in aerobic refuse stabilization. The innovation in the DAT process is the passive aeration achieved by thermally driven advection through open windrows caused by temperature differences between the degrading material and the outside environment. This paper investigates the application of Dome Aeration Technology to pine bark composting as part of an integrated waste management strategy. A full-scale field experiment was performed at the Bisasar Road Landfill Site in Durban to assess the influence of climate, waste composition and operational conditions on the process. A test windrow was constructed and measurements of temperature and airflow through the material were taken. The

Utilization of high temperature compost in space agriculture: the model compost kills Escherichia coli

NASA Astrophysics Data System (ADS)

Oshima, Tairo; Moriya, Toshiyuki; Yoshii, Takahiro

The author and his colleagues have proposed the use of high temperature composting in space inhabitation. Composting has many advantages over burning in organic waste treatments. Composting is self-heating processes and needs no extra fuel. Composting requires no sophis-ticated equipment such as an incinerator. Composting emits no hazardous gases such as NOx, SOx and dioxines which are often produced by burning. The final product can be used as fer-tilizer in space farm land; resources recycling society can be constructed in space stations and space cities. In addition to these advantages, composting and compost soil may contribute to the environmental cleanup. During composting processes, harmful compounds to agricultural plants and animals can be destroyed. Seeds of weeds can be killed by high heat. Likewise pathogenic microbes in the waste can be eliminated during fermentation inside the composts. Recently we measured the survivability of E. coli in compost. E. coli was used as the represen-tative of the Gram-negative bacteria. Since many pathogenic strains belong to Gram-negative bacteria and Gram-negative bacteria are more resistant to antibiotics than gram-positive bac-teria. When E. coli cells were mixed in the compost pile of which inside temperature reaches up to 75oC, they died within a short period as expected. However, E. coli DNA was detected even after a day in high temperature compost. RNA has a shorter life-span than DNA, but was detected after incubation in compost for several hours. In addition to sterilizing effects due to high temperature, we found our compost soil has E. coli killing activity. When mixed with the compost soil at room temperature, E. coli died gradually. Extract of the compost soil also killed E. coli at room temperature, but it took a few days to eliminate E. coli completely. During the killing process, total number of living bacteria did not change, indicating that the killing activity is limited to some specific

Successful School Composting.

ERIC Educational Resources Information Center

Mahar, Rhea Dawn

2001-01-01

School composting programs that have met the challenges inherent in long-term composting have several traits in common: a supportive educational program, schoolwide participation, and a consistent maintenance program. Examines the elements of success, offers examples of incorporating composting into the curriculum, and describes three methods of…

Diversity, abundance, and persistence of antibiotic resistance genes in various types of animal manure following industrial composting.

PubMed

Qian, Xun; Gu, Jie; Sun, Wei; Wang, Xiao-Juan; Su, Jian-Qiang; Stedfeld, Robert

2018-02-15

Aerobic composting is used widely for animal manure recycling, and it may reduce the amount of antibiotic resistance genes (ARGs) that enter the environment. We sampled three types of animal (bovine, chicken, and pig) manure and the corresponding composts from 12 large-scale farms, and tested multiple ARGs and mobile genetic elements (MGEs) by high-throughput qPCR. A total of 109 ARGs were detected in the manure and compost samples, thereby demonstrating that both are important ARG reservoirs. The diversity and abundance of ARGs were significantly higher in chicken and pig manure than bovine manure, but industrial composting was more efficient at reducing the ARGs in chicken manure than pig and bovine manure. Composting universally reduced some ARGs, but inconsistently influenced other ARGs from different types of animal manures. Network analysis detected the widespread co-occurrence of ARGs and MGEs. floR, ermF, catB3, aac(6')-lb(akaaacA4), and aadA were identified as suitable indicator genes for estimating the total abundance of ARGs. Our results suggest that different animal species had significant effects on the diversity, abundance, and persistence of ARGs, where the abundance of transposons, heavy metal concentration, total nitrogen level, and the dosage and duration of exposure to antibiotics may explain these differences. Copyright © 2017 Elsevier B.V. All rights reserved.

Composting of rice straw with effective microorganisms (EM) and its influence on compost quality

PubMed Central

2013-01-01

This study aims to assess the effect of EM application on the composting process of rice straw with goat manure and green waste and to evaluate the quality of both compost treatments. There are two treatment piles in this study, in which one pile was applied with EM and another pile without EM. Each treatment was replicated three times with 90 days of composting duration. The parameters for the temperature, pH, TOC and C/N ratio, show that decomposition of organic matter occurs during the 90-day period. The t-test conducted shows that there is a significant difference between compost with EM and compost without EM. The application of EM in compost increases the macro and micronutrient content. The following parameters support this conclusion: compost applied with EM has more N, P and K content (P < 0.05) compared to compost without EM. Although the Fe in compost with EM is much higher (P < 0.05) than in the compost without EM, for Zn and Cu, there is no significant difference between treatments. This study suggests that the application of EM is suitable to increase the mineralization in the composting process. The final resultant compost indicated that it was in the range of the matured level and can be used without any restriction. PMID:23390930

Composting rice straw with sewage sludge and compost effects on the soil-plant system.

PubMed

Roca-Pérez, L; Martínez, C; Marcilla, P; Boluda, R

2009-05-01

Composting organic residue is an interesting alternative to recycling waste as the compost obtained may be used as organic fertilizer. This study aims to assess the composting process of rice straw and sewage sludge on a pilot-scale, to evaluate both the quality of the composts obtained and the effects of applying such compost on soil properties and plant development in pot experiments. Two piles, with shredded and non-shredded rice straw, were composted as static piles with passive aeration. Throughout the composting process, a number of parameters were determined, e.g. colour, temperature, moisture, pH, electrical conductivity, organic matter, C/N ratio, humification index, cation exchange capacity, chemical oxygen demand, and germination index. Moreover, sandy and clayey soils were amended with different doses of mature compost and strewed with barley in pot experiments. The results show that compost made from shredded rice straw reached the temperatures required to maximise product sanitisation, and that the parameters indicating compost maturity were all positive; however, the humification index and NH(4) content were more selective. Therefore, using compost-amended soils at a dose of 34 Mg ha(-1) for sandy soil, and of 11 Mg ha(-1) for clayey soil improves soil properties and the growth of Hordeum vulgare plants. Under there conditions, the only limiting factor of agronomic compost utilisation was the increased soil salinity.

Composting of rice straw with effective microorganisms (EM) and its influence on compost quality.

PubMed

Jusoh, Mohd Lokman Che; Manaf, Latifah Abd; Latiff, Puziah Abdul

2013-02-07

This study aims to assess the effect of EM application on the composting process of rice straw with goat manure and green waste and to evaluate the quality of both compost treatments. There are two treatment piles in this study, in which one pile was applied with EM and another pile without EM. Each treatment was replicated three times with 90 days of composting duration. The parameters for the temperature, pH, TOC and C/N ratio, show that decomposition of organic matter occurs during the 90-day period. The t-test conducted shows that there is a significant difference between compost with EM and compost without EM. The application of EM in compost increases the macro and micronutrient content. The following parameters support this conclusion: compost applied with EM has more N, P and K content (P < 0.05) compared to compost without EM. Although the Fe in compost with EM is much higher (P < 0.05) than in the compost without EM, for Zn and Cu, there is no significant difference between treatments. This study suggests that the application of EM is suitable to increase the mineralization in the composting process. The final resultant compost indicated that it was in the range of the matured level and can be used without any restriction.

Study on the quality and stability of compost through a Demo Compost Plant.

PubMed

Hasan, K M M; Sarkar, G; Alamgir, M; Bari, Q H; Haedrich, G

2012-11-01

This study is concerned with the performance of a Demo Compost Plant for the development of acceptable composting technology in Bangladesh. The Demo Compost Plant was setup at the adjacent area of an existing compost plant located at Khulna city in Bangladesh. Four different composting technologies were considered, where Municipal Solid Waste (MSW) were used as a raw material for composting, collected from the adjacent areas of the plant. Initially the whole composting system was conducted through two experimental setups. In the 1st setup three different types of aerators (horizontal and vertical passively aerator and forced aerator) were selected. For a necessary observation four piles, using only MSW as the input materials in the first three compost pile, the fourth one was the existing Samadhan's compost pile. Based on the analysis of the experimental findings, the horizontal passively aerated composting technique is suitable for Bangladesh as it had better performance for reducing composting period than that of the others. It was being observed from the quality parameters of compost in the both 1st and 2nd setup that as the waste directly come from kitchen, degradation rate of waste shows a positive result for reducing this waste and there is no possibility of toxic contamination, when it would be used as a soil conditioner. Though there is no significant improvement in the quality of the final product in the 2nd setup as comparing with the 1st setup but it fulfills one of the main objectives of this study is to reduce the whole composting period as well as immediate management of the increasing amount of waste and reducing load on landfill. Selfheating tests reveal that degree of stability of compost with respect to maturation period was remained in the acceptable level, which was further accelerated due to the use of organic additives. Copyright © 2012 Elsevier Ltd. All rights reserved.

Composts containing fluorescent pseudomonads suppress fusarium root and stem rot development on greenhouse cucumber.

PubMed

Bradley, Geoffrey G; Punja, Zamir K

2010-11-01

Three composts (Ball, dairy, and greenhouse) were tested for the ability to suppress the development of Fusarium root and stem rot (caused by Fusarium oxysporum f. sp. radicis-cucumerinum) on greenhouse cucumber. Dairy and greenhouse composts significantly reduced disease severity (P = 0.05), while Ball compost had no effect. Assessment of total culturable microbes in the composts showed a positive relationship between disease suppressive ability and total population levels of pseudomonads. In vitro antagonism assays between compost-isolated bacterial strains and the pathogen showed that strains of Pseudomonas aeruginosa exhibited the greatest antagonism. In growth room trials, strains of P. aeruginosa and nonantagonistic Pseudomonas maculicola, plus 2 biocontrol strains of Pseudomonas fluorescens, were tested for their ability to reduce (i) survival of F. oxysporum, (ii) colonization of plants by the pathogen, and (iii) disease severity. Cucumber seedlings grown in compost receiving P. aeruginosa and P. fluorescens had reduced disease severity index scores after 8 weeks compared with control plants without bacteria. Internal stem colonization by F. oxysporum was significantly reduced by P. aeruginosa. The bacteria colonized plant roots at 1.9 × 10(6) ± 0.73 × 10(6) CFU·(g root tissue)-1 and survival was >107 CFU·(g compost)-1 after 6 weeks. The locus for 2,4-diacetylphloroglucinol production was detected by Southern blot analysis and confirmed by PCR. The production of the antibiotic 2,4-diacetylphloroglucinol in liquid culture by P. aeruginosa was confirmed by thin layer chromatography. These results demonstrate that composts containing antibiotic-producing P. aeruginosa have the potential to suppress diseases caused by Fusarium species.

Composting of empty fruit bunches in the tower composter - effect of air intake holes

NASA Astrophysics Data System (ADS)

Irvan; Husaini, T.; Trisakti, B.; Batubara, F.; Daimon, H.

2018-02-01

The process of composting empty fruit bunches (EFB) by mixing with activated liquid organic fertilizer (ALOF) is an alternative utilization of solid waste generated from palm oil mill. This study aims to find composting techniques of EFB and to obtain degradation data of composting EFB by varying the air intake holes to produce good quality compost. Composting process was carried out by tearing the EFB into four shreds, then put into the tower composter while adding ALOF until it reached the optimum moisture content of 55 -65%. During the composting process, we maintained moisture content at optimum conditions by adding ALOF. Variations of air intake holes area to the outer surface area of the composter are 0/44.314; 72.39/44.314 and 144.78/44.314 (cm2/cm2). Composting is carried out for forty days, however, based on the result, compost began to mature on the 10th day. The results revealed that there was an influence of air intake holes to the composting process. The best degradation of EFB was obtained on the variation of air intake holes 72.39/44.314 (cm2/cm2), pH 8.1, moisture content 79.14%, water holding capacity 60%, electrical conductivity 4.725 dS/m and C/N ratio 20.97.

Biochar, compost and biochar-compost blend as options to recover nutrients and sequester carbon.

PubMed

Oldfield, Thomas L; Sikirica, Nataša; Mondini, Claudio; López, Guadalupe; Kuikman, Peter J; Holden, Nicholas M

2018-07-15

This work assessed the potential environmental impact of recycling organic materials in agriculture via pyrolysis (biochar) and composting (compost), as well its combination (biochar-compost blend) versus business-as-usual represented by mineral fertiliser. Life cycle assessment methodology was applied using data sourced from experiments (FP7 project Fertiplus) in three countries (Spain, Italy and Belgium), and considering three environmental impact categories, (i) global warming; (ii) acidification and (iii) eutrophication. The novelty of this analysis is the inclusion of the biochar-compost blend with a focus on multiple European countries, and the inclusion of the acidification and eutrophication impact categories. Biochar, compost and biochar-compost blend all resulted in lower environmental impacts than mineral fertiliser from a systems perspective. Regional differences were found between biochar, compost and biochar-compost blend. The biochar-compost blend offered benefits related to available nutrients and sequestered C. It also produced yields of similar magnitude to mineral fertiliser, which makes its acceptance by farmers more likely whilst reducing environmental impacts. However, careful consideration of feedstock is required. Copyright © 2018 Elsevier Ltd. All rights reserved.

Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allgaier, M.; Reddy, A.; Park, J. I.

2009-11-15

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence datamore » from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, {approx}10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.« less

Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reddy, Amitha; Allgaier, Martin; Park, Joshua I.

2011-05-11

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence datamore » from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.« less

Simulation of Organic Matter and Pollutant Evolution during Composting: The COP-Compost Model.

PubMed

Lashermes, G; Zhang, Y; Houot, S; Steyer, J P; Patureau, D; Barriuso, E; Garnier, P

2013-01-01

Organic pollutants (OPs) are potentially present in composts and the assessment of their content and bioaccessibility in these composts is of paramount importance. In this work, we proposed a model to simulate the behavior of OPs and the dynamic of organic C during composting. This model, named COP-Compost, includes two modules. An existing organic C module is based on the biochemical composition of the initial waste mixture and simulates the organic matter transformation during composting. An additional OP module simulates OP mineralization and the evolution of its bioaccessibility. Coupling hypotheses were proposed to describe the interactions between organic C and OP modules. The organic C module, evaluated using experimental data obtained from 4-L composting pilots, was independently tested. The COP-Compost model was evaluated during composting experiments containing four OPs representative of the major pollutants detected in compost and targeted by current and future regulations. These OPs included a polycyclic aromatic hydrocarbon (fluoranthene), two surfactants (4--nonylphenol and a linear alkylbenzene sulfonate), and an herbicide (glyphosate). Residues of C-labeled OP with different bioaccessibility were characterized by sequential extraction and quantified as soluble, sorbed, and nonextractable fractions. The model was calibrated and coupling the organic C and OP modules improved the simulation of the OP behavior and bioaccessibility during composting. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Microbiological parameters and maturity degree during composting of Posidonia oceanica residues mixed with vegetable wastes in semi-arid pedo-climatic condition.

PubMed

Saidi, Neyla; Kouki, Soulwene; M'hiri, Fadhel; Jedidi, Naceur; Mahrouk, Meriam; Hassen, Abdennaceur; Ouzari, Hadda

2009-01-01

The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with residues of Posidonia oceanica (PoR), collected from Tunis beaches. The accumulation in beaches (as well as their removal) constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion: (a) C/N ratio < 15; (b) NH4+-N < 400 mg/kg; (c) CO2-C < 2000 mg CO2-C/kg; (d) dehydrogenase activity < 1 mg TPF/g dry matter; (e) germination index (GI) > 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N (13.0 g/kg), P (4.74 g/kg) and MgO (15.80 g/kg). Thus composting definitively constitutes the most optimal option to exploit these wastes.

Biohazards and ecotoxicological considerations of landspreading of spent compost wastes.

PubMed

Rao, J R; Nelson, D; Lafferty, N; Moore, J E; Millar, B C; Xu, J; Watabe, M

2003-01-01

Spent mushroom compost (SMC) is a major waste of the mushroom industry with low economic value. SMC arises after mushroom production in phase II compost (pIIC), predominantly comprising straw and chicken litter as principal raw ingredients. The majority of SMC waste is disposed off by application to agricultural land. It is an attractive proposition for utilising SMC as soil inorganic fertiliser supplementation. However, there is limited data available as to the consequences of this method of disposal either in terms of microbiological loading of food-borne pathogens and those of concern to mushroom industry itself. The resulting imbalance of the natural flora of the agricultural land has not been properly audited. This study aims to initially examine SMC for prevalence of faecal bacterial pathogens including Campylobacter spp., Salmonella spp. and Listeria monocytogenes that may arise from chicken litter. At another level, it aims to ascertain the pathogenic bacteria (Pseudomonas syringae, pv phaseolicola or tolasii) and fungal populations (Trichoderma, Verticillium species) originating mainly from the straw component of the SMC, which are of concern to the mushroom industry. Lastly, the study would also qualitatively identify the diversity of bacterial populations within SMC. This was largely accomplished through employment of rDNA, PCR and direct sequencing strategies on the culturable microflora. However, for specific mushroom pathogens, nucleic acids (DNA or RNA) were directly extracted from composts before subjecting to sequence analysis. In accordance with the current legislation (ABP 02/02, Animal By Products wastes disposal EC No. 1774/2002), it is imperative to regulate the farm wastes carrying residues from animal sources including SMC before they are regarded safe for land spreading operations. The ecological microbe-microbe and plant-microbe interactions that potentially occur between the native bacterial soil flora and those added annually

Chestnut green waste composting for sustainable forest management: Microbiota dynamics and impact on plant disease control.

PubMed

Ventorino, Valeria; Parillo, Rita; Testa, Antonino; Viscardi, Sharon; Espresso, Francesco; Pepe, Olimpia

2016-01-15

Making compost from chestnut lignocellulosic waste is a possible sustainable management strategy for forests that employs a high-quality renewable organic resource. Characterization of the microbiota involved in composting is essential to better understand the entire process as well as the properties of the final product. Therefore, this study investigated the microbial communities involved in the composting of chestnut residues obtained from tree cleaning and pruning. The culture-independent approach taken highlighted the fact that the microbiota varied only slightly during the process, with the exception of those of the starting substrate and mature compost. The statistical analysis indicated that most of the bacterial and fungal species in the chestnut compost persisted during composting. The dominant microbial population detected during the process belonged to genera known to degrade recalcitrant lignocellulosic materials. Specifically, we identified fungal genera, such as Penicillium, Fusarium, Cladosporium, Aspergillus and Mucor, and prokaryotic species affiliated with Bacilli, Actinobacteria, Flavobacteria and γ-Proteobacteria. The suppressive properties of compost supplements for the biocontrol of Sclerotinia minor and Rhizoctonia solani were also investigated. Compared to pure substrate, the addition of compost to the peat-based growth substrates resulted in a significant reduction of disease in tomato plants of up to 70 % or 51 % in the presence of Sclerotinia minor or Rhizoctonia solani, respectively. The obtained results were related to the presence of putative bio-control agents and plant growth-promoting rhizobacteria belonging to the genera Azotobacter, Pseudomonas, Stenotrophomonas, Bacillus, Flavobacterium, Streptomyces and Actinomyces in the chestnut compost. The composting of chestnut waste may represent a sustainable agricultural practice for disposing of lignocellulosic waste by transforming it into green waste compost that can be used to

Heat inactivation of Salmonella spp. in fresh poultry compost by simulating early phase of composting process.

PubMed

Singh, R; Kim, J; Jiang, X

2012-05-01

The purpose of this study was to determine the effect of moisture on thermal inactivation of Salmonella spp. in poultry litter under optimal composting conditions. Thermal inactivation of Salmonella was studied in fresh poultry compost by simulating early phase of composting process. A mixture of three Salmonella serotypes grown in Tryptic soy broth with rifampin (TSB-R) was inoculated in fresh compost with 40 or 50% moisture at a final concentration of c. 7 log CFU g(-1). The inoculated compost was kept in an environmental chamber which was programmed to rise from room temperature to target composting temperatures in 2 days. In poultry compost with optimal moisture content (50%), Salmonella spp. survived for 96, 72 and 24 h at 50, 55 and 60°C, respectively, as compared with 264, 144 and 72 h at 50, 55 and 60°C, respectively, in compost with suboptimal moisture (40%). Pathogen decline was faster during the come-up time owing to higher ammonia volatilization. Our results demonstrated that Salmonella spp. survived longer in fresh poultry compost with suboptimal moisture of 40% than in compost with optimal moisture of 50% during thermophilic composting. High nitrogen content of the poultry compost is an additional factor contributing to Salmonella inactivation through ammonia volatilization during thermal exposure. This research validated the effectiveness of the current composting guidelines on Salmonella inactivation in fresh poultry compost. Both initial moisture level and ammonia volatilization are important factors affecting microbiological safety and quality of compost product. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Effects of chlortetracycline on the fate of multi-antibiotic resistance genes and the microbial community during swine manure composting.

PubMed

Chen, Zhiqiang; Wang, Yao; Wen, Qinxue

2018-06-01

Excessive use of antibiotics in breeding industry leads to accumulation of antibiotic residuals and antibiotic resistance genes (ARGs) in environment from improperly treated livestock excrements. Four commonly used veterinary antibiotics including chlortetracycline (CTC), sulfamerazine (SMZ), enrofloxacin (ENR) and erythromycin (ERY) were monitored in the swine manure composting. Co-resistance and cross-resistance effects among relative ARGs, correlations between ARGs and bacterial community under multiple antibiotics residual during the composting were investigated in this research. With CTC addition up to 20 mg/kg, more than 99% of CTC removal was achieved after composting, and most of the other antibiotics can be thoroughly removed as well. The variations in ARGs during the composting were strongly correlated to the compositions of the microbial community, Bacteroides and Sporosarcina were main ARGs carriers in the thermophlic phase. Clostridium Ⅺ, Clostridium sensu stricto, and Pseudoxanthomonas, might spread ARGs in cooling and maturing stage. Most of the tested ARGs in swine manure can be effectively reduced through composting, thus makes the compost products safe for soil fertilization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of Bacillus sp. TAT105 to reduce ammonia emissions during pilot-scale composting of swine manure.

PubMed

Kuroda, Kazutaka; Tanaka, Akihiro; Furuhashi, Kenich; Nakasaki, Kiyohiko

2017-12-01

Thermophilic ammonium-tolerant bacterium Bacillus sp. TAT105 grows and reduces ammonia (NH 3 ) emissions by assimilating ammonium nitrogen during composting of swine feces. To evaluate the efficacy of a biological additive containing TAT105 at reducing NH 3 emissions, composting tests of swine manure on a pilot scale (1.8 m 3 ) were conducted. In the TAT105-added treatment, NH 3 emissions and nitrogen loss were lower than those in the control treatment without TAT105. No significant difference was detected in losses in the weight and volatile solids between the treatments. Concentration of thermophilic ammonium-tolerant bacteria in the compost increased in both treatments at the initial stage of composting. In the TAT105-added treatment, bacterial concentration reached ~10 9 colony-forming units per gram of dry matter, several-fold higher than that in the control and stayed at the same level until the end. These results suggest that TAT105 grows during composting and reduces NH 3 emissions in TAT105-added treatment.

Analysis of volatile organic compounds in compost samples: A potential tool to determine appropriate composting time.

PubMed

Zhu, Fengxiang; Pan, Zaifa; Hong, Chunlai; Wang, Weiping; Chen, Xiaoyang; Xue, Zhiyong; Yao, Yanlai

2016-12-01

Changes in volatile organic compound contents in compost samples during pig manure composting were studied using a headspace, solid-phase micro-extraction method (HS-SPME) followed by gas chromatography with mass spectrometric detection (GC/MS). Parameters affecting the SPME procedure were optimized as follows: the coating was carbon molecular sieve/polydimethylsiloxane (CAR/PDMS) fiber, the temperature was 60°C and the time was 30min. Under these conditions, 87 compounds were identified from 17 composting samples. Most of the volatile components could only be detected before day 22. However, benzenes, alkanes and alkenes increased and eventually stabilized after day 22. Phenol and acid substances, which are important factors for compost quality, were almost undetectable on day 39 in natural compost (NC) samples and on day 13 in maggot-treated compost (MC) samples. Our results indicate that the approach can be effectively used to determine the composting times by analysis of volatile substances in compost samples. An appropriate composting time not only ensures the quality of compost and reduces the loss of composting material but also reduces the generation of hazardous substances. The appropriate composting times for MC and NC were approximately 22days and 40days, respectively, during the summer in Zhejiang. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of copper on the composition and diversity of microbial communities in laboratory-scale swine manure composting.

PubMed

Yin, Yanan; Gu, Jie; Wang, Xiaojuan; Tuo, Xiaxia; Zhang, Kaiyu; Zhang, Li; Guo, Aiyun; Zhang, Xin

2018-06-01

This study investigated the effects of adding copper at 3 treatment levels (0 (control: CK), 200 (low: L), and 2000 (high: H) mg·kg -1 treatments) on the bacterial communities during swine manure composting. The abundances of the bacteria were determined by quantitative PCR and their compositions were evaluated by high-throughput sequencing. The results showed that the abundance of bacteria was inhibited by the H treatment during days 7-35, and principal component analysis clearly separated the H treatment from the CK and L treatments. Actinobacteria, Firmicutes, and Proteobacteria were the dominant bacterial taxa, and a high copper concentration decreased the abundances of bacteria that degrade cellulose and lignin (e.g., class Bacilli and genus Truepera), especially in the mesophilic and thermophilic phases. Moreover, network analysis showed that copper might alter the co-occurrence patterns of bacterial communities by changing the properties of the networks and the keystone taxa, and increase the competition by increasing negative associations between bacteria during composting. Temperature, water-soluble carbohydrates, and copper significantly affected the variations in the bacterial community according to redundancy analysis. The copper content mainly contributed to the bacterial community in the thermophilic and cooling phases, where it had positive relationships with potentially pathogenic bacteria (e.g., Corynebacterium_1 and Acinetobacter).

Bioelectrochemically-assisted anaerobic composting process enhancing compost maturity of dewatered sludge with synchronous electricity generation.

PubMed

Yu, Hang; Jiang, Junqiu; Zhao, Qingliang; Wang, Kun; Zhang, Yunshu; Zheng, Zhen; Hao, Xiaodi

2015-10-01

Bioelectrochemically-assisted anaerobic composting process (AnCBE) with dewatered sludge as the anode fuel was constructed to accelerate composting of dewatered sludge, which could increase the quality of the compost and harvest electric energy in comparison with the traditional anaerobic composting (AnC). Results revealed that the AnCBE yielded a voltage of 0.60 ± 0.02 V, and total COD (TCOD) removal reached 19.8 ± 0.2% at the end of 35 d. The maximum power density was 5.6 W/m(3). At the end of composting, organic matter content (OM) reduction rate increased to 19.5 ± 0.2% in AnCBE and to 12.9 ± 0.1% in AnC. The fuzzy comprehensive assessment (FCA) result indicated that the membership degree of class I of AnCBE compost (0.64) was higher than that of AnC compost (0.44). It was demonstrated that electrogenesis in the AnCBE could improve the sludge stabilization degree, accelerate anaerobic composting process and enhance composting maturity with bioelectricity generation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of compost covers on the efficiency of biowaste composting process.

PubMed

Marešová, Karolina; Kollárová, Mária

2010-12-01

The temperature of matured compost is an indicator of feedstock quality and also a good feedback informing about the suitability of an applied technological procedure. Two independent experiments using the technology of windrow composting at open area were conducted with the final goal to evaluate the effect of compost pile covering (in comparison with uncovered piles) on the course of composting process - behaviour of temperature over time and oxygen content. Two types of sheets were used - Top Tex permeable sheet and impermeable polyethylene sheet. The experiment I (summer months) aimed at comparison of efficiency between the Top Tex sheet cover and the uncovered compost piles, while experiment II (autumn months) compared treatments using the Top Tex sheet and polyethylene sheet by contrast. Within the experiment I the composts consisted of cattle slurry and fresh grass matter at a ratio of 1:1, in case of experiment II consisted of pig/cattle manure, fresh grass matter and chipped material at a ratio of about 1:2:1. The obtained data showed no significant differences among the cover treatments according to ANOVA. The only exception was oxygen content in pile 4 (experiment II) under Top Tex sheet, where a markedly higher oxygen content than under polyethylene sheet was measured during the whole composting period. It was the only case where statistical analysis proved a significant difference; the p-value was 0.0002. Copyright © 2010. Published by Elsevier Ltd.

Linking N2O emission from biochar-amended composting process to the abundance of denitrify (nirK and nosZ) bacteria community.

PubMed

Li, Shuqing; Song, Lina; Jin, Yaguo; Liu, Shuwei; Shen, Qirong; Zou, Jianwen

2016-12-01

Manure composting has been recognized as an important anthropogenic source of nitrous oxide (N2O) contributing to global warming. However, biochar effect on N2O emissions from manure composting is rarely evaluated, especially by linking it to abundance of denitrifying bacteria community. Results of this study indicated that biochar amendment significantly reduced N2O emissions from manure composting, primarily due to suppression of the nirK gene abundance of denitrifying bacteria. Pearson's correlation analysis showed a significant positive correlation between nirK abundance and N2O fluxes, while a negative correlation between nosZ density and N2O fluxes. Simultaneously, a linear correlation between nirK gene abundance minus nosZ gene abundance with N2O fluxes was also observed. In addition, a statistical model for estimating N2O emissions based on the bacterial denitrifying functional genes was developed and verified to adequately fit the observed emissions. Our results highlighted that biochar amendment would be an alternative strategy for mitigating N2O emissions during manure composting, and the information of related functional bacterial communities could be helpful for understanding the mechanism of N2O emissions.

Progress of organic matter degradation and maturity of compost produced in a large-scale composting facility.

PubMed

Nakasaki, Kiyohiko; Marui, Taketoshi

2011-06-01

To monitor the progress of organic matter degradation in a large-scale composting facility, the percentage of organic matter degradation was determined by measuring CO(2) evolution during recomposting of compost samples withdrawn from the facility. The percentage of organic matter degradation was calculated as the ratio of the amount of CO(2) evolved from compost raw material to that evolved from each sample during recomposting in the laboratory composting apparatus. It was assumed that the difference in the cumulative emission of CO(2) between the compost raw material and a sample corresponds to the amount of CO( 2) evolved from the sample in the composting facility. Using this method, the changes in organic matter degradation during composting in practical large-scale composting facilities were estimated and it was found that the percentage of organic matter degradation increased more vigorously in the earlier stages than in the later stages of composting. The percentage of organic matter degradation finally reached 78 and 55% for the compost produced from garbage-animal manure mixture and distillery waste (shochu residue), respectively. It was thus ascertained that organic matter degradation progressed well in both composting facilities. Furthermore, by performing a plant growth assay, it was observed that the compost products of both the facilities did not inhibit seed germination and thus were useful in promoting plant growth.

Effects of bedding type on compost quality of equine stall waste: implications for small horse farms.

PubMed

Komar, S; Miskewitz, R; Westendorf, M; Williams, C A

2012-03-01

Our objective in this study is to compare 4 of the most common bedding materials used by equine operations on the chemical and physical characteristics of composted equine stall waste. Twelve Standardbred horses were adapted to the barn and surrounding environment for 2 wk before the start of the study. Groups of 3 horses were bedded on 1 of 4 different bedding types (wood shavings, pelletized wood materials, long straw, and pelletized straw) for 16 h per day for 18 d. Stalls were cleaned by trained staff daily, and all contents removed were weighed and stored separately by bedding material on a level covered concrete pad for the duration of the study. Compost piles were constructed using 3 replicate piles of each bedding type in a randomized complete block design. Each pile was equipped with a temperature sensor and data logger. Water was added and piles were turned weekly throughout the 100-d compost process. Initial and final samples were taken, dried, and analyzed for DM mass, OM, inorganic nitrogen (nitrate-N and ammonium-N), electrical conductivity, and soluble (plant-available) nutrients. Data were analyzed using the GLM procedure, and means were separated using Fischer's protected LSD test (P < 0.05). No significant temperature differences were observed among the bedding materials. The composting process resulted in significant reductions (P < 0.05) in DM mass for each of the 4 bedding materials. The composting process resulted in significant reductions (P < 0.05) in OM and C:N ratio for all 4 bedding materials. The composted long straw material had greater concentrations of total Kjeldahl nitrogen (P < 0.05), nitrate-N (P < 0.05), and ammonium-N (P < 0.05) than the composted wood shavings. This study demonstrated that incorporating a simple aerobic composting system may greatly reduce the overall volume of manure and yield a material that is beneficial for land application in pasture-based systems. The straw-based materials may be better suited for

Assessment of co-composting process with high load of an inorganic industrial waste.

PubMed

Soares, Micaela A R; Quina, Margarida J; Reis, Marco S; Quinta-Ferreira, Rosa

2017-01-01

This study aims to investigate the co-composting of an inorganic industrial waste (eggshell - ES) in very high levels (up to 60% w/w). Since composting is a process in which solid, liquid and gaseous phases interact in a very complex way, there is a need to shed light on statistical tools that can unravel the main relationships structuring the variability associated to this process. In this study, PCA and data visualisation were used with that purpose. The co-composting tests were designed with increasing quantities of ES (0, 10, 20, 30 and 60%ES w/w) mixed with industrial potato peel and rice husks. Principal component analysis showed that physical properties like free air space, bulk density and moisture are the most relevant variables for explaining the variability due to ES content. On the other hand, variability in time dynamics is mostly driven by some chemical and phytoxicological parameters, such as organic matter decay and nitrate content. Higher ES incorporation (60% ES) enhanced the initial biological activity of the mixture, but the higher bulk density and lower water holding capacity had a negative effect on the aerobic biological activity as the process evolved. Nevertheless, pathogen-killing temperatures (>70°C for 11h) were attained. All the final products obtained after 90days were stable and non-phytotoxic. This work proved that valorisation of high amounts of eggshell by co-composting is feasible, but prone to be influenced by the physical properties of the mixtures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Monitoring of pile composting process of OFMSW at full scale and evaluation of odour emission impact.

PubMed

Gutiérrez, M C; Martín, M A; Serrano, A; Chica, A F

2015-03-15

In this study, the evolution of odour concentration (ouE/m(3)STP) emitted during the pile composting of the organic fraction of municipal solid waste (OFMSW) was monitored by dynamic olfactometry. Physical-chemical variables as well as the respirometric variables were also analysed. The aim of this work was twofold. The first was to determine the relationship between odour and traditional variables to determine if dynamic olfactometry is a feasible and adequate technique for monitoring an aerobic stabilisation process (composting). Second, the composting process odour impact on surrounding areas was simulated by a dispersion model. The results showed that the decrease of odour concentration, total organic carbon and respirometric variables was similar (around 96, 96 y 98% respectively). The highest odour emission (5224 ouE/m(3)) was reached in parallel with the highest microbiological activity (SOUR and OD20 values of 25 mgO2/gVS · h and 70 mgO2/gVS, respectively). The validity of monitoring odour emissions during composting in combination with traditional and respirometric variables was demonstrated by the adequate correlation obtained between the variables. Moreover, the quantification of odour emissions by dynamic olfactometry and the subsequent application of the dispersion model permitted making an initial prediction of the impact of odorous emissions on the population. Finally, the determination of CO2 and CH4 emissions allowed the influence of composting process on carbon reservoirs and global warming to be evaluated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Compost feedstock characteristics and ratio modelling for organic waste materials co-composting in Malaysia.

PubMed

Chai, E W; H'ng, P S; Peng, S H; Wan-Azha, W M; Chin, K L; Chow, M J; Wong, W Z

2013-01-01

In Malaysia, large amounts of organic materials, which lead to disposal problems, are generated from agricultural residues especially from palm oil industries. Increasing landfill costs and regulations, which limit many types of waste accepted at landfills, have increased the interest in composting as a component of waste management. The objectives of this study were to characterize compost feedstock properties of common organic waste materials available in Malaysia. Thus, a ratio modelling of matching ingredients for empty fruit bunches (EFBs) co-composting using different organic materials in Malaysia was done. Organic waste materials with a C/N ratio of < 30 can be applied as a nitrogen source in EFB co-composting. The outcome of this study suggested that the percentage of EFB ranged between 50% and 60%, which is considered as the ideal mixing ratio in EFB co-composting. Conclusively, EFB can be utilized in composting if appropriate feedstock in term of physical and chemical characteristics is coordinated in the co-composting process.

Biodegradation of compostable and oxodegradable plastic films by backyard composting and bioaugmentation.

PubMed

Quecholac-Piña, Xochitl; García-Rivera, Mariel Anel; Espinosa-Valdemar, Rosa María; Vázquez-Morillas, Alethia; Beltrán-Villavicencio, Margarita; Cisneros-Ramos, Adriana de la Luz

2017-11-01

Plastics are widely used in the production of short-life products, which are discarded producing an accumulation of these materials and problems due to their persistence in the environment and waste management systems. Degradable plastics (compostable, oxodegradable) have been presented as an alternative to decrease the negative effect of plastic waste. In this research, the feasibility of degrading a commercially available compostable film and oxodegradable polyethylene, with and without previous abiotic oxidation, is assessed in a home composting system. Reactors (200 L) were used to degrade the plastic films along with a mixture of organic food waste (50 %), mulch (25 %), and dry leaves (25 %), amended with yeast and a solution of brown sugar to increase the speed of the process. The presence of the plastic film did not affect the composting process, which showed an initial increase in temperature and typical profiles for moisture content, pH, with a final C/N of 17.4. After 57 days, the compostable plastic has decreased its mechanical properties in more than 90 %, while the oxodegradable film did not show significant degradation if it was not previously degraded by UV radiation. The use of these plastics should be assessed against the prevailing waste management system in each city or country. In the case of Mexico, which lacks the infrastructure for industrial composting, home composting could be an option to degrade compostable plastics along organic waste. However, more testing is needed in order to set the optimal parameters of the process.

Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

PubMed

Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

2016-04-01

We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria.

Microbial, chemical and physical aspects of citrus waste composting.

PubMed

van Heerden, I; Cronjé, C; Swart, S H; Kotzé, J M

2002-01-01

Citrus waste supplemented with calcium hydroxide and with a C/N ratio of 24:1, pH of 6.3 and moisture content of 60% was composted by piling under shelter. With regular turning over of the pile and replenishment of moisture, the thermic phase lasted for 65-70 days and composting was completed after 3 months. Compost thus prepared had an air-filled porosity of 14%, water-holding capacity of 590 ml l(-1), bulk density of 1.05 g cm(-3) and conductivity of 480 mS m(-1). Phosphorus content (in mg l(-1)) was 15, potassium 1,170, calcium 362, magnesium 121, sodium 32, chloride 143, boron 0.31, and water-soluble nitrogen and organic matter 126 and 4788, respectively. Total carbon amounted to 8.85% and total nitrogen to 1.26% of the dry weight, giving a C/N ratio of 7. Mature compost showed some, but acceptable, levels of phytotoxicity. Raw citrus waste was predominantly colonised by mesophilic yeasts. Thermophilous microorganisms present during the thermic phase mainly comprised the bacterial species Bacillus licheniformis, B. macerans and B. stearothermophilus and, to a lesser extent, fungi such as Absidia corymbifera, Aspergillus fumigatus, Emericella nidulans, Penicillium diversum, Paecilomyces variotii, Rhizomucor pusillus, Talaromyces thermophilus and Thermomyces lanuginosus. Bacteria prevalent in the final product included B. licheniformis, B. macerans, Proteus vulgaris, Pseudomonas aeruginosa, P. fluorescens, P. luteola and Serratia marcescens, whereas fungi isolated most frequently comprised Aspergillus puniceus, A. ustus, E. nidulans. Paecilomyces lilacinus, T lanuginosus, yeasts and a basidiomycetous species, probably Coprinus lagopus.

Assessing the effect of biodegradable and degradable plastics on the composting of green wastes and compost quality.

PubMed

Unmar, G; Mohee, R

2008-10-01

An assessment of the effect of the composting potential of Mater-Bi biodegradable plastic with green wastes, noted by GBIO, and degradable plastic (PDQ-H additive) with green wastes, noted by GDEG, was carried out in a lagged two-compartment compost reactor. The composting time was determined until constant mass of the composting substrates was reached. The green wastes composting process was used as control (G). After one week of composting, the biodegradable plastics disappeared completely, while 2% of the original degradable plastic still remained after about 8 weeks of composting. A net reduction in volatile solids contents of 61.8%, 56.5% and 53.2% were obtained for G, GBIO and GDEG, respectively. Compost quality was assessed in terms of nitrogen, potassium and phosphorus contents, which were found to be highest for GBIO compost. From the phytotoxicity test, it has been observed that a diluted extract of GBIO compost has produced the longest length of radicle. From the respiration test, no significant difference in the amount of carbon dioxide released by the composting of GDEG and G was observed. This study showed that the quality of the compost is not affected by the presence of the biodegradable and degradable plastics in the raw materials.

Bacterial Selection during the Formation of Early-Stage Aerobic Granules in Wastewater Treatment Systems Operated Under Wash-Out Dynamics

PubMed Central

Weissbrodt, David G.; Lochmatter, Samuel; Ebrahimi, Sirous; Rossi, Pierre; Maillard, Julien; Holliger, Christof

2012-01-01

Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activities during the formation of early-stage granules from activated sludge of two wastewater treatment plants (WWTP) over start-up periods of maximum 60 days. Five bubble-column sequencing batch reactors were operated with feast-famine regimes consisting of rapid pulse or slow anaerobic feeding followed by aerobic starvation. Slow-settling fluffy granules were formed when an insufficient superficial air velocity (SAV; 1.8 cm s−1) was applied, when the inoculation sludge was taken from a WWTP removing organic matter only, or when reactors were operated at 30°C. Fast-settling dense granules were obtained with 4.0 cm s−1 SAV, or when the inoculation sludge was taken from a WWTP removing all nutrients biologically. However, only carbon was aerobically removed during start-up. Fluffy granules and dense granules were displaying distinct predominant phylotypes, namely filamentous Burkholderiales affiliates and Zoogloea relatives, respectively. The latter were predominant in dense granules independently from the feeding regime. A combination of insufficient solid retention time and of leakage of acetate into the aeration phase during intensive biomass wash-out was the cause for the proliferation of Zoogloea spp. in dense granules, and for the deterioration of BNR performances. It is however not certain that Zoogloea-like organisms are essential in granule formation. Optimal operation conditions should be elucidated for maintaining a balance between organisms with granulation propensity and nutrient removing organisms in order to form granules with BNR activities in short

Bacterial Selection during the Formation of Early-Stage Aerobic Granules in Wastewater Treatment Systems Operated Under Wash-Out Dynamics.

PubMed

Weissbrodt, David G; Lochmatter, Samuel; Ebrahimi, Sirous; Rossi, Pierre; Maillard, Julien; Holliger, Christof

2012-01-01

Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activities during the formation of early-stage granules from activated sludge of two wastewater treatment plants (WWTP) over start-up periods of maximum 60 days. Five bubble-column sequencing batch reactors were operated with feast-famine regimes consisting of rapid pulse or slow anaerobic feeding followed by aerobic starvation. Slow-settling fluffy granules were formed when an insufficient superficial air velocity (SAV; 1.8 cm s(-1)) was applied, when the inoculation sludge was taken from a WWTP removing organic matter only, or when reactors were operated at 30°C. Fast-settling dense granules were obtained with 4.0 cm s(-1) SAV, or when the inoculation sludge was taken from a WWTP removing all nutrients biologically. However, only carbon was aerobically removed during start-up. Fluffy granules and dense granules were displaying distinct predominant phylotypes, namely filamentous Burkholderiales affiliates and Zoogloea relatives, respectively. The latter were predominant in dense granules independently from the feeding regime. A combination of insufficient solid retention time and of leakage of acetate into the aeration phase during intensive biomass wash-out was the cause for the proliferation of Zoogloea spp. in dense granules, and for the deterioration of BNR performances. It is however not certain that Zoogloea-like organisms are essential in granule formation. Optimal operation conditions should be elucidated for maintaining a balance between organisms with granulation propensity and nutrient removing organisms in order to form granules with BNR activities in short

Combining woody biomass for combustion with green waste composting: Effect of removal of woody biomass on compost quality.

PubMed

Vandecasteele, Bart; Boogaerts, Christophe; Vandaele, Elke

2016-12-01

The question was tackled on how the green waste compost industry can optimally apply the available biomass resources for producing both bioenergy by combustion of the woody fraction, and high quality soil improvers as renewable sources of carbon and nutrients. Compost trials with removal of woody biomass before or after composting were run at 9 compost facilities during 3 seasons to include seasonal variability of feedstock. The project focused on the changes in feedstock and the effect on the end product characteristics (both compost and recovered woody biomass) of this woody biomass removal. The season of collection during the year clearly affected the biochemical and chemical characteristics of feedstock, woody biomass and compost. On one hand the effect of removal of the woody fraction before composting did not significantly affect compost quality when compared to the scenario where the woody biomass was sieved from the compost at the end of the composting process. On the other hand, quality of the woody biomass was not strongly affected by extraction before or after composting. The holocellulose:lignin ratio was used in this study as an indicator for (a) the decomposition potential of the feedstock mixture and (b) to assess the stability of the composts at the end of the process. Higher microbial activity in green waste composts (indicated by higher oxygen consumption) and thus a lower compost stability resulted in higher N immobilization in the compost. Removal of woody biomass from the green waste before composting did not negatively affect the compost quality when more intensive composting was applied. The effect of removal of the woody fraction on the characteristics of the green waste feedstock and the extracted woody biomass is depending on the season of collection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparing composts formed by different technological processing

NASA Astrophysics Data System (ADS)

Lyckova, B.; Mudrunka, J.; Kucerova, R.; Glogarova, V.

2017-10-01

The presented article compares quality of composts which were formed by different technological processes. The subject to comparison was a compost which was created in a closed fermenter where ideal conditions for decomposition and organic substances conversion were ensured, with compost which was produced in an open box of community composting. The created composts were analysed to determine whether it is more important for the final compost to comply with the composting conditions or better sorting of raw materials needed for compost production. The results of the carried out experiments showed that quality of the resulting compost cannot be determined unequivocally.

Presence of Legionella and Free-Living Amoebae in Composts and Bioaerosols from Composting Facilities

PubMed Central

Conza, Lisa; Pagani, Simona Casati; Gaia, Valeria

2013-01-01

Several species of Legionella cause Legionnaires’ disease (LD). Infection may occur through inhalation of Legionella or amoebal vesicles. The reservoirs of Legionella are water, soil, potting soil and compost. Some species of free-living amoebae (FLA) that are naturally present in water and soil were described as hosts for Legionella. This study aimed to understand whether or not the composting facilities could be sources of community-acquired Legionella infections after development of bioaerosols containing Legionella or FLA. We looked for the presence of Legionella (by co-culture) and FLA (by culture) in composts and bioaerosols collected at four composting facilities located in southern Switzerland. We investigated the association between the presence of Legionella and compost and air parameters and presence of FLA. Legionella spp. (including L. pneumophila) were detected in 69.3% (61/88) of the composts and FLA (mainly Acanthamoeba, Vermamoeba, Naegleria and Stenamoeba) in 92.0% (81/88). L. pneumophila and L. bozemanii were most frequently isolated. FLA as potential host for Legionella spp. were isolated from 40.9% (36/88) of the composts in all facilities. In Legionella-positive samples the temperature of compost was significantly lower (P = 0.012) than in Legionella-negative samples. Of 47 bioaerosol samples, 19.1% (9/47) were positive for FLA and 10.6% (5/47) for L. pneumophila. Composts (62.8%) were positive for Legionella and FLA contemporaneously, but both microorganisms were never detected simultaneously in bioaerosols. Compost can release bioaerosol containing FLA or Legionella and could represent a source of infection of community-acquired Legionella infections for workers and nearby residents. PMID:23844174

Normal bacterial flora from vaginas of Criollo Limonero cows.

PubMed

Zambrano-Nava, Sunny; Boscán-Ocando, Julio; Nava, Jexenia

2011-02-01

In order to describe the normal bacterial flora in vaginas of Criollo Limonero cows, 51 healthy multiparous cows, at least 90-day postpartum, were selected. Duplicated swabs (N = 102) were taken from the vaginal fornix of cows to perform aerobic and anaerobic cultures as well as conventional biochemical tests. Out of 102 swabs, bacterial growth was obtained in 55 (53.9%) while the remaining 47 (46.1%) did not exhibited any bacterial growth. Of the 55 bacterial growths, 23 (41.8%) were aerobic whereas 32 (58.1%) were anaerobic. Likewise, 29 (52.72%) of bacterial growths were pure and 26 (47.27%) were mixed. Under both aerobic and anaerobic conditions, Gram positive bacteria were predominant (81.82% and 73.08%, respectively) over Gram negative bacteria (18.18% and 26.92%, respectively). Isolated bacteria were Arcanobacterium pyogenes (22.92%), Staphylococcus aureus (15.63%), Staphylococcus coagulase negative (17.71%), Erysipelothrix rhusiopathiae (6.25%), Bacteroides spp. (13.54%), and Peptostreptococcus spp. (7.29%). In conclusion, normal vaginal bacterial flora of Criollo Limonero cows was predominantly Gram positive and included A. pyogenes, S. aureus, coagulase negative Staphylococcus, E. rhusiopathiae, Bacteroides spp., and Peptostreptococcus spp. In Criollo Limonero cattle, adaptive aspects such as development of humoral and physical mechanisms for defense, and bacterial adaptation to host deserve research attention.

Biochar amendment before or after composting affects compost quality and N losses, but not P plant uptake.

PubMed

Vandecasteele, Bart; Sinicco, Tania; D'Hose, Tommy; Vanden Nest, Thijs; Mondini, Claudio

2016-03-01

We investigated the use of biochar (10% on a dry weight basis) to improve the composting process and/or the compost quality by adding it to either the feedstock mixture or the mature compost. The addition of biochar to the feedstocks was essayed in a full scale trial using a mixture of green waste and the organic fraction of municipal solid waste. Addition of biochar to mature compost was performed in a medium scale experiment. The use of biochar, even in small amounts, changed the composting process and the properties of the end products. However these effects depended on the time of application. We observed a faster decomposition in the bio-oxidative phase and lower greenhouse gas emissions when biochar was added at the beginning of the composting process, and a reduction in readily available P when biochar was applied during compost storage. Biochar as a means to increase the C content of the compost was only effective during compost storage. The P fertilizer replacement value of the compost with and without biochar was tested in a plant trial with annual ryegrass. While there was a clear effect on readily available P concentrations in the compost, adding biochar to the feedstock or the compost did not affect the P fertilizer replacement value. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Aerated Compost Tea on the Growth Promotion of Lettuce, Soybean, and Sweet Corn in Organic Cultivation

PubMed Central

Kim, Min Jeong; Shim, Chang Ki; Kim, Yong Ki; Hong, Sung Jun; Park, Jong Ho; Han, Eun Jung; Kim, Jin Ho; Kim, Suk Chul

2015-01-01

This study investigated the chemical characteristics and microbial population during incubation of four kinds of aerated compost teas based on oriental medicinal herbs compost, vermicompost, rice straw compost, and mixtures of three composts (MOVR). It aimed to determine the effects of the aerated compost tea (ACT) based on MOVR on the growth promotion of red leaf lettuce, soybean and sweet corn. Findings showed that the pH level and EC of the compost tea slightly increased based on the incubation time except for rice straw compost tea. All compost teas except for oriental medicinal herbs and rice straw compost tea contained more NO−3-N than NH+4-N. Plate counts of bacteria and fungi were significantly higher than the initial compost in ACT. Microbial communities of all ACT were predominantly bacteria. The dominant bacterial genera were analyzed as Bacillus (63.0%), Ochrobactrum (13.0%), Spingomonas (6.0%) and uncultured bacterium (4.0%) by 16S rDNA analysis. The effect of four concentrations, 0.1%, 0.2%, 0.4% and 0.8% MOVR on the growth of red leaf lettuce, soybean and sweet corn was also studied in the greenhouse. The red leaf lettuce with 0.4% MOVR had the most effective concentration on growth parameters in foliage part. However, 0.8% MOVR significantly promoted the growth of root and shoot of both soybean and sweet corn. The soybean treated with higher MOVR concentration was more effective in increasing the root nodule formation by 7.25 times than in the lower MOVR concentrations Results indicated that ACT could be used as liquid nutrient fertilizer with active microorganisms for culture of variable crops under organic farming condition. PMID:26361474

Effect of Aerated Compost Tea on the Growth Promotion of Lettuce, Soybean, and Sweet Corn in Organic Cultivation.

PubMed

Kim, Min Jeong; Shim, Chang Ki; Kim, Yong Ki; Hong, Sung Jun; Park, Jong Ho; Han, Eun Jung; Kim, Jin Ho; Kim, Suk Chul

2015-09-01

This study investigated the chemical characteristics and microbial population during incubation of four kinds of aerated compost teas based on oriental medicinal herbs compost, vermicompost, rice straw compost, and mixtures of three composts (MOVR). It aimed to determine the effects of the aerated compost tea (ACT) based on MOVR on the growth promotion of red leaf lettuce, soybean and sweet corn. Findings showed that the pH level and EC of the compost tea slightly increased based on the incubation time except for rice straw compost tea. All compost teas except for oriental medicinal herbs and rice straw compost tea contained more NO(-) 3-N than NH(+) 4-N. Plate counts of bacteria and fungi were significantly higher than the initial compost in ACT. Microbial communities of all ACT were predominantly bacteria. The dominant bacterial genera were analyzed as Bacillus (63.0%), Ochrobactrum (13.0%), Spingomonas (6.0%) and uncultured bacterium (4.0%) by 16S rDNA analysis. The effect of four concentrations, 0.1%, 0.2%, 0.4% and 0.8% MOVR on the growth of red leaf lettuce, soybean and sweet corn was also studied in the greenhouse. The red leaf lettuce with 0.4% MOVR had the most effective concentration on growth parameters in foliage part. However, 0.8% MOVR significantly promoted the growth of root and shoot of both soybean and sweet corn. The soybean treated with higher MOVR concentration was more effective in increasing the root nodule formation by 7.25 times than in the lower MOVR concentrations Results indicated that ACT could be used as liquid nutrient fertilizer with active microorganisms for culture of variable crops under organic farming condition.

Effects of rhamnolipid and initial compost particle size on the two-stage composting of green waste.

PubMed

Zhang, Lu; Sun, Xiangyang

2014-07-01

Composting is a potential alternative to green waste incineration or deposition in landfills. The effects of the biosurfactant rhamnolipid (RL) (at 0.0%, 0.15%, and 0.30%) and initial compost particle size (IPS) (10, 15, and 25 mm) on a new, two-stage method for composting green waste was investigated. A combination of RL addition and IPS adjustment improved the quality of the finished compost in terms of its physical characteristics, pH, C/N ratio, nutrient content, cellulose and hemicellulose contents, water-soluble carbon (WSC) content, xylanase and CMCase activities, numbers of culturable microorganisms (bacteria, actinomycetes, and fungi), and toxicity to germinating seeds. The production of a stable and mature compost required only 24 days with the optimized two-stage composting method described here rather than the 90-270 days required with traditional composting. The best quality compost was obtained with 0.15% RL and an IPS of 15 mm. Copyright © 2014 Elsevier Ltd. All rights reserved.

Benefits to decomposition rates when using digestate as compost co-feedstock: Part II - Focus on microbial community dynamics.

PubMed

Arab, Golnaz; Razaviarani, Vahid; Sheng, Zhiya; Liu, Yang; McCartney, Daryl

2017-10-01

Linkage between composting reactor performance and microbial community dynamics was investigated during co-composting of digestate and fresh feedstock (organic fraction of municipal solid waste) using 25L reactors. Previously, the relationship between composting performance and various physicochemical parameters were reported in Part I of the study (Arab and McCartney, 2017). Three digestate to fresh feedstock ratios (0, 40, and 100%; wet weight basis) were selected for analysis of microbial community dynamics. The 40% ratio was selected because it was found to perform the best (Arab and McCartney, 2017). Illumina sequencing results revealed that the reactor with a greater composting performance (higher organic matter degradation and higher heat generation; 40% ratio) was associated with higher microbial diversity. Two specific bacterial orders that might result in higher performance were Thermoactinomycetaceae and Actinomycetales with a higher sequence abundance during thermophilic composting phase and during the maturing composting phase, respectively. Galactomyces, Pichia, Chaetomium, and Acremonium were the four fungal genera that are probably also involved in higher organic matter degradation in the reactor with better performance. The redundancy analysis (RDA) biplot indicated that among the studied environmental variables, temperature, total ammonia nitrogen and nitrate concentration accounted for much of the major shifts in microbial sequence abundance during the co-composting process. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Cultural, Transcriptomic, and Proteomic Analyses of Water-Stressed Cells of Actinobacterial Strains Isolated from Compost: Ecological Implications in the Fed-Batch Composting Process.

PubMed

Narihiro, Takashi; Kanosue, Yuji; Hiraishi, Akira

2016-06-25

This study was undertaken to examine the effects of water activity (aw) on the viability of actinobacterial isolates from a fed-batch composting (FBC) process by comparing culturability and stainability with 5-cyano-2,3-ditoryl tetrazolium chloride (CTC). The FBC reactor as the source of these bacteria was operated with the daily loading of household biowaste for 70 d. During this period of composting, aw in the reactor decreased linearly with time and reached approximately 0.95 at the end of operation. The plate counts of aerobic chemoorganotrophic bacteria were 3.2-fold higher than CTC-positive (CTC+) counts on average at the fully acclimated stage (after 7 weeks of operation), in which Actinobacteria predominated, as shown by lipoquinone profiling and cultivation methods. When the actinobacterial isolates from the FBC process were grown under aw stress, no significant differences were observed in culturability among the cultures, whereas CTC stainability decreased with reductions in aw levels. A cDNA microarray-based transcriptomic analysis of a representative isolate showed that many of the genes involved in cellular metabolism and genetic information processing were down-regulated by aw stress. This result was fully supported by a proteomic analysis. The results of the present study suggest that, in low aw mature compost, the metabolic activity of the community with Actinobacteria predominating is temporarily reduced to a level that hardly reacts with CTC; however, these bacteria are easily recoverable by exposure to a high aw culture medium. This may be a plausible reason why acclimated FBC reactors in which Actinobacteria predominate yields higher plate counts than CTC+ counts.

Phytate degradation by fungi and bacteria that inhabit sawdust and coffee residue composts.

PubMed

Fathallh Eida, Mohamed; Nagaoka, Toshinori; Wasaki, Jun; Kouno, Kenji

2013-01-01

Phytate is the primary source of organic phosphorus, but it cannot be directly utilized by plants and is strongly adsorbed by the soil, reducing bioavailability. Composting is a process used to improve the bioavailability of phytate in organic wastes through degradation by microorganisms. In this study, we aimed to investigate the phytate-degrading ability of fungi and bacteria that inhabit sawdust compost and coffee residue compost, and their contribution to the composting process. In the plate assay, the fungi that formed clear zones around their colonies belonged to the genera Mucor, Penicillium, Galactomyces, Coniochaeta, Aspergillus, and Fusarium, while the bacteria belonged to the genera Pseudomonas, Enterobacter, Chitinophaga, and Rahnella. Eight fungal isolates (genera Mucor, Penicillium, Galactomyces, and Coniochaeta) and four bacterial isolates (genera Pseudomonas, Enterobacter, and Rahnella) were selected to evaluate phytase activity in their liquid culture and their ability to degrade phytate in organic materials composed of mushroom media residue and rice bran. The selected fungi degraded phytate in organic materials to varying degrees. Penicillium isolates showed the highest degradation ability and Coniochaeta isolate exhibited relatively high degradation ability. The clear zone diameters of these fungal isolates displayed significantly positive and negative correlations with inorganic and phytate phosphorus contents in the organic materials after incubation, respectively; however, none of the selected bacteria reduced phytate phosphorus in organic materials. It is therefore possible that fungi are major contributors to phytate degradation during composting.

Phytate Degradation by Fungi and Bacteria that Inhabit Sawdust and Coffee Residue Composts

PubMed Central

Eida, Mohamed Fathallh; Nagaoka, Toshinori; Wasaki, Jun; Kouno, Kenji

2013-01-01

Phytate is the primary source of organic phosphorus, but it cannot be directly utilized by plants and is strongly adsorbed by the soil, reducing bioavailability. Composting is a process used to improve the bioavailability of phytate in organic wastes through degradation by microorganisms. In this study, we aimed to investigate the phytate-degrading ability of fungi and bacteria that inhabit sawdust compost and coffee residue compost, and their contribution to the composting process. In the plate assay, the fungi that formed clear zones around their colonies belonged to the genera Mucor, Penicillium, Galactomyces, Coniochaeta, Aspergillus, and Fusarium, while the bacteria belonged to the genera Pseudomonas, Enterobacter, Chitinophaga, and Rahnella. Eight fungal isolates (genera Mucor, Penicillium, Galactomyces, and Coniochaeta) and four bacterial isolates (genera Pseudomonas, Enterobacter, and Rahnella) were selected to evaluate phytase activity in their liquid culture and their ability to degrade phytate in organic materials composed of mushroom media residue and rice bran. The selected fungi degraded phytate in organic materials to varying degrees. Penicillium isolates showed the highest degradation ability and Coniochaeta isolate exhibited relatively high degradation ability. The clear zone diameters of these fungal isolates displayed significantly positive and negative correlations with inorganic and phytate phosphorus contents in the organic materials after incubation, respectively; however, none of the selected bacteria reduced phytate phosphorus in organic materials. It is therefore possible that fungi are major contributors to phytate degradation during composting. PMID:23100024

Carbohydrate composition of compost during composting and mycelium growth of Agaricus bisporus.

PubMed

Jurak, Edita; Kabel, Mirjam A; Gruppen, Harry

2014-01-30

Changes of plant cell wall carbohydrate structures occurring during the process to make suitable compost for growth of Agaricus bisporus are unknown. In this paper, composition and carbohydrate structures in compost samples collected during composting and mycelium growth were analyzed. Furthermore, different extracts of compost samples were prepared with water, 1M and 4M alkali and analyzed. At the beginning of composting, 34% and after 16 days of mycelium growth 27% of dry matter was carbohydrates. Carbohydrate composition analysis showed that mainly cellulose and poorly substituted xylan chains with similar amounts and ratios of xylan building blocks were present in all phases studied. Nevertheless, xylan solubility increased 20% over the period of mycelium growth indicating partial degradation of xylan backbone. Apparently, degradation of carbohydrates occurred over the process studied by both bacteria and fungi, mainly having an effect on xylan-chain length and solubility. Copyright © 2013 Elsevier Ltd. All rights reserved.

Selective medium for aerobic incubation of Campylobacter

USDA-ARS?s Scientific Manuscript database

Studies were conducted on the formulation of a selective medium that could be used to isolate Campylobacter from mixed bacterial cultures using aerobic incubation. A non-selective, basal broth medium was prepared and supplemented with Bolton, Cefex, or Skirrow antibiotic mixtures. The ability of pur...

Strike It Rich with Classroom Compost.

ERIC Educational Resources Information Center

Jones, Linda L. Cronin

1992-01-01

Discusses composting of organic materials as an alternative to landfills. Lists uses of composts and describes details of a simple composting activity for high school students. Includes an information sheet for students and a student data sheet. Suggests other composting activities. (PR)

Physical and chemical properties of biochars co-composted with biowastes and incubated with a chicken litter compost.

PubMed

Khan, Naser; Clark, Ian; Sánchez-Monedero, Miguel A; Shea, Syd; Meier, Sebastian; Qi, Fangjie; Kookana, Rai S; Bolan, Nanthi

2016-01-01

Two experiments were conducted where three biochars, made from macadamia nutshell (MS), hardwood shaving (WS) and chicken litter (CL), were co-composted with chicken manure and sawdust, and also incubated with a chicken litter based commercial compost. Biochars were added at the rates of 5% and 10% in the co-composting and 10% and 20% in the incubation experiment. The rates of biochar had no consistent effect on the change in element contents of composted- or incubated-biochars. The biochar C demonstrated recalcitrance in both composting and incubation systems. Composting increased the CEC of biochars probably due to thermophilic oxidation. The increases in CEC of WS and CL were 6.5 and 2.2 times, respectively, for composting. Translocation of elements, between biochar and compost medium, occurred in both directions. In most cases, biochars gained elements under the influence of positive difference of concentrations (i.e., when compost medium had higher concentration of elements than biochar), while in some cases they lost elements despite a positive difference. Biochar lost some elements (WS: B; CL: B, Mg and S) under the influence of negative difference of concentrations. Some biochars showed strong affinity for B, C, N and S: the concentration of these elements gained by biochars surpassed the concentration in the respective composting medium. The material difference in the biochars did not have influence on N retention: all three netbag-biochars increased their N content. The cost of production of biochar-compost will be lower in co-composting than incubation, which involves two separate processes, i.e., composting and subsequent incubation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Composting of Sewage Sludge Using Recycled Matured Compost as a Single Bulking Agent

NASA Astrophysics Data System (ADS)

Zhang, Xiangyang; Ren, Jian; Niu, Huasi; Wu, Xingwu

2010-11-01

Pretreatment (bulking agent choice and mixing) is an essential phase of dewatered raw sludge (RS) composting affecting its industrialization significantly. In this paper recycled compost (RC) was chosen as a single bulking agent in the composting experiment instead of other agents such as sawdust, rice straw, MSW, and the mixing machine was developed for mixing of SS and RC. According to the mixing experiment, SS and RC can be mixed uniformly and formed into small particles of 10˜15 mm in diameter, which improved the availability of oxygen during composting. The effect of different volumetric ratios of RS to RC, 1:1 (Exp.1), 1:2 (Exp.2) and 1:4 (Exp.3), on the performance of composting was investigated in detail. Temperature, oxygen consumption rate, organic matter, C/N ratio and moisture content were monitored in each experiment. In despite of low initial C/N of the mixture, intensive fermentation happened in all the experiments. Exp.1 and Exp.2 achieved stability and sanitization, but Exp 1 took more days to accomplish the fermentation. Exp 3 maintained thermophilic temperatures for a shortest time and did not satisfy the necessary sanitation requirements because more RC was recycled. In all experiments, the moisture content of their final composts were too high to be used as bulking agents before extra moisture was reduced. RS: RC = 1:2 (v/v) was the optimum and advisable proportion for the industrialization of sewage sludge composting of, the composting period was about 10 days, and the aeration rate 0.05 m3/(m3ṡmin) was appropriate in this study.

Aerobic biodegradation kinetics of solid organic wastes on earth and for applications in space

NASA Astrophysics Data System (ADS)

Ramirez Perez, Javier Christian

Aerobic biodegradation plays an important role in recycling organic matter and nutrients on earth. It is also a candidate technology for waste processing and resource recovery in Advanced Life Support (ALS) systems, such as a proposed planetary base on Mars. Important questions are how long should wastes be treated, and what is the quality (stability/maturity) of the product. To address these questions two aerobic composting systems were evaluated. One treated (252 days) horse manure and cranberry fruit in duplicate open windrows (HCC) as a reference earth application. The other was a pilot-scale (330 L) enclosed, in-vessel system treating (162 days) inedible biomass collected from plant growth systems at NASA, amended with food and human wastes simulant for potential space application (ALSC). Samples were taken from both systems over time and product quality assessed with a range of physical, chemical, biological, toxicological, respirometry and plant growth analyses that were developed and standardized. Because plant growth analyses take so long, a hypothesis was that some parameters could be used to predict compost quality and suitability for growing plants. Maximum temperatures in the thermophilic range were maintained for both systems (HCC > 60°C for >129 days, ALSC > 55°C for >40 days. Fecal streptococci were reduced by 4.8 log-units for HCC and 7.8 for ALSC. Volume/mass reductions achieved were 63%/62% for HCC and 79%/67% for ALSC. Phytotoxicity tests performed on aqueous extracts to recover plant nutrients found decreasing sensitivity: arabidopsis > lettuce > tomato > wheat > cucumber, corresponding with seed size and food reserve capacity. The germination index (GI) of HCC increased over composting time indicating decreasing phytotoxicity. However, GIs for ALSC leachate decreased or fluctuated over composting time. Selected samples of HCC at 31, 157 and 252 days alone and combined with promix (1:1), and of ALSC at 7, 14, 21, 28, 40 and 84 days, or fresh

Chemical structures and characteristics of animal manures and composts during composting and assessment of maturity indices

PubMed Central

Huang, Jieying; Yu, Zixuan; Gao, Hongjian; Yan, Xiaoming; Chang, Jiang; Wang, Chengming; Hu, Jingwei

2017-01-01

Changes in physicochemical characteristics, chemical structures and maturity of swine, cattle and chicken manures and composts during 70-day composting without addition of bulking agents were investigated. Physicochemical characteristics were measured by routine analyses and chemical structures by solid-state 13C NMR and FT-IR. Three manures were of distinct properties. Their changes in physicochemical characteristics, chemical structures, and maturity were different not only from each other but also from those with addition of bulking agents during composting. Aromaticity in chicken manure composts decreased at first, and then increased whereas that in cattle and swine manure composts increased. Enhanced ammonia volatilization occurred without addition of bulking agents. NMR structural information indicated that cattle and chicken composts were relatively stable at day 36 and 56, respectively, but swine manure composts were not mature up to day 70. Finally, the days required for three manures to reach the threshold values of different maturity indices were different. PMID:28604783

Effects of age of cattle, turning technology and compost environment on disappearance of bone from mortality compost.

PubMed

Stanford, K; Hao, X; Xu, S; McAllister, T A; Larney, F; Leonard, J J

2009-10-01

As residual bones in mortality compost negatively impact subsequent tillage, two studies were performed. For the first study, windrows of mature cattle or calves were placed on a base of barley straw and covered with beef manure. Windrows were divided into two sections and turned at 3-month intervals. Approximately 5000 kg of finished compost per windrow was passed through a 6mm trommel screen, with bones collected and weighed. Bone weight was 0.66% of mature cattle compost and 0.38% of calf compost on a dry matter basis, but did not differ after adjustment for weights of compost ingredients. In a subsequent study, four windrows were constructed containing mortalities, straw and beef manure (STATC) or straw, manure and slaughter waste (STATW). Also, straw, beef manure and slaughter waste was added to an 850 L rolling drum composter (DRUMW). Fresh bovine long-bones from calves were collected, weighed and embedded in the compost. Bones were retrieved and weighed when windrows were turned, or with DRUMW, after 8 weeks. Temperatures achieved followed the order STATW>STATC>DRUMW (p<0.05). Rate of bone disappearance followed a pattern identical to temperature, with the weight of bones in STATW declining by 53.7% during 7 weeks of composting. For STATC, temperatures were uniform over three composting periods, but bone disappearance was improved (p<0.05) when compost dry matter was lower (46%), as compared to 58%. Using a ratio of five parts manure to one part mortalities, results of this study demonstrated that residual bone was <1% of cured cattle compost and may be reduced by maintaining a high compost temperature and moisture content.

Composting Phragmites australis Cav. plant material and compost effects on soil and tomato (Lycopersicon esculentum Mill.) growth.

PubMed

Toumpeli, Anna; Pavlatou-Ve, Athina K; Kostopoulou, Sofia K; Mamolos, Andreas P; Siomos, Anastasios S; Kalburtji, Kiriaki L

2013-10-15

Composting organic residues is a friendly to the environment alternative to producing fertilizer. This research was carried out to study the process of composting Phragmites australis Cav. plant material alone or with animal manure on a pilot-scale, to evaluate firstly the quality of the composts produced and secondly, using a pot experiment, the effects of their application on soil physicochemical characteristics and tomato plants development. For the compost production a randomized complete block design was used with five treatments (five compost types) and four replications. For the pot experiment, a completely randomized design was used with 17 treatments (plain soil, soil with synthetic fertilizer and the application of five compost types, at three rates each) and five replications. Compost N increased with composting time, while C/N ratio decreased significantly and by the end it ranged from 43.3 for CM to 22.6 for CY. Compost pH became almost neutral, ranging from 6.73 for CY to 7.21 for CM3Y3AM4 by the end. Compost combinations CY7AM3 and CM7AM3 had a more positive influence on the soil physicochemical characteristics than the others. Soil N, P, Ca and Mg concentrations and the reduction of clay dispersion were the highest when CM7AM3 compost was added. The macro-aggregate stability was the highest for CY7AM3, which also sustained plant growth. The latter compost combination improved most of the soil physicochemical characteristics and plant growth especially, when the application rate was 4% (w/w), which equals to 156 Mg ha(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

Quantification, Distribution, and Possible Source of Bacterial Biofilm in Mouse Automated Watering Systems

PubMed Central

Meier, Thomas R; Maute, Carrie J; Cadillac, Joan M; Lee, Ji Young; Righter, Daniel J; Hugunin, Kelly MS; Deininger, Rolf A; Dysko, Robert C

2008-01-01

The use of automated watering systems for providing drinking water to rodents has become commonplace in the research setting. Little is known regarding bacterial biofilm growth within the water piping attached to the racks (manifolds). The purposes of this project were to determine whether the mouse oral flora contributed to the aerobic bacterial component of the rack biofilm, quantify bacterial growth in rack manifolds over 6 mo, assess our rack sanitation practices, and quantify bacterial biofilm development within sections of the manifold. By using standard methods of bacterial identification, the aerobic oral flora of 8 strains and stocks of mice were determined on their arrival at our animal facility. Ten rack manifolds were sampled before, during, and after sanitation and monthly for 6 mo. Manifolds were evaluated for aerobic bacterial growth by culture on R2A and trypticase soy agar, in addition to bacterial ATP quantification by bioluminescence. In addition, 6 racks were sampled at 32 accessible sites for evaluation of biofilm distribution within the watering manifold. The identified aerobic bacteria in the oral flora were inconsistent with the bacteria from the manifold, suggesting that the mice do not contribute to the biofilm bacteria. Bacterial growth in manifolds increased while they were in service, with exponential growth of the biofilm from months 3 to 6 and a significant decrease after sanitization. Bacterial biofilm distribution was not significantly different across location quartiles of the rack manifold, but bacterial levels differed between the shelf pipe and connecting elbow pipes. PMID:18351724

Quantification, distribution, and possible source of bacterial biofilm in mouse automated watering systems.

PubMed

Meier, Thomas R; Maute, Carrie J; Cadillac, Joan M; Lee, Ji Young; Righter, Daniel J; Hugunin, Kelly M S; Deininger, Rolf A; Dysko, Robert C

2008-03-01

The use of automated watering systems for providing drinking water to rodents has become commonplace in the research setting. Little is known regarding bacterial biofilm growth within the water piping attached to the racks (manifolds). The purposes of this project were to determine whether the mouse oral flora contributed to the aerobic bacterial component of the rack biofilm, quantify bacterial growth in rack manifolds over 6 mo, assess our rack sanitation practices, and quantify bacterial biofilm development within sections of the manifold. By using standard methods of bacterial identification, the aerobic oral flora of 8 strains and stocks of mice were determined on their arrival at our animal facility. Ten rack manifolds were sampled before, during, and after sanitation and monthly for 6 mo. Manifolds were evaluated for aerobic bacterial growth by culture on R2A and trypticase soy agar, in addition to bacterial ATP quantification by bioluminescence. In addition, 6 racks were sampled at 32 accessible sites for evaluation of biofilm distribution within the watering manifold. The identified aerobic bacteria in the oral flora were inconsistent with the bacteria from the manifold, suggesting that the mice do not contribute to the biofilm bacteria. Bacterial growth in manifolds increased while they were in service, with exponential growth of the biofilm from months 3 to 6 and a significant decrease after sanitization. Bacterial biofilm distribution was not significantly different across location quartiles of the rack manifold, but bacterial levels differed between the shelf pipe and connecting elbow pipes.

Opportunities and barriers to on-farm composting and compost application: A case study from northwestern Europe.

PubMed

Viaene, J; Van Lancker, J; Vandecasteele, B; Willekens, K; Bijttebier, J; Ruysschaert, G; De Neve, S; Reubens, B

2016-02-01

Maintaining and increasing soil quality and fertility in a sustainable way is an important challenge for modern agriculture. The burgeoning bioeconomy is likely to put further pressure on soil resources unless they are managed carefully. Compost has the potential to be an effective soil improver because of its multiple beneficial effects on soil quality. Additionally, it fits within the bioeconomy vision because it can valorize biomass from prior biomass processing or valorize biomass unsuitable for other processes. However, compost is rarely used in intensive agriculture, especially in regions with high manure surpluses. The aim of this research is to identify the barriers to on-farm composting and the application of compost in agriculture, using a mixed method approach for the case of Flanders. The significance of the 28 identified barriers is analyzed and they are categorized as market and financial, policy and institutional, scientific and technological and informational and behavioral barriers. More specifically, the shortage of woody biomass, strict regulation, considerable financial and time investment, and lack of experience and knowledge are hindering on-farm composting. The complex regulation, manure surplus, variable availability and transport of compost, and variable compost quality and composition are barriers to apply compost. In conclusion, five recommendations are suggested that could alleviate certain hindering factors and thus increase attractiveness of compost use in agriculture. Copyright © 2015 Elsevier Ltd. All rights reserved.

Meat waste as feedstock for home composting: Effects on the process and quality of compost.

PubMed

Storino, Francesco; Arizmendiarrieta, Joseba S; Irigoyen, Ignacio; Muro, Julio; Aparicio-Tejo, Pedro M

2016-10-01

Home composting is a powerful tool, which is spreading in different parts of the world, to reduce the generation of municipal waste. However, there is debate concerning the appropriateness, in terms of domestic hygiene and safety, of keeping a composter bin in the household deputed to kitchen waste of animal origin, such as meat or fish scraps and pet droppings. The purpose of our work was to study how the addition of meat scraps to household waste influences the composting process and the quality of the final compost obtained. We compared four raw material mixtures, characterized by a different combination of vegetable and meat waste and different ratios of woody bulking agent. Changes in temperature, mass and volume, phenotypic microbial diversity (by Biolog™) and organic matter humification were determined during the process. At the end of the experiment, the four composts were weighed and characterized by physicochemical analysis. In addition, the presence of viable weed seeds was investigated and a germination bioassay was carried out to determine the level of phytotoxicity. Finally, the levels of pathogens (Escherichia coli and Salmonella spp.) were also determined in the final compost. Here we show that the presence of meat waste as raw feedstock for composting in bins can improve the activity of the process, the physicochemical characteristics and maturity of the compost obtained, without significantly affecting its salinity, pH and phytotoxicity. Pathogen levels were low, showing that they can be controlled by an intensive management and proper handling of the composter bins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of biochar on volatile fatty acids accumulation and microbial community succession during biosolids composting.

PubMed

Awasthi, Mukesh Kumar; Awasthi, Sanjeev Kumar; Wang, Quan; Wang, Zhen; Lahori, Altaf Hussain; Ren, Xiuna; Chen, Hongyu; Wang, Meijing; Zhao, Junchao; Zhang, Zengqiang

2018-03-01

The impact of biochar amendment on volatile fatty acids (VFAs) and odor generation during the biosolids-wheat straw composting was investigated. Five treatments were design using the same mixture of biosolids-wheat straw with different dosage of biochar blending (2%, 4%, 8% and 12% on dry weight basis) and without biochar applied treatment served as control. The results of VFAs and Odour Index (OI) profile designated that compost with 8-12% biochar became more rapidly humified with less quantity of VFAs and OI generation content compared to control. Consequently, the VFAs degrading and total bacterial abundance are also significantly higher recorded in 8-12% biochar than 2% biochar and control. In addition, 8-12% biochar applied treatment has significantly maximum close correlation among the all physicochemical and gaseous emission parameters. Finally, results designated that higher dosage of biochar (8-12% biochar) was more feasible approach for biosolids composting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Compost: Brown gold or toxic trouble?

USGS Publications Warehouse

Kovacic, D.A.; Cahill, R.A.; Bicki, T.J.

1992-01-01

Limited data are available regarding the occurrence of potentially hazardous constituents in raw, uncomposted yard wastes, partially composted yard wastes, and finished compost (15, 16). Environmental monitoring at composting operations or facilities is lacking, and currently published research on the environmental fate of composted yard waste constituents is extremely limited. The cost of thoroughly investigating the fate of toxicants in yard waste may seem needlessly expensive, but it is much less than the cost of cleaning up contaminated sites and groundwater. Could yard waste compost sites become Superfund sites? The cost of a thorough testing program throughout the United States may be several million dollars, but that is only a fraction of the funds spent initiating and developing yard waste composting facilities, let alone the potentially much greater cost of environmental remediation. There is still time to address these problems and to develop sound state and federal guidelines for siting and operating yard waste compost facilities. The rush to implement landfill alternatives such as composting should not be the major driving force in determining legislation governing solid waste management. ?? 1991 American Chemical Society.

Feasibility of medical stone amendment for sewage sludge co-composting and production of nutrient-rich compost.

PubMed

Awasthi, Mukesh Kumar; Wang, Quan; Awasthi, Sanjeev Kumar; Li, Ronghua; Zhao, Junchao; Ren, Xiuna; Wang, Meijing; Chen, Hongyu; Zhang, Zengqiang

2018-06-15

The feasibility of medical stone (MS) amendment as an innovative additive for dewatered fresh sewage sludge (DFSS) co-composting was assessed using a 130-L vessel-scale composter. To verify successful composting, five treatments were designed with four different dosages (2, 4, 6, and 10) % of MS with a 1:1 mixture (dry weight) of DFSS + wheat straw (WS). The WS was used as a bulking agent. A control without any amendment treatment was carried out for the purpose of comparison. For DFSS co-composting, the amendment with MS improved the mineralization efficiency and compost quality in terms of CO 2 emissions, dehydrogenase enzyme (DE), electrical conductivity (EC), water-solubility, and total nutrients transformation. The DTPA-extractable Cu and Zn were also estimated to confirm the immobilization ability of the applied MS. Seed germination and plant growth tests were conducted to ensure the compost stability and phytotoxicity for Chinese cabbage (Brassica rapa chinensis L.) growth and biomass, as well as chlorophyll content. The results showed that during the bio-oxidative phase, DOC, DON, AP, NH 4 + -N, and NO 3 - -N increased drastically in all the MS-blended treatments, except the application of 2% MS and the control treatment; significantly lower water-soluble nutrients were observed in the 2% MS and control treatments. A novel additive with 6-10% MS dosages considerably enhanced the organic matter conversion in the stable end-product (compost) and reduced the maturity period by two weeks compared to the 2% MS and control treatments. Consequently, the maturity parameters (e.g., EC, SGI, NH 4 + -N, DOC, and DON) confirmed that compost with 6-10% MS became more stable and mature within four weeks of DFSS co-composting. At the end of composting, significantly higher DTPA-extractable Cu and Zn contents were observed in the control treatment, and subsequently, in the very low application (10%) of MS. Higher MS dosage lowered the pH and EC to within the permissible

Composting of waste algae: a review.

PubMed

Han, Wei; Clarke, William; Pratt, Steven

2014-07-01

Although composting has been successfully used at pilot scale to manage waste algae removed from eutrophied water environments and the compost product applied as a fertiliser, clear guidelines are not available for full scale algae composting. The review reports on the application of composting to stabilize waste algae, which to date has mainly been macro-algae, and identifies the peculiarities of algae as a composting feedstock, these being: relatively low carbon to nitrogen (C/N) ratio, which can result in nitrogen loss as NH3 and even N2O; high moisture content and low porosity, which together make aeration challenging; potentially high salinity, which can have adverse consequence for composting; and potentially have high metals and toxin content, which can affect application of the product as a fertiliser. To overcome the challenges that these peculiarities impose co-compost materials can be employed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessing thermal conductivity of composting reactor with attention on varying thermal resistance between compost and the inner surface.

PubMed

Wang, Yongjiang; Niu, Wenjuan; Ai, Ping

2016-12-01

Dynamic estimation of heat transfer through composting reactor wall was crucial for insulating design and maintaining a sanitary temperature. A model, incorporating conductive, convective and radiative heat transfer mechanisms, was developed in this paper to provide thermal resistance calculations for composting reactor wall. The mechanism of thermal transfer from compost to inner surface of structural layer, as a first step of heat loss, was important for improving insulation performance, which was divided into conduction and convection and discussed specifically in this study. It was found decreasing conductive resistance was responsible for the drop of insulation between compost and reactor wall. Increasing compost porosity or manufacturing a curved surface, decreasing the contact area of compost and the reactor wall, might improve the insulation performance. Upon modeling of heat transfers from compost to ambient environment, the study yielded a condensed and simplified model that could be used to conduct thermal resistance analysis for composting reactor. With theoretical derivations and a case application, the model was applicable for both dynamic estimation and typical composting scenario. Copyright © 2016 Elsevier Ltd. All rights reserved.

Insight into effects of mature compost recycling on N2O emission and denitrification genes in sludge composting.

PubMed

Wang, Ke; Wu, Yiqi; Li, Weiguang; Wu, Chuandong; Chen, Zhiqiang

2018-03-01

Mature compost recycling is widely used to reduce the dosage of organic bulking agent in actual composting process. In this study, the effects of mature compost amendment on N 2 O emission and denitrification genes were investigated in 47 days composting of sewage sludge and rice husks. The results showed that mature compost amendment dramatically augmented N 2 O emission rate in mesophilic phase and CO 2 emission rate in thermophilic phase of composting, respectively. The cumulative amount of N 2 O emission increased by more than 23 times compared to the control. Mature compost amendment not only reduced moisture and pH, but also significantly increased NO 3 - -N and NO 2 - -N concentrations. The correlation matrices indicated that NO 3 - -N, narG and norB were the main factors influencing N 2 O emission rate in sludge composting with mature compost recycling, but the N 2 O emission rate was significantly correlated to NO 2 - -N, nirK and norB in the control. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of different compost amendments on the abundance and composition of alkB harboring bacterial communities in a soil under industrial use contaminated with hydrocarbons

PubMed Central

Wallisch, Stefanie; Gril, Tjasa; Dong, Xia; Welzl, Gerd; Bruns, Christian; Heath, Ester; Engel, Marion; Suhadolc, Marjetka; Schloter, Michael

2014-01-01

Alkane degrading microorganisms play an important role for the bioremediation of petrogenic contaminated environments. In this study, we investigated the effects of compost addition on the abundance and diversity of bacteria harboring the alkane monooxygenase gene (alkB) in an oil-contaminated soil originated from an industrial zone in Celje, Slovenia (Technosol). Soil without any amendments (control soil) and soil amended with two composts differing in their maturation stage and nutrient availability, were incubated under controlled conditions in a microcosm experiment and sampled after 0, 6, 12, and 36 weeks of incubation. As expected the addition of compost stimulated the degradation of alkanes in the investigated soil shortly after the addition. By using quantitative real-time PCR higher number of alkB genes were detected in soil samples amended with compost compared to the control soils. To get an insight into the composition of alkB harboring microbial communities, we performed next generation sequencing of amplicons of alkB gene fragment. Richness and diversity of alkB gene harboring prokaryotes was higher in soil mixed with compost compared to control soils with stronger effects of the less maturated, nutrient poor compost. The phylogenetic analysis of communities suggested that the addition of compost stimulated the abundance of alkB harboring Actinobacteria during the experiment independent from the maturation stage of the compost. AlkB harboring γ-proteobacteria like Shewanella or Hydrocarboniphaga as well as α-proteobacteria of the genus Agrobacterium responded also positively to the addition of compost to soil. The amendment of the less maturated, nutrient poor compost resulted in addition in a large increase of alkB harboring bacteria of the Cytophaga group (Microscilla) mainly at the early sampling time points. Our data indicates that compost amendments significantly change abundance and diversity pattern of alkB harboring microbes in Technosol and

Effects of different compost amendments on the abundance and composition of alkB harboring bacterial communities in a soil under industrial use contaminated with hydrocarbons.

PubMed

Wallisch, Stefanie; Gril, Tjasa; Dong, Xia; Welzl, Gerd; Bruns, Christian; Heath, Ester; Engel, Marion; Suhadolc, Marjetka; Schloter, Michael

2014-01-01

Alkane degrading microorganisms play an important role for the bioremediation of petrogenic contaminated environments. In this study, we investigated the effects of compost addition on the abundance and diversity of bacteria harboring the alkane monooxygenase gene (alkB) in an oil-contaminated soil originated from an industrial zone in Celje, Slovenia (Technosol). Soil without any amendments (control soil) and soil amended with two composts differing in their maturation stage and nutrient availability, were incubated under controlled conditions in a microcosm experiment and sampled after 0, 6, 12, and 36 weeks of incubation. As expected the addition of compost stimulated the degradation of alkanes in the investigated soil shortly after the addition. By using quantitative real-time PCR higher number of alkB genes were detected in soil samples amended with compost compared to the control soils. To get an insight into the composition of alkB harboring microbial communities, we performed next generation sequencing of amplicons of alkB gene fragment. Richness and diversity of alkB gene harboring prokaryotes was higher in soil mixed with compost compared to control soils with stronger effects of the less maturated, nutrient poor compost. The phylogenetic analysis of communities suggested that the addition of compost stimulated the abundance of alkB harboring Actinobacteria during the experiment independent from the maturation stage of the compost. AlkB harboring γ-proteobacteria like Shewanella or Hydrocarboniphaga as well as α-proteobacteria of the genus Agrobacterium responded also positively to the addition of compost to soil. The amendment of the less maturated, nutrient poor compost resulted in addition in a large increase of alkB harboring bacteria of the Cytophaga group (Microscilla) mainly at the early sampling time points. Our data indicates that compost amendments significantly change abundance and diversity pattern of alkB harboring microbes in Technosol and

The Campylobacter jejuni MarR-like transcriptional regulators RrpA and RrpB both influence bacterial responses to oxidative and aerobic stresses.

PubMed

Gundogdu, Ozan; da Silva, Daiani T; Mohammad, Banaz; Elmi, Abdi; Mills, Dominic C; Wren, Brendan W; Dorrell, Nick

2015-01-01

The ability of the human intestinal pathogen Campylobacter jejuni to respond to oxidative stress is central to bacterial survival both in vivo during infection and in the environment. Re-annotation of the C. jejuni NCTC11168 genome revealed the presence of two MarR-type transcriptional regulators Cj1546 and Cj1556, originally annotated as hypothetical proteins, which we have designated RrpA and RrpB (regulator of response to peroxide) respectively. Previously we demonstrated a role for RrpB in both oxidative and aerobic (O2) stress and that RrpB was a DNA binding protein with auto-regulatory activity, typical of MarR-type transcriptional regulators. In this study, we show that RrpA is also a DNA binding protein and that a rrpA mutant in strain 11168H exhibits increased sensitivity to hydrogen peroxide oxidative stress. Mutation of either rrpA or rrpB reduces catalase (KatA) expression. However, a rrpAB double mutant exhibits higher levels of resistance to hydrogen peroxide oxidative stress, with levels of KatA expression similar to the wild-type strain. Mutation of either rrpA or rrpB also results in a reduction in the level of katA expression, but this reduction was not observed in the rrpAB double mutant. Neither the rrpA nor rrpB mutant exhibits any significant difference in sensitivity to either cumene hydroperoxide or menadione oxidative stresses, but both mutants exhibit a reduced ability to survive aerobic (O2) stress, enhanced biofilm formation and reduced virulence in the Galleria mellonella infection model. The rrpAB double mutant exhibits wild-type levels of biofilm formation and wild-type levels of virulence in the G mellonella infection model. Together these data indicate a role for both RrpA and RrpB in the C. jejuni peroxide oxidative and aerobic (O2) stress responses, enhancing bacterial survival in vivo and in the environment.

Evaluation of the slurry management strategy and the integration of the composting technology in a pig farm - Agronomical and environmental implications.

PubMed

Sáez, José A; Clemente, Rafael; Bustamante, M Ángeles; Yañez, David; Bernal, M Pilar

2017-05-01

The changes in livestock production systems towards intensification frequently lead to an excess of manure generation with respect to the agricultural land available for its soil application. However, treatment technologies can help in the management of manures, especially in N-surplus areas. An integrated slurry treatment system based on solid-liquid separation, aerobic treatment of the liquid and composting the solid fraction was evaluated in a pig farm (sows and piglets) in the South of Spain. Solid fraction separation using a filter band connected to a screw press had low efficiency (38%), which was greatly improved incorporating a rotatory sieve (61%). The depuration system was very efficient for the liquid, with total removal of 84% total solids, 87% volatile solids, and 98% phosphorus. Two composting systems were tested through mechanical turning of: 1- a mixture of solid fraction stored for 1 month after solid-liquid separation and cereal straw; 2- recently-separated solid fraction mixed with cotton gin waste. System 2 was recommended for the farm, as it exhibited a fast temperature rise and a long thermophilic phase to ensure compost sanitisation, and high recovery of nutrients (TN 77%, P and K > 85%) and organic matter (45%). The composts obtained were mature, stable and showed a high degree of humification of their organic matter, absence of phytotoxicity and concentrations of nutrients similar to other composts from pig manure or separated slurry solids. However, the introduction of slurry from piglets into the solid-liquid separation system should be avoided in order to reduce the content of Zn in the compost, which lowers its quality. The slurry separation followed by composting of the solid fraction using a passive windrow system, and aeration of the liquid phase, was the most recommendable procedure for the reduction of GHG emissions on the farm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of matured compost as an inoculating agent on odour removal and maturation of vegetable and fruit waste compost.

PubMed

Chen, Chih-Yu; Kuo, Jong-Tar; Chung, Ying-Chien

2013-01-01

The use of matured compost as an inoculation agent to improve the composting of vegetable and fruit wastes in a laboratory-scale composter was evaluated, and the commercial feasibility of this approach in a pilot-scale (1.8 x 10(4) L) composter was subsequently confirmed. The effect of aeration rate on the physico-chemical and biological properties of compost was also studied. Aeration rate affected the fermentation temperature, moisture content, pH, O2 consumption rate, CO2 production rate and the formation of odour. The optimal aeration rate was 2.5 L air/kg dry solid/min. The CO2 production rate approached the theoretical value during composting and was linearly dependent on temperature, indicating that the compost system had good operating characteristics. The inoculation of cellulolytic bacteria and deodorizing bacteria to compost in the pilot-scale composter led to an 18.2% volatile solids loss and a 64.3% volume reduction ratio in 52 h; only 1.5 ppm(v) odour was detected. This is the first study to focus on both operating performance and odour removal in a pilot-scale composter.

The Learning of Compost Practice in University

NASA Astrophysics Data System (ADS)

Agustina, T. W.; Rustaman, N. Y.; Riandi; Purwianingsih, W.

2017-09-01

The compost as one of the topics of the Urban Farming Movement in Bandung city, Indonesia. The preliminary study aims to obtain a description of the performance capabilities and compost products made by students with STREAM (Science-Technology-Religion-Art-Mathematics) approach. The method was explanatory sequential mixed method. The study was conducted on one class of Biology Education students at the one of the universities in Bandung, Indonesia. The sample was chosen purposively with the number of students as many as 44 people. The instruments were making Student Worksheets, Observation Sheets of Performance and Product Assessment, Rubric of Performance and Product, and Field Notes. The indicators of performance assessment rubrics include Stirring of Compost Materials and Composting Technology in accordance with the design. The product assessment rubric are a Good Composting Criteria and Compost Packaging. The result of can be stated most students have good performance. However, the ability to design of compost technology, compost products and the ability to pack compost are still lacking. The implication of study is students of Biology Education require habituation in the ability of designing technology.

Production of well-matured compost from night-soil sludge by an extremely short period of thermophilic composting.

PubMed

Nakasaki, Kiyohiko; Ohtaki, Akihito; Takemoto, Minoru; Fujiwara, Shunrokuro

2011-03-01

The effect of various operational conditions on the decomposition of organic material during the composting of night-soil treatment sludge was quantitatively examined. The optimum composting conditions were found to be a temperature of ca. 60°C and an initial pH value of 8. Rapid decomposition of organic matter ceased by the sixth day of composting under these optimum conditions, and the final value of the cumulative emission of carbon (E(C)), which represents the degree of organic matter decomposition, was less than 40%, indicating that the sludge contained only a small amount of easily degradable organic material. A plant growth assay using Komatsuna (Brassica campestris L. var. rapiferafroug) in a 1/5000a standard cultivation pot was then conducted for the compost at various degrees of organic matter decomposition: the raw composting material, the final compost obtained on day 6, and the 2 intermediate compost products (i.e., E(C)=10% and 20%). It was found that the larger the E(C), the greater the yield of Komatsuna growth. It was also found that 6 days of composting is sufficient to promote Komatsuna growth at the standard loading level, which is equivalent to a 1.5 g N/pot, since the promotion effect was as high as that obtained using chemical fertilizer. It can therefore be concluded that well-matured compost could be obtained in a short period of time (i.e., as early as 6 days), when night-soil sludge is composted under optimum conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

Composting of the solid fraction of digestate derived from pig slurry: Biological processes and compost properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tambone, Fulvia, E-mail: fulvia.tambone@unimi.it; Terruzzi, Laura; Scaglia, Barbara

Highlights: • Anaerobic digestion leads to the production of a biologically stable digestate. • Solid–liquid separation produces a solid fraction having high fertilizer value. • Composting process shows low biological activity due to high biological stability of digestate. • Solid digestate fraction can be composted in a short time or used directly as organic fertilizer. - Abstract: The aim of this paper was to assess the characteristics of the solid fractions (SF) obtained by mechanical separation of digestate, their compostability and compost quality. To do so, the SF of digestates obtained from anaerobic digestion of pig slurry, energy crops andmore » agro-industrial residues were sampled in five plants located in Northern Italy. Results obtained indicated that anaerobic digestion by itself promoted the high biological stability of biomasses with a Potential Dynamic Respiration Index (PDRI) close to 1000 mgO{sub 2} kg V S{sup −1} h{sup −1}. Subsequent composting of digestates, with an added bulking agent, did not give remarkably different results, and led only to a slight modification of the characteristics of the initial non-composted mixtures; the composts obtained fully respected the legal limits for high quality compost. Chemical studies of organic matter composition of the biomasses by using CP MAS {sup 13}C NMR, indicated that the compost was composed of a high relative content of O-alkyl-C (71.47% of total C) (cellulose and hemicelluloses) and a low alkyl-C (12.42%) (i.e. volatile fatty acids, steroid-like molecules, aliphatic biopolymers and proteins)« less

Effects of woody peat and superphosphate on compost maturity and gaseous emissions during pig manure composting.

PubMed

Zhang, Difang; Luo, Wenhai; Yuan, Jing; Li, Guoxue; Luo, Yuan

2017-10-01

This study investigated the effect of calcium superphosphate on compost maturity and gaseous emissions during pig manure composting with woody peat as the bulking agent. Two treatments were conducted with or without the addition of calcium superphosphate (10% dry weight of the composting mass), which were denoted as the control and superphosphate-amended treatment, respectively. Results show that the composting temperature of both treatments was higher than 50°C for more than 5days, which is typically required for pathogen destruction during manure composting. Compared to the control treatment, the superphosphate-amended treatment increased the emission of nitrogen oxide, but reduced the emission of methane, ammonia and hydrogen sulfide by approximately 35.5%, 37.9% and 65.5%, respectively. As a result, the total greenhouse gas (GHG) emission during manure composting was reduced by nearly 34.7% with the addition of calcium superphosphate. The addition of calcium superphosphate increased the content of humic acid (indicated by E 4 /E 6 ratio). Nevertheless, the superphosphate-amended treatment postponed the biological degradation of organic matter and produced the mature compost with a higher electrical conductivity in comparison with the control treatment. Copyright © 2017. Published by Elsevier Ltd.

Composting of the solid fraction of digestate derived from pig slurry: Biological processes and compost properties.

PubMed

Tambone, Fulvia; Terruzzi, Laura; Scaglia, Barbara; Adani, Fabrizio

2015-01-01

The aim of this paper was to assess the characteristics of the solid fractions (SF) obtained by mechanical separation of digestate, their compostability and compost quality. To do so, the SF of digestates obtained from anaerobic digestion of pig slurry, energy crops and agro-industrial residues were sampled in five plants located in Northern Italy. Results obtained indicated that anaerobic digestion by itself promoted the high biological stability of biomasses with a Potential Dynamic Respiration Index (PDRI) close to 1000 mgO2 kg V S(-1)h(-1). Subsequent composting of digestates, with an added bulking agent, did not give remarkably different results, and led only to a slight modification of the characteristics of the initial non-composted mixtures; the composts obtained fully respected the legal limits for high quality compost. Chemical studies of organic matter composition of the biomasses by using CP MAS (13)C NMR, indicated that the compost was composed of a high relative content of O-alkyl-C (71.47% of total C) (cellulose and hemicelluloses) and a low alkyl-C (12.42%) (i.e. volatile fatty acids, steroid-like molecules, aliphatic biopolymers and proteins). Copyright © 2014 Elsevier Ltd. All rights reserved.

Aerobic granulation in a modified oxidation ditch with an adjustable volume intraclarifier.

PubMed

Li, Jun; Cai, Ang; Wang, Miao; Ding, Libin; Ni, Yongjiong

2014-04-01

A modified oxidation ditch (MOD) with an adjustable volume intraclarifier was proposed and used to achieve aerobic sludge granulation in continuous flow process. This MOD with working volume of 60L treated onsite wastewater from a town. Excellent aerobic granules with mean diameter of 600μm and sludge volume index (SVI) of 44mL/g were obtained in 120day. Bacterial community analysis revealed that most species from seed sludge were preserved in both MOD and granule SBR (G-SBR) except bacteria (Bacteroidetes) might be easily washed out during granulation. Some different bacterial communities were found in sludges from sequencing batch and continuous flow reactors. Presence of metal ions and inorganics in raw wastewater had positive effect on granule formation, but an adjustable volume intraclarifier for controlling selection pressure and deleting return sludge pump played a key role in aerobic sludge granulation. Copyright © 2014 Elsevier Ltd. All rights reserved.

A comparative study of two composts as filter media for the removal of gaseous reduced sulfur compounds (RSCs) by biofiltration: application at industrial scale.

PubMed

Hort, C; Gracy, S; Platel, V; Moynault, L

2013-01-01

This work presents the use of two composts as filter media for the treatment by biofiltration of odors emitted during the aerobic composting of a mixture containing sewage sludge and yard waste. The chemical analysis of the waste gas showed that the malodorous compounds at trace level were the reduced sulfur compounds (RSCs) which were dimethyl sulfide (Me(2)S), methanethiol (MeSH) and hydrogen sulfide (H(2)S). Laboratory tests for biofiltration treatment of RSCs were performed in order to compare the properties of two filter media, consisted of a mature compost with yard waste (YW) and a mixture of mature compost with sewage sludge and yard waste (SS/YW). The maximum elimination capacity (EC) values obtained with the YW mature compost as packing material were 12.5 mg m(-3)h(-1) for H(2)S, 7.9 mg m(-3)h(-1) for MeSH and 34 mg m(-3)h(-1) for Me(2)S, and the removal efficiency decreased in the order of: H(2)S>MeSH>Me(2)S. Moreover, the YW compost filter medium had a better behavior than the filter medium based on SS/YW in terms of acclimation of the microbial communities and moisture content. According to these results, a YW mature compost as packing material for an industrial biofilter were designed and this industrial biofilter was found effective under specified conditions (without inoculation and addition of water). The results showed that the maximum EC value of RSCs was 935 mg m(-3)h(-1) (100% removal efficiency, RE) for an inlet loads (IL) between 0 and 1000 mg m(-3)h(-1). Thus, YW compost medium was proven efficient for biofiltration of RSCs both at laboratory and industrial scale. Copyright © 2012 Elsevier Ltd. All rights reserved.

Modelling of composting process of different organic waste at pilot scale: Biodegradability and odor emissions.

PubMed

Gutiérrez, M C; Siles, J A; Diz, J; Chica, A F; Martín, M A

2017-01-01

The composting process of six different compostable substrates and one of these with the addition of bacterial inoculums carried out in a dynamic respirometer was evaluated. Despite the heterogeneity of the compostable substrates, cumulative oxygen demand (OD, mgO 2 kgVS) was fitted adequately to an exponential regression growing until reaching a maximum in all cases. According to the kinetic constant of the reaction (K) values obtained, the wastes that degraded more slowly were those containing lignocellulosic material (green wastes) or less biodegradable wastes (sewage sludge). The odor emissions generated during the composting processes were also fitted in all cases to a Gaussian regression with R 2 values within the range 0.8-0.9. The model was validated representing real odor concentration near the maximum value against predicted odor concentration of each substrate, (R 2 =0.9314; 95% prediction interval). The variables of maximum odor concentration (ou E /m 3 ) and the time (h) at which the maximum was reached were also evaluated statistically using ANOVA and a post-hoc Tukey test taking the substrate as a factor, which allowed homogeneous groups to be obtained according to one or both of these variables. The maximum oxygen consumption rate or organic matter degradation during composting was directly related to the maximum odor emission generation rate (R 2 =0.9024, 95% confidence interval) when only the organic wastes with a low content in lignocellulosic materials and no inoculated waste (HRIO) were considered. Finally, the composting of OFMSW would produce a higher odor impact than the other substrates if this process was carried out without odor control or open systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predictive value for preterm birth of abnormal vaginal flora, bacterial vaginosis and aerobic vaginitis during the first trimester of pregnancy.

PubMed

Donders, G G; Van Calsteren, K; Bellen, G; Reybrouck, R; Van den Bosch, T; Riphagen, I; Van Lierde, S

2009-09-01

Abnormal vaginal flora (AVF) before 14 gestational weeks is a risk factor for preterm birth (PTB). The presence of aerobic microorganisms and an inflammatory response in the vagina may also be important risk factors. The primary aim of the study was to investigate the differential influences of AVF, full and partial bacterial vaginosis, and aerobic vaginitis in the first trimester on PTB rate. The secondary aim was to elucidate why treatment with metronidazole has not been found to be beneficial in previous studies. Unselected women with low-risk pregnancies attending the prenatal unit of the Heilig Hart General Hospital in Tienen, Belgium, were included in the study. At the first prenatal visit, 1026 women were invited to undergo sampling of the vaginal fluid for wet mount microscopy and culture, of whom 759 were fully evaluable. Abnormal vaginal flora (AVF; disappearance of lactobacilli), bacterial vaginosis (BV), aerobic vaginitis (AV), increased inflammation (more than ten leucocytes per epithelial cell) and vaginal colonisation with Candida (CV) were scored according to standardised definitions. Partial BV was defined as patchy streaks of BV flora or sporadic clue cells mixed with other flora, and full BV as a granular anaerobic-type flora or more than 20% clue cells. Vaginal fluid was cultured for aerobic bacteria, Mycoplasma hominis and Ureaplasma urealyticum. Outcome was recorded as miscarriage

Characteristics and performance of aerobic algae-bacteria granular consortia in a photo-sequencing batch reactor.

PubMed

Liu, Lin; Zeng, Zhichao; Bee, Mingyang; Gibson, Valerie; Wei, Lili; Huang, Xu; Liu, Chaoxiang

2018-05-05

The characteristics and performance of algae-bacteria granular consortia which cultivated with aerobic granules and targeted algae (Chlorella and Scenedesmus), and the essential difference between granular consortia and aerobic granules were investigated in this experiment. The result indicated that algae-bacteria granular consortia could be successfully developed, and the algae present in the granular consortia were mainly Chlorella and Scenedesmus. Although the change of chlorophyll composition revealed the occurrence of light limitation for algal growth, the granular consortia could maintain stable granular structure, and even showed better settling property than aerobic granules. Total nitrogen and phosphate in the algal-bacterial granular system showed better removal efficiencies (50.2% and 35.7%) than those in the aerobic granular system (32.8% and 25.6%) within one cycle (6 h). The biodiesel yield of aerobic granules could be significantly improved by algal coupled process, yet methyl linolenate and methyl palmitoleate were the dominant composition of biodiesel obtained from granular consortia and aerobic granules, respectively. Meanwhile, the difference of dominant bacterial communities in the both granules was found at the order level and family level, and alpha diversity indexes revealed the granular consortia had a higher microbial diversity. Copyright © 2018. Published by Elsevier B.V.

Composting of food wastes: Status and challenges.

PubMed

Cerda, Alejandra; Artola, Adriana; Font, Xavier; Barrena, Raquel; Gea, Teresa; Sánchez, Antoni

2018-01-01

This review analyses the main challenges of the process of food waste composting and examines the crucial aspects related to the quality of the produced compost. Although recent advances have been made in crucial aspects of the process, such composting microbiology, improvements are needed in process monitoring. Therefore, specific problems related to food waste composting, such as the presence of impurities, are thoroughly analysed in this study. In addition, environmental impacts related to food waste composting, such as emissions of greenhouse gases and odours, are discussed. Finally, the use of food waste compost in soil bioremediation is discussed in detail. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pathogen re-colonization of in-house composted and non-composted broiler litter

USDA-ARS?s Scientific Manuscript database

“In-house” litter composting has been reintroduced to the industry and shown to reduce bacteria by as much as two orders of magnitude. Other industries have demonstrated that pathogens can recolonize a waste-residual when microbial competition has been reduced or inhibited following composting. Po...

Dissolved organic matter dynamic and resident microbiota evolution in soil amended with fresh and composted olive mill wastes

NASA Astrophysics Data System (ADS)

Gigliotti, Giovanni; Massaccesi, Luisa; Federici, Ermanno; Fidati, Laura; Nasini, Luigi; Proietti, Primo

2013-04-01

the composted husk. FT-IR spectra and SUVA254 data confirmed the changes in DOM composition caused by the amendments. Denaturing gradient gel electrophoresis (DGGE) analyses of 16S and 18S rRNA genes was used to characterize the microbiota in both amendments and soils. Interestingly, the DGGE profiles changed after composting the humid husk, indicating how the organic matter transformations occurring during this process profoundly altered the microbial communities of the OMW. Soil bacterial communities were very complex and presented a high species richness throughout the entire trial. In particular, the fresh and the composted husk appeared to have only a slight effect on the bacterial community structure. This effect was observed only during the first 60 days, while after 90 days no differences with the control plot were present. On the contrary, the fungal communities presented a lower biodiversity and more variable DGGE profiles than the bacterial communities. Both treatments clearly altered the structure of the soil fungal community throughout the entire trial. Interestingly, the fungal communities profiles were different when the fresh or the composted husk was used, with the former showing more profound and stable effects.

Temperature effects on the aerobic metabolism of glycogen-accumulating organisms.

PubMed

Lopez-Vazquez, Carlos M; Song, Young-Il; Hooijmans, Christine M; Brdjanovic, Damir; Moussa, Moustafa S; Gijzen, Huub J; van Loosdrecht, Mark C M

2008-10-01

Short-term temperature effects on the aerobic metabolism of glycogen-accumulating organisms (GAO) were investigated within a temperature range from 10 to 40 degrees C. Candidatus Competibacter Phosphatis, known GAO, were the dominant microorganisms in the enriched culture comprising 93 +/- 1% of total bacterial population as indicated by fluorescence in situ hybridization (FISH) analysis. Between 10 and 30 degrees C, the aerobic stoichiometry of GAO was insensitive to temperature changes. Around 30 degrees C, the optimal temperature for most of the aerobic kinetic rates was found. At temperatures higher than 30 degrees C, a decrease on the aerobic stoichiometric yields combined with an increase on the aerobic maintenance requirements were observed. An optimal overall temperature for both anaerobic and aerobic metabolisms of GAO appears to be found around 30 degrees C. Furthermore, within a temperature range (10-30 degrees C) that covers the operating temperature range of most of domestic wastewater treatment systems, GAOs aerobic kinetic rates exhibited a medium degree of dependency on temperature (theta = 1.046-1.090) comparable to that of phosphorus accumulating organisms (PAO). We conclude that GAO do not have metabolic advantages over PAO concerning the effects of temperature on their aerobic metabolism, and competitive advantages are due to anaerobic processes.

Emission of methane and carbon dioxide and earthworm survival during composting of pharmaceutical sludge and spent mycelia.

PubMed

Majumdar, Deepanjan; Patel, Jigisha; Bhatt, Neha; Desai, Priyanka

2006-03-01

Emissions of methane (CH4) and carbon dioxide (CO2) from spent mycelia of the mold Penicilium notatum and sludge from the effluent treatment facility (ETPS) of a pharmaceutical industry were estimated twice during a two-week composting before vermicomposting. These wastes are dumped in landfills or sometimes used in agricultural fields and no reports are available on their greenhouse gas producing potentials. The solid wastes contained appreciable organic carbon and nitrogen while very high Fe, Mn and Zn were found in ETPS only. Pure wastes did not support germination of Vigna radiata L. while mixing soil with ETPS and spent mycelia at the ratios of 12:1 and 14:1 led to 80% and 50% germination, respectively. The wastes were mixed with cowdung at the ratios of 1:1, 1:3 and 3:1 for composting. Carbon dioxide emissions were always significantly higher than CH4 emissions from all the treatments due to prevalence of aerobic condition during composting. From some treatments, CH4 emissions increased with time, indicating increasing activity of anaerobic bacteria in the waste mixtures. Methane emissions ranged from 21.6 to 231.7 microg m(-2) day(-1) while CO2 emissions were greater than thousand times at 39.8-894.8 mg m(-2) day(-1). The amount of C emitted as CH4-C and CO2-C from ranged from 0.007% to 0.081% of total C composted. Cowdung emitted highest CH4 followed by spent mycelia and ETPS while ETPS emitted more CO2 than spent mycelia but lesser than cowdung. Global warming potential of emitted CH4 was found to be in the range of 10.6-27.7 mg-CO2-equivalent on a 20-year time horizon. The results suggest that pharmaceutical wastes can be an important source of CH4 and CO2 during composting or any other stockpiling under suitable moisture conditions. The waste mixtures were found not suitable for vermicomposting after two weeks composting and earthworms did not survive long in the mixtures.

The Compost Pile Meets the 1990's.

ERIC Educational Resources Information Center

Paddock, Todd

1991-01-01

Advocates composting as a valuable alternative to the landfill for waste management. As much as two-thirds of garbage can be composted, and the process has become more cost effective. Some challenges to composting are producing a compost product that will sell and dealing with the odor created by the process. (KS)

Inoculation of Pichia kudriavzevii RB1 degrades the organic acids present in raw compost material and accelerates composting.

PubMed

Nakasaki, Kiyohiko; Araya, Shogo; Mimoto, Hiroshi

2013-09-01

In this study, the yeast strain Pichia kudriavzevii RB1 was used as an inoculum to accelerate organic matter degradation of rabbit food with added organic acids, which was used as a model food waste for composting. The RB1 strain rapidly degraded the organic acids present in the raw compost material, leading to an increase in pH beyond the neutral level, within 2 days. Both mesophilic and thermophilic bacteria proliferated faster in the compost with RB1 inoculation than in that without inoculation. Although the yeast died with the increase in compost temperature, it affected the early stages of composting prior to the thermophilic stage and accelerated the composting process by 2 days by eliminating the initial lag phase seen in the growth of other microorganisms. Moreover, populations of Bacillus thermoamylovorans, Bacillus foraminis, and Bacillus coagulans became dominant during the thermophilic stages of both composting with and without RB1 inoculation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Media for aerobic recovery of campylobacter from mixed bacterial cultures

USDA-ARS?s Scientific Manuscript database

A non-selective medium for culturing Campylobacter aerobically was recently described. The objective of the present study was to determine if a selective medium could be formulated by supplementing the new medium with the Bolton antibiotic mixture. Basal medium containing beef extract, 50 g; tryptos...

Compost maturity and nitrogen availability by co-composting of paddy husk and chicken manure amended with clinoptilolite zeolite.

PubMed

Latifah, Omar; Ahmed, Osumanu Haruna; Susilawati, Kassim; Majid, Nik Muhamad

2015-04-01

The availability of paddy husk from rice processing plants remains high owing to increase in the worldwide rice consumption. Increasing demand for chicken products leads to poultry wastes production. Co-composting of the aforementioned wastes could solve the indiscriminate disposal of these wastes. Thus, co-composting of paddy husk and chicken slurry with clinoptilolite zeolite and urea as additive was carried out. Clinoptilolite zeolite was used to enhance ammonium and nitrate retention in the compost. Temperature of the compost was monitored three times daily for 55 days. Cation exchange capacity, organic matter, ash, humic acids, pH, total C, N, C/N ratio; total P, exchangeable Ca, Mg, K, NH4+, NO3-, and heavy metals contents were determined using standard procedures. pH, total N, humic acids, ash, NH4+, NO3-, P, Ca, Mg, and K contents increased but the salinity, heavy metals contents, and microbial population were low after the co-composting process. Zea mays L. (test crop) seed germination rate in distilled water and the compost were not significantly different. Growth of Spinach oleracea (test crop) on a peat-based growing medium and the compost was also not significantly different. These findings were possible because the clinoptilolite zeolite used in co-composting reduced accumulation of heavy metals that may have damage effects on the test crops. Mature compost with good agronomic properties can be produced by co-composting chicken slurry and paddy husk using clinoptilolite zeolite and urea as additives. © The Author(s) 2015.

Whole Animal Composting of Beef Cattle

USDA-ARS?s Scientific Manuscript database

Composting is the natural decomposition of organic materials by microorganisms that require oxygen. Although many aspects of composting are not exact, there are several factors that affect the success of the composting process which are 1) carbon and nitrogen ratios (C:N ratio), 2) moisture content...

Dioxins and dioxin-like compounds in composts and digestates from European countries as determined by the in vitro bioassay and chemical analysis.

PubMed

Beníšek, Martin; Kukučka, Petr; Mariani, Giulio; Suurkuusk, Gert; Gawlik, Bernd M; Locoro, Giovanni; Giesy, John P; Bláha, Luděk

2015-03-01

Aerobic composting and anaerobic digestion plays an important role in reduction of organic waste by transforming the waste into humus, which is an excellent soil conditioner. However, applications of chemical-contaminated composts on soils may have unwanted consequences such as accumulation of persistent compounds and their transfer into food chains. The present study investigated burden of composts and digestates collected in 16 European countries (88 samples) by the compounds causing dioxin-like effects as determined by use of an in vitro transactivation assay to quantify total concentrations of aryl hydrocarbon receptor-(AhR) mediated potency. Measured concentrations of 2,3,7,8-Tetrachlorodibeno-p-dioxin (2,3,7,8-TCDD) equivalents (TEQbio) were compared to concentrations of polycyclic aromatic hydrocarbons (PAHs) and selected chlorinated compounds, including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), co-planar polychlorinated biphenyls (PCBs), indicator PCB congeners and organochlorine pesticides (OCPs). Median concentrations of TEQbio (dioxin-like compounds) determined by the in vitro assay in crude extracts of various types of composts ranged from 0.05 to 1.2 with a maximum 8.22μg (TEQbio)kg(-1) dry mass. Potencies were mostly associated with less persistent compounds such as PAHs because treatment with sulfuric acid removed bioactivity from most samples. The pan-European investigation of contamination by organic contaminants showed generally good quality of the composts, the majority of which were in compliance with conservative limits applied in some countries. Results demonstrate performance and added value of rapid, inexpensive, effect-based monitoring, and points out the need to derive corresponding effect-based trigger values for the risk assessment of complex contaminated matrices such as composts. Copyright © 2014 Elsevier Ltd. All rights reserved.

The distinctive microbial community improves composting efficiency in a full-scale hyperthermophilic composting plant.

PubMed

Yu, Zhen; Tang, Jia; Liao, Hanpeng; Liu, Xiaoming; Zhou, Puxiong; Chen, Zhi; Rensing, Christopher; Zhou, Shungui

2018-06-07

The application of conventional thermophilic composting (TC) is limited by poor efficiency. Newly-developed hyperthermophilic composting (HTC) is expected to overcome this shortcoming. However, the characterization of microbial communities associated with HTC remains unclear. Here, we compared the performance of HTC and TC in a full-scale sludge composting plant, and found that HTC running at the hyperthermophilic and thermophilic phases for 21 days, led to higher composting efficiency and techno-economic advantages over TC. Results of high-throughput sequencing showed drastic changes in the microbial community during HTC. Thermaceae (35.5-41.7%) was the predominant family in the hyperthermophilic phase, while the thermophilic phase was dominated by both Thermaceae (28.0-53.3%) and Thermoactinomycetaceae (29.9-36.1%). The change of microbial community could be the cause of continuous high temperature in HTC, and thus improve composting efficiency by accelerating the maturation process. This work has provided theoretical and practical guidance for managing sewage sludge by HTC. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enumeration, isolation and identification of diazotrophs from Korean wetland rice varieties grown with long-term application of N and compost and their short-term inoculation effect on rice plants.

PubMed

Muthukumarasamy, R; Kang, U G; Park, K D; Jeon, W-T; Park, C Y; Cho, Y S; Kwon, S-W; Song, J; Roh, D-H; Revathi, G

2007-04-01

This study has been aimed (i) to isolate and identify diazotrophs from Korean rice varieties; (ii) to examine the long-term effect of N and compost on the population dynamics of diazotrophs and (iii) to realize the shot-term inoculation effect of these diazotrophs on rice seedlings. Diazotrophic and heterotrophic bacterial numbers were enumerated by most probable number method and the isolates were identified based on morphological, physiological, biochemical and 16s rDNA sequence analysis. Long-term application of fertilizer N with compost enhanced both these numbers in rice plants and its environment. Bacteria were high in numbers when malate and azelaic acids were used as carbon source, but less when sucrose was used as a carbon substrate. The combined application promoted the association of diazotrophic bacteria like Azospirillum spp., Herbaspirillum spp., Burkholderia spp., Gluconacetobacter diazotrophicus and Pseudomonas spp. in wetland rice plants. Detection of nifD genes from different diazotrophic isolates indicated their nitrogen fixing ability. Inoculation of a representative isolate from each group onto rice seedlings of the variety IR 36 grown in test tubes indicated the positive effect of these diazotrophs on the growth of rice seedlings though the percentage of N present in the plants did not differ much. Application of compost with fertilizer N promoted the diazotrophic and heterotrophic bacterial numbers and their association with wetland rice and its environment. Compost application in high N fertilized fields would avert the reduction of N(2)-fixing bacterial numbers and their association was beneficial to the growth of rice plants. The inhibitory effect of high N fertilization on diazotrophic bacterial numbers could be reduced by the application of compost and this observation would encourage more usage of organic manure. This study has also thrown light on the wider geographic distribution of G. diazotrophicus with wetland rice in temperate

Numerical simulation of organic waste aerobic biodegradation: a new way to correlate respiration kinetics and organic matter fractionation.

PubMed

Denes, Jeremy; Tremier, Anne; Menasseri-Aubry, Safya; Walter, Christian; Gratteau, Laurette; Barrington, Suzelle

2015-02-01

Composting wastes permits the reuse of organic matter (OM) as agricultural amendments. The fate of OM during composting and the subsequent degradation of composts in soils largely depend on waste OM quality. The proposed study aimed at developing a model to predict the evolution in organic matter quality during the aerobic degradation of organic waste, based on the quantification of the various OM fractions contained in the wastes. The model was calibrated from data gathered during the monitoring of four organic wastes (two non-treated wastes and their digestates) exposed to respirometric tests. The model was successfully fitted for all four wastes and permitted to predict respiration kinetics, expressed as CO2 production rates, and the evolution of OM fractions. The calibrated model demonstrated that hydrolysis rates of OM fractions were similar for all four wastes whereas the parameters related to microbial activity (eg. growth and death rates) were specific to each substrate. These later parameters have been estimated by calibration on respirometric data, thus demonstrating that coupling analyses of OM fractions in initial wastes and respirometric tests permit the simulation of the biodegradation of various type of waste. The biodegradation model presented in this paper could thereafter be integrated in a composting model by implementing mass and heat balance equations. Copyright © 2014 Elsevier Ltd. All rights reserved.

COP-compost: a software to study the degradation of organic pollutants in composts.

PubMed

Zhang, Y; Lashermes, G; Houot, S; Zhu, Y-G; Barriuso, E; Garnier, P

2014-02-01

Composting has been demonstrated to be effective in degrading organic pollutants (OP) whose behaviour depends on the composting conditions, the microbial populations activated and interactions with organic matters. The fate of OP during composting involves complex mechanisms and models can be helpful tools for educational and scientific purposes, as well as for industrialists who want to optimise the composting process for OP elimination. A COP-Compost model, which couples an organic carbon (OC) module and an organic pollutant (OP) module and which simulates the changes of organic matter, organic pollutants and the microbial activities during the composting process, has been proposed and calibrated for a first set of OP in a previous study. The objectives of the present work were (1) to introduce the COP-Compost model from its convenient interface to a potential panel of users, (2) to show the variety of OP that could be simulated, including the possibility of choosing between degradation through co-metabolism or specific metabolism and (3) to show the effect of the initial characteristics of organic matter quality and its microbial biomass on the simulated results of the OP dynamic. In the model, we assumed that the pollutants can be adsorbed on organic matter according to the biochemical quality of the OC and that the microorganisms can degrade the pollutants at the same time as they degrade OC (by co-metabolism). A composting experiment describing two different (14)C-labelled organic pollutants, simazine and pyrene, were chosen from the literature because the four OP fractions simulated in the model were measured during the study (the mineralised, soluble, sorbed and non-extractable fractions). Except for the mineralised fraction of simazine, a good agreement was achieved between the simulated and experimental results describing the evolution of the different organic fractions. For simazine, a specific biomass had to be added. To assess the relative importance

Bioleached sludge composting drastically reducing ammonia volatilization as well as decreasing bulking agent dosage and improving compost quality: A case study.

PubMed

Hu, Weitong; Zheng, Guanyu; Fang, Di; Cui, Chunhong; Liang, Jianru; Zhou, Lixiang

2015-10-01

Sludge bioleaching technology with Acidithiobacillus species has been commercially adopted for improving advanced dewatering of sludge in China since 2010. However, up to now, little information on bioleached dewatered sludge (BS) composting is available. Here, we report the changes of physicochemical and biological properties in BS composting and evaluate compost product quality compared to conventional dewatered sludge (CS) composting in an engineering scale composting facility. The results showed that the amount of bulking agents required in BS composting was only about 10% of CS composting to obtain optimum moisture content, reducing about 700 kg bulking agents per ton fresh sludge. pH of BS composting mixture was slightly lower consistently by about 0.2-0.3 pH units than that in CS mixture in the first 30 days. Organic matter biodegradation in BS system mainly occurred in the first 9 days of composting. In spite of higher content of NH4(+)-N was found in BS mixture in related to CS mixture; unexpectedly the cumulative ammonia volatilization in the former was only 51% of the latter, indicating that BS composting drastically reduced nitrogen loss. Compared to CS composting system, the relative lower pH, the higher intensity of microbial assimilation, and the presence of water soluble Fe in BS system might jointly reduce ammonia volatilization. Consequently, BS compost product exhibited higher fertilizer values (N+P2O5+K2O=8.38%) as well as lower heavy metal levels due to the solubilization of sludge-borne heavy metals during bioleaching process. Therefore, composting of BS possesses more advantages over the CS composting process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inside the small-scale composting of kitchen and garden wastes: Thermal performance and stratification effect in vertical compost bins.

PubMed

Arrigoni, Juan Pablo; Paladino, Gabriela; Garibaldi, Lucas Alejandro; Laos, Francisca

2018-06-01

Decentralized composting has been proposed as a best available practice, with a highly positive impact on municipal solid wastes management plans. However, in cold climates, decentralized small-scale composting performance to reach thermophilic temperatures (required for the product sanitization) could be poor, due to a lack of critical mass to retain heat. In addition, in these systems the composting process is usually disturbed when new portions of fresh organic waste are combined with previous batches. This causes modifications in the well-known composting evolution pattern. The objective of this work was to improve the understanding of these technical aspects through a real-scale decentralized composting experience carried out under cold climate conditions, in order to assess sanitization performance and to study the effects of fresh feedstock additions in the process evolution. Kitchen and garden organic wastes were composted in 500 L-static compost bins (without turning) for 244 days under cold climate conditions (Bariloche, NW Patagonia, Argentina), using pine wood shavings in a ratio of 1.5:1 v: v (waste: bulking agent). Temperature profile, stability indicators (microbial activity, carbon and nitrogen contents and ratio) and other variables (pH and electrical conductivity), were monitored throughout the experience. Our results indicate that small-scale composting (average generation rate of 7 kg d -1 ) is viable under cold weather conditions, since thermophilic sanitization temperatures (> 55 °C) were maintained for 3 consecutive days in most of the composting mass, according to available USEPA regulations commonly used as a reference for pathogens control in sewage sludge. On the other hand, stability indicators showed a differentiated organic matter degradation process along the compost bins height. Particularly, in the bottommost composting mix layer the process took a longer period to achieve compost stability than the upper layers, suggesting

Aerobic De-Epoxydation of Trichothecene Mycotoxins by a Soil Bacterial Consortium Isolated Using In Situ Soil Enrichment.

PubMed

He, Wei-Jie; Yuan, Qing-Song; Zhang, You-Bing; Guo, Mao-Wei; Gong, An-Dong; Zhang, Jing-Bo; Wu, Ai-Bo; Huang, Tao; Qu, Bo; Li, He-Ping; Liao, Yu-Cai

2016-09-24

Globally, the trichothecene mycotoxins deoxynivalenol (DON) and nivalenol (NIV) are among the most widely distributed mycotoxins that contaminate small grain cereals. In this study, a bacterial consortium, PGC-3, with de-epoxydation activity was isolated from soil by an in situ soil enrichment method. Screening of 14 soil samples that were sprayed with DON revealed that 4 samples were able to biotransform DON into de-epoxydized DON (dE-DON). Among these, the PGC-3 consortium showed the highest and most stable activity to biotransform DON into dE-DON and NIV into dE-NIV. PGC-3 exhibited de-epoxydation activity at a wide range of pH (5-10) and temperatures (20-37 °C) values under aerobic conditions. Sequential subculturing with a continued exposure to DON substantially reduced the microbial population diversity of this consortium. Analyses of the 16S rDNA sequences indicated that PGC-3 comprised 10 bacterial genera. Among these, one species, Desulfitobacterium, showed a steady increase in relative abundance, from 0.03% to 1.55% (a 52-fold increase), as higher concentrations of DON were used in the subculture media, from 0 to 500 μg/mL. This study establishes the foundation to further develop bioactive agents that can detoxify trichothecene mycotoxins in cereals and enables for the characterization of detoxifying genes and their regulation.

Aerobic De-Epoxydation of Trichothecene Mycotoxins by a Soil Bacterial Consortium Isolated Using In Situ Soil Enrichment

PubMed Central

He, Wei-Jie; Yuan, Qing-Song; Zhang, You-Bing; Guo, Mao-Wei; Gong, An-Dong; Zhang, Jing-Bo; Wu, Ai-Bo; Huang, Tao; Qu, Bo; Li, He-Ping; Liao, Yu-Cai

2016-01-01

Globally, the trichothecene mycotoxins deoxynivalenol (DON) and nivalenol (NIV) are among the most widely distributed mycotoxins that contaminate small grain cereals. In this study, a bacterial consortium, PGC-3, with de-epoxydation activity was isolated from soil by an in situ soil enrichment method. Screening of 14 soil samples that were sprayed with DON revealed that 4 samples were able to biotransform DON into de-epoxydized DON (dE-DON). Among these, the PGC-3 consortium showed the highest and most stable activity to biotransform DON into dE-DON and NIV into dE-NIV. PGC-3 exhibited de-epoxydation activity at a wide range of pH (5–10) and temperatures (20–37 °C) values under aerobic conditions. Sequential subculturing with a continued exposure to DON substantially reduced the microbial population diversity of this consortium. Analyses of the 16S rDNA sequences indicated that PGC-3 comprised 10 bacterial genera. Among these, one species, Desulfitobacterium, showed a steady increase in relative abundance, from 0.03% to 1.55% (a 52-fold increase), as higher concentrations of DON were used in the subculture media, from 0 to 500 μg/mL. This study establishes the foundation to further develop bioactive agents that can detoxify trichothecene mycotoxins in cereals and enables for the characterization of detoxifying genes and their regulation. PMID:27669304

Aerobic biodegradation of trichloroethene without auxiliary substrates.

PubMed

Schmidt, Kathrin R; Gaza, Sarah; Voropaev, Andrey; Ertl, Siegmund; Tiehm, Andreas

2014-08-01

Trichloroethene (TCE) represents a priority pollutant and is among the most frequently detected contaminants in groundwater. The current bioremediation measures have certain drawbacks like e.g. the need for auxiliary substrates. Here, the aerobic biodegradation of TCE as the sole growth substrate is demonstrated. This new process of metabolic TCE degradation was first detected in groundwater samples. TCE degradation was stable in an enriched mixed bacterial culture in mineral salts medium for over five years and repeated transfers of the culture resulting in a 10(10) times dilution of the original groundwater. Aerobic TCE degradation resulted in stoichiometric chloride formation. Stable carbon isotope fractionation was observed providing a reliable analytical tool to assess this new biodegradation process at field sites. The results suggest that aerobic biodegradation of TCE without auxiliary substrate could be considered as an option for natural attenuation or engineered bioremediation of contaminated sites. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determining thermal inactivation of Escherichia coli O157:H7 in fresh compost by simulating early phases of the composting process.

PubMed

Singh, Randhir; Kim, Jinkyung; Shepherd, Marion W; Luo, Feng; Jiang, Xiuping

2011-06-01

A three-strain mixture of Escherichia coli O157:H7 was inoculated into fresh dairy compost (ca. 10(7) CFU/g) with 40 or 50% moisture and was placed in an environmental chamber (ca. 70% humidity) that was programmed to ramp from room temperature to selected composting temperatures in 2 and 5 days to simulate the early composting phase. The surviving E. coli O157:H7 population was analyzed by direct plating and enrichment. Optimal and suboptimal compost mixes, with carbon/nitrogen (C/N) ratios of 25:1 and 16:1, respectively, were compared in this study. In the optimal compost mix, E. coli O157:H7 survived for 72, 48, and 24 h in compost with 40% moisture and for 72, 24, and 24 h with 50% moisture at 50, 55, and 60°C, respectively, following 2 days of come-up time (rate of heating up). However, in the suboptimal compost mix, the pathogen survived for 288, 72, and 48 h in compost with 40% moisture and for 240, 72, 24 h in compost with 50% moisture at the same temperatures, respectively. Pathogen survival was longer, with 5 days of come-up time compared with 2 days of come-up. Overall, E. coli O157:H7 was inactivated faster in the compost with 50% moisture than in the compost with 40% at 55 and 60°C. Both moisture and come-up time were significant factors affecting Weibull model parameters. Our results suggest that slow come-up time at the beginning of composting can extend pathogen survival during composting. Additionally, both the C/N ratio and the initial moisture level in the compost mix affect the rate of pathogen inactivation as well.

Kinetics and mechanism of the biodegradation of PLA/clay nanocomposites during thermophilic phase of composting process.

PubMed

Stloukal, Petr; Pekařová, Silvie; Kalendova, Alena; Mattausch, Hannelore; Laske, Stephan; Holzer, Clemens; Chitu, Livia; Bodner, Sabine; Maier, Guenther; Slouf, Miroslav; Koutny, Marek

2015-08-01

The degradation mechanism and kinetics of polylactic acid (PLA) nanocomposite films, containing various commercially available native or organo-modified montmorillonites (MMT) prepared by melt blending, were studied under composting conditions in thermophilic phase of process and during abiotic hydrolysis and compared to the pure polymer. Described first order kinetic models were applied on the data from individual experiments by using non-linear regression procedures to calculate parameters characterizing aerobic composting and abiotic hydrolysis, such as carbon mineralization, hydrolysis rate constants and the length of lag phase. The study showed that the addition of nanoclay enhanced the biodegradation of PLA nanocomposites under composting conditions, when compared with pure PLA, particularly by shortening the lag phase at the beginning of the process. Whereas the lag phase of pure PLA was observed within 27days, the onset of CO2 evolution for PLA with native MMT was detected after just 20days, and from 13 to 16days for PLA with organo-modified MMT. Similarly, the hydrolysis rate constants determined tended to be higher for PLA with organo-modified MMT, particularly for the sample PLA-10A with fastest degradation, in comparison with pure PLA. The acceleration of chain scission in PLA with nanoclays was confirmed by determining the resultant rate constants for the hydrolytical chain scission. The critical molecular weight for the hydrolysis of PLA was observed to be higher than the critical molecular weight for onset of PLA mineralization, suggesting that PLA chains must be further shortened so as to be assimilated by microorganisms. In conclusion, MMT fillers do not represent an obstacle to acceptance of the investigated materials in composting facilities. Copyright © 2015 Elsevier Ltd. All rights reserved.